From 45561536b295313085a76b3b51aa8988f8b63940 Mon Sep 17 00:00:00 2001 From: Douglas Q Hawkins Date: Wed, 15 Jul 2026 16:30:58 -0400 Subject: [PATCH] Store known span tags densely in TagMap by tag-id MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Known tags (keyOf resolves to a stored id) are held in insertion-ordered parallel arrays (knownIds/knownValues) with NO per-tag Entry object — the allocation lever. Lazily allocated on the first known-tag write; custom tags stay in the hash buckets. Disjoint by construction (known-ness is global), so read-through shadow checks stay within-region and the bucket path is unchanged. - KnownTagCodec (id encoding + resolver) + hand-written KnownTags (keyOf substrate over StringIndex). - The KnownTagCodec is ALWAYS present: CoreTracer registers the real resolver unconditionally at init (so keyOf/nameOf name resolution is always live — the OTel-name mapping later in the stack depends on this), and on first use with nothing registered the codec lazily installs an empty NoKnownTagCodec. Either way it locks after first use, so a map can never be built half-bucketed then half-dense by a late registration. - Dense ROUTING is decoupled from resolution and gated separately by the const-folded KnownTagCodec.DENSE_STORE, captured from the new trace.experimental.dense.tags.enabled Config flag (off by default). TagMap computes keyOf only under this gate, so when off the dense branches dead-code-eliminate and tag storage is byte-identical to the bucket store. - Sizing is a generous fixed stopgap (KNOWN_INIT_CAP=12, the per-type max); exact per-type sizing comes with the tag registry. Reconciled onto the level-split stack (fold + read-through + StringIndex); built on the folded final-class TagMap. Co-Authored-By: Claude Opus 4.8 --- .../trace/api/config/TracerConfig.java | 7 + .../java/datadog/trace/core/CoreTracer.java | 8 + .../trace/api/DenseStoreAllocBenchmark.java | 150 +++++ .../main/java/datadog/trace/api/Config.java | 7 + .../java/datadog/trace/api/KnownTagCodec.java | 253 +++++++++ .../java/datadog/trace/api/KnownTags.java | 330 +++++++++++ .../main/java/datadog/trace/api/TagMap.java | 528 +++++++++++++++--- .../java/datadog/trace/api/KnownTagsTest.java | 152 +++++ .../trace/api/TagMapDenseForkedTest.java | 283 ++++++++++ .../trace/api/TagMapDenseFuzzForkedTest.java | 210 +++++++ metadata/supported-configurations.json | 8 + 11 files changed, 1872 insertions(+), 64 deletions(-) create mode 100644 internal-api/src/jmh/java/datadog/trace/api/DenseStoreAllocBenchmark.java create mode 100644 internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java create mode 100644 internal-api/src/main/java/datadog/trace/api/KnownTags.java create mode 100644 internal-api/src/test/java/datadog/trace/api/KnownTagsTest.java create mode 100644 internal-api/src/test/java/datadog/trace/api/TagMapDenseForkedTest.java create mode 100644 internal-api/src/test/java/datadog/trace/api/TagMapDenseFuzzForkedTest.java diff --git a/dd-trace-api/src/main/java/datadog/trace/api/config/TracerConfig.java b/dd-trace-api/src/main/java/datadog/trace/api/config/TracerConfig.java index 860abb4c87b..3a3d1737e03 100644 --- a/dd-trace-api/src/main/java/datadog/trace/api/config/TracerConfig.java +++ b/dd-trace-api/src/main/java/datadog/trace/api/config/TracerConfig.java @@ -182,5 +182,12 @@ public final class TracerConfig { public static final String TRACE_ORG_GUARD_STRICT = "trace.org.guard.strict"; public static final String TRACE_ORG_GUARD_TRUSTED_OPMS = "trace.org.guard.trusted.opms"; + /** + * Routes known tags through the dense (id-keyed) tag store instead of per-tag entries. + * Experimental, OFF by default. The {@code KnownTagCodec} is registered regardless; this flag + * only selects whether tags take the dense storage path. + */ + public static final String TRACE_DENSE_TAGS_ENABLED = "trace.experimental.dense.tags.enabled"; + private TracerConfig() {} } diff --git a/dd-trace-core/src/main/java/datadog/trace/core/CoreTracer.java b/dd-trace-core/src/main/java/datadog/trace/core/CoreTracer.java index 6b2e41a9b1d..53a5fc06eab 100644 --- a/dd-trace-core/src/main/java/datadog/trace/core/CoreTracer.java +++ b/dd-trace-core/src/main/java/datadog/trace/core/CoreTracer.java @@ -41,6 +41,7 @@ import datadog.trace.api.EndpointTracker; import datadog.trace.api.IdGenerationStrategy; import datadog.trace.api.InstrumenterConfig; +import datadog.trace.api.KnownTags; import datadog.trace.api.Pair; import datadog.trace.api.TagMap; import datadog.trace.api.TraceConfig; @@ -663,6 +664,13 @@ private CoreTracer( // preload this enum to avoid triggering classloading on the hot path TraceCollector.PublishState.values(); + // Register the KnownTagCodec resolver unconditionally so tag-id name resolution (keyOf/nameOf, + // OTel name mapping) is always live. Whether known tags actually take the dense store is a + // separate, const-folded decision (KnownTagCodec.DENSE_STORE, from + // trace.experimental.dense.tags.enabled); when that flag is off, tag storage is byte-identical + // to the bucket-only behavior. + KnownTags.init(); + if (reportInTracerFlare) { TracerFlare.addReporter(this); } diff --git a/internal-api/src/jmh/java/datadog/trace/api/DenseStoreAllocBenchmark.java b/internal-api/src/jmh/java/datadog/trace/api/DenseStoreAllocBenchmark.java new file mode 100644 index 00000000000..b749f346aec --- /dev/null +++ b/internal-api/src/jmh/java/datadog/trace/api/DenseStoreAllocBenchmark.java @@ -0,0 +1,150 @@ +package datadog.trace.api; + +import datadog.trace.bootstrap.instrumentation.api.Tags; +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.Level; +import org.openjdk.jmh.annotations.Measurement; +import org.openjdk.jmh.annotations.Mode; +import org.openjdk.jmh.annotations.OutputTimeUnit; +import org.openjdk.jmh.annotations.Param; +import org.openjdk.jmh.annotations.Scope; +import org.openjdk.jmh.annotations.Setup; +import org.openjdk.jmh.annotations.State; +import org.openjdk.jmh.annotations.Threads; +import org.openjdk.jmh.annotations.Warmup; +import org.openjdk.jmh.infra.Blackhole; + +/** + * Deterministic allocation A/B for the dense known-tag store, using the REAL {@link KnownTags} + * resolver (a {@code StringIndex} probe + a constant-returning {@code switch} — allocation-free, + * exactly like production). An earlier synthetic prefix resolver allocated in {@code keyOf} + * (substring) and {@code nameOf} (concat), contaminating the dense arm; this measures the store, + * not the resolver. + * + *

Models how a real span's tags route: {@code today} = all custom (what ships now — every tag + * buckets, since nothing is registered as known), {@code dense} = the same tag count with a + * realistic fraction routed to the dense store (real known tag names) and the rest custom. Run with + * {@code -prof gc}; the {@code gc.alloc.rate.norm} (B/op) delta at the same {@code tagCount} is + * what enabling the dense store does to a real span's per-build allocation. + * + *

Results — buildMap, JDK 17 (Zulu 17.0.7, Apple Silicon), {@code -prof gc -f 1 -wi 2 -i 3}, + * 2026-07-08. Allocation is deterministic (±0.001 B/op); throughput on this run is NOT + * trustworthy (single fork, short) — read B/op only. + * + * 

{@code
+ * scenario    tagCount=7   tagCount=12
+ * today          408 B/op     704 B/op
+ * dense          376 B/op     416 B/op
+ * allKnown       176 B/op     400 B/op
+ * }
+ * + *

Gate met: {@code dense < today} at both counts (the over-provision artifact is gone). The + * Entry-less win scales with the known-tag fraction — ~8% at 7 tags (~70% known), ~41% at 12; + * {@code allKnown} (the codegen endgame / read-through parent shape) reaches ~57% at 7. + * + *

Serialize paths (same run, B/op). {@code buildAndSerialize} (alloc-free {@code forEach} + * flyweight) adds a flat +16 B/op over {@code buildMap} in every scenario (7: 392, 12: 432 dense). + * {@code buildAndSerializeViaIterator} — the {@code EntryReader} enhanced-for modeling the count + * pre-pass at {@code TraceMapperV0_4:95} — adds a CONSTANT per-call cost (+56 custom / +80 dense, + * identical at 7 and 12 tags): that flat-vs-tagCount signature is the {@code EntryReaderIterator} + * OBJECT, NOT per-tag Entry — the iterator reuses a dense flyweight (TagMap:2182/2652). So the + * dense win SURVIVES serialization; the only nit is {@code iterator()} allocating one Iterator per + * call, which {@code forEach} avoids and which can be recycled away. + */ +@State(Scope.Benchmark) +@BenchmarkMode(Mode.Throughput) +@OutputTimeUnit(TimeUnit.SECONDS) +@Warmup(iterations = 2, time = 2) +@Measurement(iterations = 3, time = 2) +@Fork( + value = 1, + jvmArgsAppend = {"-Ddd.trace.experimental.dense.tags.enabled=true"}) +@Threads(1) +public class DenseStoreAllocBenchmark { + + // Real stored (dense-routed) tag names — a realistic web/db span's known set. + static final String[] KNOWN = + new String[] { + DDTags.BASE_SERVICE, + Tags.VERSION, + Tags.COMPONENT, + Tags.SPAN_KIND, + Tags.HTTP_METHOD, + Tags.HTTP_ROUTE, + Tags.DB_TYPE, + Tags.DB_INSTANCE, + Tags.PEER_HOSTNAME, + Tags.DB_USER, + DDTags.LANGUAGE_TAG_KEY, + Tags.PEER_PORT, + }; + + // today = all custom (all bucket, what ships now); dense = ~70% known + custom (a real span); + // allKnown = 100% known (the trace-tier read-through parent's shape — exercises lazy buckets). + @Param({"today", "dense", "allKnown"}) + String scenario; + + @Param({"7", "12"}) + int tagCount; + + private String[] keys; + private String[] values; + + @Setup(Level.Trial) + public void setup() { + KnownTags.init(); // registers the real (allocation-free) resolver + int knownCount; + if ("allKnown".equals(scenario)) { + knownCount = tagCount; // 100% known (<= KNOWN.length) + } else if ("dense".equals(scenario)) { + knownCount = (tagCount * 7) / 10; // ~70% known + custom + } else { + knownCount = 0; // today: all custom (all bucket) + } + this.keys = new String[tagCount]; + this.values = new String[tagCount]; + for (int i = 0; i < tagCount; i++) { + this.keys[i] = i < knownCount ? KNOWN[i] : "custom.tag." + i; + this.values[i] = "value-" + i; + } + } + + @Benchmark + public TagMap buildMap() { + TagMap m = TagMap.create(16); + for (int i = 0; i < tagCount; i++) { + m.set(keys[i], values[i]); + } + return m; + } + + @Benchmark + public void buildAndSerialize(Blackhole bh) { + TagMap m = TagMap.create(16); + for (int i = 0; i < tagCount; i++) { + m.set(keys[i], values[i]); + } + // forEach: the alloc-free flyweight emit for dense + m.forEach(reader -> bh.consume(reader.objectValue())); + bh.consume(m); + } + + @Benchmark + public void buildAndSerializeViaIterator(Blackhole bh) { + TagMap m = TagMap.create(16); + for (int i = 0; i < tagCount; i++) { + m.set(keys[i], values[i]); + } + // models the REAL serializer's count pre-pass (TraceMapperV0_4:95). The EntryReader iterator + // uses a reused dense flyweight (NO per-tag Entry alloc — TagMap:2182/2652), so the dense win + // SURVIVES; the only extra cost vs forEach is the EntryReaderIterator object itself (a fixed + // per-call cost, constant across tagCount — not per-tag). forEach avoids even that. + for (TagMap.EntryReader reader : m) { + bh.consume(reader.objectValue()); + } + bh.consume(m); + } +} diff --git a/internal-api/src/main/java/datadog/trace/api/Config.java b/internal-api/src/main/java/datadog/trace/api/Config.java index b5880033dac..d273ad3dd45 100644 --- a/internal-api/src/main/java/datadog/trace/api/Config.java +++ b/internal-api/src/main/java/datadog/trace/api/Config.java @@ -1447,6 +1447,7 @@ public static String getHostName() { private final boolean jdkSocketEnabled; private final boolean spanBuilderReuseEnabled; + private final boolean traceDenseTagsEnabled; private final int tagNameUtf8CacheSize; private final int tagValueUtf8CacheSize; private final int stackTraceLengthLimit; @@ -3414,6 +3415,8 @@ PROFILING_DATADOG_PROFILER_ENABLED, isDatadogProfilerSafeInCurrentEnvironment()) this.spanBuilderReuseEnabled = configProvider.getBoolean(GeneralConfig.SPAN_BUILDER_REUSE_ENABLED, true); + this.traceDenseTagsEnabled = + configProvider.getBoolean(TracerConfig.TRACE_DENSE_TAGS_ENABLED, false); this.tagNameUtf8CacheSize = Math.max(configProvider.getInteger(GeneralConfig.TAG_NAME_UTF8_CACHE_SIZE, 128), 0); this.tagValueUtf8CacheSize = @@ -5338,6 +5341,10 @@ public boolean isSpanBuilderReuseEnabled() { return spanBuilderReuseEnabled; } + public boolean isTraceDenseTagsEnabled() { + return traceDenseTagsEnabled; + } + public int getTagNameUtf8CacheSize() { return tagNameUtf8CacheSize; } diff --git a/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java b/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java new file mode 100644 index 00000000000..f1e1354f6a3 --- /dev/null +++ b/internal-api/src/main/java/datadog/trace/api/KnownTagCodec.java @@ -0,0 +1,253 @@ +package datadog.trace.api; + +/** + * Registry for generated tag ID ↔ name resolution. The code generator populates this at tracer init + * via {@link #register(Resolver)}. Once registered, HotSpot CHA devirtualizes and inlines the + * resolver's switch, making {@link #nameOf}/{@link #keyOf} effectively zero-overhead. + */ +public final class KnownTagCodec { + // Plain (non-volatile) fast-path flag: false until a mapping-bearing resolver is registered (it + // stays false when the codec freezes as the empty NoKnownTagCodec). A plain read is free and + // hoistable, unlike a volatile read of `resolver` (costly on weak memory models such as ARM). A + // stale `false` is benign — callers treat the tag as unknown and use the hash buckets, which is + // correct, just unoptimized; the next read after publication takes the slot path. + private static boolean active; + + // The installed codec. There is always conceptually a codec: either a real resolver (via + // register, at tracer init) or the empty NoKnownTagCodec, lazily installed on first use if + // nothing + // was registered. Resolved exactly once, then LOCKED — so a map can never be built half-bucketed + // then half-dense by a late registration. + private static volatile Resolver resolver; + + // True once `resolver` is resolved (real via register, or lazy NoKnownTagCodec). Cold-path only. + private static volatile boolean locked; + + /** Fast-path gate: true once a mapping-bearing resolver has been registered. */ + public static boolean isActive() { + return active; + } + + /* + * tagId bit layout: [63 intercepted] [62-48 globalSerial (15 bits)] [47-32 fieldPos] + * [31-0 nameHash]. Bit 63 (the sign bit) marks a tag the tag interceptor must see, so the check + * is a single {@code tagId < 0}. globalSerial is globally unique per known tag; fieldPos is its + * slot in the global positional layout (TagMap.knownEntries index); nameHash is + * TagMap.Entry#_hash(name) and is layout-independent. Unknown (string-only) tags have the upper + * 32 bits zero. NOTE: TagMap.Entry decodes nameHash inline as (int) tagId on its hot path, so the + * low-32 encoding here must stay in sync with that. + */ + public static int globalSerial(long tagId) { + return (int) ((tagId >>> 48) & 0x7FFF); + } + + /** + * Flag bit (the sign bit) marking a tag the tag interceptor must process — reserved/"virtual" + * tags AND intercepted-but-stored tags (e.g. http.method, which the interceptor side-effects and + * also stores). Encoded in the id so {@code DDSpanContext.setTag(long)} can route with a single + * sign test ({@link #isIntercepted}) instead of resolving the name. Non-intercepted tags (peer.*, + * base.service, …) leave it clear and take the fast store path. Must agree with the interceptor's + * name-based {@code needsIntercept} for every assigned id. + */ + public static final long INTERCEPTED = Long.MIN_VALUE; // 1L << 63 + + /** True if the tagId is flagged for tag-interceptor processing. */ + public static boolean isIntercepted(long tagId) { + return tagId < 0L; + } + + /** Returns the tagId with the {@link #INTERCEPTED} flag set. */ + public static long intercepted(long tagId) { + return tagId | INTERCEPTED; + } + + public static int fieldPos(long tagId) { + return (int) ((tagId >>> 32) & 0xFFFF); + } + + public static int nameHash(long tagId) { + return (int) tagId; + } + + /** + * globalSerial partition. {@code [1, FIRST_STORED_SERIAL)} is reserved for "virtual" tags that + * are specially handled (redirected to span fields or processed by the tag interceptor) and are + * NOT stored in the TagMap — these are hand-assigned in tracer core. {@code [FIRST_STORED_SERIAL, + * ..]