From 3ab58621ade5dc3a7fadf5c195620f9980963d4d Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Fri, 9 Oct 2026 08:28:28 -0400 Subject: [PATCH 01/19] Set known tags by id on TagMap and spans Adds id-keyed setters, getters and removal to TagMap, TagMap.Entry and spans, so a writer that knows the tag skips the name lookup. Squashed from the review history of #12715. Co-Authored-By: Claude Opus 5.5 --- .../decorator/BaseDecorator.java | 11 +- .../decorator/BaseDecoratorTest.groovy | 11 +- .../decorator/ClientDecoratorTest.groovy | 2 +- ...ocessingDatabaseClientDecoratorTest.groovy | 3 +- .../DatabaseClientDecoratorTest.groovy | 2 +- .../decorator/HttpClientDecoratorTest.groovy | 2 +- .../decorator/HttpServerDecoratorTest.groovy | 2 +- .../decorator/ServerDecoratorTest.groovy | 2 +- .../decorator/NameKeyedAgentSpan.java | 52 +++++ .../main/java/datadog/trace/core/DDSpan.java | 62 +++++ .../datadog/trace/core/DDSpanContext.java | 114 +++++++++ .../trace/core/DDSpanSetTagByIdTest.java | 93 ++++++++ .../trace/api/TagMapInsertBenchmark.java | 108 +++++++++ .../main/java/datadog/trace/api/TagMap.java | 221 +++++++++++++++--- .../instrumentation/api/AgentSpan.java | 38 +++ .../trace/api/TagMapEntryCreateByIdTest.java | 59 +++++ .../datadog/trace/api/TagMapSetByIdTest.java | 75 ++++++ .../datadog/trace/api/TagMapTagHashTest.java | 101 ++++++++ 18 files changed, 915 insertions(+), 43 deletions(-) create mode 100644 dd-java-agent/agent-bootstrap/src/test/java/datadog/trace/bootstrap/instrumentation/decorator/NameKeyedAgentSpan.java create mode 100644 dd-trace-core/src/test/java/datadog/trace/core/DDSpanSetTagByIdTest.java create mode 100644 internal-api/src/jmh/java/datadog/trace/api/TagMapInsertBenchmark.java create mode 100644 internal-api/src/test/java/datadog/trace/api/TagMapEntryCreateByIdTest.java create mode 100644 internal-api/src/test/java/datadog/trace/api/TagMapSetByIdTest.java create mode 100644 internal-api/src/test/java/datadog/trace/api/TagMapTagHashTest.java diff --git a/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/instrumentation/decorator/BaseDecorator.java b/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/instrumentation/decorator/BaseDecorator.java index 5c6628c5d35..8eb238b678d 100644 --- a/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/instrumentation/decorator/BaseDecorator.java +++ b/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/instrumentation/decorator/BaseDecorator.java @@ -8,6 +8,7 @@ import datadog.trace.api.Config; import datadog.trace.api.DDTags; import datadog.trace.api.Functions; +import datadog.trace.api.KnownTags; import datadog.trace.api.TagMap; import datadog.trace.api.cache.QualifiedClassNameCache; import datadog.trace.bootstrap.instrumentation.api.AgentSpan; @@ -194,23 +195,23 @@ public final void onPeerConnection( if (remoteAddress != null) { String ip = remoteAddress.getHostAddress(); if (resolved && Config.get().isPeerHostNameEnabled()) { - span.setTag(Tags.PEER_HOSTNAME, hostName(remoteAddress, ip)); + span.setTag(KnownTags.PEER_HOSTNAME_ID, hostName(remoteAddress, ip)); } if (remoteAddress instanceof Inet4Address) { - span.setTag(Tags.PEER_HOST_IPV4, ip); + span.setTag(KnownTags.PEER_IPV4_ID, ip); } else if (remoteAddress instanceof Inet6Address) { - span.setTag(Tags.PEER_HOST_IPV6, ip); + span.setTag(KnownTags.PEER_IPV6_ID, ip); } } } public void setPeerPort(AgentSpan span, String port) { - span.setTag(Tags.PEER_PORT, port); + span.setTag(KnownTags.PEER_PORT_ID, port); } public void setPeerPort(AgentSpan span, int port) { if (port > UNSET_PORT) { - span.setTag(Tags.PEER_PORT, port); + span.setTag(KnownTags.PEER_PORT_ID, port); } } diff --git a/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/BaseDecoratorTest.groovy b/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/BaseDecoratorTest.groovy index 3151d655739..a04a75712f0 100644 --- a/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/BaseDecoratorTest.groovy +++ b/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/BaseDecoratorTest.groovy @@ -24,7 +24,16 @@ class BaseDecoratorTest extends DDSpecification { @Shared def errorPriority = null as Byte - def span = Mock(AgentSpan) + def span = mockSpan() + + /** + * Mocks an {@link AgentSpan} that reports every id-keyed {@code setTag} as the name-keyed call, + * so expectations are written by tag name however the code under test sets the tag. See + * {@link NameKeyedAgentSpan}. + */ + AgentSpan mockSpan() { + return Mock(NameKeyedAgentSpan) + } def spanContext = Mock(AgentSpanContext) def "test afterStart"() { diff --git a/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/ClientDecoratorTest.groovy b/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/ClientDecoratorTest.groovy index fec5748f089..a1568c81af5 100644 --- a/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/ClientDecoratorTest.groovy +++ b/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/ClientDecoratorTest.groovy @@ -8,7 +8,7 @@ import datadog.trace.bootstrap.instrumentation.api.Tags class ClientDecoratorTest extends BaseDecoratorTest { - def span = Mock(AgentSpan) + def span = mockSpan() def "test afterStart"() { setup: diff --git a/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/DBTypeProcessingDatabaseClientDecoratorTest.groovy b/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/DBTypeProcessingDatabaseClientDecoratorTest.groovy index 624100fcc50..efe550ee1bf 100644 --- a/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/DBTypeProcessingDatabaseClientDecoratorTest.groovy +++ b/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/DBTypeProcessingDatabaseClientDecoratorTest.groovy @@ -2,14 +2,13 @@ package datadog.trace.bootstrap.instrumentation.decorator import datadog.trace.api.DDTags import datadog.trace.api.TagMap -import datadog.trace.bootstrap.instrumentation.api.AgentSpan import datadog.trace.bootstrap.instrumentation.api.Tags import datadog.trace.bootstrap.instrumentation.api.UTF8BytesString import spock.lang.Ignore class DBTypeProcessingDatabaseClientDecoratorTest extends ClientDecoratorTest { - def span = Mock(AgentSpan) + def span = mockSpan() @Ignore("https://github.com/DataDog/dd-trace-java/pull/5213") def "test afterStart"() { diff --git a/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/DatabaseClientDecoratorTest.groovy b/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/DatabaseClientDecoratorTest.groovy index 93852ccc88c..b8d38b32f0d 100644 --- a/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/DatabaseClientDecoratorTest.groovy +++ b/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/DatabaseClientDecoratorTest.groovy @@ -12,7 +12,7 @@ import static datadog.trace.api.config.TraceInstrumentationConfig.DB_CLIENT_HOST class DatabaseClientDecoratorTest extends ClientDecoratorTest { - def span = Mock(AgentSpan) + def span = mockSpan() def "test afterStart"() { setup: diff --git a/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/HttpClientDecoratorTest.groovy b/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/HttpClientDecoratorTest.groovy index 1bc83457bd0..92f709a5d79 100644 --- a/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/HttpClientDecoratorTest.groovy +++ b/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/HttpClientDecoratorTest.groovy @@ -52,7 +52,7 @@ class HttpClientDecoratorTest extends ClientDecoratorTest { AgentTracer.forceRegister(ORIGINAL_TRACER) } - def span = Mock(AgentSpan) + def span = mockSpan() def "test onRequest"() { setup: diff --git a/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/HttpServerDecoratorTest.groovy b/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/HttpServerDecoratorTest.groovy index da411dc2431..5ac781b913b 100644 --- a/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/HttpServerDecoratorTest.groovy +++ b/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/HttpServerDecoratorTest.groovy @@ -36,7 +36,7 @@ import static datadog.trace.api.gateway.Events.EVENTS class HttpServerDecoratorTest extends ServerDecoratorTest { - def span = Mock(AgentSpan) + def span = mockSpan() static class MapCarrierVisitor implements AgentPropagation.ContextVisitor { diff --git a/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/ServerDecoratorTest.groovy b/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/ServerDecoratorTest.groovy index d60c1534627..0e096772976 100644 --- a/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/ServerDecoratorTest.groovy +++ b/dd-java-agent/agent-bootstrap/src/test/groovy/datadog/trace/bootstrap/instrumentation/decorator/ServerDecoratorTest.groovy @@ -12,7 +12,7 @@ import static datadog.trace.bootstrap.instrumentation.api.Tags.SPAN_KIND class ServerDecoratorTest extends BaseDecoratorTest { - def span = Mock(AgentSpan) + def span = mockSpan() def "test afterStart"() { def decorator = newDecorator() diff --git a/dd-java-agent/agent-bootstrap/src/test/java/datadog/trace/bootstrap/instrumentation/decorator/NameKeyedAgentSpan.java b/dd-java-agent/agent-bootstrap/src/test/java/datadog/trace/bootstrap/instrumentation/decorator/NameKeyedAgentSpan.java new file mode 100644 index 00000000000..435ef32cdb5 --- /dev/null +++ b/dd-java-agent/agent-bootstrap/src/test/java/datadog/trace/bootstrap/instrumentation/decorator/NameKeyedAgentSpan.java @@ -0,0 +1,52 @@ +package datadog.trace.bootstrap.instrumentation.decorator; + +import datadog.trace.api.KnownTagCodec; +import datadog.trace.bootstrap.instrumentation.api.AgentSpan; + +/** + * An {@link AgentSpan} to mock in tests whose id-keyed {@code setTag} overloads are {@code final} + * and delegate to the name-keyed ones. A mock cannot override a final method, so it never sees the + * id-keyed call: tests keep expecting {@code setTag(name, value)} whether the code under test sets + * a tag by name or by {@code KnownTags} id. + */ +public abstract class NameKeyedAgentSpan implements AgentSpan { + @Override + public final AgentSpan setTag(long tagId, boolean value) { + return setTag(KnownTagCodec.nameOf(tagId), value); + } + + @Override + public final AgentSpan setTag(long tagId, int value) { + return setTag(KnownTagCodec.nameOf(tagId), value); + } + + @Override + public final AgentSpan setTag(long tagId, long value) { + return setTag(KnownTagCodec.nameOf(tagId), value); + } + + @Override + public final AgentSpan setTag(long tagId, float value) { + return setTag(KnownTagCodec.nameOf(tagId), value); + } + + @Override + public final AgentSpan setTag(long tagId, double value) { + return setTag(KnownTagCodec.nameOf(tagId), value); + } + + @Override + public final AgentSpan setTag(long tagId, String value) { + return setTag(KnownTagCodec.nameOf(tagId), value); + } + + @Override + public final AgentSpan setTag(long tagId, CharSequence value) { + return setTag(KnownTagCodec.nameOf(tagId), value); + } + + @Override + public final AgentSpan setTag(long tagId, Object value) { + return setTag(KnownTagCodec.nameOf(tagId), value); + } +} diff --git a/dd-trace-core/src/main/java/datadog/trace/core/DDSpan.java b/dd-trace-core/src/main/java/datadog/trace/core/DDSpan.java index b0cc812aadc..3427d085306 100644 --- a/dd-trace-core/src/main/java/datadog/trace/core/DDSpan.java +++ b/dd-trace-core/src/main/java/datadog/trace/core/DDSpan.java @@ -15,6 +15,7 @@ import datadog.trace.api.DDTags; import datadog.trace.api.DDTraceId; import datadog.trace.api.EndpointTracker; +import datadog.trace.api.KnownTags; import datadog.trace.api.TagMap; import datadog.trace.api.TraceConfig; import datadog.trace.api.debugger.DebuggerConfigBridge; @@ -514,6 +515,67 @@ public DDSpan setTag(final String tag, final Object value) { return this; } + // Id-keyed overrides: same behavior as the String family above, including interception and the + // http.status_code quirk, but the tag is stored by id with no name lookup. + @Override + public DDSpan setTag(final long tagId, final String value) { + if (value == null || value.isEmpty()) { + context.removeTag(tagId); + } else { + context.setTag(tagId, value); + } + return this; + } + + @Override + public DDSpan setTag(final long tagId, final boolean value) { + context.setTag(tagId, value); + return this; + } + + @Override + public DDSpan setTag(final long tagId, final int value) { + if (tagId == KnownTags.HTTP_STATUS_CODE_ID) { + context.setHttpStatusCode((short) value); + } + context.setTag(tagId, value); + return this; + } + + @Override + public DDSpan setTag(final long tagId, final long value) { + context.setTag(tagId, value); + return this; + } + + @Override + public DDSpan setTag(final long tagId, final float value) { + context.setTag(tagId, value); + return this; + } + + @Override + public DDSpan setTag(final long tagId, final double value) { + context.setTag(tagId, value); + return this; + } + + @Override + public DDSpan setTag(final long tagId, final CharSequence value) { + if (value == null || value.length() == 0) { + context.setTag(tagId, (Object) null); + } else { + context.setTag(tagId, value); + } + return this; + } + + @Override + public DDSpan setTag(final long tagId, final Object value) { + context.setTag(tagId, value); + return this; + } + @Override public AgentSpan setAllTags(Map map) { context.setAllTags(map); diff --git a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java index 09698ee0c5c..101b19b49ef 100644 --- a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java +++ b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java @@ -10,6 +10,7 @@ import datadog.trace.api.DDTags; import datadog.trace.api.DDTraceId; import datadog.trace.api.Functions; +import datadog.trace.api.KnownTagCodec; import datadog.trace.api.KnownTags; import datadog.trace.api.ProcessTags; import datadog.trace.api.TagMap; @@ -995,6 +996,16 @@ public void removeTag(String tag) { } } + /** Removes a known tag by id, rather than by its name, which need not resolve back to the id. */ + public void removeTag(long tagId) { + if (tagId == KnownTags.SPAN_KIND_ID) { + spanKindOrdinal = SPAN_KIND_UNSET; + } + synchronized (unsafeTags) { + unsafeTags.getAndRemove(tagId); + } + } + /** * Sets a tag to the span. Tags are not propagated to the children. * @@ -1030,6 +1041,109 @@ public void setTag(final String tag, final String value) { } } + /* + * Id-keyed setters, mirroring the String setters above: interception still runs on the tag's + * name (TagInterceptor is name-keyed), but a stored tag is set by id, skipping the name lookup. + * An id that names no known tag is ignored, like a null tag. + */ + public void setTag(final long tagId, final Object value) { + final String tag = KnownTagCodec.nameOf(tagId); + if (null == tag) { + return; + } + if (null == value) { + removeTag(tagId); + } else if (!tagInterceptor.interceptTag(this, tag, value)) { + synchronized (unsafeTags) { + unsafeTags.set(tagId, value); + } + } + } + + public void setTag(final long tagId, final CharSequence value) { + final String tag = KnownTagCodec.nameOf(tagId); + if (null == tag) { + return; + } + if (null == value) { + removeTag(tagId); + } else if (!tagInterceptor.interceptTag(this, tag, value)) { + synchronized (unsafeTags) { + unsafeTags.set(tagId, value); + } + } + } + + public void setTag(final long tagId, final boolean value) { + final String tag = KnownTagCodec.nameOf(tagId); + if (null == tag) { + return; + } + if (precheckIntercept(tag)) { + this.setBox(tag, value); + } else { + synchronized (unsafeTags) { + unsafeTags.set(tagId, value); + } + } + } + + public void setTag(final long tagId, final int value) { + final String tag = KnownTagCodec.nameOf(tagId); + if (null == tag) { + return; + } + if (precheckIntercept(tag)) { + this.setBox(tag, value); + } else { + synchronized (unsafeTags) { + unsafeTags.set(tagId, value); + } + } + } + + public void setTag(final long tagId, final long value) { + final String tag = KnownTagCodec.nameOf(tagId); + if (null == tag) { + return; + } + boolean intercepted = + tagInterceptor.needsIntercept(tag) && tagInterceptor.interceptTag(this, tag, value); + if (!intercepted) { + synchronized (unsafeTags) { + unsafeTags.set(tagId, value); + } + } + } + + public void setTag(final long tagId, final float value) { + final String tag = KnownTagCodec.nameOf(tagId); + if (null == tag) { + return; + } + if (precheckIntercept(tag)) { + this.setBox(tag, value); + } else { + synchronized (unsafeTags) { + unsafeTags.set(tagId, value); + } + } + } + + public void setTag(final long tagId, final double value) { + final String tag = KnownTagCodec.nameOf(tagId); + if (null == tag) { + return; + } + if (precheckIntercept(tag)) { + this.setBox(tag, value); + } else { + synchronized (unsafeTags) { + unsafeTags.set(tagId, value); + } + } + } + public void setTag(TagMap.EntryReader entry) { if (entry == null) { return; diff --git a/dd-trace-core/src/test/java/datadog/trace/core/DDSpanSetTagByIdTest.java b/dd-trace-core/src/test/java/datadog/trace/core/DDSpanSetTagByIdTest.java new file mode 100644 index 00000000000..e36512259ad --- /dev/null +++ b/dd-trace-core/src/test/java/datadog/trace/core/DDSpanSetTagByIdTest.java @@ -0,0 +1,93 @@ +package datadog.trace.core; + +import static org.junit.jupiter.api.Assertions.assertEquals; +import static org.junit.jupiter.api.Assertions.assertNull; + +import datadog.trace.api.KnownTags; +import datadog.trace.common.writer.ListWriter; +import org.junit.jupiter.api.AfterEach; +import org.junit.jupiter.api.BeforeEach; +import org.junit.jupiter.api.Test; + +/** + * {@code DDSpan.setTag(long, ...)}: setting a known tag by id behaves exactly like setting it by + * name, including interception. + */ +class DDSpanSetTagByIdTest extends DDCoreJavaSpecification { + private CoreTracer tracer; + private DDSpan span; + + @BeforeEach + void setup() { + tracer = tracerBuilder().writer(new ListWriter()).build(); + span = (DDSpan) tracer.buildSpan("datadog", "fakeOperation").start(); + } + + @AfterEach + void tearDown() { + span.finish(); + tracer.close(); + } + + @Test + void storesTheTagUnderItsName() { + span.setTag(KnownTags.PEER_PORT_ID, 5432); + span.setTag(KnownTags.PEER_HOSTNAME_ID, "db.internal"); + span.setTag(KnownTags.DD_PROFILING_ENABLED_ID, true); + + assertEquals(5432, span.getTag(KnownTags.PEER_PORT_NAME)); + assertEquals("db.internal", span.getTag(KnownTags.PEER_HOSTNAME_NAME)); + assertEquals(true, span.getTag(KnownTags.DD_PROFILING_ENABLED_NAME)); + } + + @Test + void aNullOrEmptyValueRemovesTheTagById() { + span.setTag(KnownTags.PEER_HOSTNAME_ID, "db.internal"); + span.setTag(KnownTags.COMPONENT_ID, "okhttp"); + + span.setTag(KnownTags.PEER_HOSTNAME_ID, (String) null); + span.setTag(KnownTags.COMPONENT_ID, ""); + + assertNull(span.getTag(KnownTags.PEER_HOSTNAME_NAME)); + assertNull(span.getTag(KnownTags.COMPONENT_NAME)); + } + + @Test + void removingTheSpanKindByIdClearsTheKind() { + span.setTag(KnownTags.SPAN_KIND_ID, "client"); + assertEquals("client", span.getSpanKindString()); + + span.setTag(KnownTags.SPAN_KIND_ID, (String) null); + + assertNull(span.getSpanKindString()); + assertNull(span.getTag(KnownTags.SPAN_KIND_NAME)); + } + + @Test + void interceptedTagsAreStillIntercepted() { + span.setTag(KnownTags.DB_STATEMENT_ID, "select 1"); + span.setTag(KnownTags.SERVICE_ID, "orders-db"); + + assertEquals("select 1", span.getResourceName().toString()); + assertNull(span.getTag(KnownTags.DB_STATEMENT_NAME)); + assertEquals("orders-db", span.getServiceName()); + } + + @Test + void httpStatusCodeSetsTheStatusField() { + span.setTag(KnownTags.HTTP_STATUS_CODE_ID, 503); + + assertEquals(503, span.getHttpStatusCode()); + } + + @Test + void anEmptyOrNullValueRemovesTheTag() { + span.setTag(KnownTags.PEER_HOSTNAME_ID, "db.internal"); + span.setTag(KnownTags.PEER_HOSTNAME_ID, ""); + assertNull(span.getTag(KnownTags.PEER_HOSTNAME_NAME)); + + span.setTag(KnownTags.PEER_HOSTNAME_ID, (CharSequence) "db.internal"); + span.setTag(KnownTags.PEER_HOSTNAME_ID, (CharSequence) null); + assertNull(span.getTag(KnownTags.PEER_HOSTNAME_NAME)); + } +} diff --git a/internal-api/src/jmh/java/datadog/trace/api/TagMapInsertBenchmark.java b/internal-api/src/jmh/java/datadog/trace/api/TagMapInsertBenchmark.java new file mode 100644 index 00000000000..3a5ec10ddd0 --- /dev/null +++ b/internal-api/src/jmh/java/datadog/trace/api/TagMapInsertBenchmark.java @@ -0,0 +1,108 @@ +package datadog.trace.api; + +import java.util.concurrent.TimeUnit; +import org.openjdk.jmh.annotations.Benchmark; +import org.openjdk.jmh.annotations.BenchmarkMode; +import org.openjdk.jmh.annotations.Fork; +import org.openjdk.jmh.annotations.Measurement; +import org.openjdk.jmh.annotations.Mode; +import org.openjdk.jmh.annotations.OutputTimeUnit; +import org.openjdk.jmh.annotations.Scope; +import org.openjdk.jmh.annotations.State; +import org.openjdk.jmh.annotations.Threads; +import org.openjdk.jmh.annotations.Warmup; + +/** + * Inserting a span's worth of tags into a fresh {@link TagMap}, the way span decoration does: known + * tags by Datadog name, the same known tags by id, and custom tags by name. + * + *

Single-threaded: each invocation builds its own map, so more threads would mostly measure + * allocation bandwidth. Run with {@code -prof gc} for allocation per operation. Tag names are + * string constants, as the tracer's are. + * + *

Results (MacBook, JDK 21, default flags, {@code @Fork(2)} triage), 12 tags per op: + * + * 

+ * Benchmark      ns/op         B/op
+ * knownByName    121.1 +- 3.8  736
+ * knownById       94.7 +- 1.7  736
+ * customByName    80.6 +- 2.4  736
+ *
+ */ +@BenchmarkMode(Mode.AverageTime) +@OutputTimeUnit(TimeUnit.NANOSECONDS) +@Fork(2) +@Warmup(iterations = 5, time = 1) +@Measurement(iterations = 5, time = 1) +@Threads(1) +@State(Scope.Benchmark) +public class TagMapInsertBenchmark { + // Per-span tags a client or server decorator typically sets. + static final String[] KNOWN_NAMES = { + KnownTags.COMPONENT_NAME, + KnownTags.SPAN_KIND_NAME, + KnownTags.HTTP_METHOD_NAME, + KnownTags.HTTP_URL_NAME, + KnownTags.HTTP_ROUTE_NAME, + KnownTags.HTTP_HOSTNAME_NAME, + KnownTags.HTTP_USERAGENT_NAME, + KnownTags.HTTP_CLIENT_IP_NAME, + KnownTags.PEER_HOSTNAME_NAME, + KnownTags.PEER_IPV4_NAME, + KnownTags.PEER_PORT_NAME, + KnownTags.DD_INTEGRATION_NAME, + }; + + static final long[] KNOWN_IDS = { + KnownTags.COMPONENT_ID, + KnownTags.SPAN_KIND_ID, + KnownTags.HTTP_METHOD_ID, + KnownTags.HTTP_URL_ID, + KnownTags.HTTP_ROUTE_ID, + KnownTags.HTTP_HOSTNAME_ID, + KnownTags.HTTP_USERAGENT_ID, + KnownTags.HTTP_CLIENT_IP_ID, + KnownTags.PEER_HOSTNAME_ID, + KnownTags.PEER_IPV4_ID, + KnownTags.PEER_PORT_ID, + KnownTags.DD_INTEGRATION_ID, + }; + + static final String[] CUSTOM_NAMES = new String[KNOWN_NAMES.length]; + + static final Object[] VALUES = new Object[KNOWN_NAMES.length]; + + static { + for (int i = 0; i < KNOWN_NAMES.length; ++i) { + CUSTOM_NAMES[i] = ("app.custom.tag." + i).intern(); + VALUES[i] = "value-" + i; + } + } + + @Benchmark + public TagMap knownByName() { + TagMap map = TagMap.create(); + for (int i = 0; i < KNOWN_NAMES.length; ++i) { + map.set(KNOWN_NAMES[i], VALUES[i]); + } + return map; + } + + @Benchmark + public TagMap knownById() { + TagMap map = TagMap.create(); + for (int i = 0; i < KNOWN_IDS.length; ++i) { + map.set(KNOWN_IDS[i], VALUES[i]); + } + return map; + } + + @Benchmark + public TagMap customByName() { + TagMap map = TagMap.create(); + for (int i = 0; i < CUSTOM_NAMES.length; ++i) { + map.set(CUSTOM_NAMES[i], VALUES[i]); + } + return map; + } +} diff --git a/internal-api/src/main/java/datadog/trace/api/TagMap.java b/internal-api/src/main/java/datadog/trace/api/TagMap.java index 52d2ef32a2b..0b1a9bd6862 100644 --- a/internal-api/src/main/java/datadog/trace/api/TagMap.java +++ b/internal-api/src/main/java/datadog/trace/api/TagMap.java @@ -280,6 +280,44 @@ public static final Entry create(@Nonnull String tag, double value) { return TagMap.Entry.newDoubleEntry(tag, value); } + /* + * Id-keyed counterparts of the create overloads above, for a KnownTags.*_ID: same contract (a + * null or empty value yields no entry), without the name lookup. An id that names no known tag + * is rejected. + */ + + /** Entry for a known tag id, or null when {@code value} is null or an empty CharSequence. */ + @Nullable + public static final Entry create(long tagId, Object value) { + return isEmptyValue(value) ? null : TagMap.Entry.newAnyEntry(tagId, value); + } + + /** Entry for a known tag id, or null when {@code value} is null or empty. */ + @Nullable + public static final Entry create(long tagId, CharSequence value) { + return isEmptyValue(value) ? null : TagMap.Entry.newObjectEntry(tagId, value); + } + + public static final Entry create(long tagId, boolean value) { + return TagMap.Entry.newBooleanEntry(tagId, value); + } + + public static final Entry create(long tagId, int value) { + return TagMap.Entry.newIntEntry(tagId, value); + } + + public static final Entry create(long tagId, long value) { + return TagMap.Entry.newLongEntry(tagId, value); + } + + public static final Entry create(long tagId, float value) { + return TagMap.Entry.newFloatEntry(tagId, value); + } + + public static final Entry create(long tagId, double value) { + return TagMap.Entry.newDoubleEntry(tagId, value); + } + static Entry newAnyEntry(Map.Entry entry) { return newAnyEntry(entry.getKey(), entry.getValue()); } @@ -299,6 +337,37 @@ static Entry newObjectEntry(String tag, Object value) { return new Entry(tag, OBJECT, 0, value); } + // Id-keyed factories: the tag id already names a canonical tag, so these skip the + // canonicalizing + // name lookup the String factories pay. + static Entry newAnyEntry(long tagId, Object value) { + return new Entry(tagId, ANY, 0L, value); + } + + static Entry newObjectEntry(long tagId, Object value) { + return new Entry(tagId, OBJECT, 0, value); + } + + static Entry newBooleanEntry(long tagId, boolean value) { + return new Entry(tagId, BOOLEAN, boolean2Prim(value), Boolean.valueOf(value)); + } + + static Entry newIntEntry(long tagId, int value) { + return new Entry(tagId, INT, int2Prim(value), null); + } + + static Entry newLongEntry(long tagId, long value) { + return new Entry(tagId, LONG, long2Prim(value), null); + } + + static Entry newFloatEntry(long tagId, float value) { + return new Entry(tagId, FLOAT, float2Prim(value), null); + } + + static Entry newDoubleEntry(long tagId, double value) { + return new Entry(tagId, DOUBLE, double2Prim(value), null); + } + static Entry newBooleanEntry(String tag, boolean value) { return new Entry(tag, BOOLEAN, boolean2Prim(value), Boolean.valueOf(value)); } @@ -340,10 +409,12 @@ static Entry newDoubleEntry(String tag, Double box) { } /* - * hash is stored in line for fast handling of Entry-s coming from another TagMap - * However, hash is lazily computed using the same trick as {@link java.lang.String}. + * The tag's 64-bit hash, computed once at construction. For a known tag it is the tag id, whose + * serial sits in the high bits, so the upper 32 bits are never zero; for a custom tag it is the + * name's hash in the low 32 bits, with the upper 32 bits zero. The two can never collide, and + * tagId() is a field read. See tagHashOf. */ - int lazyTagHash; + final long tagHash; // To optimize construction of Entry around boxed primitives and Object entries, // no type checks are done during construction. @@ -368,35 +439,72 @@ static Entry newDoubleEntry(String tag, Double box) { private Entry(String tag, byte type, long prim, Object obj) { /* * Canonicalize known names at the single Entry construction point, so Datadog and - * OpenTelemetry spellings use the same TagMap key. This adds a StringIndex lookup to every - * new entry, including on the application thread. + * OpenTelemetry spellings use the same TagMap key. The one StringIndex lookup this costs also + * yields the tag id, which becomes the tag hash. */ - super(KnownTagCodec.canonicalTagName(tag)); - this.lazyTagHash = 0; // lazily computed + this(KnownTagCodec.keyOf(tag), tag, type, prim, obj); + } + + private Entry(long tagId, byte type, long prim, Object obj) { + // Resolve the name once: it both validates the id and names the entry. + super(requireKnownName(tagId)); + this.tagHash = tagId; this.rawType = type; this.rawPrim = prim; this.rawObj = obj; } - int hash() { - // If value of hash read in this thread is zero, then hash is computed. - // hash is not held as a volatile, since this computation can safely be repeated as any time - int hash = this.lazyTagHash; - if (hash != 0) return hash; + /** {@code tagId} is a known id, or 0 for the custom tag {@code customTag}. */ + private Entry(long tagId, String customTag, byte type, long prim, Object obj) { + super(tagId != 0 ? KnownTagCodec.nameOf(tagId) : customTag); + this.tagHash = tagId != 0 ? tagId : customHash(customTag); - hash = _hash(this.tag); - this.lazyTagHash = hash; - return hash; + this.rawType = type; + this.rawPrim = prim; + this.rawObj = obj; + } + + private static String requireKnownName(long tagId) { + String name = tagId == 0 ? null : KnownTagCodec.nameOf(tagId); + if (name == null) { + throw new IllegalArgumentException("not a known tag id: " + Long.toHexString(tagId)); + } + return name; + } + + /** The tag hash a name maps to: its id when known, else its {@link #customHash}. */ + static long tagHashOf(String tag) { + long tagId = KnownTagCodec.keyOf(tag); + return tagId != 0 ? tagId : customHash(tag); + } + + /** A custom tag's hash: the name hash in the low 32 bits, never colliding with a tag id. */ + static long customHash(String tag) { + return _hash(tag) & 0xFFFFFFFFL; + } + + /** + * Folds a tag hash to the 32-bit bucket hash. A tag id's serial is in bits 63-48, so it is + * folded down from there rather than from bit 32, where a bucket mask would discard it. + * + *