} is for generated convention tags that ARE stored (slotted/bucketed). {@code globalSerial + * == 0} means unknown / string-only. Both core and the code generator must agree on this + * boundary. + */ + public static final int FIRST_STORED_SERIAL = 256; + + /** True if the tagId names a reserved "virtual"/specially-handled tag (not stored in the map). */ + public static boolean isReserved(long tagId) { + int globalSerial = globalSerial(tagId); + return globalSerial > 0 && globalSerial < FIRST_STORED_SERIAL; + } + + /** True if the tagId names a generated, map-stored (slotted/bucketed) tag. */ + public static boolean isStored(long tagId) { + return globalSerial(tagId) >= FIRST_STORED_SERIAL; + } + + /** + * Dense-store routing gate, decoupled from name resolution. The {@link Resolver} is registered + * unconditionally at tracer init (so {@code keyOf}/{@code nameOf} — and OTel name mapping — + * always work); this flag, captured once from {@code trace.experimental.dense.tags.enabled}, + * separately decides whether known tags actually take the dense store. As a {@code static final} + * it constant-folds, so the dense branches in {@link TagMap} dead-code-eliminate when off. + */ + public static final boolean DENSE_STORE = Config.get().isTraceDenseTagsEnabled(); + + /** + * True iff the tagId should route to the dense store: it names a stored tag AND the dense store + * is enabled. This is the single predicate {@link TagMap} branches on — {@link #isStored} alone + * is layout identity, independent of whether dense routing is switched on. + */ + public static boolean routesToDense(long tagId) { + return DENSE_STORE && isStored(tagId); + } + + /** + * Sentinel {@code fieldPos} meaning "no positional slot". It is the maximum value the 16-bit + * fieldPos field can hold, so it always compares {@code >= slotCount()} and routes to the hash + * buckets rather than the fast positional array. Two kinds of tagId use it: + * + *

+ */ + public static final int NO_SLOT = 0xFFFF; + + /** + * True if the tagId names a stored tag that deliberately has no positional slot (bucket-only). + */ + public static boolean isUnslotted(long tagId) { + return isStored(tagId) && fieldPos(tagId) == NO_SLOT; + } + + /** + * Builds a tagId from its parts: {@code globalSerial} (globally unique per known tag), {@code + * fieldPos} (the tag's slot within its span type's positional table), and the tag {@code name} + * (whose hash is computed via the same function the runtime uses, so the low 32 bits match {@link + * TagMap.Entry#hash()}). Inverse of {@link #globalSerial}/{@link #fieldPos}/{@link #nameHash}. + * Intended for the code generator and tests. + */ + public static long tagId(int globalSerial, int fieldPos, String name) { + long nameHash = TagMap.Entry._hash(name) & 0xFFFFFFFFL; + return ((long) globalSerial << 48) | ((long) (fieldPos & 0xFFFF) << 32) | nameHash; + } + + /** + * Builds a tagId with no positional slot ({@code fieldPos == }{@link #NO_SLOT}). Use for reserved + * "virtual" tags and for "low-priority" stored tags that get a stable id but are intentionally + * kept out of the fast slot array (they route to the hash buckets). See {@link #NO_SLOT}. + */ + public static long tagId(int globalSerial, String name) { + return tagId(globalSerial, NO_SLOT, name); + } + + // Number of positional slots in the global layout = (max stored fieldPos) + 1, declared by the + // registered provider. Captured once at registration and read as a dynamic constant; TagMap sizes + // its knownEntries array to exactly this rather than a hardcoded max. 0 when no resolver. + private static int slotCount; + + /** Slot count of the registered provider (max stored fieldPos + 1); 0 if none. */ + public static int slotCount() { + return slotCount; + } + + public interface Resolver { + String nameOf(long tagId); + + long keyOf(String name); + + /** Number of positional slots this provider uses: (max stored fieldPos) + 1. */ + int slotCount(); + } + + /** + * Empty null-object codec: no name↔id mappings, no slots. Installed lazily on first use when + * nothing was registered, so the codec is always present. Its behavior is byte-identical to the + * pre-registry world — {@code keyOf} returns 0, {@code nameOf} returns null, every tag is unknown + * and takes the hash buckets. + */ + private static final class NoKnownTagCodec implements Resolver { + static final NoKnownTagCodec INSTANCE = new NoKnownTagCodec(); + + @Override + public String nameOf(long tagId) { + return null; + } + + @Override + public long keyOf(String name) { + return 0L; + } + + @Override + public int slotCount() { + return 0; + } + } + + // active/slotCount are plain by design: written once here at tracer-init registration (before any + // span processing) and read plain on the hot path. A stale read is benign — the tag is treated as + // unknown and takes the hash-bucket path — so plain reads are deliberately preferred over a + // costly + // volatile read on weak memory models. + public static synchronized void register(Resolver resolver) { + if (resolver == null) { + throw new NullPointerException("resolver"); + } + if (locked) { + if (KnownTagCodec.resolver == resolver) { + return; // idempotent: the same resolver may be registered again (e.g. repeated init()) + } + throw new IllegalStateException( + "KnownTagCodec is already locked; a resolver cannot be registered after first use"); + } + KnownTagCodec.resolver = resolver; // volatile write publishes the resolver + KnownTagCodec.slotCount = resolver.slotCount(); + KnownTagCodec.locked = true; + KnownTagCodec.active = true; // plain write; readers re-read resolver volatile anyway + } + + // Freeze the codec as the empty NoKnownTagCodec when nothing was registered by first use. Keeps + // `active` false (No has no mappings) so the hot path stays a plain-boolean short-circuit. + private static synchronized void freezeAsNoCodec() { + if (locked) { + return; + } + KnownTagCodec.resolver = NoKnownTagCodec.INSTANCE; + KnownTagCodec.locked = true; + } + + public static String nameOf(long tagId) { + if (active) { + return resolver.nameOf(tagId); + } + if (!locked) { + freezeAsNoCodec(); + } + return null; + } + + public static long keyOf(String name) { + if (active) { + return resolver.keyOf(name); + } + if (!locked) { + freezeAsNoCodec(); + } + return 0L; + } + + private KnownTagCodec() {} +} diff --git a/internal-api/src/main/java/datadog/trace/api/KnownTags.java b/internal-api/src/main/java/datadog/trace/api/KnownTags.java new file mode 100644 index 00000000000..cfdaf4fef6c --- /dev/null +++ b/internal-api/src/main/java/datadog/trace/api/KnownTags.java @@ -0,0 +1,330 @@ +package datadog.trace.api; + +import datadog.trace.bootstrap.instrumentation.api.Tags; +import datadog.trace.util.StringIndex; + +/** + * Hand-assigned tag-id constants for well-known tags, plus the {@link KnownTagCodec.Resolver} that + * resolves them. This is the single registry shared by the tracer core and by instrumentation + * (decorators) — it lives in {@code internal-api} so both layers can reference the ids; the + * eventual code generator will replace the hand assignment here. + * + *

Reserved serials {@code [1, KnownTagCodec.FIRST_STORED_SERIAL)} name "virtual" tags handled by + * the tag interceptor / span fields and are NOT stored in the {@code TagMap}; their {@code + * fieldPos} is the {@link KnownTagCodec#NO_SLOT} sentinel that is out of slot range, so any + * incidental store routes to the hash buckets rather than a positional slot. Serials {@code >= + * FIRST_STORED_SERIAL} name stored tags that slot/bucket normally (or, with {@code NO_SLOT}, are + * stored bucket-only). + * + *

The resolver registers on class initialization, so simply referencing any constant here makes + * tag-id resolution live before the first span is built. + * + *

Slice-1 note (keyOf substrate): the {@code fieldPos} assignments below (and {@link + * #SLOT_COUNT}) describe a single universal positional layout (slots 0..25). That layout is + * currently dormant — no dense store consumes {@code fieldPos} yet — and is provisional: the + * dense-store slice replaces the universal layout with per-role / per-type sizing (see the + * over-provision finding in {@code dense-tagmap-design.md}). {@code keyOf}/{@code nameOf} depend + * only on {@code globalSerial} + name, not {@code fieldPos}, so the ids themselves are stable + * across any layout scheme. + */ +public final class KnownTags { + // slot count = (max stored fieldPos) + 1. Stored tags use fieldPos 0..25. PROVISIONAL universal + // layout — see the slice-1 note above; the dense-store slice supersedes this with role/type + // sizing. + static final int SLOT_COUNT = 26; + + // ---- reserved / virtual (tag-interceptor handled, not stored) ---- + // Reserved tags are always intercepted -> set the INTERCEPTED flag. + public static final int ERROR_SERIAL = 1; + public static final long ERROR_ID = + KnownTagCodec.intercepted(KnownTagCodec.tagId(ERROR_SERIAL, Tags.ERROR)); + + // ---- stored (slotted / bucketed) ---- + public static final int PARENT_ID_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL; + public static final long PARENT_ID = KnownTagCodec.tagId(PARENT_ID_SERIAL, 0, DDTags.PARENT_ID); + + // common (process-constant) tags added by InternalTagsAdder to ~every span + public static final int BASE_SERVICE_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 1; + public static final long BASE_SERVICE_ID = + KnownTagCodec.tagId(BASE_SERVICE_SERIAL, 1, DDTags.BASE_SERVICE); + + public static final int VERSION_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 2; + public static final long VERSION_ID = KnownTagCodec.tagId(VERSION_SERIAL, 2, Tags.VERSION); + + // build-time-known constant tags merged into defaultSpanTags (see CoreTracer.withTracerTags). + // "env" is a base-mixin tag; the *_ENABLED flags are product-mixin tags. Hand-assigned for now. + public static final String ENV = "env"; + public static final int ENV_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 3; + public static final long ENV_ID = KnownTagCodec.tagId(ENV_SERIAL, 3, ENV); + + public static final int DJM_ENABLED_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 4; + public static final long DJM_ENABLED_ID = + KnownTagCodec.tagId(DJM_ENABLED_SERIAL, 4, DDTags.DJM_ENABLED); + + public static final int DSM_ENABLED_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 5; + public static final long DSM_ENABLED_ID = + KnownTagCodec.tagId(DSM_ENABLED_SERIAL, 5, DDTags.DSM_ENABLED); + + // common tags added by the tag post-processors (RemoteHostnameAdder / IntegrationAdder / + // ServiceNameSourceAdder). Not intercepted; stored. + public static final int TRACER_HOST_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 6; + public static final long TRACER_HOST_ID = + KnownTagCodec.tagId(TRACER_HOST_SERIAL, 