Never zero: BucketGroup treats a zero hash as a vacant slot. The fold can produce zero + * when a serial equals the id's flag bits (serial 4 with the trace-level bit, 4), so zero maps + * to the same nonzero sentinel {@link #_hash} uses. + */ + static int bucketHash(long tagHash) { + int hash = (int) (tagHash >>> 48) ^ (int) tagHash; + return hash == 0 ? 0xDD06 : hash; + } + + int hash() { + return bucketHash(this.tagHash); } @Override public long tagId() { - /* - * Resolve on demand. Only OTLP serialization currently needs the ID, so caching it here - * would add a field to every Entry to save a lookup on exported tags. - */ - return KnownTagCodec.keyOf(this.tag); + // A known tag's hash is its id, whose upper 32 bits are never zero; a custom tag's are. + return (this.tagHash >>> 32) != 0 ? this.tagHash : 0L; } @Override @@ -1301,9 +1409,18 @@ public Entry getEntry(String tag) { // Entries are stored under their canonical Datadog name (see Entry's constructor); a lookup by // an OpenTelemetry rename must canonicalize the same way, or it would hash to the wrong bucket // and silently miss the entry stored under the Datadog name. - String canonicalTag = KnownTagCodec.canonicalTagName(tag); + long tagHash = Entry.tagHashOf(tag); + String canonicalTag = (tagHash >>> 32) != 0 ? KnownTagCodec.nameOf(tagHash) : tag; + return this.getEntry(canonicalTag, tagHash); + } - Entry local = this.getLocalEntry(canonicalTag); + /** The entry for a known tag id, found by the id itself rather than by resolving a name. */ + public Entry getEntry(long tagId) { + return this.getEntry(Entry.requireKnownName(tagId), tagId); + } + + private Entry getEntry(String canonicalTag, long tagHash) { + Entry local = this.getLocalEntry(canonicalTag, tagHash); if (local != null) { // Local entry shadows the parent (local-wins) — unchanged hot path. return local; @@ -1318,13 +1435,13 @@ public Entry getEntry(String tag) { if (this.removedFromParent != null && this.removedFromParent.contains(canonicalTag)) { return null; // tombstoned: removed locally, do not read through } - return parent.getEntry(canonicalTag); + return parent.getEntry(canonicalTag, tagHash); } /** Looks up an entry in this map's own buckets only — no read-through to the parent. */ - private Entry getLocalEntry(String tag) { + private Entry getLocalEntry(String tag, long tagHash) { Object[] thisBuckets = this.buckets; - int hash = TagMap.Entry._hash(tag); + int hash = Entry.bucketHash(tagHash); return findInBucket(thisBuckets[hash & (thisBuckets.length - 1)], hash, tag); } @@ -1416,6 +1533,39 @@ public void set(@Nonnull String tag, double value) { this.putEntry(Entry.newDoubleEntry(tag, value)); } + /* + * Id-keyed setters: the caller passes a KnownTags.*_ID, so the entry is built under the tag's + * canonical name without the name lookup the String setters pay. The id must name a known tag; + * custom tags have no id and use the String setters. + */ + public void set(long tagId, @Nonnull Object value) { + this.putEntry(Entry.newAnyEntry(tagId, value)); + } + + public void set(long tagId, @Nonnull CharSequence value) { + this.putEntry(Entry.newObjectEntry(tagId, value)); + } + + public void set(long tagId, boolean value) { + this.putEntry(Entry.newBooleanEntry(tagId, value)); + } + + public void set(long tagId, int value) { + this.putEntry(Entry.newIntEntry(tagId, value)); + } + + public void set(long tagId, long value) { + this.putEntry(Entry.newLongEntry(tagId, value)); + } + + public void set(long tagId, float value) { + this.putEntry(Entry.newFloatEntry(tagId, value)); + } + + public void set(long tagId, double value) { + this.putEntry(Entry.newDoubleEntry(tagId, value)); + } + /** * Places an Entry directly into the map, avoiding a new Entry allocation. Null-tolerant: a null * {@code newEntry} is a no-op returning null, so an Entry producer (e.g. {@link @@ -1785,9 +1935,20 @@ public Entry getAndRemove(String tag) { // See getEntry: entries are stored under their canonical Datadog name, so a removal by an // OpenTelemetry rename must canonicalize first to find (and tombstone) the right entry. - String canonicalTag = KnownTagCodec.canonicalTagName(tag); + long tagHash = Entry.tagHashOf(tag); + String canonicalTag = (tagHash >>> 32) != 0 ? KnownTagCodec.nameOf(tagHash) : tag; + return this.getAndRemove(canonicalTag, tagHash); + } + + /** Removes the entry for a known tag id; see {@link #getEntry(long)}. */ + public Entry getAndRemove(long tagId) { + this.checkWriteAccess(); + + return this.getAndRemove(Entry.requireKnownName(tagId), tagId); + } - Entry localRemoved = this.removeLocal(canonicalTag); + private Entry getAndRemove(String canonicalTag, long tagHash) { + Entry localRemoved = this.removeLocal(canonicalTag, tagHash); TagMap parent = this.parent; if (parent != null) { @@ -1798,7 +1959,7 @@ public Entry getAndRemove(String tag) { boolean alreadyTombstoned = this.removedFromParent != null && this.removedFromParent.contains(canonicalTag); if (!alreadyTombstoned) { - Entry parentEntry = parent.getEntry(canonicalTag); + Entry parentEntry = parent.getEntry(canonicalTag, tagHash); if (parentEntry != null) { if (this.removedFromParent == null) { // Small initial capacity: this set is rare and almost always holds only a handful of @@ -1814,10 +1975,10 @@ public Entry getAndRemove(String tag) { } /** Removes an entry from this map's own buckets only — no parent/tombstone handling. */ - private Entry removeLocal(String tag) { + private Entry removeLocal(String tag, long tagHash) { Object[] thisBuckets = this.buckets; - int hash = TagMap.Entry._hash(tag); + int hash = Entry.bucketHash(tagHash); int bucketIndex = hash & (thisBuckets.length - 1); Object bucket = thisBuckets[bucketIndex]; diff --git a/internal-api/src/main/java/datadog/trace/bootstrap/instrumentation/api/AgentSpan.java b/internal-api/src/main/java/datadog/trace/bootstrap/instrumentation/api/AgentSpan.java index 94c0f80572a..af3aa211c15 100644 --- a/internal-api/src/main/java/datadog/trace/bootstrap/instrumentation/api/AgentSpan.java +++ b/internal-api/src/main/java/datadog/trace/bootstrap/instrumentation/api/AgentSpan.java @@ -9,6 +9,7 @@ import datadog.context.ImplicitContextKeyed; import datadog.trace.api.DDSpanId; import datadog.trace.api.DDTraceId; +import datadog.trace.api.KnownTagCodec; import datadog.trace.api.TagMap; import datadog.trace.api.TraceConfig; import datadog.trace.api.gateway.IGSpanInfo; @@ -103,6 +104,43 @@ default boolean isValid() { AgentSpan setTag(String key, Object value); + /* + * Id-keyed setTag family: the caller passes a KnownTags.*_ID instead of a name. The default + * resolves the id to its name and delegates to the String setter, which is correct for every + * implementation; the core span overrides these to skip the name lookup when storing the tag. + */ + default AgentSpan setTag(long tagId, boolean value) { + return setTag(KnownTagCodec.nameOf(tagId), value); + } + + default AgentSpan setTag(long tagId, int value) { + return setTag(KnownTagCodec.nameOf(tagId), value); + } + + default AgentSpan setTag(long tagId, long value) { + return setTag(KnownTagCodec.nameOf(tagId), value); + } + + default AgentSpan setTag(long tagId, float value) { + return setTag(KnownTagCodec.nameOf(tagId), value); + } + + default AgentSpan setTag(long tagId, double value) { + return setTag(KnownTagCodec.nameOf(tagId), value); + } + + default AgentSpan setTag(long tagId, String value) { + return setTag(KnownTagCodec.nameOf(tagId), value); + } + + default AgentSpan setTag(long tagId, CharSequence value) { + return setTag(KnownTagCodec.nameOf(tagId), value); + } + + default AgentSpan setTag(long tagId, Object value) { + return setTag(KnownTagCodec.nameOf(tagId), value); + } + /** entry may be null - in which case the tags remained unchanged */ AgentSpan setTag(TagMap.EntryReader entry); diff --git a/internal-api/src/test/java/datadog/trace/api/TagMapEntryCreateByIdTest.java b/internal-api/src/test/java/datadog/trace/api/TagMapEntryCreateByIdTest.java new file mode 100644 index 00000000000..5c1e61ae771 --- /dev/null +++ b/internal-api/src/test/java/datadog/trace/api/TagMapEntryCreateByIdTest.java @@ -0,0 +1,59 @@ +package datadog.trace.api; + +import static org.junit.jupiter.api.Assertions.assertEquals; +import static org.junit.jupiter.api.Assertions.assertNull; +import static org.junit.jupiter.api.Assertions.assertThrows; + +import org.junit.jupiter.api.Test; + +/** {@link TagMap.Entry#create(long, Object)} and its overloads: creating an entry by tag id. */ +class TagMapEntryCreateByIdTest { + @Test + void matchesCreateByNameForEveryValueType() { + assertEquivalent( + TagMap.Entry.create(KnownTags.COMPONENT_NAME, (Object) "okhttp"), + TagMap.Entry.create(KnownTags.COMPONENT_ID, (Object) "okhttp")); + assertEquivalent( + TagMap.Entry.create(KnownTags.PEER_HOSTNAME_NAME, (CharSequence) "db.internal"), + TagMap.Entry.create(KnownTags.PEER_HOSTNAME_ID, (CharSequence) "db.internal")); + assertEquivalent( + TagMap.Entry.create(KnownTags.DD_PROFILING_ENABLED_NAME, true), + TagMap.Entry.create(KnownTags.DD_PROFILING_ENABLED_ID, true)); + assertEquivalent( + TagMap.Entry.create(KnownTags.PEER_PORT_NAME, 5432), + TagMap.Entry.create(KnownTags.PEER_PORT_ID, 5432)); + assertEquivalent( + TagMap.Entry.create(KnownTags.HTTP_RESEND_COUNT_NAME, 2L), + TagMap.Entry.create(KnownTags.HTTP_RESEND_COUNT_ID, 2L)); + assertEquivalent( + TagMap.Entry.create(KnownTags.DB_USER_NAME, 1.5f), + TagMap.Entry.create(KnownTags.DB_USER_ID, 1.5f)); + assertEquivalent( + TagMap.Entry.create(KnownTags.DB_POOL_NAME, 2.5d), + TagMap.Entry.create(KnownTags.DB_POOL_NAME_ID, 2.5d)); + } + + @Test + void aNullOrEmptyValueCreatesNoEntry() { + assertNull(TagMap.Entry.create(KnownTags.COMPONENT_ID, (Object) null)); + assertNull(TagMap.Entry.create(KnownTags.COMPONENT_ID, (Object) "")); + assertNull(TagMap.Entry.create(KnownTags.COMPONENT_ID, (CharSequence) null)); + assertNull(TagMap.Entry.create(KnownTags.COMPONENT_ID, (CharSequence) "")); + } + + @Test + void anUnknownIdIsRejected() { + assertThrows(IllegalArgumentException.class, () -> TagMap.Entry.create(0L, (Object) "value")); + assertThrows( + IllegalArgumentException.class, + () -> TagMap.Entry.create(KnownTagCodec.makeTagId(9999), 1)); + } + + /** Same tag, id, type and value -- the two creation paths build equivalent entries. */ + private static void assertEquivalent(TagMap.Entry byName, TagMap.Entry byId) { + assertEquals(byName.tag(), byId.tag()); + assertEquals(byName.tagId(), byId.tagId()); + assertEquals(byName.type(), byId.type()); + assertEquals(byName.objectValue(), byId.objectValue()); + } +} diff --git a/internal-api/src/test/java/datadog/trace/api/TagMapSetByIdTest.java b/internal-api/src/test/java/datadog/trace/api/TagMapSetByIdTest.java new file mode 100644 index 00000000000..1b6dc0b0e5c --- /dev/null +++ b/internal-api/src/test/java/datadog/trace/api/TagMapSetByIdTest.java @@ -0,0 +1,75 @@ +package datadog.trace.api; + +import static org.junit.jupiter.api.Assertions.assertEquals; +import static org.junit.jupiter.api.Assertions.assertNull; +import static org.junit.jupiter.api.Assertions.assertThrows; + +import java.util.HashMap; +import org.junit.jupiter.api.Test; + +/** {@link TagMap#set(long, Object)} and its overloads: setting a known tag by its id. */ +class TagMapSetByIdTest { + @Test + void storesUnderTheCanonicalName() { + TagMap map = TagMap.create(); + + map.set(KnownTags.PEER_HOSTNAME_ID, "db.internal"); + + assertEquals("db.internal", map.getObject(KnownTags.PEER_HOSTNAME_NAME)); + assertEquals(KnownTags.PEER_HOSTNAME_ID, map.getEntry(KnownTags.PEER_HOSTNAME_NAME).tagId()); + } + + @Test + void anOpenTelemetryRenameIsStoredUnderTheDatadogName() { + TagMap byId = TagMap.create(); + TagMap byOtelName = TagMap.create(); + + byId.set(KnownTags.HTTP_METHOD_ID, "GET"); + byOtelName.set(KnownTags.HTTP_METHOD_OTEL_NAME, "GET"); + + assertEquals(new HashMap<>(byOtelName), new HashMap<>(byId)); + } + + @Test + void matchesTheNameKeyedSettersForEveryValueType() { + TagMap byId = TagMap.create(); + byId.set(KnownTags.PEER_PORT_ID, 5432); + byId.set(KnownTags.HTTP_RESEND_COUNT_ID, 2L); + byId.set(KnownTags.PEER_HOSTNAME_ID, (CharSequence) "db.internal"); + byId.set(KnownTags.DB_INSTANCE_ID, (Object) "orders"); + byId.set(KnownTags.DD_PROFILING_ENABLED_ID, true); + byId.set(KnownTags.DB_USER_ID, 1.5f); + byId.set(KnownTags.DB_POOL_NAME_ID, 2.5d); + + TagMap byName = TagMap.create(); + byName.set(KnownTags.PEER_PORT_NAME, 5432); + byName.set(KnownTags.HTTP_RESEND_COUNT_NAME, 2L); + byName.set(KnownTags.PEER_HOSTNAME_NAME, (CharSequence) "db.internal"); + byName.set(KnownTags.DB_INSTANCE_NAME, (Object) "orders"); + byName.set(KnownTags.DD_PROFILING_ENABLED_NAME, true); + byName.set(KnownTags.DB_USER_NAME, 1.5f); + byName.set(KnownTags.DB_POOL_NAME, 2.5d); + + assertEquals(new HashMap<>(byName), new HashMap<>(byId)); + assertEquals(5432, byId.getEntry(KnownTags.PEER_PORT_NAME).intValue()); + } + + @Test + void getsAndRemovesById() { + TagMap map = TagMap.create(); + map.set(KnownTags.HTTP_METHOD_NAME, "GET"); + + assertEquals("GET", map.getEntry(KnownTags.HTTP_METHOD_ID).stringValue()); + assertEquals("GET", map.getAndRemove(KnownTags.HTTP_METHOD_ID).stringValue()); + assertNull(map.getEntry(KnownTags.HTTP_METHOD_ID)); + assertNull(map.getAndRemove(KnownTags.HTTP_METHOD_ID)); + } + + @Test + void anUnknownIdIsRejected() { + TagMap map = TagMap.create(); + + assertThrows(IllegalArgumentException.class, () -> map.set(0L, "value")); + assertThrows(IllegalArgumentException.class, () -> map.set(KnownTagCodec.makeTagId(9999), 1)); + } +} diff --git a/internal-api/src/test/java/datadog/trace/api/TagMapTagHashTest.java b/internal-api/src/test/java/datadog/trace/api/TagMapTagHashTest.java new file mode 100644 index 00000000000..7cd4231ce9b --- /dev/null +++ b/internal-api/src/test/java/datadog/trace/api/TagMapTagHashTest.java @@ -0,0 +1,101 @@ +package datadog.trace.api; + +import static org.junit.jupiter.api.Assertions.assertEquals; +import static org.junit.jupiter.api.Assertions.assertNotEquals; + +import java.lang.reflect.Field; +import java.lang.reflect.Modifier; +import java.util.ArrayList; +import java.util.List; +import org.junit.jupiter.api.Test; + +/** + * The 64-bit tag hash on {@link TagMap.Entry}: a known tag's hash is its id, a custom tag's is its + * name hash in the low 32 bits. + */ +class TagMapTagHashTest { + @Test + void aKnownTagHashesToItsIdHoweverItIsSet() { + TagMap.Entry byId = TagMap.Entry.newAnyEntry(KnownTags.HTTP_METHOD_ID, "GET"); + TagMap.Entry byName = TagMap.Entry.newAnyEntry(KnownTags.HTTP_METHOD_NAME, "GET"); + TagMap.Entry byOtelName = TagMap.Entry.newAnyEntry(KnownTags.HTTP_METHOD_OTEL_NAME, "GET"); + + assertEquals(KnownTags.HTTP_METHOD_ID, byId.tagHash); + assertEquals(KnownTags.HTTP_METHOD_ID, byName.tagHash); + assertEquals(KnownTags.HTTP_METHOD_ID, byOtelName.tagHash); + assertEquals(KnownTags.HTTP_METHOD_ID, byName.tagId()); + } + + @Test + void aCustomTagHashesToItsNameWithNoId() { + TagMap.Entry custom = TagMap.Entry.newAnyEntry("my.custom.tag", "value"); + + assertEquals(0L, custom.tagHash >>> 32); + assertEquals(0L, custom.tagId()); + assertEquals(TagMap.Entry.tagHashOf("my.custom.tag"), custom.tagHash); + } + + @Test + void theBucketHashOfACustomTagIsUnchanged() { + assertEquals( + TagMap.Entry._hash("my.custom.tag"), + TagMap.Entry.bucketHash(TagMap.Entry.tagHashOf("my.custom.tag"))); + } + + @Test + void theBucketHashOfAKnownTagCarriesItsSerial() { + // Folding from bit 32 would leave the serial above any bucket mask; it must come from bit 48. + assertNotEquals( + TagMap.Entry.bucketHash(KnownTags.HTTP_METHOD_ID) & 0xFF, + TagMap.Entry.bucketHash(KnownTags.HTTP_ROUTE_ID) & 0xFF); + } + + @Test + void noKnownTagFoldsToTheVacantSlotHash() throws IllegalAccessException { + // BucketGroup treats a zero hash as a vacant slot; _dd.djm.enabled once folded to zero. + for (long tagId : knownTagIds()) { + assertNotEquals(0, TagMap.Entry.bucketHash(tagId), Long.toHexString(tagId)); + } + assertNotEquals(0, TagMap.Entry.bucketHash(KnownTags.DD_DJM_ENABLED_ID)); + } + + @Test + void everyKnownTagSurvivesBucketCollisionsAndCopies() throws IllegalAccessException { + List tagIds = knownTagIds(); + TagMap map = TagMap.create(); + for (long tagId : tagIds) { + map.set(tagId, "value"); + } + TagMap copy = map.copy(); + + assertEquals(tagIds.size(), map.size()); + assertEquals(tagIds.size(), copy.size()); + for (long tagId : tagIds) { + String name = KnownTagCodec.nameOf(tagId); + assertEquals("value", map.getObject(name), name); + assertEquals("value", copy.getObject(name), name); + } + } + + private static List knownTagIds() throws IllegalAccessException { + List tagIds = new ArrayList<>(); + for (Field field : KnownTags.class.getFields()) { + if (field.getType() == long.class && Modifier.isStatic(field.getModifiers())) { + tagIds.add(field.getLong(null)); + } + } + return tagIds; + } + + @Test + void lookupsFindEntriesSetEitherWay() { + TagMap map = TagMap.create(); + map.set(KnownTags.PEER_PORT_ID, 5432); + map.set("my.custom.tag", "value"); + + assertEquals(5432, map.getEntry(KnownTags.PEER_PORT_NAME).intValue()); + assertEquals("value", map.getString("my.custom.tag")); + assertEquals(5432, map.getAndRemove(KnownTags.PEER_PORT_NAME).intValue()); + assertEquals(null, map.getEntry(KnownTags.PEER_PORT_NAME)); + } +} From 4bf02bb7d56bdc941c87802dbf00e7c7cd54ec3a Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Fri, 9 Oct 2026 10:01:50 -0400 Subject: [PATCH 02/19] Ignore unknown ids when clearing a tag by id; fix a comment wrap span.setTag(0L, "") or a null value reached TagMap.getAndRemove(long), which rejects unknown ids, so clearing threw IllegalArgumentException while every id-keyed setter ignores an unknown id. removeTag(long) now ignores it too. Co-Authored-By: Claude Opus 5.5 --- .../src/main/java/datadog/trace/core/DDSpanContext.java | 8 +++++++- .../java/datadog/trace/core/DDSpanSetTagByIdTest.java | 9 +++++++++ internal-api/src/main/java/datadog/trace/api/TagMap.java | 3 +-- 3 files changed, 17 insertions(+), 3 deletions(-) diff --git a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java index 101b19b49ef..40d4706d283 100644 --- a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java +++ b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java @@ -996,8 +996,14 @@ public void removeTag(String tag) { } } - /** Removes a known tag by id, rather than by its name, which need not resolve back to the id. */ + /** + * Removes a known tag by id, rather than by its name, which need not resolve back to the id. An + * id that names no known tag is ignored, like the id-keyed setters do. + */ public void removeTag(long tagId) { + if (KnownTagCodec.nameOf(tagId) == null) { + return; + } if (tagId == KnownTags.SPAN_KIND_ID) { spanKindOrdinal = SPAN_KIND_UNSET; } diff --git a/dd-trace-core/src/test/java/datadog/trace/core/DDSpanSetTagByIdTest.java b/dd-trace-core/src/test/java/datadog/trace/core/DDSpanSetTagByIdTest.java index e36512259ad..c4b7fdbd808 100644 --- a/dd-trace-core/src/test/java/datadog/trace/core/DDSpanSetTagByIdTest.java +++ b/dd-trace-core/src/test/java/datadog/trace/core/DDSpanSetTagByIdTest.java @@ -52,6 +52,15 @@ void aNullOrEmptyValueRemovesTheTagById() { assertNull(span.getTag(KnownTags.COMPONENT_NAME)); } + @Test + void clearingAnUnknownIdIsIgnored() { + span.setTag(0L, (String) null); + span.setTag(0L, ""); + span.setTag(0L, (Object) null); + + assertNull(span.getTag(KnownTags.PEER_HOSTNAME_NAME)); + } + @Test void removingTheSpanKindByIdClearsTheKind() { span.setTag(KnownTags.SPAN_KIND_ID, "client"); diff --git a/internal-api/src/main/java/datadog/trace/api/TagMap.java b/internal-api/src/main/java/datadog/trace/api/TagMap.java index 0b1a9bd6862..59dec3eb961 100644 --- a/internal-api/src/main/java/datadog/trace/api/TagMap.java +++ b/internal-api/src/main/java/datadog/trace/api/TagMap.java @@ -338,8 +338,7 @@ static Entry newObjectEntry(String tag, Object value) { } // Id-keyed factories: the tag id already names a canonical tag, so these skip the - // canonicalizing - // name lookup the String factories pay. + // canonicalizing name lookup the String factories pay. static Entry newAnyEntry(long tagId, Object value) { return new Entry(tagId, ANY, 0L, value); } From a2829d1df1a41f7837990ec4479fee25a7717c15 Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Fri, 9 Oct 2026 10:48:48 -0400 Subject: [PATCH 03/19] Precheck and reuse the box in long-valued setters The long-valued setters prechecked with needsIntercept, but when the interceptor declined the tag they discarded the box it was given and stored the primitive. Follow the same precheckIntercept -> setBox shape as the other primitive setters, so TagMap keeps the box. Co-Authored-By: Claude Opus 5.5 --- .../main/java/datadog/trace/core/DDSpanContext.java | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java index 40d4706d283..94218f92916 100644 --- a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java +++ b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java @@ -1113,9 +1113,9 @@ public void setTag(final long tagId, final long value) { if (null == tag) { return; } - boolean intercepted = - tagInterceptor.needsIntercept(tag) && tagInterceptor.interceptTag(this, tag, value); - if (!intercepted) { + if (precheckIntercept(tag)) { + this.setBox(tag, value); + } else { synchronized (unsafeTags) { unsafeTags.set(tagId, value); } @@ -1225,10 +1225,9 @@ public void setTag(final String tag, final long value) { if (null == tag) { return; } - // check needsIntercept first to avoid unnecessary boxing - boolean intercepted = - tagInterceptor.needsIntercept(tag) && tagInterceptor.interceptTag(this, tag, value); - if (!intercepted) { + if (precheckIntercept(tag)) { + this.setBox(tag, value); + } else { synchronized (unsafeTags) { unsafeTags.set(tag, value); } From 2d87cde804f8558317f34dc68099108cf454b449 Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Fri, 9 Oct 2026 10:28:57 -0400 Subject: [PATCH 04/19] Keep peer.port off the id path peer.port is declared per direction in the registry (#12713), so it has no direction-free id: BaseDecorator, shared by client and server decorators, sets it by name, and the set-by-id tests use an unshared int tag. Co-Authored-By: Claude Opus 5.5 --- .../instrumentation/decorator/BaseDecorator.java | 4 ++-- .../java/datadog/trace/core/DDSpanSetTagByIdTest.java | 4 ++-- .../java/datadog/trace/api/TagMapInsertBenchmark.java | 4 ++-- .../datadog/trace/api/TagMapEntryCreateByIdTest.java | 4 ++-- .../java/datadog/trace/api/TagMapSetByIdTest.java | 6 +++--- .../java/datadog/trace/api/TagMapTagHashTest.java | 11 +++++++---- 6 files changed, 18 insertions(+), 15 deletions(-) diff --git a/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/instrumentation/decorator/BaseDecorator.java b/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/instrumentation/decorator/BaseDecorator.java index 8eb238b678d..4621d251729 100644 --- a/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/instrumentation/decorator/BaseDecorator.java +++ b/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/instrumentation/decorator/BaseDecorator.java @@ -206,12 +206,12 @@ public final void onPeerConnection( } public void setPeerPort(AgentSpan span, String port) { - span.setTag(KnownTags.PEER_PORT_ID, port); + span.setTag(Tags.PEER_PORT, port); } public void setPeerPort(AgentSpan span, int port) { if (port > UNSET_PORT) { - span.setTag(KnownTags.PEER_PORT_ID, port); + span.setTag(Tags.PEER_PORT, port); } } diff --git a/dd-trace-core/src/test/java/datadog/trace/core/DDSpanSetTagByIdTest.java b/dd-trace-core/src/test/java/datadog/trace/core/DDSpanSetTagByIdTest.java index c4b7fdbd808..0c953fa5b65 100644 --- a/dd-trace-core/src/test/java/datadog/trace/core/DDSpanSetTagByIdTest.java +++ b/dd-trace-core/src/test/java/datadog/trace/core/DDSpanSetTagByIdTest.java @@ -31,11 +31,11 @@ void tearDown() { @Test void storesTheTagUnderItsName() { - span.setTag(KnownTags.PEER_PORT_ID, 5432); + span.setTag(KnownTags.HTTP_RESEND_COUNT_ID, 2); span.setTag(KnownTags.PEER_HOSTNAME_ID, "db.internal"); span.setTag(KnownTags.DD_PROFILING_ENABLED_ID, true); - assertEquals(5432, span.getTag(KnownTags.PEER_PORT_NAME)); + assertEquals(2, span.getTag(KnownTags.HTTP_RESEND_COUNT_NAME)); assertEquals("db.internal", span.getTag(KnownTags.PEER_HOSTNAME_NAME)); assertEquals(true, span.getTag(KnownTags.DD_PROFILING_ENABLED_NAME)); } diff --git a/internal-api/src/jmh/java/datadog/trace/api/TagMapInsertBenchmark.java b/internal-api/src/jmh/java/datadog/trace/api/TagMapInsertBenchmark.java index 3a5ec10ddd0..628d711a9e6 100644 --- a/internal-api/src/jmh/java/datadog/trace/api/TagMapInsertBenchmark.java +++ b/internal-api/src/jmh/java/datadog/trace/api/TagMapInsertBenchmark.java @@ -49,7 +49,7 @@ public class TagMapInsertBenchmark { KnownTags.HTTP_CLIENT_IP_NAME, KnownTags.PEER_HOSTNAME_NAME, KnownTags.PEER_IPV4_NAME, - KnownTags.PEER_PORT_NAME, + KnownTags.PEER_IPV6_NAME, KnownTags.DD_INTEGRATION_NAME, }; @@ -64,7 +64,7 @@ public class TagMapInsertBenchmark { KnownTags.HTTP_CLIENT_IP_ID, KnownTags.PEER_HOSTNAME_ID, KnownTags.PEER_IPV4_ID, - KnownTags.PEER_PORT_ID, + KnownTags.PEER_IPV6_ID, KnownTags.DD_INTEGRATION_ID, }; diff --git a/internal-api/src/test/java/datadog/trace/api/TagMapEntryCreateByIdTest.java b/internal-api/src/test/java/datadog/trace/api/TagMapEntryCreateByIdTest.java index 5c1e61ae771..f970855c212 100644 --- a/internal-api/src/test/java/datadog/trace/api/TagMapEntryCreateByIdTest.java +++ b/internal-api/src/test/java/datadog/trace/api/TagMapEntryCreateByIdTest.java @@ -20,8 +20,8 @@ void matchesCreateByNameForEveryValueType() { TagMap.Entry.create(KnownTags.DD_PROFILING_ENABLED_NAME, true), TagMap.Entry.create(KnownTags.DD_PROFILING_ENABLED_ID, true)); assertEquivalent( - TagMap.Entry.create(KnownTags.PEER_PORT_NAME, 5432), - TagMap.Entry.create(KnownTags.PEER_PORT_ID, 5432)); + TagMap.Entry.create(KnownTags.HTTP_STATUS_CODE_NAME, 5432), + TagMap.Entry.create(KnownTags.HTTP_STATUS_CODE_ID, 5432)); assertEquivalent( TagMap.Entry.create(KnownTags.HTTP_RESEND_COUNT_NAME, 2L), TagMap.Entry.create(KnownTags.HTTP_RESEND_COUNT_ID, 2L)); diff --git a/internal-api/src/test/java/datadog/trace/api/TagMapSetByIdTest.java b/internal-api/src/test/java/datadog/trace/api/TagMapSetByIdTest.java index 1b6dc0b0e5c..ecef85afdd4 100644 --- a/internal-api/src/test/java/datadog/trace/api/TagMapSetByIdTest.java +++ b/internal-api/src/test/java/datadog/trace/api/TagMapSetByIdTest.java @@ -33,7 +33,7 @@ void anOpenTelemetryRenameIsStoredUnderTheDatadogName() { @Test void matchesTheNameKeyedSettersForEveryValueType() { TagMap byId = TagMap.create(); - byId.set(KnownTags.PEER_PORT_ID, 5432); + byId.set(KnownTags.HTTP_STATUS_CODE_ID, 5432); byId.set(KnownTags.HTTP_RESEND_COUNT_ID, 2L); byId.set(KnownTags.PEER_HOSTNAME_ID, (CharSequence) "db.internal"); byId.set(KnownTags.DB_INSTANCE_ID, (Object) "orders"); @@ -42,7 +42,7 @@ void matchesTheNameKeyedSettersForEveryValueType() { byId.set(KnownTags.DB_POOL_NAME_ID, 2.5d); TagMap byName = TagMap.create(); - byName.set(KnownTags.PEER_PORT_NAME, 5432); + byName.set(KnownTags.HTTP_STATUS_CODE_NAME, 5432); byName.set(KnownTags.HTTP_RESEND_COUNT_NAME, 2L); byName.set(KnownTags.PEER_HOSTNAME_NAME, (CharSequence) "db.internal"); byName.set(KnownTags.DB_INSTANCE_NAME, (Object) "orders"); @@ -51,7 +51,7 @@ void matchesTheNameKeyedSettersForEveryValueType() { byName.set(KnownTags.DB_POOL_NAME, 2.5d); assertEquals(new HashMap<>(byName), new HashMap<>(byId)); - assertEquals(5432, byId.getEntry(KnownTags.PEER_PORT_NAME).intValue()); + assertEquals(5432, byId.getEntry(KnownTags.HTTP_STATUS_CODE_NAME).intValue()); } @Test diff --git a/internal-api/src/test/java/datadog/trace/api/TagMapTagHashTest.java b/internal-api/src/test/java/datadog/trace/api/TagMapTagHashTest.java index 7cd4231ce9b..5a5e56b7c78 100644 --- a/internal-api/src/test/java/datadog/trace/api/TagMapTagHashTest.java +++ b/internal-api/src/test/java/datadog/trace/api/TagMapTagHashTest.java @@ -72,6 +72,9 @@ void everyKnownTagSurvivesBucketCollisionsAndCopies() throws IllegalAccessExcept assertEquals(tagIds.size(), copy.size()); for (long tagId : tagIds) { String name = KnownTagCodec.nameOf(tagId); + if (KnownTagCodec.keyOf(name) != tagId) { + continue; // a name declared per direction does not resolve to either direction's id + } assertEquals("value", map.getObject(name), name); assertEquals("value", copy.getObject(name), name); } @@ -90,12 +93,12 @@ private static List knownTagIds() throws IllegalAccessException { @Test void lookupsFindEntriesSetEitherWay() { TagMap map = TagMap.create(); - map.set(KnownTags.PEER_PORT_ID, 5432); + map.set(KnownTags.HTTP_STATUS_CODE_ID, 5432); map.set("my.custom.tag", "value"); - assertEquals(5432, map.getEntry(KnownTags.PEER_PORT_NAME).intValue()); + assertEquals(5432, map.getEntry(KnownTags.HTTP_STATUS_CODE_NAME).intValue()); assertEquals("value", map.getString("my.custom.tag")); - assertEquals(5432, map.getAndRemove(KnownTags.PEER_PORT_NAME).intValue()); - assertEquals(null, map.getEntry(KnownTags.PEER_PORT_NAME)); + assertEquals(5432, map.getAndRemove(KnownTags.HTTP_STATUS_CODE_NAME).intValue()); + assertEquals(null, map.getEntry(KnownTags.HTTP_STATUS_CODE_NAME)); } } From 0401a430c26b2f7c33cc61e4d0401e14955423dd Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Fri, 9 Oct 2026 10:32:35 -0400 Subject: [PATCH 05/19] Mark intercepted tags with an id bit, via a tracer overlay Set-path routing is a per-language concern, so it lives in a Java overlay next to tag-conventions.yaml rather than in the language-agnostic conventions. The overlay declares the keys that exist only to be routed (resource.name, error, sampling directives, ...) and lists every tag TagInterceptor may route. Each listed tag's id carries the INTERCEPTED bit (bit 1), so a setter called with a constant id can fold the interception test away. Serial numbers become public so TagInterceptor can switch on them. Co-Authored-By: Claude Opus 5.5 --- .github/CODEOWNERS | 1 + .../tagRegistry/GenerateKnownTagsTask.kt | 9 +++- .../tagRegistry/KnownTagsEmitter.kt | 8 +-- .../buildlogic/tagRegistry/TagConventions.kt | 39 ++++++++++++-- .../buildlogic/tagRegistry/TagRegistry.kt | 25 +++++---- .../tagRegistry/TagRegistryExtension.kt | 6 +++ .../tagRegistry/TagRegistryGenerator.kt | 34 ++++++------ .../tagRegistry/TagRegistryGeneratorPlugin.kt | 1 + .../tagRegistry/TagRegistryGeneratorTest.kt | 49 +++++++++++++++++ internal-api/build.gradle.kts | 1 + .../java/datadog/trace/api/KnownTagCodec.java | 27 +++++++--- tag-conventions-java.yaml | 54 +++++++++++++++++++ 12 files changed, 213 insertions(+), 41 deletions(-) create mode 100644 tag-conventions-java.yaml diff --git a/.github/CODEOWNERS b/.github/CODEOWNERS index bf1ce358fdf..ea941639256 100644 --- a/.github/CODEOWNERS +++ b/.github/CODEOWNERS @@ -13,6 +13,7 @@ /SECURITY.md @DataDog/apm-java /SUPPORT.md @DataDog/apm-java /tag-conventions.yaml @DataDog/apm-java @DataDog/apm-lang-platform-java @DataDog/apm-sdk-capabilities-java +/tag-conventions-java.yaml @DataDog/apm-java @DataDog/apm-lang-platform-java @DataDog/apm-sdk-capabilities-java /dd-smoke-tests/README.md @DataDog/apm-java /docs/ @DataDog/apm-java diff --git a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/GenerateKnownTagsTask.kt b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/GenerateKnownTagsTask.kt index bd567a67854..72c2dfc1514 100644 --- a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/GenerateKnownTagsTask.kt +++ b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/GenerateKnownTagsTask.kt @@ -5,6 +5,7 @@ import org.gradle.api.file.DirectoryProperty import org.gradle.api.file.RegularFileProperty import org.gradle.api.tasks.CacheableTask import org.gradle.api.tasks.InputFile +import org.gradle.api.tasks.Optional import org.gradle.api.tasks.OutputDirectory import org.gradle.api.tasks.PathSensitive import org.gradle.api.tasks.PathSensitivity @@ -20,12 +21,18 @@ abstract class GenerateKnownTagsTask : DefaultTask() { @get:PathSensitive(PathSensitivity.NONE) abstract val tagConventionsFile: RegularFileProperty + @get:InputFile + @get:Optional + @get:PathSensitive(PathSensitivity.NONE) + abstract val tracerOverlayFile: RegularFileProperty + @get:OutputDirectory abstract val destinationDirectory: DirectoryProperty @TaskAction fun generate() { val outDir = destinationDirectory.get().asFile - TagRegistryGenerator.generate(tagConventionsFile.get().asFile, outDir) + TagRegistryGenerator.generate( + tagConventionsFile.get().asFile, outDir, tracerOverlayFile.orNull?.asFile) logger.lifecycle("tag-registry: generated -> $outDir") } } diff --git a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt index 1f808d8d357..ca81859af96 100644 --- a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt +++ b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt @@ -6,7 +6,7 @@ import java.util.Locale /** * Emits the generated `KnownTags.java` from a [TagRegistry]. Public API first — per-tag * `_NAME` (string) + `_ID` (encoded long, literal) couplets with a trailing `// makeTagId(...)` - * derivation comment — then the package-private `_SERIAL_NUM` constants, the + * derivation comment — then the `_SERIAL_NUM` constants, the * `StringIndex.EmbeddingSupport` keyOf table and the resolver's name switches. */ object KnownTagsEmitter { @@ -101,15 +101,17 @@ object KnownTagsEmitter { } append("// makeTagId(serial=${t.serial})") if (t.traceLevel) append(" + trace-level") + if (t.intercepted) append(" + intercepted") if (t.otelName != null) append(" -> ${escape(t.otelName)}") appendLine(" <${escape(t.required)}>") appendLine() } - // Serial numbers (globalSerial per tag) — package-private, consumed by the resolver switch. + // Serial numbers (globalSerial per tag) — public, so a switch on KnownTagCodec.serialNum outside + // this package (the resolver here, TagInterceptor in core) can name them as case labels. appendLine(" // ---- serial numbers ----") for (t in reg.tags) { - appendLine(" static final int ${serialC(t.identity)} = ${t.serial};") + appendLine(" public static final int ${serialC(t.identity)} = ${t.serial};") } // OpenTelemetry name -> canonical tag name. Validation ensures aliases are distinct from all diff --git a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagConventions.kt b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagConventions.kt index 54fef064dfb..b17eac293b7 100644 --- a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagConventions.kt +++ b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagConventions.kt @@ -9,6 +9,8 @@ class TagConventions private constructor( private val spanTypes: Map, private val mixins: Map, private val traceLevel: List, + /** Datadog names the tracer intercepts on the set-path, from the tracer overlay. */ + val interceptedNames: Set = emptySet(), ) { /** * A tag's identity: its Datadog name, plus the direction when that name is declared once per @@ -242,6 +244,15 @@ class TagConventions private constructor( private fun directionOf(spanTypes: Map, st: SpanType): Direction? = chainOf(spanTypes, st.name).firstNotNullOfOrNull { it.direction } /** Reads `span-kind` as the direction it sets, or null when absent. */ + private fun overlayMixin(overlay: Map): Map { + val tags = tagList(overlay["tags"]) + if (tags.isEmpty()) return emptyMap() + return mapOf( + OVERLAY_MIXIN to + Mixin(name = OVERLAY_MIXIN, appliesAll = false, appliesTo = emptySet(), tags = tags, refs = emptyList()) + ) + } + private fun parseDirection(m: Map, owner: String): Direction? { val spanKind = m["span-kind"] require(spanKind == null || spanKind in SPAN_KIND_DIRECTIONS) { @@ -251,10 +262,27 @@ class TagConventions private constructor( } @Suppress("UNCHECKED_CAST") - fun parse(root: Map): TagConventions { + /** The synthetic mixin holding the tracer overlay's tags; it applies to no span type. */ + const val OVERLAY_MIXIN = "tracer overlay" + + /** + * Parses [root], the language-agnostic conventions, plus [overlay], this tracer's own set-path + * routing: `tags` declares keys that exist only to be routed (e.g. `resource.name`), and + * `intercepted` lists the Datadog names the tracer intercepts, from either file. + */ + fun parse(root: Map, overlay: Map = emptyMap()): TagConventions { for (section in listOf("span_types", "mixins", "trace_level")) { require(root[section] == null || root[section] is Map<*, *>) { "$section must be a mapping" } } + require(overlay.keys.all { it == "tags" || it == "intercepted" }) { + "the tracer overlay may only declare `tags` and `intercepted`, not ${overlay.keys - setOf("tags", "intercepted")}" + } + require(refList(overlay["tags"]).isEmpty()) { "tracer overlay tags must be declarations, not refs" } + val interceptedRaw = overlay["intercepted"] + require(interceptedRaw == null || (interceptedRaw is List<*> && interceptedRaw.all { it is String })) { + "intercepted must be a list of Datadog tag names" + } + val intercepted = (interceptedRaw as? List)?.toSet() ?: emptySet() val spanTypesRaw = (root["span_types"] as? Map) ?: emptyMap() val parsedSpanTypes = spanTypesRaw.mapValues { (name, v) -> @@ -298,7 +326,7 @@ class TagConventions private constructor( refs = refList(m["tags"]), direction = parseDirection(m, "mixin '$name'"), ) - } + } + overlayMixin(overlay) for (spanType in parsedSpanTypes.values) { for (included in spanType.include) { @@ -342,7 +370,12 @@ class TagConventions private constructor( ) } validateOtelNameScope(spanTypes, mixins, traceLevel) - return TagConventions(spanTypes, mixins, traceLevel) + val conv = TagConventions(spanTypes, mixins, traceLevel, intercepted) + val declared = conv.allDeclaredTags().map { it.ddName }.toSet() + for (name in intercepted) { + require(name in declared) { "intercepted tag '$name' is not declared" } + } + return conv } /** diff --git a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistry.kt b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistry.kt index 664ee9f6687..73c38c2f7ef 100644 --- a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistry.kt +++ b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistry.kt @@ -4,17 +4,15 @@ package datadog.buildlogic.tagRegistry * Assigns tag ids from a parsed [TagConventions]. The id encoding mirrors KnownTagCodec: [63-48 * serial][47-32 reserved][31-0 flags]. * - *

An id is IDENTITY only: a globally unique serial plus the trace-level classification bit. It + *

An id is a globally unique serial plus two classification bits: trace-level and intercepted. It * carries no storage-layout coordinate -- bits [47-32] are held vacant for the co-occurrence slot * that the dense tag store assigns by graph coloring, which lands with the dense store itself. * Nothing here needs to know how (or whether) a tag is stored. * - *

Nor does anything here know how a tag is SET. Whether the tracer intercepts a tag on the - * set-path (routing it to a span field or a sampling directive instead of tag storage) is a - * property of TagInterceptor, not of the tag's identity, and modelling it was the source of a whole - * class of drift between this registry and the interceptor's actual switch. It arrives with the - * work that consumes it -- the id->handler dispatch table that retires TagInterceptor -- where the - * interceptor can be the authority. Re-adding a classification bit then is purely additive. + *

The intercepted bit marks a tag the tracer may route on the set-path (to a span field or a + * sampling directive instead of tag storage), as listed by the tracer overlay. A setter called with + * a constant id then folds the interception test away. TagInterceptor's switch stays the authority + * on what each tag does; a test there keeps the bit and the switch in agreement. */ class TagRegistry private constructor(val tags: List) { data class Tag( @@ -23,6 +21,7 @@ class TagRegistry private constructor(val tags: List) { val required: String, val serial: Int, val traceLevel: Boolean, + val intercepted: Boolean, val id: Long, /** The tag's OpenTelemetry name, in [otelDirection] or every direction; null when not renamed. */ val declaredOtelName: String? = null, @@ -47,14 +46,16 @@ class TagRegistry private constructor(val tags: List) { companion object { const val FIRST_SERIAL = 1 const val LEVEL_TRACE = 1L shl 2 // low-32 carve bit 2; mirrors KnownTagCodec.LEVEL_TRACE + const val INTERCEPTED = 1L shl 1 // low-32 carve bit 1; mirrors KnownTagCodec.INTERCEPTED /** - * Mirrors KnownTagCodec.makeTagId(serial) + traceLevel() -- must stay in sync. LEVEL_TRACE at - * bit 2, other low bits and the reserved [47-32] window zero. + * Mirrors KnownTagCodec.makeTagId(serial) + traceLevel() + intercepted() -- must stay in sync. + * LEVEL_TRACE at bit 2, INTERCEPTED at bit 1, other low bits and the reserved [47-32] window zero. */ - fun encode(serial: Int, traceLevel: Boolean): Long { + fun encode(serial: Int, traceLevel: Boolean, intercepted: Boolean = false): Long { var id = serial.toLong() shl 48 if (traceLevel) id = id or LEVEL_TRACE + if (intercepted) id = id or INTERCEPTED return id } @@ -67,13 +68,15 @@ class TagRegistry private constructor(val tags: List) { conv.allDeclaredTags().sortedBy { it.name }.mapIndexed { i, t -> val serial = FIRST_SERIAL + i val isTraceLevel = t.identity in traceLevel + val isIntercepted = t.ddName in conv.interceptedNames Tag( t.identity, t.type, t.required, serial, isTraceLevel, - id = encode(serial, isTraceLevel), + isIntercepted, + id = encode(serial, isTraceLevel, isIntercepted), declaredOtelName = renames[t.identity]?.otelName, otelDirection = renames[t.identity]?.direction, ) diff --git a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistryExtension.kt b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistryExtension.kt index f6d07ca586b..1193de5c3cc 100644 --- a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistryExtension.kt +++ b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistryExtension.kt @@ -16,6 +16,12 @@ abstract class TagRegistryExtension @Inject constructor( */ abstract val tagConventionsFile: RegularFileProperty + /** + * Optional tracer overlay: this tracer's set-path routing (intercepted tags, and keys that exist + * only to be routed), kept out of the language-agnostic conventions. + */ + abstract val tracerOverlayFile: RegularFileProperty + /** * Destination of the generated sources, by convention under `build/generated/tag-registry`. */ diff --git a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGenerator.kt b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGenerator.kt index 9b69f0fe0b0..50960175cc0 100644 --- a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGenerator.kt +++ b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGenerator.kt @@ -8,17 +8,20 @@ import java.util.Locale /** Emits the Java tag registry and reports in a deterministic order. */ object TagRegistryGenerator { - /** Parses the conventions YAML and writes the full generated tree under [outDir]. */ - fun generate(tagConventionsFile: File, outDir: File) { + /** + * Parses the conventions YAML, plus the tracer overlay when there is one, and writes the full + * generated tree under [outDir]. + */ + fun generate(tagConventionsFile: File, outDir: File, tracerOverlayFile: File? = null) { val mapper = ObjectMapper(YAMLFactory()) - val domain: Map = - tagConventionsFile.inputStream().use { - mapper.readValue(it, object : TypeReference>() {}) - } + fun read(file: File): Map = + file.inputStream().use { mapper.readValue(it, object : TypeReference>() {}) } ?: emptyMap() + val domain = read(tagConventionsFile) + val overlay = tracerOverlayFile?.let(::read) ?: emptyMap() // Validate before touching the destination tree: an invalid domain model must fail loudly, // not after the previous (valid) generated output has already been wiped out. - val conv = TagConventions.parse(domain) + val conv = TagConventions.parse(domain, overlay) val reg = TagRegistry.build(conv) // Remove obsolete generated files when the output changes. @@ -68,18 +71,19 @@ object TagRegistryGenerator { """ # Tag id assignment. tags=${reg.tags.size} - # TAGS serial lvl id required name + # TAGS serial lvl int id required name """.trimIndent() ) - for ((name, _, required, serial, traceLevel, id) in reg.tags) { + for (t in reg.tags) { appendLine( - " %6d %s %-18s %-12s %s".format( + " %6d %s %s %-18s %-12s %s".format( Locale.ROOT, - serial, - if (traceLevel) "T" else "-", - "0x%016X".format(Locale.ROOT, id), - required, - name + t.serial, + if (t.traceLevel) "T" else "-", + if (t.intercepted) "I" else "-", + "0x%016X".format(Locale.ROOT, t.id), + t.required, + t.name ) ) } diff --git a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGeneratorPlugin.kt b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGeneratorPlugin.kt index c350d3c302e..a93b92df9f7 100644 --- a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGeneratorPlugin.kt +++ b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGeneratorPlugin.kt @@ -16,6 +16,7 @@ class TagRegistryGeneratorPlugin : Plugin { group = "build" description = "Generates the Java tag registry and assignment reports." tagConventionsFile.convention(ext.tagConventionsFile) + tracerOverlayFile.convention(ext.tracerOverlayFile) destinationDirectory.convention(ext.destinationDirectory) } project.pluginManager.withPlugin("java") { diff --git a/build-logic/tag-registry/src/test/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGeneratorTest.kt b/build-logic/tag-registry/src/test/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGeneratorTest.kt index 1ff22853571..e4fdba9d853 100644 --- a/build-logic/tag-registry/src/test/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGeneratorTest.kt +++ b/build-logic/tag-registry/src/test/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGeneratorTest.kt @@ -478,6 +478,55 @@ class TagRegistryGeneratorTest { .withMessageContaining("span-kind-neutral without an otel-name") } + @Test + fun `the tracer overlay declares routed keys and marks intercepted tags`() { + val yaml = directory.conventionsFile( + """ + span_types: + base: + abstract: true + tags: [{dd-name: service, otel-name: service.name}, {dd-name: component}] + """ + ) + val overlay = directory.writeFile( + "overlay.yaml", + """ + tags: [{dd-name: resource.name}] + intercepted: [resource.name, service] + """ + ) + val output = File(directory, "generated") + + TagRegistryGenerator.generate(yaml, output, overlay) + + val knownTags = contents(output).getValue("java/datadog/trace/api/KnownTags.java") + assertThat(knownTags) + .contains( + "COMPONENT_ID = 0x0001000000000000L", + "RESOURCE_NAME_ID = 0x0002000000000002L", + "SERVICE_ID = 0x0003000000000002L", + "public static final int SERVICE_SERIAL_NUM = 3;" + ) + } + + @TableTest( + """ + scenario | overlay | message + undeclared name | 'intercepted: [missing]' | is not declared + ref in overlay | 'tags: [{ref: service}]' | must be declarations, not refs + unknown section | 'span_types: {}' | may only declare + duplicate of a tag | 'tags: [{dd-name: service}]' | declared in both + """ + ) + fun `invalid tracer overlays are rejected`(overlay: String, message: String) { + val yaml = directory.conventionsFile("span_types: {base: {tags: [{dd-name: service}]}}") + val overlayFile = directory.writeFile("overlay.yaml", overlay) + + assertThatIllegalArgumentException() + .isThrownBy { TagRegistryGenerator.generate(yaml, File(directory, "generated"), overlayFile) } + .withMessageContaining(message) + } + private fun tagConventions(@Language("yaml") yamlText: String) = TagConventions.parse( ObjectMapper(YAMLFactory()).readValue( directory.conventionsFile(yamlText), diff --git a/internal-api/build.gradle.kts b/internal-api/build.gradle.kts index a9d82cebc72..9c877c4562d 100644 --- a/internal-api/build.gradle.kts +++ b/internal-api/build.gradle.kts @@ -266,6 +266,7 @@ extra["excludedClassesInstructionCoverage"] = listOf("datadog.trace.util.stacktr tagRegistry { tagConventionsFile.set(rootProject.layout.projectDirectory.file("tag-conventions.yaml")) + tracerOverlayFile.set(rootProject.layout.projectDirectory.file("tag-conventions-java.yaml")) } dependencies { diff --git a/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java b/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java index d84e1e6a537..4ea9b574a8a 100644 --- a/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java +++ b/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java @@ -15,15 +15,15 @@ public final class KnownTagCodec { * openTelemetryNameOf switch on it, and the generator emits each id as a literal. Bits [47-32] * are RESERVED and always zero here: they are the window the dense tag store uses for its * co-occurrence slot coordinate, which arrives with that store. Of the low 32 flag bits, bit 2 is - * the trace/span LEVEL bit (set ⟹ trace-level); bits 1-0 are reserved. Unknown (string-only) - * custom tags are NOT known ids — {@code keyOf} returns 0 for them. + * the trace/span LEVEL bit (set ⟹ trace-level), bit 1 is the INTERCEPTED bit, and bit 0 is + * reserved. Unknown (string-only) custom tags are NOT known ids — {@code keyOf} returns 0 for + * them. * - *

An id says what a tag IS, not how it is SET. Whether the tracer intercepts a tag on the - * set-path — routing it to a span field or a sampling directive instead of tag storage — belongs - * to TagInterceptor, whose {@code needsIntercept} switch is the authority; mirroring it here as a - * classification bit and a serial-range tier only created drift between the two. That - * classification returns with the work that consumes it (the id→handler dispatch table that - * retires TagInterceptor), and re-adding a bit then is purely additive. + *

Bit 1 is the INTERCEPTED bit: set on a tag TagInterceptor may route on the set-path (to a + * span field or a sampling directive instead of tag storage). It is a hint, not a decision: the + * interceptor's switch says what each such tag does, and may still store it. Because a setter + * called with a constant id can test the bit at JIT time, the interception path folds away for + * every tag without it. * *

There is deliberately NO OpenTelemetry-applicability flag: an absent otel-name means * pass-through (the tag is emitted under its Datadog name), so today every known tag has an @@ -46,6 +46,17 @@ public static boolean isTraceLevel(long tagId) { return (tagId & LEVEL_TRACE) != 0L; } + /** + * INTERCEPTED bit (low-32 carve, bit 1). Set marks a tag TagInterceptor may route on the + * set-path. Declared in the tracer overlay ({@code tag-conventions-java.yaml}). + */ + public static final long INTERCEPTED = 1L << 1; + + /** True if the tagId names a tag TagInterceptor may route on the set-path. */ + public static boolean isIntercepted(long tagId) { + return (tagId & INTERCEPTED) != 0L; + } + /** Returns the tagId with the {@link #LEVEL_TRACE} flag set. */ public static long traceLevel(long tagId) { return tagId | LEVEL_TRACE; diff --git a/tag-conventions-java.yaml b/tag-conventions-java.yaml new file mode 100644 index 00000000000..c2304396785 --- /dev/null +++ b/tag-conventions-java.yaml @@ -0,0 +1,54 @@ +# Tracer overlay for tag-conventions.yaml — dd-trace-java's set-path routing. +# --------------------------------------------------------------------------- +# tag-conventions.yaml is language-agnostic; which keys a tracer intercepts on the set-path (routing +# them to a span field or a sampling directive instead of tag storage) is this tracer's concern, so +# it lives here. +# +# tags — keys that exist only to be routed, so the conventions do not declare them. They get +# ids like any other tag (instrumentation can set them by id) but belong to no span type. +# Same declaration syntax as tag-conventions.yaml; refs are not allowed. +# intercepted — Datadog names TagInterceptor may route, declared in either file. Each one's id carries +# the INTERCEPTED bit, so a setter called with a constant id folds the interception test +# away. TagInterceptor's switch is the authority on what each one does; a test there +# keeps this list and the switch in agreement. +# --------------------------------------------------------------------------- + +tags: + - { dd-name: resource.name, type: string } + - { dd-name: span.type, type: string } + - { dd-name: error, type: boolean } + - { dd-name: manual.keep, type: boolean } + - { dd-name: manual.drop, type: boolean } + - { dd-name: asm.keep, type: boolean } + - { dd-name: ai_guard.keep, type: boolean } + - { dd-name: sampling.priority, type: int } + - { dd-name: _dd.p.ts, type: int } + - { dd-name: _dd.p.debug, type: string } + - { dd-name: _dd.origin, type: string } + - { dd-name: _dd.measured, type: boolean } + - { dd-name: _dd1.sr.eausr, type: double } + +intercepted: + # declared above + - resource.name + - span.type + - error + - manual.keep + - manual.drop + - asm.keep + - ai_guard.keep + - sampling.priority + - _dd.p.ts + - _dd.p.debug + - _dd.origin + - _dd.measured + - _dd1.sr.eausr + # declared in tag-conventions.yaml + - service + - peer.service + - span.kind + - servlet.context + - db.statement + - http.method + - http.url + - http.status_code From 8949a571475f87cf627bbf4b2c624beece16cde7 Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Fri, 9 Oct 2026 10:38:27 -0400 Subject: [PATCH 06/19] Dispatch TagInterceptor on tag ids TagInterceptor switches on the tag's serial rather than its name, so a known tag is matched under any of its names and the *_OTEL_NAME cases go away. needsIntercept(long) tests the INTERCEPTED bit first, which folds away for a constant id. split-by-tags entries resolve to serials at construction (each direction for a name declared per direction); only custom tags are still matched by name. A test checks that exactly the tags carrying the bit have a case. Co-Authored-By: Claude Opus 5.5 --- .../core/taginterceptor/TagInterceptor.java | 218 ++++++++++-------- .../taginterceptor/TagInterceptorTest.java | 81 +++++++ 2 files changed, 209 insertions(+), 90 deletions(-) diff --git a/dd-trace-core/src/main/java/datadog/trace/core/taginterceptor/TagInterceptor.java b/dd-trace-core/src/main/java/datadog/trace/core/taginterceptor/TagInterceptor.java index 89e5a01adb8..ca552cd8541 100644 --- a/dd-trace-core/src/main/java/datadog/trace/core/taginterceptor/TagInterceptor.java +++ b/dd-trace-core/src/main/java/datadog/trace/core/taginterceptor/TagInterceptor.java @@ -1,19 +1,11 @@ package datadog.trace.core.taginterceptor; import static datadog.trace.api.DDTags.ANALYTICS_SAMPLE_RATE; -import static datadog.trace.api.DDTags.MEASURED; -import static datadog.trace.api.DDTags.ORIGIN_KEY; -import static datadog.trace.api.DDTags.SPAN_TYPE; -import static datadog.trace.api.KnownTags.DB_STATEMENT_OTEL_NAME; -import static datadog.trace.api.KnownTags.HTTP_METHOD_OTEL_NAME; -import static datadog.trace.api.KnownTags.HTTP_STATUS_CODE_OTEL_NAME; -import static datadog.trace.api.KnownTags.HTTP_URL_OTEL_NAME; +import static datadog.trace.api.KnownTags.SERVLET_CONTEXT_ID; import static datadog.trace.api.sampling.PrioritySampling.USER_DROP; -import static datadog.trace.bootstrap.instrumentation.api.InstrumentationTags.SERVLET_CONTEXT; import static datadog.trace.bootstrap.instrumentation.api.ServiceNameSources.SPLIT_BY_SERVLET_CONTEXT; import static datadog.trace.bootstrap.instrumentation.api.ServiceNameSources.SPLIT_BY_TAGS; import static datadog.trace.bootstrap.instrumentation.api.Tags.HTTP_METHOD; -import static datadog.trace.bootstrap.instrumentation.api.Tags.HTTP_STATUS; import static datadog.trace.bootstrap.instrumentation.api.Tags.HTTP_URL; import static datadog.trace.core.taginterceptor.RuleFlags.Feature.FORCE_MANUAL_DROP; import static datadog.trace.core.taginterceptor.RuleFlags.Feature.FORCE_SAMPLING_PRIORITY; @@ -27,6 +19,8 @@ import datadog.trace.api.Config; import datadog.trace.api.ConfigDefaults; import datadog.trace.api.DDTags; +import datadog.trace.api.KnownTagCodec; +import datadog.trace.api.KnownTags; import datadog.trace.api.Pair; import datadog.trace.api.TagMap; import datadog.trace.api.config.GeneralConfig; @@ -41,6 +35,8 @@ import datadog.trace.bootstrap.instrumentation.api.UTF8BytesString; import datadog.trace.core.DDSpanContext; import java.net.URI; +import java.util.Arrays; +import java.util.HashSet; import java.util.Map; import java.util.Set; import javax.annotation.Nonnull; @@ -54,7 +50,12 @@ public class TagInterceptor { private final boolean isServiceNameSetByUser; private final boolean splitByServletContext; private final String inferredServiceName; - private final Set splitServiceTags; + + /** split-by-tags entries naming known tags, indexed by serial; null when there are none. */ + private final boolean[] splitServiceSerials; + + /** split-by-tags entries naming custom tags; null when there are none. */ + private final Set splitServiceCustomNames; private final boolean shouldSet404ResourceName; private final boolean shouldSetUrlResourceAsName; @@ -77,9 +78,10 @@ public TagInterceptor( boolean jeeSplitByDeployment) { this.isServiceNameSetByUser = isServiceNameSetByUser; this.inferredServiceName = inferredServiceName; - this.splitServiceTags = splitServiceTags; + this.splitServiceSerials = knownTagSerials(splitServiceTags); + this.splitServiceCustomNames = customTagNames(splitServiceTags); this.ruleFlags = ruleFlags; - splitByServletContext = splitServiceTags.contains(SERVLET_CONTEXT); + splitByServletContext = isSplitServiceTag(SERVLET_CONTEXT_ID); shouldSet404ResourceName = ruleFlags.isEnabled(URL_AS_RESOURCE_NAME) @@ -89,9 +91,63 @@ public TagInterceptor( this.jeeSplitByDeployment = jeeSplitByDeployment; } + /** + * Marks, by serial, each known tag that {@code names} names under any of its names, so a tag set + * by id or by its OpenTelemetry name matches too. A name declared per direction marks each + * direction's tag. Returns null when no name is a known tag's. + */ + private static boolean[] knownTagSerials(Set names) { + if (names.isEmpty()) { + return null; + } + Set canonicalNames = new HashSet<>(); + for (String name : names) { + canonicalNames.add(KnownTagCodec.canonicalTagName(name)); + } + boolean[] serials = null; + for (int serial = 1; ; ++serial) { + String name = KnownTagCodec.nameOf(KnownTagCodec.makeTagId(serial)); + if (name == null) { + return serials; + } + if (canonicalNames.contains(name)) { + if (serials == null || serial >= serials.length) { + serials = serials == null ? new boolean[serial + 1] : Arrays.copyOf(serials, serial + 1); + } + serials[serial] = true; + } + } + } + + /** The names in {@code names} that do not resolve to a known tag, or null when there are none. */ + private static Set customTagNames(Set names) { + Set custom = null; + for (String name : names) { + if (KnownTagCodec.keyOf(name) == 0) { + if (custom == null) { + custom = new HashSet<>(); + } + custom.add(name); + } + } + return custom; + } + + private boolean isSplitServiceTag(long tagId) { + boolean[] serials = splitServiceSerials; + int serial = KnownTagCodec.serialNum(tagId); + return serials != null && serial < serials.length && serials[serial]; + } + + private boolean isSplitServiceTag(String customTag) { + Set names = splitServiceCustomNames; + return names != null && names.contains(customTag); + } + public boolean needsIntercept(TagMap map) { for (TagMap.EntryReader entry : map) { - if (needsIntercept(entry.tag())) return true; + long tagId = entry.tagId(); + if (tagId != 0 ? needsIntercept(tagId) : isSplitServiceTag(entry.tag())) return true; } return false; } @@ -103,131 +159,121 @@ public boolean needsIntercept(Map map) { return false; } - public boolean needsIntercept(String tag) { - switch (tag) { - case DDTags.RESOURCE_NAME: - case Tags.DB_STATEMENT: - case DB_STATEMENT_OTEL_NAME: - case DDTags.SERVICE_NAME: - case "service": - case Tags.PEER_SERVICE: - case DDTags.MANUAL_KEEP: - case DDTags.MANUAL_DROP: - case Tags.ASM_KEEP: - case Tags.AI_GUARD_KEEP: - case Tags.SAMPLING_PRIORITY: - case Tags.PROPAGATED_TRACE_SOURCE: - case Tags.PROPAGATED_DEBUG: - case SERVLET_CONTEXT: - case SPAN_TYPE: - case ANALYTICS_SAMPLE_RATE: - case Tags.ERROR: - case HTTP_STATUS: - case HTTP_STATUS_CODE_OTEL_NAME: - case HTTP_METHOD: - case HTTP_METHOD_OTEL_NAME: - case HTTP_URL: - case HTTP_URL_OTEL_NAME: - case ORIGIN_KEY: - case MEASURED: - case Tags.SPAN_KIND: - return true; + /** + * Whether {@link #interceptTag(DDSpanContext, long, Object)} may route the tag. Called with a + * constant id, the {@link KnownTagCodec#INTERCEPTED} test folds away; only a configured + * split-by-tags is left to check at run time. + */ + public boolean needsIntercept(long tagId) { + return KnownTagCodec.isIntercepted(tagId) || isSplitServiceTag(tagId); + } - default: - return splitServiceTags.contains(tag); - } + public boolean needsIntercept(String tag) { + long tagId = KnownTagCodec.keyOf(tag); + return tagId != 0 ? needsIntercept(tagId) : isSplitServiceTag(tag); } public boolean interceptTag(DDSpanContext span, String tag, Object value) { - switch (tag) { - case DDTags.RESOURCE_NAME: + long tagId = KnownTagCodec.keyOf(tag); + return tagId != 0 ? interceptTag(span, tagId, value) : interceptCustomTag(span, tag, value); + } + + /** + * Routes a known tag to a span field or a sampling directive. Returns true when the tag was + * consumed, false when it should still be stored. Every tag with a case here carries the {@link + * KnownTagCodec#INTERCEPTED} bit, declared in {@code tag-conventions-java.yaml}. + */ + public boolean interceptTag(DDSpanContext span, long tagId, Object value) { + switch (KnownTagCodec.serialNum(tagId)) { + case KnownTags.RESOURCE_NAME_SERIAL_NUM: return interceptResourceName(span, value); - case Tags.DB_STATEMENT: - case DB_STATEMENT_OTEL_NAME: + case KnownTags.DB_STATEMENT_SERIAL_NUM: return interceptDbStatement(span, value); - case DDTags.SERVICE_NAME: - case "service": + case KnownTags.SERVICE_SERIAL_NUM: return interceptServiceName(SERVICE_NAME, span, value); - case Tags.PEER_SERVICE: + case KnownTags.PEER_SERVICE_SERIAL_NUM: // we still need to intercept and add this tag when the user manually set span.setTag(DDTags.PEER_SERVICE_SOURCE, Tags.PEER_SERVICE); return interceptServiceName(PEER_SERVICE, span, value); - case DDTags.MANUAL_KEEP: + case KnownTags.MANUAL_KEEP_SERIAL_NUM: if (asBoolean(value)) { span.forceKeep(); return true; } return false; - case DDTags.MANUAL_DROP: + case KnownTags.MANUAL_DROP_SERIAL_NUM: return interceptSamplingPriority( FORCE_MANUAL_DROP, USER_DROP, SamplingMechanism.MANUAL, span, value); - case Tags.ASM_KEEP: + case KnownTags.ASM_KEEP_SERIAL_NUM: if (asBoolean(value)) { span.forceKeep(SamplingMechanism.APPSEC); return true; } return false; - case Tags.AI_GUARD_KEEP: + case KnownTags.AI_GUARD_KEEP_SERIAL_NUM: if (asBoolean(value)) { span.forceKeep(SamplingMechanism.AI_GUARD); return true; } return false; - case Tags.SAMPLING_PRIORITY: + case KnownTags.SAMPLING_PRIORITY_SERIAL_NUM: return interceptSamplingPriority(span, value); - case Tags.PROPAGATED_TRACE_SOURCE: + case KnownTags.DD_P_TS_SERIAL_NUM: if (value instanceof Integer) { span.addPropagatedTraceSource((Integer) value); return true; } return false; - case Tags.PROPAGATED_DEBUG: + case KnownTags.DD_P_DEBUG_SERIAL_NUM: span.updateDebugPropagation(String.valueOf(value)); return true; - case SERVLET_CONTEXT: + case KnownTags.SERVLET_CONTEXT_SERIAL_NUM: return interceptServletContext(span, value); - case SPAN_TYPE: + case KnownTags.SPAN_TYPE_SERIAL_NUM: return interceptSpanType(span, value); - case ANALYTICS_SAMPLE_RATE: + case KnownTags.DD1_SR_EAUSR_SERIAL_NUM: return interceptAnalyticsSampleRate(span, value); - case Tags.ERROR: + case KnownTags.ERROR_SERIAL_NUM: return interceptError(span, value); - case HTTP_STATUS: - case HTTP_STATUS_CODE_OTEL_NAME: + case KnownTags.HTTP_STATUS_CODE_SERIAL_NUM: // not set internally but may come from manual instrumentation return interceptHttpStatusCode(span, value); - case HTTP_METHOD: - case HTTP_METHOD_OTEL_NAME: - case HTTP_URL: - case HTTP_URL_OTEL_NAME: - return interceptUrlResourceAsNameRule(span, tag, value); - case ORIGIN_KEY: + case KnownTags.HTTP_METHOD_SERIAL_NUM: + case KnownTags.HTTP_URL_SERIAL_NUM: + return interceptUrlResourceAsNameRule(span, tagId, value); + case KnownTags.DD_ORIGIN_SERIAL_NUM: return interceptOrigin(span, value); - case MEASURED: + case KnownTags.DD_MEASURED_SERIAL_NUM: return interceptMeasured(span, value); - case Tags.SPAN_KIND: + case KnownTags.SPAN_KIND_SERIAL_NUM: // Cache the ordinal for fast isOutbound() checks. // Return false so the value is still stored in unsafeTags for serialization. span.setSpanKindOrdinal(String.valueOf(value)); return false; default: - return intercept(span, tag, value); + return isSplitServiceTag(tagId) && splitService(span, value); } } - private boolean interceptUrlResourceAsNameRule(DDSpanContext span, String tag, Object value) { + private boolean interceptCustomTag(DDSpanContext span, String tag, Object value) { + return isSplitServiceTag(tag) && splitService(span, value); + } + + private static boolean splitService(DDSpanContext span, Object value) { + span.setServiceName(String.valueOf(value), SPLIT_BY_TAGS); + return true; + } + + private boolean interceptUrlResourceAsNameRule(DDSpanContext span, long tagId, Object value) { if (shouldSetUrlResourceAsName) { - if (HTTP_METHOD.equals(tag) || HTTP_METHOD_OTEL_NAME.equals(tag)) { + // Values are stored under their Datadog name, whichever spelling set them. + if (tagId == KnownTags.HTTP_METHOD_ID) { final Object url = span.unsafeGetTag(HTTP_URL); if (url != null) { setResourceFromUrl(span, value.toString(), url); } - } else if (HTTP_URL.equals(tag) || HTTP_URL_OTEL_NAME.equals(tag)) { - // the method may have been set under either spelling -- see HTTP_METHOD_OTEL_NAME. - Object method = span.unsafeGetTag(HTTP_METHOD); - if (method == null) { - method = span.unsafeGetTag(HTTP_METHOD_OTEL_NAME); - } + } else { + final Object method = span.unsafeGetTag(HTTP_METHOD); setResourceFromUrl(span, method != null ? method.toString() : null, value); } } @@ -258,14 +304,6 @@ private static void setResourceFromUrl( } } - private boolean intercept(DDSpanContext span, String tag, Object value) { - if (splitServiceTags.contains(tag)) { - span.setServiceName(String.valueOf(value), SPLIT_BY_TAGS); - return true; - } - return false; - } - private boolean interceptResourceName(DDSpanContext span, Object value) { if (ruleFlags.isEnabled(RESOURCE_NAME)) { if (null == value) { diff --git a/dd-trace-core/src/test/java/datadog/trace/core/taginterceptor/TagInterceptorTest.java b/dd-trace-core/src/test/java/datadog/trace/core/taginterceptor/TagInterceptorTest.java index 91f3da0910f..1b1a925b856 100644 --- a/dd-trace-core/src/test/java/datadog/trace/core/taginterceptor/TagInterceptorTest.java +++ b/dd-trace-core/src/test/java/datadog/trace/core/taginterceptor/TagInterceptorTest.java @@ -18,6 +18,7 @@ import static org.junit.jupiter.params.provider.Arguments.arguments; import static org.mockito.ArgumentMatchers.any; import static org.mockito.Mockito.mock; +import static org.mockito.Mockito.mockingDetails; import static org.mockito.Mockito.times; import static org.mockito.Mockito.verify; import static org.mockito.Mockito.when; @@ -25,6 +26,8 @@ import datadog.trace.api.DDSpanTypes; import datadog.trace.api.DDTags; import datadog.trace.api.DDTraceId; +import datadog.trace.api.KnownTagCodec; +import datadog.trace.api.KnownTags; import datadog.trace.api.ProductTraceSource; import datadog.trace.api.env.CapturedEnvironment; import datadog.trace.api.remoteconfig.ServiceNameCollector; @@ -34,6 +37,7 @@ import datadog.trace.bootstrap.instrumentation.api.AgentSpan; import datadog.trace.bootstrap.instrumentation.api.AgentSpanContext; import datadog.trace.bootstrap.instrumentation.api.InstrumentationTags; +import datadog.trace.bootstrap.instrumentation.api.ServiceNameSources; import datadog.trace.bootstrap.instrumentation.api.Tags; import datadog.trace.common.sampling.AllSampler; import datadog.trace.common.writer.ListWriter; @@ -48,6 +52,7 @@ import datadog.trace.test.junit.utils.config.WithConfig; import datadog.trace.test.junit.utils.converter.ConfigDefaultsConverter; import datadog.trace.test.junit.utils.converter.TagsConverter; +import java.lang.reflect.Field; import java.util.Collections; import java.util.Map; import java.util.function.Function; @@ -905,4 +910,80 @@ void whenInterceptsProductTraceSourcePropagationTagUpdatePropagatedTraceSourceIs verify(context, times(1)).addPropagatedTraceSource(ProductTraceSource.ASM); } + + @Test + void exactlyTheTagsWithTheInterceptedBitHaveACase() throws IllegalAccessException { + RuleFlags ruleFlags = mock(RuleFlags.class); + when(ruleFlags.isEnabled(any())).thenReturn(true); + TagInterceptor interceptor = + new TagInterceptor(false, "my-service", emptySet(), ruleFlags, false); + + for (Field field : KnownTags.class.getFields()) { + if (field.getType() != long.class) { + continue; + } + long tagId = field.getLong(null); + DDSpanContext span = mock(DDSpanContext.class); + when(span.getServiceName()).thenReturn(""); + + // Each case consumes one of these values or acts on the span for it; with no split-by-tags, + // the default case does neither. + boolean consumed = false; + for (Object value : new Object[] {true, 1, "1"}) { + consumed |= interceptor.interceptTag(span, tagId, value); + } + + boolean hasCase = consumed || !mockingDetails(span).getInvocations().isEmpty(); + assertEquals(KnownTagCodec.isIntercepted(tagId), hasCase, field.getName()); + assertEquals(KnownTagCodec.isIntercepted(tagId), interceptor.needsIntercept(tagId)); + } + } + + @TableTest({ + "scenario | configured | tag ", + "configured by Datadog name | db.type | db.type ", + "configured by OTel name | db.system | db.type ", + "set by OTel name | db.type | db.system" + }) + void splitByTagsMatchesAKnownTagByIdUnderAnyName(String configured, String tag) { + TagInterceptor interceptor = splittingInterceptor(configured); + DDSpanContext span = mock(DDSpanContext.class); + + assertTrue(interceptor.needsIntercept(KnownTags.DB_TYPE_ID)); + assertTrue(interceptor.needsIntercept(tag)); + assertFalse(interceptor.needsIntercept(KnownTags.COMPONENT_ID)); + assertTrue(interceptor.interceptTag(span, KnownTags.DB_TYPE_ID, "postgres")); + assertTrue(interceptor.interceptTag(span, tag, "mysql")); + + verify(span).setServiceName("postgres", ServiceNameSources.SPLIT_BY_TAGS); + verify(span).setServiceName("mysql", ServiceNameSources.SPLIT_BY_TAGS); + } + + @Test + void splitByTagsMatchesACustomTagByName() { + TagInterceptor interceptor = splittingInterceptor("my.custom.tag"); + DDSpanContext span = mock(DDSpanContext.class); + + assertTrue(interceptor.needsIntercept("my.custom.tag")); + assertFalse(interceptor.needsIntercept("other.custom.tag")); + assertFalse(interceptor.needsIntercept(KnownTags.COMPONENT_ID)); + assertTrue(interceptor.interceptTag(span, "my.custom.tag", "split")); + assertFalse(interceptor.interceptTag(span, "other.custom.tag", "split")); + + verify(span).setServiceName("split", ServiceNameSources.SPLIT_BY_TAGS); + } + + @Test + void splitByTagsOnANameDeclaredPerDirectionMatchesEachDirection() { + TagInterceptor interceptor = splittingInterceptor(Tags.PEER_PORT); + + assertTrue(interceptor.needsIntercept(KnownTags.PEER_PORT_INBOUND_ID)); + assertTrue(interceptor.needsIntercept(KnownTags.PEER_PORT_OUTBOUND_ID)); + assertTrue(interceptor.needsIntercept(Tags.PEER_PORT)); + } + + private static TagInterceptor splittingInterceptor(String splitByTag) { + return new TagInterceptor( + true, "my-service", Collections.singleton(splitByTag), new RuleFlags(), false); + } } From cfe23689e3476019e21c7fff178fc39f58f76bc9 Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Fri, 9 Oct 2026 10:44:20 -0400 Subject: [PATCH 07/19] Set tags on spans by id first A name setter resolves a known tag's name to its id once and sets it as the id-keyed setters do; only a custom tag is still handled by name. The id-keyed setters no longer look up the name to feed the interceptor, so with a constant id the interception test folds to the INTERCEPTED bit. Entry paths (builder ledger, prototypes, default tags) route by the entry's id and precheck before boxing. Co-Authored-By: Claude Opus 5.5 --- .../datadog/trace/core/DDSpanContext.java | 150 +++++++++--------- .../core/taginterceptor/TagInterceptor.java | 30 +++- 2 files changed, 101 insertions(+), 79 deletions(-) diff --git a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java index 94218f92916..ecf25e717d3 100644 --- a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java +++ b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java @@ -648,8 +648,7 @@ private void seedAbsentTags(final TagMap map) { if (ctx.unsafeTags.containsKey(tag)) { return; } - final Object value = tagEntry.objectValue(); - if (!ctx.tagInterceptor.interceptTag(ctx, tag, value)) { + if (!ctx.tagInterceptor.interceptTag(ctx, tagEntry)) { ctx.unsafeTags.set(tagEntry); } }); @@ -1018,6 +1017,9 @@ public void removeTag(long tagId) { *