6, DDTags.TRACER_HOST); + + public static final int INTEGRATION_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 7; + public static final long INTEGRATION_ID = + KnownTagCodec.tagId(INTEGRATION_SERIAL, 7, DDTags.DD_INTEGRATION); + + public static final int SVC_SRC_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 8; + public static final long SVC_SRC_ID = KnownTagCodec.tagId(SVC_SRC_SERIAL, 8, DDTags.DD_SVC_SRC); + + // peer.service tags, read/written by PeerServiceCalculator (post-processor; uses Map put/get that + // bypass the interceptor). peer.service is intercepted on the set-path but STORED, so it slots. + public static final int PEER_SERVICE_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 9; + public static final long PEER_SERVICE_ID = + KnownTagCodec.intercepted(KnownTagCodec.tagId(PEER_SERVICE_SERIAL, 9, Tags.PEER_SERVICE)); + + public static final int PEER_SERVICE_REMAPPED_FROM_SERIAL = + KnownTagCodec.FIRST_STORED_SERIAL + 10; + public static final long PEER_SERVICE_REMAPPED_FROM_ID = + KnownTagCodec.tagId(PEER_SERVICE_REMAPPED_FROM_SERIAL, 10, DDTags.PEER_SERVICE_REMAPPED_FROM); + + // HTTP tags read by HttpEndpointPostProcessor. http.method/http.url are intercepted-but-stored + // (interceptTag side-effects then returns false → stored); http.route is not intercepted. All + // stored, so the string set-path slots them via keyOf and the id reads here find them. + public static final int HTTP_METHOD_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 11; + public static final long HTTP_METHOD_ID = + KnownTagCodec.intercepted(KnownTagCodec.tagId(HTTP_METHOD_SERIAL, 11, Tags.HTTP_METHOD)); + + public static final int HTTP_ROUTE_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 12; + public static final long HTTP_ROUTE_ID = + KnownTagCodec.tagId(HTTP_ROUTE_SERIAL, 12, Tags.HTTP_ROUTE); + + public static final int HTTP_URL_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 13; + public static final long HTTP_URL_ID = + KnownTagCodec.intercepted(KnownTagCodec.tagId(HTTP_URL_SERIAL, 13, Tags.HTTP_URL)); + + // peer connection tags set by BaseDecorator.onPeerConnection on ~every client/producer span. + // Not intercepted; stored. Slotted (common across client instrumentations). + public static final int PEER_HOSTNAME_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 14; + public static final long PEER_HOSTNAME_ID = + KnownTagCodec.tagId(PEER_HOSTNAME_SERIAL, 14, Tags.PEER_HOSTNAME); + + public static final int PEER_HOST_IPV4_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 15; + public static final long PEER_HOST_IPV4_ID = + KnownTagCodec.tagId(PEER_HOST_IPV4_SERIAL, 15, Tags.PEER_HOST_IPV4); + + public static final int PEER_HOST_IPV6_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 16; + public static final long PEER_HOST_IPV6_ID = + KnownTagCodec.tagId(PEER_HOST_IPV6_SERIAL, 16, Tags.PEER_HOST_IPV6); + + public static final int PEER_PORT_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 17; + public static final long PEER_PORT_ID = KnownTagCodec.tagId(PEER_PORT_SERIAL, 17, Tags.PEER_PORT); + + // Universal decorator tags — set on ~every span (component/span.kind via Base/Server/Client + // decorators, language via ServerDecorator). span.kind is intercepted (setSpanKindOrdinal). + public static final int COMPONENT_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 18; + public static final long COMPONENT_ID = KnownTagCodec.tagId(COMPONENT_SERIAL, 18, Tags.COMPONENT); + + public static final int SPAN_KIND_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 19; + public static final long SPAN_KIND_ID = + KnownTagCodec.intercepted(KnownTagCodec.tagId(SPAN_KIND_SERIAL, 19, Tags.SPAN_KIND)); + + public static final int LANGUAGE_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 20; + public static final long LANGUAGE_ID = + KnownTagCodec.tagId(LANGUAGE_SERIAL, 20, DDTags.LANGUAGE_TAG_KEY); + + // JDBC / database-client tags — set on every db span (58% of petclinic spans). Not intercepted + // (only db.statement is, and that's handled separately). + public static final int DB_TYPE_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 21; + public static final long DB_TYPE_ID = KnownTagCodec.tagId(DB_TYPE_SERIAL, 21, Tags.DB_TYPE); + + public static final int DB_INSTANCE_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 22; + public static final long DB_INSTANCE_ID = + KnownTagCodec.tagId(DB_INSTANCE_SERIAL, 22, Tags.DB_INSTANCE); + + public static final int DB_USER_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 23; + public static final long DB_USER_ID = KnownTagCodec.tagId(DB_USER_SERIAL, 23, Tags.DB_USER); + + public static final int DB_OPERATION_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 24; + public static final long DB_OPERATION_ID = + KnownTagCodec.tagId(DB_OPERATION_SERIAL, 24, Tags.DB_OPERATION); + + public static final int DB_POOL_NAME_SERIAL = KnownTagCodec.FIRST_STORED_SERIAL + 25; + public static final long DB_POOL_NAME_ID = + KnownTagCodec.tagId(DB_POOL_NAME_SERIAL, 25, Tags.DB_POOL_NAME); + + // Open-addressed name -> id table backing keyOf (data, not a switch): scales flat as the known + // set grows, where a generated switch eventually falls off the inline threshold. KEYOF_NAMES and + // KEYOF_VALUES are parallel; the table places names by hash and a parallel ids[] by slot. + private static final String[] KEYOF_NAMES = { + Tags.ERROR, + DDTags.PARENT_ID, + DDTags.BASE_SERVICE, + Tags.VERSION, + ENV, + DDTags.DJM_ENABLED, + DDTags.DSM_ENABLED, + DDTags.TRACER_HOST, + DDTags.DD_INTEGRATION, + DDTags.DD_SVC_SRC, + Tags.PEER_SERVICE, + DDTags.PEER_SERVICE_REMAPPED_FROM, + Tags.HTTP_METHOD, + Tags.HTTP_ROUTE, + Tags.HTTP_URL, + Tags.PEER_HOSTNAME, + Tags.PEER_HOST_IPV4, + Tags.PEER_HOST_IPV6, + Tags.PEER_PORT, + Tags.COMPONENT, + Tags.SPAN_KIND, + DDTags.LANGUAGE_TAG_KEY, + Tags.DB_TYPE, + Tags.DB_INSTANCE, + Tags.DB_USER, + Tags.DB_OPERATION, + Tags.DB_POOL_NAME, + }; + + private static final long[] KEYOF_VALUES = { + ERROR_ID, + PARENT_ID, + BASE_SERVICE_ID, + VERSION_ID, + ENV_ID, + DJM_ENABLED_ID, + DSM_ENABLED_ID, + TRACER_HOST_ID, + INTEGRATION_ID, + SVC_SRC_ID, + PEER_SERVICE_ID, + PEER_SERVICE_REMAPPED_FROM_ID, + HTTP_METHOD_ID, + HTTP_ROUTE_ID, + HTTP_URL_ID, + PEER_HOSTNAME_ID, + PEER_HOST_IPV4_ID, + PEER_HOST_IPV6_ID, + PEER_PORT_ID, + COMPONENT_ID, + SPAN_KIND_ID, + LANGUAGE_ID, + DB_TYPE_ID, + DB_INSTANCE_ID, + DB_USER_ID, + DB_OPERATION_ID, + DB_POOL_NAME_ID, + }; + + // Static-final raw arrays placed by StringIndex.EmbeddingSupport: the JIT folds these refs to + // constants on + // the keyOf hot path (the fastest of StringIndex's three usage modes — no instance dereference). + private static final int[] KEYOF_HASHES; + private static final String[] KEYOF_KEYS; + private static final long[] KEYOF_IDS; + + static { + StringIndex.Data data = StringIndex.EmbeddingSupport.create(KEYOF_NAMES); + long[] ids = new long[data.names.length]; + for (int j = 0; j < KEYOF_NAMES.length; j++) { + ids[StringIndex.EmbeddingSupport.indexOf(data.hashes, data.names, KEYOF_NAMES[j])] = + KEYOF_VALUES[j]; + } + KEYOF_HASHES = data.hashes; + KEYOF_KEYS = data.names; + KEYOF_IDS = ids; + } + + static final KnownTagCodec.Resolver RESOLVER = + new KnownTagCodec.Resolver() { + @Override + public String nameOf(long tagId) { + switch (KnownTagCodec.globalSerial(tagId)) { + case ERROR_SERIAL: + return Tags.ERROR; + case PARENT_ID_SERIAL: + return DDTags.PARENT_ID; + case BASE_SERVICE_SERIAL: + return DDTags.BASE_SERVICE; + case VERSION_SERIAL: + return Tags.VERSION; + case ENV_SERIAL: + return ENV; + case DJM_ENABLED_SERIAL: + return DDTags.DJM_ENABLED; + case DSM_ENABLED_SERIAL: + return DDTags.DSM_ENABLED; + case TRACER_HOST_SERIAL: + return DDTags.TRACER_HOST; + case INTEGRATION_SERIAL: + return DDTags.DD_INTEGRATION; + case SVC_SRC_SERIAL: + return DDTags.DD_SVC_SRC; + case PEER_SERVICE_SERIAL: + return Tags.PEER_SERVICE; + case PEER_SERVICE_REMAPPED_FROM_SERIAL: + return DDTags.PEER_SERVICE_REMAPPED_FROM; + case HTTP_METHOD_SERIAL: + return Tags.HTTP_METHOD; + case HTTP_ROUTE_SERIAL: + return Tags.HTTP_ROUTE; + case HTTP_URL_SERIAL: + return Tags.HTTP_URL; + case PEER_HOSTNAME_SERIAL: + return Tags.PEER_HOSTNAME; + case PEER_HOST_IPV4_SERIAL: + return Tags.PEER_HOST_IPV4; + case PEER_HOST_IPV6_SERIAL: + return Tags.PEER_HOST_IPV6; + case PEER_PORT_SERIAL: + return Tags.PEER_PORT; + case COMPONENT_SERIAL: + return Tags.COMPONENT; + case SPAN_KIND_SERIAL: + return Tags.SPAN_KIND; + case LANGUAGE_SERIAL: + return DDTags.LANGUAGE_TAG_KEY; + case DB_TYPE_SERIAL: + return Tags.DB_TYPE; + case DB_INSTANCE_SERIAL: + return Tags.DB_INSTANCE; + case DB_USER_SERIAL: + return Tags.DB_USER; + case DB_OPERATION_SERIAL: + return Tags.DB_OPERATION; + case DB_POOL_NAME_SERIAL: + return Tags.DB_POOL_NAME; + default: + return null; + } + } + + @Override + public int slotCount() { + return SLOT_COUNT; + } + + @Override + public long keyOf(String name) { + int slot = StringIndex.EmbeddingSupport.indexOf(KEYOF_HASHES, KEYOF_KEYS, name); + return slot < 0 ? 0L : KEYOF_IDS[slot]; + } + }; + + static { + KnownTagCodec.register(RESOLVER); + } + + /** + * Forces resolver registration. Merely invoking this static method runs {@code } (which + * registers {@link #RESOLVER}), so calling it once at tracer init makes tag-id name resolution + * ({@code keyOf}/{@code nameOf}) live; idempotent. Whether known tags then take the dense store + * is a separate, const-folded decision ({@link KnownTagCodec#DENSE_STORE}). Until something + * references this class the registry stays dormant and {@code keyOf} returns 0, so tag storage is + * byte-identical to the bucket-only behavior. + */ + public static void init() {} + + private KnownTags() {} +} 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 39160ae11ff..32314d018d1 100644 --- a/internal-api/src/main/java/datadog/trace/api/TagMap.java +++ b/internal-api/src/main/java/datadog/trace/api/TagMap.java @@ -48,10 +48,9 @@ */ public final class TagMap implements Map, Iterable { /** Immutable empty TagMap - similar to {@link Collections#emptyMap()} */ - // Frozen view over a length-1 array: bucket masking needs a power-of-two array length (size 0 - // would fail with ArrayIndexOutOfBoundsException, size 1 works), and the private constructor - // reads no statics, so this is safe to build directly during TagMap's . - public static final TagMap EMPTY = new TagMap(new Object[1], 0); + // Frozen view over a power-of-two array; the private constructor reads no statics, so this is + // safe to build directly during TagMap's . + public static final TagMap EMPTY = new TagMap(new Object[1 << 4], 0); /** Creates a new mutable TagMap that contains the contents of map */ public static final TagMap fromMap(@Nonnull Map map) { @@ -1023,10 +1022,44 @@ public EntryChange next() { * removed from the collision chain. */ - private final Object[] buckets; + // Shared immutable