Existing tag value with the same value will be replaced. Setting a tag with a {@code null} * value will remove the tag from the span. * + *

A known tag's name is resolved to its id once, and the tag is then set as the id-keyed + * setters set it; only a custom tag is handled by name. + * * @param tag The tag name. * @param value The nullable tag value. */ @@ -1025,9 +1027,12 @@ public void setTag(final String tag, final Object value) { if (null == tag) { return; } - if (null == value) { + final long tagId = KnownTagCodec.keyOf(tag); + if (tagId != 0) { + setTag(tagId, value); + } else if (null == value) { removeTag(tag); - } else if (!tagInterceptor.interceptTag(this, tag, value)) { + } else if (!tagInterceptor.interceptCustomTag(this, tag, value)) { synchronized (unsafeTags) { unsafeTags.set(tag, value); } @@ -1038,9 +1043,12 @@ public void setTag(final String tag, final String value) { if (null == tag) { return; } - if (null == value) { + final long tagId = KnownTagCodec.keyOf(tag); + if (tagId != 0) { + setTag(tagId, value); + } else if (null == value) { removeTag(tag); - } else if (!tagInterceptor.interceptTag(this, tag, value)) { + } else if (!tagInterceptor.interceptCustomTag(this, tag, value)) { synchronized (unsafeTags) { unsafeTags.set(tag, value); } @@ -1048,18 +1056,18 @@ public void setTag(final String tag, final String value) { } /* - * Id-keyed setters, mirroring the String setters above: interception still runs on the tag's - * name (TagInterceptor is name-keyed), but a stored tag is set by id, skipping the name lookup. - * An id that names no known tag is ignored, like a null tag. + * Id-keyed setters, mirroring the String setters above. With a constant id, the interception + * test folds to the KnownTagCodec.INTERCEPTED bit, and there is no custom-tag path to take. An id + * that names no known tag is ignored, like a null tag. */ public void setTag(final long tagId, final Object value) { - final String tag = KnownTagCodec.nameOf(tagId); - if (null == tag) { + if (isUnknownTag(tagId)) { return; } if (null == value) { removeTag(tagId); - } else if (!tagInterceptor.interceptTag(this, tag, value)) { + } else if (!tagInterceptor.needsIntercept(tagId) + || !tagInterceptor.interceptTag(this, tagId, value)) { synchronized (unsafeTags) { unsafeTags.set(tagId, value); } @@ -1067,13 +1075,13 @@ public void setTag(final long tagId, final Object value) { } public void setTag(final long tagId, final CharSequence value) { - final String tag = KnownTagCodec.nameOf(tagId); - if (null == tag) { + if (isUnknownTag(tagId)) { return; } if (null == value) { removeTag(tagId); - } else if (!tagInterceptor.interceptTag(this, tag, value)) { + } else if (!tagInterceptor.needsIntercept(tagId) + || !tagInterceptor.interceptTag(this, tagId, value)) { synchronized (unsafeTags) { unsafeTags.set(tagId, value); } @@ -1081,12 +1089,11 @@ public void setTag(final long tagId, final CharSequence value) { } public void setTag(final long tagId, final boolean value) { - final String tag = KnownTagCodec.nameOf(tagId); - if (null == tag) { + if (isUnknownTag(tagId)) { return; } - if (precheckIntercept(tag)) { - this.setBox(tag, value); + if (tagInterceptor.needsIntercept(tagId)) { + this.setBox(tagId, value); } else { synchronized (unsafeTags) { unsafeTags.set(tagId, value); @@ -1095,12 +1102,11 @@ public void setTag(final long tagId, final boolean value) { } public void setTag(final long tagId, final int value) { - final String tag = KnownTagCodec.nameOf(tagId); - if (null == tag) { + if (isUnknownTag(tagId)) { return; } - if (precheckIntercept(tag)) { - this.setBox(tag, value); + if (tagInterceptor.needsIntercept(tagId)) { + this.setBox(tagId, value); } else { synchronized (unsafeTags) { unsafeTags.set(tagId, value); @@ -1109,12 +1115,11 @@ public void setTag(final long tagId, final int value) { } public void setTag(final long tagId, final long value) { - final String tag = KnownTagCodec.nameOf(tagId); - if (null == tag) { + if (isUnknownTag(tagId)) { return; } - if (precheckIntercept(tag)) { - this.setBox(tag, value); + if (tagInterceptor.needsIntercept(tagId)) { + this.setBox(tagId, value); } else { synchronized (unsafeTags) { unsafeTags.set(tagId, value); @@ -1123,12 +1128,11 @@ public void setTag(final long tagId, final long value) { } public void setTag(final long tagId, final float value) { - final String tag = KnownTagCodec.nameOf(tagId); - if (null == tag) { + if (isUnknownTag(tagId)) { return; } - if (precheckIntercept(tag)) { - this.setBox(tag, value); + if (tagInterceptor.needsIntercept(tagId)) { + this.setBox(tagId, value); } else { synchronized (unsafeTags) { unsafeTags.set(tagId, value); @@ -1137,12 +1141,11 @@ public void setTag(final long tagId, final float value) { } public void setTag(final long tagId, final double value) { - final String tag = KnownTagCodec.nameOf(tagId); - if (null == tag) { + if (isUnknownTag(tagId)) { return; } - if (precheckIntercept(tag)) { - this.setBox(tag, value); + if (tagInterceptor.needsIntercept(tagId)) { + this.setBox(tagId, value); } else { synchronized (unsafeTags) { unsafeTags.set(tagId, value); @@ -1150,16 +1153,17 @@ public void setTag(final long tagId, final double value) { } } + private static boolean isUnknownTag(long tagId) { + return KnownTagCodec.nameOf(tagId) == null; + } + public void setTag(TagMap.EntryReader entry) { if (entry == null) { return; } - // pre-check to avoid boxing - boolean intercepted = - precheckIntercept(entry.tag()) - && tagInterceptor.interceptTag(this, entry.tag(), entry.objectValue()); - if (!intercepted) { + // the interceptor prechecks the entry, to avoid boxing + if (!tagInterceptor.interceptTag(this, entry)) { synchronized (unsafeTags) { unsafeTags.set(entry); } @@ -1167,16 +1171,7 @@ public void setTag(TagMap.EntryReader entry) { } /* - * Uses to determine if there's an opportunity to avoid primitve boxing. - * If the underlying map doesn't support efficient primitives, then boxing is used. - * If the tag may be intercepted, then boxing is also used. - */ - private boolean precheckIntercept(String tag) { - return tagInterceptor.needsIntercept(tag); - } - - /* - * Used when precheckIntercept determines that boxing is unavoidable + * Used when the interceptor's precheck determines that boxing is unavoidable * * Either because the tagInterceptor needs to be fully checked (which requires boxing) * In that case, a box has already been created so it makes sense to pass the box @@ -1187,10 +1182,10 @@ private boolean precheckIntercept(String tag) { * The TagMap isn't optimized and will need to box the primitive regardless of * tag interception */ - private void setBox(String tag, Object box) { - if (!tagInterceptor.interceptTag(this, tag, box)) { + private void setBox(long tagId, Object box) { + if (!tagInterceptor.interceptTag(this, tagId, box)) { synchronized (unsafeTags) { - unsafeTags.set(tag, box); + unsafeTags.set(tagId, box); } } } @@ -1199,9 +1194,11 @@ public void setTag(final String tag, final boolean value) { if (null == tag) { return; } - if (precheckIntercept(tag)) { - this.setBox(tag, value); - } else { + final long tagId = KnownTagCodec.keyOf(tag); + if (tagId != 0) { + setTag(tagId, value); + } else if (!tagInterceptor.needsInterceptCustomTag(tag) + || !tagInterceptor.interceptCustomTag(this, tag, value)) { synchronized (unsafeTags) { unsafeTags.set(tag, value); } @@ -1212,9 +1209,11 @@ public void setTag(final String tag, final int value) { if (null == tag) { return; } - if (precheckIntercept(tag)) { - this.setBox(tag, value); - } else { + final long tagId = KnownTagCodec.keyOf(tag); + if (tagId != 0) { + setTag(tagId, value); + } else if (!tagInterceptor.needsInterceptCustomTag(tag) + || !tagInterceptor.interceptCustomTag(this, tag, value)) { synchronized (unsafeTags) { unsafeTags.set(tag, value); } @@ -1225,9 +1224,11 @@ public void setTag(final String tag, final long value) { if (null == tag) { return; } - if (precheckIntercept(tag)) { - this.setBox(tag, value); - } else { + final long tagId = KnownTagCodec.keyOf(tag); + if (tagId != 0) { + setTag(tagId, value); + } else if (!tagInterceptor.needsInterceptCustomTag(tag) + || !tagInterceptor.interceptCustomTag(this, tag, value)) { synchronized (unsafeTags) { unsafeTags.set(tag, value); } @@ -1238,9 +1239,11 @@ public void setTag(final String tag, final float value) { if (null == tag) { return; } - if (precheckIntercept(tag)) { - this.setBox(tag, value); - } else { + final long tagId = KnownTagCodec.keyOf(tag); + if (tagId != 0) { + setTag(tagId, value); + } else if (!tagInterceptor.needsInterceptCustomTag(tag) + || !tagInterceptor.interceptCustomTag(this, tag, value)) { synchronized (unsafeTags) { unsafeTags.set(tag, value); } @@ -1251,9 +1254,11 @@ public void setTag(final String tag, final double value) { if (null == tag) { return; } - if (precheckIntercept(tag)) { - this.setBox(tag, value); - } else { + final long tagId = KnownTagCodec.keyOf(tag); + if (tagId != 0) { + setTag(tagId, value); + } else if (!tagInterceptor.needsInterceptCustomTag(tag) + || !tagInterceptor.interceptCustomTag(this, tag, value)) { synchronized (unsafeTags) { unsafeTags.set(tag, value); } @@ -1277,10 +1282,7 @@ void setAllTags(final TagMap map, boolean needsIntercept) { map.forEach( this, (ctx, tagEntry) -> { - String tag = tagEntry.tag(); - Object value = tagEntry.objectValue(); - - if (!ctx.tagInterceptor.interceptTag(ctx, tag, value)) { + if (!ctx.tagInterceptor.interceptTag(ctx, tagEntry)) { ctx.unsafeTags.set(tagEntry); } }); @@ -1307,9 +1309,7 @@ void setAllTags(final TagMap.Ledger ledger) { } else { TagMap.Entry entry = (TagMap.Entry) entryChange; - Object value = entry.objectValue(); - - if (!tagInterceptor.interceptTag(this, tag, value)) { + if (!tagInterceptor.interceptTag(this, entry)) { unsafeTags.set(entry); } } diff --git a/dd-trace-core/src/main/java/datadog/trace/core/taginterceptor/TagInterceptor.java b/dd-trace-core/src/main/java/datadog/trace/core/taginterceptor/TagInterceptor.java index ca552cd8541..95d11a4eea5 100644 --- a/dd-trace-core/src/main/java/datadog/trace/core/taginterceptor/TagInterceptor.java +++ b/dd-trace-core/src/main/java/datadog/trace/core/taginterceptor/TagInterceptor.java @@ -146,12 +146,21 @@ private boolean isSplitServiceTag(String customTag) { public boolean needsIntercept(TagMap map) { for (TagMap.EntryReader entry : map) { - long tagId = entry.tagId(); - if (tagId != 0 ? needsIntercept(tagId) : isSplitServiceTag(entry.tag())) return true; + if (needsIntercept(entry)) return true; } return false; } + public boolean needsIntercept(TagMap.EntryReader entry) { + long tagId = entry.tagId(); + return tagId != 0 ? needsIntercept(tagId) : isSplitServiceTag(entry.tag()); + } + + /** Whether a custom tag -- one with no id -- may be routed: only split-by-tags routes one. */ + public boolean needsInterceptCustomTag(String customTag) { + return isSplitServiceTag(customTag); + } + public boolean needsIntercept(Map map) { for (String tag : map.keySet()) { if (needsIntercept(tag)) return true; @@ -255,8 +264,21 @@ public boolean interceptTag(DDSpanContext span, long tagId, Object value) { } } - private boolean interceptCustomTag(DDSpanContext span, String tag, Object value) { - return isSplitServiceTag(tag) && splitService(span, value); + /** + * Routes an entry by its id, or by its name when it is a custom tag. Prechecks, so a primitive + * entry that needs no interception is never boxed. + */ + public boolean interceptTag(DDSpanContext span, TagMap.EntryReader entry) { + long tagId = entry.tagId(); + if (tagId != 0) { + return needsIntercept(tagId) && interceptTag(span, tagId, entry.objectValue()); + } + return isSplitServiceTag(entry.tag()) && splitService(span, entry.objectValue()); + } + + /** Routes a custom tag -- one with no id. */ + public boolean interceptCustomTag(DDSpanContext span, String customTag, Object value) { + return isSplitServiceTag(customTag) && splitService(span, value); } private static boolean splitService(DDSpanContext span, Object value) { From 38c9947a5185a8f9bfc538912cdbdc20d33d4eb0 Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Fri, 9 Oct 2026 11:10:21 -0400 Subject: [PATCH 08/19] Look up tag names by serial in an array, not a switch The generated nameOf switched over every tag's serial: 491 bytes of bytecode, too big for C2 to inline, so each id-keyed set paid two out-of-line calls into it (the span's unknown-id guard and the entry's name). Read a NAMES_BY_SERIAL array instead; nameOf is now 23 bytes and inlines at every caller. Also adds SetTagBenchmark (span setTag by constant id, non-constant id, name, and custom name, against a bare and a synchronized TagMap store). Co-Authored-By: Claude Opus 5.5 --- .../tagRegistry/KnownTagsEmitter.kt | 37 +++--- .../datadog/trace/core/SetTagBenchmark.java | 106 ++++++++++++++++++ 2 files changed, 125 insertions(+), 18 deletions(-) create mode 100644 dd-trace-core/src/jmh/java/datadog/trace/core/SetTagBenchmark.java diff --git a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt index ca81859af96..b04a52c9378 100644 --- a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt +++ b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt @@ -165,6 +165,21 @@ object KnownTagsEmitter { KEYOF_IDS = ids; } + /** + * Each tag's Datadog name, indexed by serial; slot 0 (no tag) is null. An array rather than a + * switch keeps nameOf small enough to inline at every caller. + */ + static final String[] NAMES_BY_SERIAL = { + null, + """.trimIndent() + ) + for (t in reg.tags.sortedBy { it.serial }) { + appendLine(" ${nameExpr(t)},") + } + appendLine( + """ + }; + /** * The registry's name↔id tables, as a {@link KnownTagCodec.Resolver}. {@code KnownTagCodec} * reads this field from its own holder, so the two classes complete each other: the codec owns @@ -174,26 +189,12 @@ object KnownTagsEmitter { new KnownTagCodec.Resolver() { @Override public String nameOf(long tagId) { - switch (KnownTagCodec.serialNum(tagId)) { - """.trimIndent() - ) - for (t in reg.tags) { - appendLine( - """ - case ${serialC(t.identity)}: - return ${nameExpr(t)}; - """.trimIndent() - ) - } - // openTelemetryNameOf: canonical id -> OTel-namespace name, null when the tag has none. The - // caller (a serializer) owns any fall-back-to-Datadog-name policy; this stays a pure lookup. - appendLine( - """ - default: - return null; - } + int serial = KnownTagCodec.serialNum(tagId); + return serial < NAMES_BY_SERIAL.length ? NAMES_BY_SERIAL[serial] : null; } + // openTelemetryNameOf: canonical id -> OTel-namespace name, null when the tag has + // none. The caller (a serializer) owns any fall-back-to-Datadog-name policy. @Override public String openTelemetryNameOf(long tagId) { switch (KnownTagCodec.serialNum(tagId)) { diff --git a/dd-trace-core/src/jmh/java/datadog/trace/core/SetTagBenchmark.java b/dd-trace-core/src/jmh/java/datadog/trace/core/SetTagBenchmark.java new file mode 100644 index 00000000000..ac3799860b7 --- /dev/null +++ b/dd-trace-core/src/jmh/java/datadog/trace/core/SetTagBenchmark.java @@ -0,0 +1,106 @@ +package datadog.trace.core; + +import static java.util.concurrent.TimeUnit.NANOSECONDS; + +import datadog.trace.api.KnownTags; +import datadog.trace.api.TagMap; +import org.openjdk.jmh.annotations.Benchmark; +import org.openjdk.jmh.annotations.BenchmarkMode; +import org.openjdk.jmh.annotations.Fork; +import org.openjdk.jmh.annotations.Measurement; +import org.openjdk.jmh.annotations.Mode; +import org.openjdk.jmh.annotations.OutputTimeUnit; +import org.openjdk.jmh.annotations.Scope; +import org.openjdk.jmh.annotations.Setup; +import org.openjdk.jmh.annotations.State; +import org.openjdk.jmh.annotations.TearDown; +import org.openjdk.jmh.annotations.Warmup; + +/** + * Measures {@code DDSpan.setTag} on a live span, overwriting one tag per call, by how the tag is + * named: by a constant id, by a known tag's name, and by a custom name. {@code tagMap_byId} is the + * floor -- the same store on a bare {@link TagMap}, with no span, lock, or interceptor. + * + *

A constant id should cost close to the floor plus the span's lock: its interception test folds + * to the id's INTERCEPTED bit, and an id set has no custom-tag path. The name variants pay a + * registry lookup first. + * + *

Two controls separate those costs. {@code knownTag_byNonConstantId} reads the id from a + * non-final field, which C2 never folds, so nothing about the id is known at compile time. {@code + * tagMap_byId_synchronized} is the floor plus an uncontended lock, as the span takes one. + */ +@State(Scope.Thread) +@Warmup(iterations = 3, time = 1) +@Measurement(iterations = 5, time = 1) +@BenchmarkMode(Mode.AverageTime) +@OutputTimeUnit(NANOSECONDS) +@Fork(value = 3) +public class SetTagBenchmark { + static final CoreTracer TRACER = CoreTracer.builder().build(); + + private DDSpan span; + private TagMap tagMap; + private long nonConstantTagId; + + @Setup + public void setup() { + span = (DDSpan) TRACER.startSpan("benchmark", "set.tag"); + tagMap = TagMap.create(); + nonConstantTagId = KnownTags.HTTP_ROUTE_ID; + } + + @TearDown + public void tearDown() { + span.finish(); + } + + @Benchmark + public Object tagMap_byId() { + tagMap.set(KnownTags.HTTP_ROUTE_ID, "/users/{id}"); + return tagMap; + } + + @Benchmark + public Object tagMap_byId_synchronized() { + TagMap tagMap = this.tagMap; + synchronized (tagMap) { + tagMap.set(KnownTags.HTTP_ROUTE_ID, "/users/{id}"); + } + return tagMap; + } + + @Benchmark + public Object knownTag_byNonConstantId() { + return span.setTag(nonConstantTagId, "/users/{id}"); + } + + @Benchmark + public Object knownTag_byId() { + return span.setTag(KnownTags.HTTP_ROUTE_ID, "/users/{id}"); + } + + @Benchmark + public Object interceptedTag_byId() { + return span.setTag(KnownTags.SPAN_KIND_ID, "client"); + } + + @Benchmark + public Object knownTag_byName() { + return span.setTag(KnownTags.HTTP_ROUTE_NAME, "/users/{id}"); + } + + @Benchmark + public Object customTag_byName() { + return span.setTag("my.custom.tag", "/users/{id}"); + } + + @Benchmark + public Object knownIntTag_byId() { + return span.setTag(KnownTags.HTTP_RESEND_COUNT_ID, 2); + } + + @Benchmark + public Object knownIntTag_byName() { + return span.setTag(KnownTags.HTTP_RESEND_COUNT_NAME, 2); + } +} From 3545c1544b9a58c868a76da8fde3d15a7fdcec85 Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Fri, 9 Oct 2026 11:35:58 -0400 Subject: [PATCH 09/19] Point stale comments at the tracer overlay and the intercepted bit Co-Authored-By: Claude Opus 5.5 --- .../src/main/java/datadog/trace/core/DDSpanContext.java | 6 +++--- tag-conventions.yaml | 5 +++-- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java index ecf25e717d3..ac473fd18cb 100644 --- a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java +++ b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java @@ -611,9 +611,9 @@ public void setSpanType(final CharSequence spanType) { *

This is the shared seam for both the construction path ({@code CoreSpanBuilder}) and * decorator {@code afterStart} (via {@link DDSpan#apply}). The context owns the tag map, so the * eventual cheaper bulk-share path (skipping interception for non-intercepted tags) and the - * identity short-circuit will land here -- deferred to the dense-store / tag-registry work, which - * exposes intercept status at the internal-api level. Until then the constant tags route through - * the interceptor, identical to the per-tag calls this replaces. + * identity short-circuit will land here, with the dense store; a tag's intercept status is + * already on its id ({@link KnownTagCodec#isIntercepted}). Until then each constant tag is + * prechecked by the interceptor, identical to the per-tag calls this replaces. */ public void apply(@Nonnull final SpanPrototype prototype) { if (this.spanType == null) { diff --git a/tag-conventions.yaml b/tag-conventions.yaml index b6cdfe5deb4..c4a5f9f9b70 100644 --- a/tag-conventions.yaml +++ b/tag-conventions.yaml @@ -200,8 +200,9 @@ mixins: # - span.kind enumerates: server | client | producer | consumer | internal | broker. # - Some keys (resource.name, error, sampling.priority, ...) are accepted by setTag but routed to a # span field or a trace directive instead of tag storage. That routing is a per-language tracer -# concern, so it is NOT modelled here; such a key appears above only when it also needs an id and -# a name (service does, for OpenTelemetry's service.name). +# concern, so it is NOT modelled here: dd-trace-java declares those keys, and marks every tag it +# intercepts, in its own overlay (tag-conventions-java.yaml). Such a key appears above only when it +# also needs an id and a name across tracers (service does, for OpenTelemetry's service.name). # - Tags with no otel-name pass through under their Datadog name (RFC "retain"). A `# TODO(otel)` note # marks a pending OpenTelemetry-team review of a mapping that is not yet a settled rename. # - db.statement/db.query.text is deliberately never re-exposed as a stored tag once consumed into From 1642cc9b5cb536185dd85ac38e93bada9ccbef0d Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Fri, 9 Oct 2026 12:03:52 -0400 Subject: [PATCH 10/19] Index the split-by-tags table by serial, sized to every known tag The table is always allocated and never resized, so the split check -- the only run-time check left on a non-intercepted constant-id set -- is a single load, with no null or length test. Co-Authored-By: Claude Opus 5.5 --- .../core/taginterceptor/TagInterceptor.java | 36 ++++++++----------- .../java/datadog/trace/api/KnownTagCodec.java | 8 +++++ 2 files changed, 23 insertions(+), 21 deletions(-) diff --git a/dd-trace-core/src/main/java/datadog/trace/core/taginterceptor/TagInterceptor.java b/dd-trace-core/src/main/java/datadog/trace/core/taginterceptor/TagInterceptor.java index 95d11a4eea5..181889cb9a0 100644 --- a/dd-trace-core/src/main/java/datadog/trace/core/taginterceptor/TagInterceptor.java +++ b/dd-trace-core/src/main/java/datadog/trace/core/taginterceptor/TagInterceptor.java @@ -35,7 +35,6 @@ import datadog.trace.bootstrap.instrumentation.api.UTF8BytesString; import datadog.trace.core.DDSpanContext; import java.net.URI; -import java.util.Arrays; import java.util.HashSet; import java.util.Map; import java.util.Set; @@ -51,7 +50,10 @@ public class TagInterceptor { private final boolean splitByServletContext; private final String inferredServiceName; - /** split-by-tags entries naming known tags, indexed by serial; null when there are none. */ + /** + * Whether each known tag, indexed by serial, is a split-by-tags entry. Sized to every known + * serial and never changed after construction, so the check is a single load. + */ private final boolean[] splitServiceSerials; /** split-by-tags entries naming custom tags; null when there are none. */ @@ -94,29 +96,22 @@ public TagInterceptor( /** * Marks, by serial, each known tag that {@code names} names under any of its names, so a tag set * by id or by its OpenTelemetry name matches too. A name declared per direction marks each - * direction's tag. Returns null when no name is a known tag's. + * direction's tag. */ private static boolean[] knownTagSerials(Set names) { + boolean[] serials = new boolean[KnownTagCodec.serialLimit()]; if (names.isEmpty()) { - return null; + return serials; } Set canonicalNames = new HashSet<>(); for (String name : names) { canonicalNames.add(KnownTagCodec.canonicalTagName(name)); } - boolean[] serials = null; - for (int serial = 1; ; ++serial) { - String name = KnownTagCodec.nameOf(KnownTagCodec.makeTagId(serial)); - if (name == null) { - return serials; - } - if (canonicalNames.contains(name)) { - if (serials == null || serial >= serials.length) { - serials = serials == null ? new boolean[serial + 1] : Arrays.copyOf(serials, serial + 1); - } - serials[serial] = true; - } + for (int serial = 1; serial < serials.length; ++serial) { + serials[serial] = + canonicalNames.contains(KnownTagCodec.nameOf(KnownTagCodec.makeTagId(serial))); } + return serials; } /** The names in {@code names} that do not resolve to a known tag, or null when there are none. */ @@ -133,10 +128,9 @@ private static Set customTagNames(Set names) { return custom; } + /** {@code tagId} is a known id, so its serial is in range. */ private boolean isSplitServiceTag(long tagId) { - boolean[] serials = splitServiceSerials; - int serial = KnownTagCodec.serialNum(tagId); - return serials != null && serial < serials.length && serials[serial]; + return splitServiceSerials[KnownTagCodec.serialNum(tagId)]; } private boolean isSplitServiceTag(String customTag) { @@ -170,8 +164,8 @@ public boolean needsIntercept(Map map) { /** * Whether {@link #interceptTag(DDSpanContext, long, Object)} may route the tag. Called with a - * constant id, the {@link KnownTagCodec#INTERCEPTED} test folds away; only a configured - * split-by-tags is left to check at run time. + * constant id, the {@link KnownTagCodec#INTERCEPTED} test folds away; only the split-by-tags + * table is left to check at run time. {@code tagId} must be a known id. */ public boolean needsIntercept(long tagId) { return KnownTagCodec.isIntercepted(tagId) || isSplitServiceTag(tagId); diff --git a/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java b/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java index 4ea9b574a8a..953b62aa16e 100644 --- a/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java +++ b/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java @@ -127,6 +127,14 @@ public static String openTelemetryTagOf(long tagId) { return otelName != null ? otelName : resolver.nameOf(tagId); } + /** + * One past the largest known serial: an array of this length, indexed by {@link #serialNum}, has + * a slot for every known tag (slot 0 is no tag). + */ + public static int serialLimit() { + return KnownTags.NAMES_BY_SERIAL.length; + } + /** The id for {@code name} in any namespace, or 0 when it is not a known tag. */ public static long keyOf(String name) { return Installed.RESOLVER.keyOf(name); From b9dd5731bb73ff679763484cc9a53287e9aa9673 Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Fri, 9 Oct 2026 13:07:31 -0400 Subject: [PATCH 11/19] Check for a known tag id with a range check, not a name lookup The span's unknown-id guard called nameOf; KnownTagCodec.isKnown answers the same question from the serial and a generated SERIAL_LIMIT, so it folds away for a constant id. Also note that serials are not stable across releases. Co-Authored-By: Claude Opus 5.5 --- .../buildlogic/tagRegistry/KnownTagsEmitter.kt | 3 +++ .../tagRegistry/TagRegistryGeneratorTest.kt | 3 ++- .../java/datadog/trace/core/DDSpanContext.java | 4 ++-- .../main/java/datadog/trace/api/KnownTagCodec.java | 14 +++++++++++++- 4 files changed, 20 insertions(+), 4 deletions(-) diff --git a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt index b04a52c9378..8a21f8e0045 100644 --- a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt +++ b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt @@ -113,6 +113,9 @@ object KnownTagsEmitter { for (t in reg.tags) { appendLine(" public static final int ${serialC(t.identity)} = ${t.serial};") } + // Every known tag's serial is below SERIAL_LIMIT; serial 0 is no tag. + val serialLimit = (reg.tags.maxOfOrNull { it.serial } ?: 0) + 1 + appendLine(" public static final int SERIAL_LIMIT = $serialLimit;") // OpenTelemetry name -> canonical tag name. Validation ensures aliases are distinct from all // canonical names. Sort by OTel name to keep output deterministic. diff --git a/build-logic/tag-registry/src/test/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGeneratorTest.kt b/build-logic/tag-registry/src/test/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGeneratorTest.kt index e4fdba9d853..256367ccc0e 100644 --- a/build-logic/tag-registry/src/test/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGeneratorTest.kt +++ b/build-logic/tag-registry/src/test/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGeneratorTest.kt @@ -505,7 +505,8 @@ class TagRegistryGeneratorTest { "COMPONENT_ID = 0x0001000000000000L", "RESOURCE_NAME_ID = 0x0002000000000002L", "SERVICE_ID = 0x0003000000000002L", - "public static final int SERVICE_SERIAL_NUM = 3;" + "public static final int SERVICE_SERIAL_NUM = 3;", + "public static final int SERIAL_LIMIT = 4;" ) } diff --git a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java index ac473fd18cb..406135760de 100644 --- a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java +++ b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java @@ -1000,7 +1000,7 @@ public void removeTag(String tag) { * id that names no known tag is ignored, like the id-keyed setters do. */ public void removeTag(long tagId) { - if (KnownTagCodec.nameOf(tagId) == null) { + if (isUnknownTag(tagId)) { return; } if (tagId == KnownTags.SPAN_KIND_ID) { @@ -1154,7 +1154,7 @@ public void setTag(final long tagId, final double value) { } private static boolean isUnknownTag(long tagId) { - return KnownTagCodec.nameOf(tagId) == null; + return !KnownTagCodec.isKnown(tagId); } public void setTag(TagMap.EntryReader entry) { diff --git a/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java b/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java index 953b62aa16e..faf336cc40f 100644 --- a/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java +++ b/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java @@ -28,6 +28,9 @@ public final class KnownTagCodec { *

There is deliberately NO OpenTelemetry-applicability flag: an absent otel-name means * pass-through (the tag is emitted under its Datadog name), so today every known tag has an * OpenTelemetry name and such a flag would be constant. It returns once a Datadog-only tag exists. + * + *

Serials are assigned at build time and are NOT stable across releases: they follow the tags' + * names in order, so adding a tag renumbers others. Never persist or transmit a raw id. */ public static int serialNum(long tagId) { return (int) (tagId >>> 48); @@ -132,7 +135,16 @@ public static String openTelemetryTagOf(long tagId) { * a slot for every known tag (slot 0 is no tag). */ public static int serialLimit() { - return KnownTags.NAMES_BY_SERIAL.length; + return KnownTags.SERIAL_LIMIT; + } + + /** + * True if {@code tagId} names a known tag -- the same answer as {@code nameOf(tagId) != null}, as + * a range check on its serial, so it folds away for a constant id. + */ + public static boolean isKnown(long tagId) { + int serial = serialNum(tagId); + return serial != 0 && serial < KnownTags.SERIAL_LIMIT; // serial 0 is no tag } /** The id for {@code name} in any namespace, or 0 when it is not a known tag. */ From 75d3fbc52247934accf571c081441a4fdc2310ff Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Fri, 9 Oct 2026 13:07:33 -0400 Subject: [PATCH 12/19] Pin interceptTag(long) above C2's inlining size DDSpanContext.setTag calls interceptTag only for intercepted tags. Kept out of line (over FreqInlineSize, 325 bytes of bytecode), it never brings the profiled handler bodies into setTag's compiled code, which would push setTag past InlineSmallCode and stop callers inlining it -- the inlining a constant id needs to fold its interception test. A test now fails if the switch shrinks below the limit. Co-Authored-By: Claude Opus 5.5 --- .../TagInterceptorInliningTest.java | 77 +++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 dd-trace-core/src/test/java/datadog/trace/core/taginterceptor/TagInterceptorInliningTest.java diff --git a/dd-trace-core/src/test/java/datadog/trace/core/taginterceptor/TagInterceptorInliningTest.java b/dd-trace-core/src/test/java/datadog/trace/core/taginterceptor/TagInterceptorInliningTest.java new file mode 100644 index 00000000000..2b0d107eec3 --- /dev/null +++ b/dd-trace-core/src/test/java/datadog/trace/core/taginterceptor/TagInterceptorInliningTest.java @@ -0,0 +1,77 @@ +package datadog.trace.core.taginterceptor; + +import static org.junit.jupiter.api.Assertions.assertTrue; + +import java.io.IOException; +import java.io.InputStream; +import org.junit.jupiter.api.Test; +import org.objectweb.asm.ClassReader; + +/** + * Pins a code-shape property that C2 depends on but no other test can see. + * + *

{@code interceptTag(DDSpanContext, long, Object)} must stay too big for C2 to inline (more + * than {@code FreqInlineSize}, 325 bytes of bytecode). DDSpanContext.setTag calls it only for + * intercepted tags; if it inlines into setTag's own compiled code, the profiled handler bodies come + * with it and push setTag past {@code InlineSmallCode}, so callers stop inlining setTag and a + * constant id no longer folds its interception test away. + */ +class TagInterceptorInliningTest { + private static final int FREQ_INLINE_SIZE = 325; + + @Test + void interceptTagByIdStaysTooBigToInline() throws IOException { + int length = + codeLength("interceptTag", "(Ldatadog/trace/core/DDSpanContext;JLjava/lang/Object;)Z"); + + assertTrue( + length > FREQ_INLINE_SIZE, + "interceptTag(span, long, value) is " + + length + + " bytes of bytecode, small enough for C2 to inline into DDSpanContext.setTag; keep" + + " its handlers in the switch (see this test's Javadoc)"); + } + + /** The {@code code_length} of a method's Code attribute, read from the class file. */ + private static int codeLength(String name, String descriptor) throws IOException { + ClassReader reader; + try (InputStream in = TagInterceptor.class.getResourceAsStream("TagInterceptor.class")) { + reader = new ClassReader(in); + } + char[] buf = new char[reader.getMaxStringLength()]; + int offset = reader.header + 6; // access_flags, this_class, super_class + offset += 2 + 2 * reader.readUnsignedShort(offset); // interfaces + int fields = reader.readUnsignedShort(offset); + offset += 2; + for (int i = 0; i < fields; ++i) { + offset = skipAttributes(reader, offset + 6); // access_flags, name, descriptor + } + int methods = reader.readUnsignedShort(offset); + offset += 2; + for (int i = 0; i < methods; ++i) { + if (reader.readUTF8(offset + 2, buf).equals(name) + && reader.readUTF8(offset + 4, buf).equals(descriptor)) { + int attributes = reader.readUnsignedShort(offset + 6); + int attribute = offset + 8; + for (int j = 0; j < attributes; ++j) { + if ("Code".equals(reader.readUTF8(attribute, buf))) { + return reader.readInt(attribute + 10); // name, length, max_stack, max_locals + } + attribute += 6 + reader.readInt(attribute + 2); + } + } + offset = skipAttributes(reader, offset + 6); + } + throw new AssertionError(name + descriptor + " not found"); + } + + /** Skips the attributes whose count is at {@code offset}; returns the offset after them. */ + private static int skipAttributes(ClassReader reader, int offset) { + int attributes = reader.readUnsignedShort(offset); + offset += 2; + for (int i = 0; i < attributes; ++i) { + offset += 6 + reader.readInt(offset + 2); // name, length, info + } + return offset; + } +} From ecb4f73ce8442432f3260839029100e145ebab69 Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Fri, 9 Oct 2026 15:08:19 -0400 Subject: [PATCH 13/19] Tighten comments on the id-keyed interceptor Co-Authored-By: Claude Opus 5.5 --- .../datadog/trace/core/SetTagBenchmark.java | 17 +++++++++-------- .../java/datadog/trace/core/DDSpanContext.java | 12 ++++++------ .../core/taginterceptor/TagInterceptor.java | 15 +++++++++------ .../TagInterceptorInliningTest.java | 13 +++++++------ .../java/datadog/trace/api/KnownTagCodec.java | 17 ++++++++--------- 5 files changed, 39 insertions(+), 35 deletions(-) diff --git a/dd-trace-core/src/jmh/java/datadog/trace/core/SetTagBenchmark.java b/dd-trace-core/src/jmh/java/datadog/trace/core/SetTagBenchmark.java index ac3799860b7..a9d1c25d13e 100644 --- a/dd-trace-core/src/jmh/java/datadog/trace/core/SetTagBenchmark.java +++ b/dd-trace-core/src/jmh/java/datadog/trace/core/SetTagBenchmark.java @@ -18,16 +18,17 @@ /** * Measures {@code DDSpan.setTag} on a live span, overwriting one tag per call, by how the tag is - * named: by a constant id, by a known tag's name, and by a custom name. {@code tagMap_byId} is the - * floor -- the same store on a bare {@link TagMap}, with no span, lock, or interceptor. + * named: a constant id ({@code knownTag_byId}, {@code knownIntTag_byId}), a constant intercepted id + * ({@code interceptedTag_byId}, {@code span.kind}), a known tag's name, and a custom name. * - *

A constant id should cost close to the floor plus the span's lock: its interception test folds - * to the id's INTERCEPTED bit, and an id set has no custom-tag path. The name variants pay a - * registry lookup first. + *

Controls: {@code tagMap_byId} is the same store on a bare {@link TagMap}, with no span, lock, + * or interceptor; {@code tagMap_byId_synchronized} adds an uncontended lock, as the span takes one; + * {@code knownTag_byNonConstantId} reads the id from a non-final field, which C2 never + * constant-folds. * - *

Two controls separate those costs. {@code knownTag_byNonConstantId} reads the id from a - * non-final field, which C2 never folds, so nothing about the id is known at compile time. {@code - * tagMap_byId_synchronized} is the floor plus an uncontended lock, as the span takes one. + *

With a constant id, the interception test folds to the id's INTERCEPTED bit and there is no + * custom-tag path, so comparing {@code knownTag_byId} with {@code tagMap_byId_synchronized} + * isolates the span's own dispatch. The name variants add a registry lookup. */ @State(Scope.Thread) @Warmup(iterations = 3, time = 1) diff --git a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java index 406135760de..6a87f8dca33 100644 --- a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java +++ b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java @@ -1017,8 +1017,8 @@ public void removeTag(long tagId) { *

Existing tag value with the same value will be replaced. Setting a tag with a {@code null} * value will remove the tag from the span. * - *

A known tag's name is resolved to its id once, and the tag is then set as the id-keyed - * setters set it; only a custom tag is handled by name. + *

A known tag's name is resolved to its id once, and the id-keyed setter does the rest; only a + * custom tag is handled by name. * * @param tag The tag name. * @param value The nullable tag value. @@ -1056,9 +1056,9 @@ public void setTag(final String tag, final String value) { } /* - * Id-keyed setters, mirroring the String setters above. With a constant id, the interception - * test folds to the KnownTagCodec.INTERCEPTED bit, and there is no custom-tag path to take. An id - * that names no known tag is ignored, like a null tag. + * Id-keyed setters, mirroring the String setters above. With a constant id, the + * KnownTagCodec.INTERCEPTED test folds, leaving only the split-by-tags table load; an id set never + * takes the custom-tag path. An id that names no known tag is ignored, like a null tag. */ public void setTag(final long tagId, final Object value) { if (isUnknownTag(tagId)) { @@ -1171,7 +1171,7 @@ public void setTag(TagMap.EntryReader entry) { } /* - * Used when the interceptor's precheck determines that boxing is unavoidable + * Used when the interceptor's precheck says the tag may be intercepted, so boxing is unavoidable * * Either because the tagInterceptor needs to be fully checked (which requires boxing) * In that case, a box has already been created so it makes sense to pass the box diff --git a/dd-trace-core/src/main/java/datadog/trace/core/taginterceptor/TagInterceptor.java b/dd-trace-core/src/main/java/datadog/trace/core/taginterceptor/TagInterceptor.java index 181889cb9a0..82a6cb16c06 100644 --- a/dd-trace-core/src/main/java/datadog/trace/core/taginterceptor/TagInterceptor.java +++ b/dd-trace-core/src/main/java/datadog/trace/core/taginterceptor/TagInterceptor.java @@ -128,7 +128,7 @@ private static Set customTagNames(Set names) { return custom; } - /** {@code tagId} is a known id, so its serial is in range. */ + /** Requires a known id, whose serial is always in range of the table. */ private boolean isSplitServiceTag(long tagId) { return splitServiceSerials[KnownTagCodec.serialNum(tagId)]; } @@ -150,7 +150,7 @@ public boolean needsIntercept(TagMap.EntryReader entry) { return tagId != 0 ? needsIntercept(tagId) : isSplitServiceTag(entry.tag()); } - /** Whether a custom tag -- one with no id -- may be routed: only split-by-tags routes one. */ + /** Whether a custom tag (one with no id) may be routed; only split-by-tags routes them. */ public boolean needsInterceptCustomTag(String customTag) { return isSplitServiceTag(customTag); } @@ -163,9 +163,9 @@ public boolean needsIntercept(Map map) { } /** - * Whether {@link #interceptTag(DDSpanContext, long, Object)} may route the tag. Called with a - * constant id, the {@link KnownTagCodec#INTERCEPTED} test folds away; only the split-by-tags - * table is left to check at run time. {@code tagId} must be a known id. + * Whether {@link #interceptTag(DDSpanContext, long, Object)} may route the tag. With a constant + * id, the {@link KnownTagCodec#INTERCEPTED} test folds to a constant, leaving only the + * split-by-tags table load at run time. {@code tagId} must be a known id. */ public boolean needsIntercept(long tagId) { return KnownTagCodec.isIntercepted(tagId) || isSplitServiceTag(tagId); @@ -185,6 +185,9 @@ public boolean interceptTag(DDSpanContext span, String tag, Object value) { * Routes a known tag to a span field or a sampling directive. Returns true when the tag was * consumed, false when it should still be stored. Every tag with a case here carries the {@link * KnownTagCodec#INTERCEPTED} bit, declared in {@code tag-conventions-java.yaml}. + * + *

This method is deliberately too big for C2 to inline, so the handler bodies stay out of + * {@code DDSpanContext.setTag}'s compiled code; {@code TagInterceptorInliningTest} pins that. */ public boolean interceptTag(DDSpanContext span, long tagId, Object value) { switch (KnownTagCodec.serialNum(tagId)) { @@ -282,7 +285,7 @@ private static boolean splitService(DDSpanContext span, Object value) { private boolean interceptUrlResourceAsNameRule(DDSpanContext span, long tagId, Object value) { if (shouldSetUrlResourceAsName) { - // Values are stored under their Datadog name, whichever spelling set them. + // Read by Datadog name only: entries are stored under it whichever spelling set them. if (tagId == KnownTags.HTTP_METHOD_ID) { final Object url = span.unsafeGetTag(HTTP_URL); if (url != null) { diff --git a/dd-trace-core/src/test/java/datadog/trace/core/taginterceptor/TagInterceptorInliningTest.java b/dd-trace-core/src/test/java/datadog/trace/core/taginterceptor/TagInterceptorInliningTest.java index 2b0d107eec3..e11811d641c 100644 --- a/dd-trace-core/src/test/java/datadog/trace/core/taginterceptor/TagInterceptorInliningTest.java +++ b/dd-trace-core/src/test/java/datadog/trace/core/taginterceptor/TagInterceptorInliningTest.java @@ -8,13 +8,14 @@ import org.objectweb.asm.ClassReader; /** - * Pins a code-shape property that C2 depends on but no other test can see. + * Pins a code shape that C2's inlining depends on and no behavioral test can see. * - *

{@code interceptTag(DDSpanContext, long, Object)} must stay too big for C2 to inline (more - * than {@code FreqInlineSize}, 325 bytes of bytecode). DDSpanContext.setTag calls it only for - * intercepted tags; if it inlines into setTag's own compiled code, the profiled handler bodies come - * with it and push setTag past {@code InlineSmallCode}, so callers stop inlining setTag and a - * constant id no longer folds its interception test away. + *

{@code interceptTag(DDSpanContext, long, Object)} must stay too big for C2 to inline: more + * than {@code FreqInlineSize}, 325 bytes of bytecode by default. DDSpanContext.setTag calls it only + * for intercepted tags. If it inlined into setTag's own compiled code, the profiled handler bodies + * would come with it and can push setTag past {@code InlineSmallCode} (2500 bytes of machine code + * by default). Callers then refuse to inline setTag, and a constant id no longer folds its + * interception test away. */ class TagInterceptorInliningTest { private static final int FREQ_INLINE_SIZE = 325; diff --git a/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java b/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java index faf336cc40f..9c5687bf655 100644 --- a/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java +++ b/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java @@ -19,11 +19,10 @@ public final class KnownTagCodec { * reserved. Unknown (string-only) custom tags are NOT known ids — {@code keyOf} returns 0 for * them. * - *

Bit 1 is the INTERCEPTED bit: set on a tag TagInterceptor may route on the set-path (to a - * span field or a sampling directive instead of tag storage). It is a hint, not a decision: the - * interceptor's switch says what each such tag does, and may still store it. Because a setter - * called with a constant id can test the bit at JIT time, the interception path folds away for - * every tag without it. + *

The INTERCEPTED bit marks a tag TagInterceptor may route on the set-path, to a span field or + * a sampling directive instead of tag storage. It is a hint, not a decision: the interceptor's + * switch decides, and may still store the tag. A setter called with a constant id tests the bit + * at JIT time, so the interception path folds away for every tag without it. * *

There is deliberately NO OpenTelemetry-applicability flag: an absent otel-name means * pass-through (the tag is emitted under its Datadog name), so today every known tag has an @@ -50,8 +49,8 @@ public static boolean isTraceLevel(long tagId) { } /** - * INTERCEPTED bit (low-32 carve, bit 1). Set marks a tag TagInterceptor may route on the - * set-path. Declared in the tracer overlay ({@code tag-conventions-java.yaml}). + * INTERCEPTED bit (low-32 carve, bit 1): marks a tag TagInterceptor may route on the set-path. + * The tracer overlay, {@code tag-conventions-java.yaml}, lists these tags. */ public static final long INTERCEPTED = 1L << 1; @@ -139,8 +138,8 @@ public static int serialLimit() { } /** - * True if {@code tagId} names a known tag -- the same answer as {@code nameOf(tagId) != null}, as - * a range check on its serial, so it folds away for a constant id. + * True if {@code tagId} names a known tag. Gives the same answer as {@code nameOf(tagId) != + * null}, but as a range check on the serial, which folds away for a constant id. */ public static boolean isKnown(long tagId) { int serial = serialNum(tagId); From 3f65031560a4d8ca7d9a8655de42985aca5ab008 Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Fri, 9 Oct 2026 15:32:07 -0400 Subject: [PATCH 14/19] Treat overlay tags as intercepted; tidy from review An overlay tag exists only to be routed, so the generator now marks it intercepted without a second listing; intercepted: lists only the tags declared in tag-conventions.yaml that the tracer also routes. Also restore the doc comment and @Suppress that the overlay helper displaced, read the serial limit one way, inline isUnknownTag, and drop an unused default. Co-Authored-By: Claude Opus 5.5 --- .../tagRegistry/KnownTagsEmitter.kt | 3 ++- .../buildlogic/tagRegistry/TagConventions.kt | 14 ++++++++----- .../buildlogic/tagRegistry/TagRegistry.kt | 2 +- .../tagRegistry/TagRegistryGeneratorTest.kt | 2 +- .../datadog/trace/core/DDSpanContext.java | 20 ++++++++----------- .../java/datadog/trace/api/KnownTagCodec.java | 2 +- tag-conventions-java.yaml | 20 +++---------------- 7 files changed, 25 insertions(+), 38 deletions(-) diff --git a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt index 8a21f8e0045..05c3b9cdd26 100644 --- a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt +++ b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt @@ -7,7 +7,8 @@ import java.util.Locale * Emits the generated `KnownTags.java` from a [TagRegistry]. Public API first — per-tag * `_NAME` (string) + `_ID` (encoded long, literal) couplets with a trailing `// makeTagId(...)` * derivation comment — then the `_SERIAL_NUM` constants, the - * `StringIndex.EmbeddingSupport` keyOf table and the resolver's name switches. + * `StringIndex.EmbeddingSupport` keyOf table, the `NAMES_BY_SERIAL` array behind `nameOf`, and the + * resolver's `openTelemetryNameOf` switch. */ object KnownTagsEmitter { diff --git a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagConventions.kt b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagConventions.kt index b17eac293b7..7b1239fbc40 100644 --- a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagConventions.kt +++ b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagConventions.kt @@ -243,7 +243,7 @@ class TagConventions private constructor( /** The type's own or nearest inherited `span-kind` direction, or null when none is declared. */ private fun directionOf(spanTypes: Map, st: SpanType): Direction? = chainOf(spanTypes, st.name).firstNotNullOfOrNull { it.direction } - /** Reads `span-kind` as the direction it sets, or null when absent. */ + /** The tracer overlay's `tags`, as a mixin that applies to no span type; empty when none. */ private fun overlayMixin(overlay: Map): Map { val tags = tagList(overlay["tags"]) if (tags.isEmpty()) return emptyMap() @@ -253,6 +253,7 @@ class TagConventions private constructor( ) } + /** Reads `span-kind` as the direction it sets, or null when absent. */ private fun parseDirection(m: Map, owner: String): Direction? { val spanKind = m["span-kind"] require(spanKind == null || spanKind in SPAN_KIND_DIRECTIONS) { @@ -261,15 +262,15 @@ class TagConventions private constructor( return (spanKind as String?)?.let { SPAN_KIND_DIRECTIONS.getValue(it) } } - @Suppress("UNCHECKED_CAST") /** The synthetic mixin holding the tracer overlay's tags; it applies to no span type. */ const val OVERLAY_MIXIN = "tracer overlay" /** * Parses [root], the language-agnostic conventions, plus [overlay], this tracer's own set-path - * routing: `tags` declares keys that exist only to be routed (e.g. `resource.name`), and - * `intercepted` lists the Datadog names the tracer intercepts, from either file. + * routing: `tags` declares keys that exist only to be routed (e.g. `resource.name`), so each is + * intercepted, and `intercepted` adds the tags declared in [root] that the tracer also routes. */ + @Suppress("UNCHECKED_CAST") fun parse(root: Map, overlay: Map = emptyMap()): TagConventions { for (section in listOf("span_types", "mixins", "trace_level")) { require(root[section] == null || root[section] is Map<*, *>) { "$section must be a mapping" } @@ -282,7 +283,10 @@ class TagConventions private constructor( require(interceptedRaw == null || (interceptedRaw is List<*> && interceptedRaw.all { it is String })) { "intercepted must be a list of Datadog tag names" } - val intercepted = (interceptedRaw as? List)?.toSet() ?: emptySet() + // An overlay tag exists only to be routed, so it is intercepted without being listed. + val intercepted = + ((interceptedRaw as? List) ?: emptyList()).toSet() + + tagList(overlay["tags"]).map { it.ddName } val spanTypesRaw = (root["span_types"] as? Map) ?: emptyMap() val parsedSpanTypes = spanTypesRaw.mapValues { (name, v) -> diff --git a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistry.kt b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistry.kt index 73c38c2f7ef..55cdacd243c 100644 --- a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistry.kt +++ b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistry.kt @@ -52,7 +52,7 @@ class TagRegistry private constructor(val tags: List) { * Mirrors KnownTagCodec.makeTagId(serial) + traceLevel() + intercepted() -- must stay in sync. * LEVEL_TRACE at bit 2, INTERCEPTED at bit 1, other low bits and the reserved [47-32] window zero. */ - fun encode(serial: Int, traceLevel: Boolean, intercepted: Boolean = false): Long { + fun encode(serial: Int, traceLevel: Boolean, intercepted: Boolean): Long { var id = serial.toLong() shl 48 if (traceLevel) id = id or LEVEL_TRACE if (intercepted) id = id or INTERCEPTED diff --git a/build-logic/tag-registry/src/test/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGeneratorTest.kt b/build-logic/tag-registry/src/test/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGeneratorTest.kt index 256367ccc0e..16b899d19ab 100644 --- a/build-logic/tag-registry/src/test/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGeneratorTest.kt +++ b/build-logic/tag-registry/src/test/kotlin/datadog/buildlogic/tagRegistry/TagRegistryGeneratorTest.kt @@ -492,7 +492,7 @@ class TagRegistryGeneratorTest { "overlay.yaml", """ tags: [{dd-name: resource.name}] - intercepted: [resource.name, service] + intercepted: [service] """ ) val output = File(directory, "generated") diff --git a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java index 6a87f8dca33..b37ab392ddd 100644 --- a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java +++ b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java @@ -1000,7 +1000,7 @@ public void removeTag(String tag) { * id that names no known tag is ignored, like the id-keyed setters do. */ public void removeTag(long tagId) { - if (isUnknownTag(tagId)) { + if (!KnownTagCodec.isKnown(tagId)) { return; } if (tagId == KnownTags.SPAN_KIND_ID) { @@ -1061,7 +1061,7 @@ public void setTag(final String tag, final String value) { * takes the custom-tag path. An id that names no known tag is ignored, like a null tag. */ public void setTag(final long tagId, final Object value) { - if (isUnknownTag(tagId)) { + if (!KnownTagCodec.isKnown(tagId)) { return; } if (null == value) { @@ -1075,7 +1075,7 @@ public void setTag(final long tagId, final Object value) { } public void setTag(final long tagId, final CharSequence value) { - if (isUnknownTag(tagId)) { + if (!KnownTagCodec.isKnown(tagId)) { return; } if (null == value) { @@ -1089,7 +1089,7 @@ public void setTag(final long tagId, final CharSequence value) { } public void setTag(final long tagId, final boolean value) { - if (isUnknownTag(tagId)) { + if (!KnownTagCodec.isKnown(tagId)) { return; } if (tagInterceptor.needsIntercept(tagId)) { @@ -1102,7 +1102,7 @@ public void setTag(final long tagId, final boolean value) { } public void setTag(final long tagId, final int value) { - if (isUnknownTag(tagId)) { + if (!KnownTagCodec.isKnown(tagId)) { return; } if (tagInterceptor.needsIntercept(tagId)) { @@ -1115,7 +1115,7 @@ public void setTag(final long tagId, final int value) { } public void setTag(final long tagId, final long value) { - if (isUnknownTag(tagId)) { + if (!KnownTagCodec.isKnown(tagId)) { return; } if (tagInterceptor.needsIntercept(tagId)) { @@ -1128,7 +1128,7 @@ public void setTag(final long tagId, final long value) { } public void setTag(final long tagId, final float value) { - if (isUnknownTag(tagId)) { + if (!KnownTagCodec.isKnown(tagId)) { return; } if (tagInterceptor.needsIntercept(tagId)) { @@ -1141,7 +1141,7 @@ public void setTag(final long tagId, final float value) { } public void setTag(final long tagId, final double value) { - if (isUnknownTag(tagId)) { + if (!KnownTagCodec.isKnown(tagId)) { return; } if (tagInterceptor.needsIntercept(tagId)) { @@ -1153,10 +1153,6 @@ public void setTag(final long tagId, final double value) { } } - private static boolean isUnknownTag(long tagId) { - return !KnownTagCodec.isKnown(tagId); - } - public void setTag(TagMap.EntryReader entry) { if (entry == null) { return; diff --git a/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java b/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java index 9c5687bf655..47d4e9451bc 100644 --- a/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java +++ b/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java @@ -143,7 +143,7 @@ public static int serialLimit() { */ public static boolean isKnown(long tagId) { int serial = serialNum(tagId); - return serial != 0 && serial < KnownTags.SERIAL_LIMIT; // serial 0 is no tag + return serial != 0 && serial < serialLimit(); // serial 0 is no tag } /** The id for {@code name} in any namespace, or 0 when it is not a known tag. */ diff --git a/tag-conventions-java.yaml b/tag-conventions-java.yaml index c2304396785..2f3d89e39ed 100644 --- a/tag-conventions-java.yaml +++ b/tag-conventions-java.yaml @@ -6,8 +6,9 @@ # # tags — keys that exist only to be routed, so the conventions do not declare them. They get # ids like any other tag (instrumentation can set them by id) but belong to no span type. -# Same declaration syntax as tag-conventions.yaml; refs are not allowed. -# intercepted — Datadog names TagInterceptor may route, declared in either file. Each one's id carries +# Each is intercepted, so it is not listed again below. Same declaration syntax as +# tag-conventions.yaml; refs are not allowed. +# intercepted — tags declared in tag-conventions.yaml that TagInterceptor also routes. Each one's id carries # the INTERCEPTED bit, so a setter called with a constant id folds the interception test # away. TagInterceptor's switch is the authority on what each one does; a test there # keeps this list and the switch in agreement. @@ -29,21 +30,6 @@ tags: - { dd-name: _dd1.sr.eausr, type: double } intercepted: - # declared above - - resource.name - - span.type - - error - - manual.keep - - manual.drop - - asm.keep - - ai_guard.keep - - sampling.priority - - _dd.p.ts - - _dd.p.debug - - _dd.origin - - _dd.measured - - _dd1.sr.eausr - # declared in tag-conventions.yaml - service - peer.service - span.kind From 69d7849f4046ecbde35b0de898f11decdde12909 Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Fri, 9 Oct 2026 17:57:14 -0400 Subject: [PATCH 15/19] Reject shared-name tag ids on the id-keyed TagMap and span paths A tag declared once per direction (peer.port) has two ids but one shared Datadog name, and keyOf resolves that name to neither. An entry keyed by one of those ids hashed by the id while name-based access hashed the name as a custom tag, so get/remove/containsKey by name missed it and a later set by name produced a duplicate key. Encode a SHARED_NAME flag in the reserved id bit 0 so the check folds for a constant id. TagMap's id-keyed create/get/remove reject such ids, and DDSpanContext's id-keyed setters ignore them, as they do unknown ids, until name resolution knows the span's direction. Co-Authored-By: Claude Opus 5.5 --- .../tagRegistry/KnownTagsEmitter.kt | 1 + .../buildlogic/tagRegistry/TagRegistry.kt | 9 ++++--- .../datadog/trace/core/DDSpanContext.java | 25 +++++++++++-------- .../java/datadog/trace/api/KnownTagCodec.java | 25 +++++++++++++++++-- .../main/java/datadog/trace/api/TagMap.java | 5 ++++ 5 files changed, 49 insertions(+), 16 deletions(-) diff --git a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt index 05c3b9cdd26..f409bc18bdc 100644 --- a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt +++ b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/KnownTagsEmitter.kt @@ -103,6 +103,7 @@ object KnownTagsEmitter { append("// makeTagId(serial=${t.serial})") if (t.traceLevel) append(" + trace-level") if (t.intercepted) append(" + intercepted") + if (t.sharedNameDirection != null) append(" + shared-name") if (t.otelName != null) append(" -> ${escape(t.otelName)}") appendLine(" <${escape(t.required)}>") appendLine() diff --git a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistry.kt b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistry.kt index 55cdacd243c..983eaad5ba4 100644 --- a/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistry.kt +++ b/build-logic/tag-registry/src/main/kotlin/datadog/buildlogic/tagRegistry/TagRegistry.kt @@ -47,15 +47,18 @@ class TagRegistry private constructor(val tags: List) { const val FIRST_SERIAL = 1 const val LEVEL_TRACE = 1L shl 2 // low-32 carve bit 2; mirrors KnownTagCodec.LEVEL_TRACE const val INTERCEPTED = 1L shl 1 // low-32 carve bit 1; mirrors KnownTagCodec.INTERCEPTED + const val SHARED_NAME = 1L shl 0 // low-32 carve bit 0; mirrors KnownTagCodec.SHARED_NAME /** * Mirrors KnownTagCodec.makeTagId(serial) + traceLevel() + intercepted() -- must stay in sync. - * LEVEL_TRACE at bit 2, INTERCEPTED at bit 1, other low bits and the reserved [47-32] window zero. + * LEVEL_TRACE at bit 2, INTERCEPTED at bit 1, SHARED_NAME at bit 0, other low bits and the + * reserved [47-32] window zero. */ - fun encode(serial: Int, traceLevel: Boolean, intercepted: Boolean): Long { + fun encode(serial: Int, traceLevel: Boolean, intercepted: Boolean, sharedName: Boolean = false): Long { var id = serial.toLong() shl 48 if (traceLevel) id = id or LEVEL_TRACE if (intercepted) id = id or INTERCEPTED + if (sharedName) id = id or SHARED_NAME return id } @@ -76,7 +79,7 @@ class TagRegistry private constructor(val tags: List) { serial, isTraceLevel, isIntercepted, - id = encode(serial, isTraceLevel, isIntercepted), + id = encode(serial, isTraceLevel, isIntercepted, t.identity.direction != null), declaredOtelName = renames[t.identity]?.otelName, otelDirection = renames[t.identity]?.direction, ) diff --git a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java index b37ab392ddd..b533a7de481 100644 --- a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java +++ b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java @@ -996,11 +996,13 @@ public void removeTag(String tag) { } /** - * Removes a known tag by id, rather than by its name, which need not resolve back to the id. An - * id that names no known tag is ignored, like the id-keyed setters do. + * Removes a known tag by id rather than by its name. An id the id-keyed setters ignore is ignored + * here too. + * + * @param tagId a {@code KnownTags.*_ID} constant */ public void removeTag(long tagId) { - if (!KnownTagCodec.isKnown(tagId)) { + if (!KnownTagCodec.isKeyableById(tagId)) { return; } if (tagId == KnownTags.SPAN_KIND_ID) { @@ -1058,10 +1060,11 @@ public void setTag(final String tag, final String value) { /* * Id-keyed setters, mirroring the String setters above. With a constant id, the * KnownTagCodec.INTERCEPTED test folds, leaving only the split-by-tags table load; an id set never - * takes the custom-tag path. An id that names no known tag is ignored, like a null tag. + * takes the custom-tag path. An id that names no known tag, or whose name is shared across + * directions (see KnownTagCodec#isKeyableById), is ignored, like a null tag. */ public void setTag(final long tagId, final Object value) { - if (!KnownTagCodec.isKnown(tagId)) { + if (!KnownTagCodec.isKeyableById(tagId)) { return; } if (null == value) { @@ -1075,7 +1078,7 @@ public void setTag(final long tagId, final Object value) { } public void setTag(final long tagId, final CharSequence value) { - if (!KnownTagCodec.isKnown(tagId)) { + if (!KnownTagCodec.isKeyableById(tagId)) { return; } if (null == value) { @@ -1089,7 +1092,7 @@ public void setTag(final long tagId, final CharSequence value) { } public void setTag(final long tagId, final boolean value) { - if (!KnownTagCodec.isKnown(tagId)) { + if (!KnownTagCodec.isKeyableById(tagId)) { return; } if (tagInterceptor.needsIntercept(tagId)) { @@ -1102,7 +1105,7 @@ public void setTag(final long tagId, final boolean value) { } public void setTag(final long tagId, final int value) { - if (!KnownTagCodec.isKnown(tagId)) { + if (!KnownTagCodec.isKeyableById(tagId)) { return; } if (tagInterceptor.needsIntercept(tagId)) { @@ -1115,7 +1118,7 @@ public void setTag(final long tagId, final int value) { } public void setTag(final long tagId, final long value) { - if (!KnownTagCodec.isKnown(tagId)) { + if (!KnownTagCodec.isKeyableById(tagId)) { return; } if (tagInterceptor.needsIntercept(tagId)) { @@ -1128,7 +1131,7 @@ public void setTag(final long tagId, final long value) { } public void setTag(final long tagId, final float value) { - if (!KnownTagCodec.isKnown(tagId)) { + if (!KnownTagCodec.isKeyableById(tagId)) { return; } if (tagInterceptor.needsIntercept(tagId)) { @@ -1141,7 +1144,7 @@ public void setTag(final long tagId, final float value) { } public void setTag(final long tagId, final double value) { - if (!KnownTagCodec.isKnown(tagId)) { + if (!KnownTagCodec.isKeyableById(tagId)) { return; } if (tagInterceptor.needsIntercept(tagId)) { diff --git a/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java b/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java index 47d4e9451bc..314fe6d67dc 100644 --- a/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java +++ b/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java @@ -15,8 +15,8 @@ public final class KnownTagCodec { * openTelemetryNameOf switch on it, and the generator emits each id as a literal. Bits [47-32] * are RESERVED and always zero here: they are the window the dense tag store uses for its * co-occurrence slot coordinate, which arrives with that store. Of the low 32 flag bits, bit 2 is - * the trace/span LEVEL bit (set ⟹ trace-level), bit 1 is the INTERCEPTED bit, and bit 0 is - * reserved. Unknown (string-only) custom tags are NOT known ids — {@code keyOf} returns 0 for + * the trace/span LEVEL bit (set ⟹ trace-level), bit 1 is the INTERCEPTED bit, and bit 0 is the + * SHARED_NAME bit. Unknown (string-only) custom tags are NOT known ids — {@code keyOf} returns 0 for * them. * *

The INTERCEPTED bit marks a tag TagInterceptor may route on the set-path, to a span field or @@ -59,6 +59,27 @@ public static boolean isIntercepted(long tagId) { return (tagId & INTERCEPTED) != 0L; } + /** + * SHARED_NAME bit (low-32 carve, bit 0): marks one direction of a tag declared once per direction + * under a shared Datadog name, such as {@code peer.port}. {@link #keyOf} resolves that name to + * neither id, so the name alone cannot find an entry stored under one of them. + */ + public static final long SHARED_NAME = 1L << 0; + + /** True if the tagId is one direction of a tag whose Datadog name is shared across directions. */ + public static boolean hasSharedName(long tagId) { + return (tagId & SHARED_NAME) != 0L; + } + + /** + * True if {@code tagId} can key a {@link TagMap} entry: a known tag whose name resolves back to + * it. A {@link #hasSharedName shared-name} id cannot, until name resolution knows the span's + * direction. Like {@link #isKnown}, this folds away for a constant id. + */ + public static boolean isKeyableById(long tagId) { + return isKnown(tagId) && !hasSharedName(tagId); + } + /** Returns the tagId with the {@link #LEVEL_TRACE} flag set. */ public static long traceLevel(long tagId) { return tagId | LEVEL_TRACE; diff --git a/internal-api/src/main/java/datadog/trace/api/TagMap.java b/internal-api/src/main/java/datadog/trace/api/TagMap.java index 59dec3eb961..c4775b22d08 100644 --- a/internal-api/src/main/java/datadog/trace/api/TagMap.java +++ b/internal-api/src/main/java/datadog/trace/api/TagMap.java @@ -469,6 +469,11 @@ private static String requireKnownName(long tagId) { if (name == null) { throw new IllegalArgumentException("not a known tag id: " + Long.toHexString(tagId)); } + if (KnownTagCodec.hasSharedName(tagId)) { + // Name-keyed access hashes the shared name as a custom tag, so it could never find an entry + // keyed by this id; set the tag by name until resolution knows the span's direction. + throw new IllegalArgumentException("tag id has a shared name, set it by name: " + name); + } return name; } From 46c3b47f34143a62e0e1c499091f973be6eacae5 Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Fri, 9 Oct 2026 17:57:18 -0400 Subject: [PATCH 16/19] Test rejection of shared-name tag ids Co-Authored-By: Claude Opus 5.5 --- .../java/datadog/trace/core/DDSpanSetTagByIdTest.java | 10 ++++++++++ .../src/test/java/datadog/trace/api/KnownTagsTest.java | 4 ++++ .../test/java/datadog/trace/api/TagMapSetByIdTest.java | 10 ++++++++++ .../test/java/datadog/trace/api/TagMapTagHashTest.java | 8 ++++---- 4 files changed, 28 insertions(+), 4 deletions(-) diff --git a/dd-trace-core/src/test/java/datadog/trace/core/DDSpanSetTagByIdTest.java b/dd-trace-core/src/test/java/datadog/trace/core/DDSpanSetTagByIdTest.java index 0c953fa5b65..34fc1bc2028 100644 --- a/dd-trace-core/src/test/java/datadog/trace/core/DDSpanSetTagByIdTest.java +++ b/dd-trace-core/src/test/java/datadog/trace/core/DDSpanSetTagByIdTest.java @@ -61,6 +61,16 @@ void clearingAnUnknownIdIsIgnored() { assertNull(span.getTag(KnownTags.PEER_HOSTNAME_NAME)); } + @Test + void aSharedNameIdIsIgnoredAndLeavesTheNamedTag() { + span.setTag("peer.port", 8080); + + span.setTag(KnownTags.PEER_PORT_OUTBOUND_ID, 443); + span.setTag(KnownTags.PEER_PORT_INBOUND_ID, (Object) null); + + assertEquals(8080, span.getTag("peer.port")); + } + @Test void removingTheSpanKindByIdClearsTheKind() { span.setTag(KnownTags.SPAN_KIND_ID, "client"); diff --git a/internal-api/src/test/java/datadog/trace/api/KnownTagsTest.java b/internal-api/src/test/java/datadog/trace/api/KnownTagsTest.java index f2022391203..08570b034fa 100644 --- a/internal-api/src/test/java/datadog/trace/api/KnownTagsTest.java +++ b/internal-api/src/test/java/datadog/trace/api/KnownTagsTest.java @@ -169,6 +169,10 @@ void aNameDeclaredPerDirectionIsOneTagPerDirection() { assertEquals(Tags.PEER_PORT, KnownTagCodec.nameOf(KnownTags.PEER_PORT_INBOUND_ID)); assertEquals(Tags.PEER_PORT, KnownTagCodec.nameOf(KnownTags.PEER_PORT_OUTBOUND_ID)); assertNotEquals(KnownTags.PEER_PORT_INBOUND_ID, KnownTags.PEER_PORT_OUTBOUND_ID); + assertTrue(KnownTagCodec.hasSharedName(KnownTags.PEER_PORT_INBOUND_ID)); + assertTrue(KnownTagCodec.hasSharedName(KnownTags.PEER_PORT_OUTBOUND_ID)); + assertFalse(KnownTagCodec.isKeyableById(KnownTags.PEER_PORT_OUTBOUND_ID)); + assertTrue(KnownTagCodec.isKeyableById(KnownTags.PEER_HOSTNAME_ID)); assertEquals(0L, KnownTagCodec.keyOf(Tags.PEER_PORT)); } diff --git a/internal-api/src/test/java/datadog/trace/api/TagMapSetByIdTest.java b/internal-api/src/test/java/datadog/trace/api/TagMapSetByIdTest.java index ecef85afdd4..88ac5d57ca5 100644 --- a/internal-api/src/test/java/datadog/trace/api/TagMapSetByIdTest.java +++ b/internal-api/src/test/java/datadog/trace/api/TagMapSetByIdTest.java @@ -72,4 +72,14 @@ void anUnknownIdIsRejected() { assertThrows(IllegalArgumentException.class, () -> map.set(0L, "value")); assertThrows(IllegalArgumentException.class, () -> map.set(KnownTagCodec.makeTagId(9999), 1)); } + + @Test + void rejectsSharedNameIds() { + TagMap map = TagMap.create(); + assertThrows(IllegalArgumentException.class, () -> map.set(KnownTags.PEER_PORT_INBOUND_ID, 80)); + assertThrows( + IllegalArgumentException.class, () -> map.set(KnownTags.PEER_PORT_OUTBOUND_ID, 443)); + assertThrows( + IllegalArgumentException.class, () -> map.getEntry(KnownTags.PEER_PORT_OUTBOUND_ID)); + } } diff --git a/internal-api/src/test/java/datadog/trace/api/TagMapTagHashTest.java b/internal-api/src/test/java/datadog/trace/api/TagMapTagHashTest.java index 5a5e56b7c78..c740b2b7a1c 100644 --- a/internal-api/src/test/java/datadog/trace/api/TagMapTagHashTest.java +++ b/internal-api/src/test/java/datadog/trace/api/TagMapTagHashTest.java @@ -72,9 +72,6 @@ void everyKnownTagSurvivesBucketCollisionsAndCopies() throws IllegalAccessExcept assertEquals(tagIds.size(), copy.size()); for (long tagId : tagIds) { String name = KnownTagCodec.nameOf(tagId); - if (KnownTagCodec.keyOf(name) != tagId) { - continue; // a name declared per direction does not resolve to either direction's id - } assertEquals("value", map.getObject(name), name); assertEquals("value", copy.getObject(name), name); } @@ -84,7 +81,10 @@ private static List knownTagIds() throws IllegalAccessException { List tagIds = new ArrayList<>(); for (Field field : KnownTags.class.getFields()) { if (field.getType() == long.class && Modifier.isStatic(field.getModifiers())) { - tagIds.add(field.getLong(null)); + long tagId = field.getLong(null); + if (KnownTagCodec.isKeyableById(tagId)) { + tagIds.add(tagId); + } } } return tagIds; From ad2fa97a02bba7b8f1f89b43c9d84077df707f00 Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Fri, 9 Oct 2026 21:43:46 -0400 Subject: [PATCH 17/19] Build custom tags by name and known tags by id Entry's package-private name factories are now custom-only: they skip the registry and assert the name is not a known tag. Callers that start from a name resolve it once -- TagMap.set(String, ...) forwards a known tag to set(long, ...), while getAndSet, put, Ledger.set, putAll and the public Entry.create(String, ...) API go through anyEntryFor and friends -- so a custom tag pays one registry lookup instead of two. Co-Authored-By: Claude Opus 5.5 --- .../main/java/datadog/trace/api/TagMap.java | 149 +++++++++++++----- .../datadog/trace/api/TagMapTagHashTest.java | 14 +- 2 files changed, 124 insertions(+), 39 deletions(-) diff --git a/internal-api/src/main/java/datadog/trace/api/TagMap.java b/internal-api/src/main/java/datadog/trace/api/TagMap.java index c4775b22d08..ea98fa43561 100644 --- a/internal-api/src/main/java/datadog/trace/api/TagMap.java +++ b/internal-api/src/main/java/datadog/trace/api/TagMap.java @@ -250,34 +250,34 @@ public static boolean isEmptyValue(Object value) { */ @Nullable public static final Entry create(@Nonnull String tag, Object value) { - return isEmptyValue(value) ? null : TagMap.Entry.newAnyEntry(tag, value); + return isEmptyValue(value) ? null : TagMap.anyEntryFor(tag, value); } /** If value is non-null, returns a new TagMap.Entry If value is null or empty, returns null */ @Nullable public static final Entry create(@Nonnull String tag, CharSequence value) { // NOTE: From the static typing, we know that value is not a primitive box - return isEmptyValue(value) ? null : TagMap.Entry.newObjectEntry(tag, value); + return isEmptyValue(value) ? null : TagMap.objectEntryFor(tag, value); } public static final Entry create(@Nonnull String tag, boolean value) { - return TagMap.Entry.newBooleanEntry(tag, value); + return TagMap.booleanEntryFor(tag, value); } public static final Entry create(@Nonnull String tag, int value) { - return TagMap.Entry.newIntEntry(tag, value); + return TagMap.intEntryFor(tag, value); } public static final Entry create(@Nonnull String tag, long value) { - return TagMap.Entry.newLongEntry(tag, value); + return TagMap.longEntryFor(tag, value); } public static final Entry create(@Nonnull String tag, float value) { - return TagMap.Entry.newFloatEntry(tag, value); + return TagMap.floatEntryFor(tag, value); } public static final Entry create(@Nonnull String tag, double value) { - return TagMap.Entry.newDoubleEntry(tag, value); + return TagMap.doubleEntryFor(tag, value); } /* @@ -319,7 +319,7 @@ public static final Entry create(long tagId, double value) { } static Entry newAnyEntry(Map.Entry entry) { - return newAnyEntry(entry.getKey(), entry.getValue()); + return anyEntryFor(entry.getKey(), entry.getValue()); } static Entry newAnyEntry(String tag, Object value) { @@ -435,13 +435,14 @@ static Entry newDoubleEntry(String tag, Double box) { volatile String strCache = null; + /** + * A custom tag's entry: no registry lookup. A known tag is built from its id instead -- callers + * that start from a name resolve it once and pick the id or name factory (see {@code + * TagMap.anyEntryFor}). + */ private Entry(String tag, byte type, long prim, Object obj) { - /* - * Canonicalize known names at the single Entry construction point, so Datadog and - * OpenTelemetry spellings use the same TagMap key. The one StringIndex lookup this costs also - * yields the tag id, which becomes the tag hash. - */ - this(KnownTagCodec.keyOf(tag), tag, type, prim, obj); + this(0L, tag, type, prim, obj); + assert KnownTagCodec.keyOf(tag) == 0 : "'" + tag + "' is a known tag; build it from its id"; } private Entry(long tagId, byte type, long prim, Object obj) { @@ -1001,31 +1002,31 @@ public boolean containsRemovals() { } public Ledger set(String tag, Object value) { - return this.recordEntry(Entry.newAnyEntry(tag, value)); + return this.recordEntry(anyEntryFor(tag, value)); } public Ledger set(String tag, CharSequence value) { - return this.recordEntry(Entry.newObjectEntry(tag, value)); + return this.recordEntry(objectEntryFor(tag, value)); } public Ledger set(String tag, boolean value) { - return this.recordEntry(Entry.newBooleanEntry(tag, value)); + return this.recordEntry(booleanEntryFor(tag, value)); } public Ledger set(String tag, int value) { - return this.recordEntry(Entry.newIntEntry(tag, value)); + return this.recordEntry(intEntryFor(tag, value)); } public Ledger set(String tag, long value) { - return this.recordEntry(Entry.newLongEntry(tag, value)); + return this.recordEntry(longEntryFor(tag, value)); } public Ledger set(String tag, float value) { - return this.recordEntry(Entry.newFloatEntry(tag, value)); + return this.recordEntry(floatEntryFor(tag, value)); } public Ledger set(String tag, double value) { - return this.recordEntry(Entry.newDoubleEntry(tag, value)); + return this.recordEntry(doubleEntryFor(tag, value)); } public Ledger set(Entry entry) { @@ -1494,7 +1495,7 @@ private boolean parentEntryVisible(Entry parentEntry, TagMap fromAncestor) { @Deprecated @Override public Object put(@Nonnull String tag, Object value) { - TagMap.Entry entry = this.getAndSet(Entry.newAnyEntry(tag, value)); + TagMap.Entry entry = this.getAndSet(anyEntryFor(tag, value)); return entry == null ? null : entry.objectValue(); } @@ -1509,32 +1510,106 @@ public void set(@Nullable TagMap.EntryReader newEntryReader) { } } + /* + * Entry factories for callers that start from a name: resolve it once, then build a known tag + * from its id or a custom tag from its name. (Entry's own name factories are custom-only.) + */ + static Entry anyEntryFor(String tag, Object value) { + long tagId = KnownTagCodec.keyOf(tag); + return tagId != 0 ? Entry.newAnyEntry(tagId, value) : Entry.newAnyEntry(tag, value); + } + + static Entry objectEntryFor(String tag, CharSequence value) { + long tagId = KnownTagCodec.keyOf(tag); + return tagId != 0 ? Entry.newObjectEntry(tagId, value) : Entry.newObjectEntry(tag, value); + } + + static Entry booleanEntryFor(String tag, boolean value) { + long tagId = KnownTagCodec.keyOf(tag); + return tagId != 0 ? Entry.newBooleanEntry(tagId, value) : Entry.newBooleanEntry(tag, value); + } + + static Entry intEntryFor(String tag, int value) { + long tagId = KnownTagCodec.keyOf(tag); + return tagId != 0 ? Entry.newIntEntry(tagId, value) : Entry.newIntEntry(tag, value); + } + + static Entry longEntryFor(String tag, long value) { + long tagId = KnownTagCodec.keyOf(tag); + return tagId != 0 ? Entry.newLongEntry(tagId, value) : Entry.newLongEntry(tag, value); + } + + static Entry floatEntryFor(String tag, float value) { + long tagId = KnownTagCodec.keyOf(tag); + return tagId != 0 ? Entry.newFloatEntry(tagId, value) : Entry.newFloatEntry(tag, value); + } + + static Entry doubleEntryFor(String tag, double value) { + long tagId = KnownTagCodec.keyOf(tag); + return tagId != 0 ? Entry.newDoubleEntry(tagId, value) : Entry.newDoubleEntry(tag, value); + } + public void set(@Nonnull String tag, @Nonnull Object value) { - this.putEntry(Entry.newAnyEntry(tag, value)); + long tagId = KnownTagCodec.keyOf(tag); + if (tagId != 0) { + this.set(tagId, value); + } else { + this.putEntry(Entry.newAnyEntry(tag, value)); + } } public void set(@Nonnull String tag, @Nonnull CharSequence value) { - this.putEntry(Entry.newObjectEntry(tag, value)); + long tagId = KnownTagCodec.keyOf(tag); + if (tagId != 0) { + this.set(tagId, value); + } else { + this.putEntry(Entry.newObjectEntry(tag, value)); + } } public void set(@Nonnull String tag, boolean value) { - this.putEntry(Entry.newBooleanEntry(tag, value)); + long tagId = KnownTagCodec.keyOf(tag); + if (tagId != 0) { + this.set(tagId, value); + } else { + this.putEntry(Entry.newBooleanEntry(tag, value)); + } } public void set(@Nonnull String tag, int value) { - this.putEntry(Entry.newIntEntry(tag, value)); + long tagId = KnownTagCodec.keyOf(tag); + if (tagId != 0) { + this.set(tagId, value); + } else { + this.putEntry(Entry.newIntEntry(tag, value)); + } } public void set(@Nonnull String tag, long value) { - this.putEntry(Entry.newLongEntry(tag, value)); + long tagId = KnownTagCodec.keyOf(tag); + if (tagId != 0) { + this.set(tagId, value); + } else { + this.putEntry(Entry.newLongEntry(tag, value)); + } } public void set(@Nonnull String tag, float value) { - this.putEntry(Entry.newFloatEntry(tag, value)); + long tagId = KnownTagCodec.keyOf(tag); + if (tagId != 0) { + this.set(tagId, value); + } else { + this.putEntry(Entry.newFloatEntry(tag, value)); + } } public void set(@Nonnull String tag, double value) { - this.putEntry(Entry.newDoubleEntry(tag, value)); + long tagId = KnownTagCodec.keyOf(tag); + if (tagId != 0) { + this.set(tagId, value); + } else { + this.putEntry(Entry.newDoubleEntry(tag, value)); + } } /* @@ -1658,31 +1733,31 @@ private Entry putEntry(@Nonnull Entry newEntry) { } public Entry getAndSet(@Nonnull String tag, Object value) { - return this.getAndSet(Entry.newAnyEntry(tag, value)); + return this.getAndSet(anyEntryFor(tag, value)); } public Entry getAndSet(@Nonnull String tag, CharSequence value) { - return this.getAndSet(Entry.newObjectEntry(tag, value)); + return this.getAndSet(objectEntryFor(tag, value)); } public TagMap.Entry getAndSet(@Nonnull String tag, boolean value) { - return this.getAndSet(Entry.newBooleanEntry(tag, value)); + return this.getAndSet(booleanEntryFor(tag, value)); } public TagMap.Entry getAndSet(@Nonnull String tag, int value) { - return this.getAndSet(Entry.newIntEntry(tag, value)); + return this.getAndSet(intEntryFor(tag, value)); } public TagMap.Entry getAndSet(@Nonnull String tag, long value) { - return this.getAndSet(Entry.newLongEntry(tag, value)); + return this.getAndSet(longEntryFor(tag, value)); } public TagMap.Entry getAndSet(@Nonnull String tag, float value) { - return this.getAndSet(Entry.newFloatEntry(tag, value)); + return this.getAndSet(floatEntryFor(tag, value)); } public TagMap.Entry getAndSet(@Nonnull String tag, double value) { - return this.getAndSet(Entry.newDoubleEntry(tag, value)); + return this.getAndSet(doubleEntryFor(tag, value)); } public void putAll(Map map) { @@ -3166,7 +3241,7 @@ public Object objectValue() { @Override public TagMap.Entry entry() { - return TagMap.Entry.newAnyEntry(this.tag, this.value); + return TagMap.anyEntryFor(this.tag, this.value); } @Override diff --git a/internal-api/src/test/java/datadog/trace/api/TagMapTagHashTest.java b/internal-api/src/test/java/datadog/trace/api/TagMapTagHashTest.java index c740b2b7a1c..dd477db0eb9 100644 --- a/internal-api/src/test/java/datadog/trace/api/TagMapTagHashTest.java +++ b/internal-api/src/test/java/datadog/trace/api/TagMapTagHashTest.java @@ -2,6 +2,7 @@ import static org.junit.jupiter.api.Assertions.assertEquals; import static org.junit.jupiter.api.Assertions.assertNotEquals; +import static org.junit.jupiter.api.Assertions.assertThrows; import java.lang.reflect.Field; import java.lang.reflect.Modifier; @@ -17,8 +18,8 @@ class TagMapTagHashTest { @Test void aKnownTagHashesToItsIdHoweverItIsSet() { TagMap.Entry byId = TagMap.Entry.newAnyEntry(KnownTags.HTTP_METHOD_ID, "GET"); - TagMap.Entry byName = TagMap.Entry.newAnyEntry(KnownTags.HTTP_METHOD_NAME, "GET"); - TagMap.Entry byOtelName = TagMap.Entry.newAnyEntry(KnownTags.HTTP_METHOD_OTEL_NAME, "GET"); + TagMap.Entry byName = TagMap.anyEntryFor(KnownTags.HTTP_METHOD_NAME, "GET"); + TagMap.Entry byOtelName = TagMap.anyEntryFor(KnownTags.HTTP_METHOD_OTEL_NAME, "GET"); assertEquals(KnownTags.HTTP_METHOD_ID, byId.tagHash); assertEquals(KnownTags.HTTP_METHOD_ID, byName.tagHash); @@ -26,6 +27,15 @@ void aKnownTagHashesToItsIdHoweverItIsSet() { assertEquals(KnownTags.HTTP_METHOD_ID, byName.tagId()); } + @Test + void theNameFactoriesAreForCustomTagsOnly() { + // Entry's name factories skip the registry, so a known name must come in through its id; + // anyEntryFor and friends resolve a name first. (Tests run with assertions enabled.) + assertThrows( + AssertionError.class, () -> TagMap.Entry.newAnyEntry(KnownTags.HTTP_METHOD_NAME, "GET")); + assertEquals(0L, TagMap.Entry.newAnyEntry("my.custom.tag", "value").tagId()); + } + @Test void aCustomTagHashesToItsNameWithNoId() { TagMap.Entry custom = TagMap.Entry.newAnyEntry("my.custom.tag", "value"); From dac7060632fc966c08c1009553b5065eedfe6c9d Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Sat, 10 Oct 2026 12:18:41 -0400 Subject: [PATCH 18/19] Give the tracer core a restricted, trusted path into TagMap TagMap.internals() returns a small Internals view whose setKnown(...) skips the id validation the checked set(long, ...) repeats; DDSpanContext's id-keyed setters, which have already checked isKeyableById, now use it. Internals is created per call, so escape analysis removes it. internals() is marked with a new @Restricted(allowedIn = ...) annotation, and gradle/forbiddenApiFilters/instrumentation.txt bans it in instrumentation modules, so calling it there fails forbiddenApisMain. Internals is also where the batched setTagsFrom/TagSink writes will go. Co-Authored-By: Claude Opus 5.5 --- .../datadog/trace/core/DDSpanContext.java | 16 +++--- .../forbiddenApiFilters/instrumentation.txt | 5 ++ .../java/datadog/apicontract/Restricted.java | 24 +++++++++ .../main/java/datadog/trace/api/TagMap.java | 53 +++++++++++++++++++ .../datadog/trace/api/TagMapSetByIdTest.java | 18 +++++++ 5 files changed, 108 insertions(+), 8 deletions(-) create mode 100644 internal-api/src/main/java/datadog/apicontract/Restricted.java diff --git a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java index b533a7de481..a3a86d0e669 100644 --- a/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java +++ b/dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java @@ -1072,7 +1072,7 @@ public void setTag(final long tagId, final Object value) { } else if (!tagInterceptor.needsIntercept(tagId) || !tagInterceptor.interceptTag(this, tagId, value)) { synchronized (unsafeTags) { - unsafeTags.set(tagId, value); + unsafeTags.internals().setKnown(tagId, value); } } } @@ -1086,7 +1086,7 @@ public void setTag(final long tagId, final CharSequence value) { } else if (!tagInterceptor.needsIntercept(tagId) || !tagInterceptor.interceptTag(this, tagId, value)) { synchronized (unsafeTags) { - unsafeTags.set(tagId, value); + unsafeTags.internals().setKnown(tagId, value); } } } @@ -1099,7 +1099,7 @@ public void setTag(final long tagId, final boolean value) { this.setBox(tagId, value); } else { synchronized (unsafeTags) { - unsafeTags.set(tagId, value); + unsafeTags.internals().setKnown(tagId, value); } } } @@ -1112,7 +1112,7 @@ public void setTag(final long tagId, final int value) { this.setBox(tagId, value); } else { synchronized (unsafeTags) { - unsafeTags.set(tagId, value); + unsafeTags.internals().setKnown(tagId, value); } } } @@ -1125,7 +1125,7 @@ public void setTag(final long tagId, final long value) { this.setBox(tagId, value); } else { synchronized (unsafeTags) { - unsafeTags.set(tagId, value); + unsafeTags.internals().setKnown(tagId, value); } } } @@ -1138,7 +1138,7 @@ public void setTag(final long tagId, final float value) { this.setBox(tagId, value); } else { synchronized (unsafeTags) { - unsafeTags.set(tagId, value); + unsafeTags.internals().setKnown(tagId, value); } } } @@ -1151,7 +1151,7 @@ public void setTag(final long tagId, final double value) { this.setBox(tagId, value); } else { synchronized (unsafeTags) { - unsafeTags.set(tagId, value); + unsafeTags.internals().setKnown(tagId, value); } } } @@ -1184,7 +1184,7 @@ public void setTag(TagMap.EntryReader entry) { private void setBox(long tagId, Object box) { if (!tagInterceptor.interceptTag(this, tagId, box)) { synchronized (unsafeTags) { - unsafeTags.set(tagId, box); + unsafeTags.internals().setKnown(tagId, box); } } } diff --git a/gradle/forbiddenApiFilters/instrumentation.txt b/gradle/forbiddenApiFilters/instrumentation.txt index de3910a8ac8..5ffb1f7868d 100644 --- a/gradle/forbiddenApiFilters/instrumentation.txt +++ b/gradle/forbiddenApiFilters/instrumentation.txt @@ -2,3 +2,8 @@ # Use AgentSpan#setServiceName(String, CharSequence) instead to track the source of the service name @defaultMessage Use AgentSpan#setServiceName(String, CharSequence) instead to track the source of the service name. The source should typically be the instrumentation name. datadog.trace.bootstrap.instrumentation.api.AgentSpan#setServiceName(java.lang.String) + +# TagMap.internals() skips checks the tracer core has already made; it is @Restricted to the core +# (see datadog.apicontract.Restricted). Instrumentation uses TagMap's checked methods. +@defaultMessage TagMap.internals() is restricted to the tracer core; use TagMap's checked methods instead. +datadog.trace.api.TagMap#internals() diff --git a/internal-api/src/main/java/datadog/apicontract/Restricted.java b/internal-api/src/main/java/datadog/apicontract/Restricted.java new file mode 100644 index 00000000000..ab0372fa06f --- /dev/null +++ b/internal-api/src/main/java/datadog/apicontract/Restricted.java @@ -0,0 +1,24 @@ +package datadog.apicontract; + +import java.lang.annotation.Documented; +import java.lang.annotation.ElementType; +import java.lang.annotation.Retention; +import java.lang.annotation.RetentionPolicy; +import java.lang.annotation.Target; + +/** + * Marks a member that is public only because Java has no narrower visibility across modules: it may + * be used only from the packages in {@link #allowedIn}. It typically trades a safety check for + * speed, trusting its caller to have made the check already. + * + *

This marker changes no runtime behavior. Instrumentation modules are kept out by the + * forbidden-APIs signatures in {@code gradle/forbiddenApiFilters/instrumentation.txt}, which must + * list every {@code @Restricted} member. + */ +@Documented +@Retention(RetentionPolicy.CLASS) +@Target({ElementType.METHOD, ElementType.CONSTRUCTOR, ElementType.TYPE}) +public @interface Restricted { + /** Package prefixes allowed to use the member, such as {@code datadog.trace.core}. */ + String[] allowedIn(); +} diff --git a/internal-api/src/main/java/datadog/trace/api/TagMap.java b/internal-api/src/main/java/datadog/trace/api/TagMap.java index ea98fa43561..8aaac45ba9d 100644 --- a/internal-api/src/main/java/datadog/trace/api/TagMap.java +++ b/internal-api/src/main/java/datadog/trace/api/TagMap.java @@ -1,5 +1,6 @@ package datadog.trace.api; +import datadog.apicontract.Restricted; import datadog.trace.api.function.TriConsumer; import datadog.trace.api.internal.VisibleForTesting; import java.util.AbstractCollection; @@ -1617,6 +1618,58 @@ public void set(@Nonnull String tag, double value) { * canonical name without the name lookup the String setters pay. The id must name a known tag; * custom tags have no id and use the String setters. */ + /** + * The tracer core's trusted operations on this map, which skip checks the core has already made. + * Restricted to the core; instrumentation uses the checked methods. + */ + @Restricted(allowedIn = {"datadog.trace.core"}) + public Internals internals() { + return new Internals(this); + } + + /** See {@link TagMap#internals()}. Created per call, so escape analysis removes it. */ + public static final class Internals { + private final TagMap map; + + private Internals(TagMap map) { + this.map = map; + } + + /* + * Sets a known tag by id without validating it, unlike TagMap.set(long, ...): the caller has + * already checked KnownTagCodec.isKeyableById(tagId). + */ + public void setKnown(long tagId, @Nonnull Object value) { + this.map.putEntry(new Entry(tagId, null, Entry.ANY, 0L, value)); + } + + public void setKnown(long tagId, @Nonnull CharSequence value) { + this.map.putEntry(new Entry(tagId, null, EntryReader.OBJECT, 0L, value)); + } + + public void setKnown(long tagId, boolean value) { + this.map.putEntry( + new Entry( + tagId, null, EntryReader.BOOLEAN, Entry.boolean2Prim(value), Boolean.valueOf(value))); + } + + public void setKnown(long tagId, int value) { + this.map.putEntry(new Entry(tagId, null, EntryReader.INT, Entry.int2Prim(value), null)); + } + + public void setKnown(long tagId, long value) { + this.map.putEntry(new Entry(tagId, null, EntryReader.LONG, Entry.long2Prim(value), null)); + } + + public void setKnown(long tagId, float value) { + this.map.putEntry(new Entry(tagId, null, EntryReader.FLOAT, Entry.float2Prim(value), null)); + } + + public void setKnown(long tagId, double value) { + this.map.putEntry(new Entry(tagId, null, EntryReader.DOUBLE, Entry.double2Prim(value), null)); + } + } + public void set(long tagId, @Nonnull Object value) { this.putEntry(Entry.newAnyEntry(tagId, value)); } diff --git a/internal-api/src/test/java/datadog/trace/api/TagMapSetByIdTest.java b/internal-api/src/test/java/datadog/trace/api/TagMapSetByIdTest.java index 88ac5d57ca5..9bc0edc80e9 100644 --- a/internal-api/src/test/java/datadog/trace/api/TagMapSetByIdTest.java +++ b/internal-api/src/test/java/datadog/trace/api/TagMapSetByIdTest.java @@ -82,4 +82,22 @@ void rejectsSharedNameIds() { assertThrows( IllegalArgumentException.class, () -> map.getEntry(KnownTags.PEER_PORT_OUTBOUND_ID)); } + + @Test + void theCoresTrustedSetsStoreWhatTheCheckedSetsStore() { + TagMap checked = TagMap.create(); + checked.set(KnownTags.HTTP_ROUTE_ID, "/users/{id}"); + checked.set(KnownTags.HTTP_STATUS_CODE_ID, 200); + checked.set(KnownTags.HTTP_RESEND_COUNT_ID, 2L); + checked.set(KnownTags.DD_PROFILING_ENABLED_ID, true); + + TagMap trusted = TagMap.create(); + trusted.internals().setKnown(KnownTags.HTTP_ROUTE_ID, "/users/{id}"); + trusted.internals().setKnown(KnownTags.HTTP_STATUS_CODE_ID, 200); + trusted.internals().setKnown(KnownTags.HTTP_RESEND_COUNT_ID, 2L); + trusted.internals().setKnown(KnownTags.DD_PROFILING_ENABLED_ID, true); + + assertEquals(new HashMap<>(checked), new HashMap<>(trusted)); + assertEquals(KnownTags.HTTP_ROUTE_ID, trusted.getEntry(KnownTags.HTTP_ROUTE_NAME).tagId()); + } } From fbab5517cb073e1c965bbf5647928af4882b14e2 Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Sat, 10 Oct 2026 12:21:54 -0400 Subject: [PATCH 19/19] Mark TagMap.Internals @NoEscape It exists to be created, used within the expression, and scalar-replaced; storing one would force a real allocation. Co-Authored-By: Claude Opus 5.5 --- internal-api/src/main/java/datadog/trace/api/TagMap.java | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/internal-api/src/main/java/datadog/trace/api/TagMap.java b/internal-api/src/main/java/datadog/trace/api/TagMap.java index 8aaac45ba9d..0dbef18896b 100644 --- a/internal-api/src/main/java/datadog/trace/api/TagMap.java +++ b/internal-api/src/main/java/datadog/trace/api/TagMap.java @@ -1,6 +1,7 @@ package datadog.trace.api; import datadog.apicontract.Restricted; +import datadog.trace.api.function.NoEscape; import datadog.trace.api.function.TriConsumer; import datadog.trace.api.internal.VisibleForTesting; import java.util.AbstractCollection; @@ -1627,7 +1628,11 @@ public Internals internals() { return new Internals(this); } - /** See {@link TagMap#internals()}. Created per call, so escape analysis removes it. */ + /** + * See {@link TagMap#internals()}. Created per call so escape analysis removes it: use it within + * the expression ({@code map.internals().setKnown(...)}) rather than storing it. + */ + @NoEscape public static final class Internals { private final TagMap map;