empty buckets (all null, length 16). Every map points here until its first + // custom-tag write copies-on-write to a private array (materializeBuckets), so an all-known / + // known-heavy map (e.g. the trace-tier read-through parent) allocates ZERO buckets. Length is + // always 16, so reads need no null guard and read-through bucket alignment (hash & 15) holds. + private static final Object[] EMPTY_BUCKETS = new Object[1 << 4]; + + private Object[] buckets; private int size; private boolean frozen; + /** + * Dense known-tag store (dense-tagmap-design §5). Values for KNOWN tags (those {@link + * KnownTagCodec#keyOf} resolves to a stored id) live in these INSERTION-ORDERED parallel arrays + * with NO per-tag {@link Entry} object — the allocation win. Lazily allocated on the first + * known-tag write ({@code null} until then, so all-unknown maps pay nothing) and grown x2 from + * {@link #KNOWN_INIT_CAP}. Matched by globalSerial via a linear scan ({@link #knownIndexOf}); + * reads aren't hot, so O(knownCount) is fine and positional indexing is deferred. Dormant until a + * resolver is registered: {@code keyOf} returns 0, so nothing routes here and production is + * byte-identical. + * + *

Disjoint from {@link #buckets} by construction: known-ness is global ({@code keyOf} is + * deterministic), so a known tag is ALWAYS dense and never bucketed, and vice-versa. That + * disjointness keeps read-through shadow checks within-region — an ancestor dense entry can only + * be shadowed by a nearer level's dense entry of the same id, an ancestor bucket entry only by a + * nearer level's bucket entry — so the bucket read-through chain walk is unchanged and the dense + * one mirrors it ({@link #parentDenseVisible}). + * + *

{@link #size} counts bucket entries only; {@link #knownCount} counts dense entries; the + * local total is {@code size + knownCount}. + */ + private long[] knownIds; + + private Object[] knownValues; + private int knownCount; + + private static final int KNOWN_INIT_CAP = + 12; // generous per-type max stopgap; exact per-type sizing comes with the tag registry + /** * Optional frozen parent for read-through. When non-null, reads that miss the local buckets fall * through to the parent chain, nearest-level-wins (a local entry shadows the parent's, a nearer @@ -1058,8 +1091,9 @@ public TagMap() { * optimizations can treat it as fixed. */ private TagMap(TagMap parent) { - // needs to be a power of 2 for bucket masking calculation to work as intended - this.buckets = new Object[1 << 4]; + // Start on the shared empty buckets; materializeBuckets() COWs to a private power-of-two array + // on the first custom-tag write. All-known maps never allocate buckets. + this.buckets = EMPTY_BUCKETS; this.size = 0; this.frozen = false; this.parent = parent; @@ -1076,8 +1110,9 @@ private TagMap(Object[] buckets, int size) { @Override public int size() { // Exact (Map contract). Under read-through resolves the union; prefer estimateSize() for hints. + int local = this.size + this.knownCount; // buckets + dense TagMap parent = this.parent; - return parent == null ? this.size : this.size + this.visibleParentCount(); + return parent == null ? local : local + this.visibleParentCount(); } /** @@ -1087,6 +1122,12 @@ public int size() { private int visibleParentCount() { int count = 0; for (TagMap ancestor = this.parent; ancestor != null; ancestor = ancestor.parent) { + // dense entries at this ancestor not shadowed/tombstoned by a nearer level + long[] ancestorIds = ancestor.knownIds; + int ancestorKnownCount = ancestor.knownCount; + for (int i = 0; i < ancestorKnownCount; ++i) { + if (this.parentDenseVisible(ancestorIds[i], ancestor)) count++; + } Object[] parentBuckets = ancestor.buckets; for (int i = 0; i < parentBuckets.length; ++i) { Object parentBucket = parentBuckets[i]; @@ -1110,7 +1151,7 @@ private int visibleParentCount() { @Override public boolean isEmpty() { // Exact (Map contract). Under read-through resolves the parent; prefer isDefinitelyEmpty(). - if (this.size != 0) { + if (this.size != 0 || this.knownCount != 0) { return false; } TagMap parent = this.parent; @@ -1131,7 +1172,7 @@ public boolean isEmpty() { public boolean isDefinitelyEmpty() { // Cheap: empty iff no level in the chain holds a local entry (ignores shadowing/tombstones). for (TagMap level = this; level != null; level = level.parent) { - if (level.size != 0) { + if (level.size != 0 || level.knownCount != 0) { return false; } } @@ -1139,10 +1180,10 @@ public boolean isDefinitelyEmpty() { } public int estimateSize() { - // Upper bound: sum of every level's local size, ignoring read-through shadowing/removals. + // Upper bound: sum of every level's local size (buckets + dense), ignoring shadowing/removals. int total = 0; for (TagMap level = this; level != null; level = level.parent) { - total += level.size; + total += level.size + level.knownCount; } return total; } @@ -1270,8 +1311,15 @@ public Entry getEntry(String tag) { return parent.getEntry(tag); } - /** Looks up an entry in this map's own buckets only — no read-through to the parent. */ + /** Looks up an entry in this map's own storage only (dense then buckets) — no read-through. */ private Entry getLocalEntry(String tag) { + // Known tags live in the dense store; resolve identity and check there first. keyOf is a no-op + // (returns 0 -> isStored false) until a resolver is registered, so this is inert in production. + long id = KnownTagCodec.DENSE_STORE ? KnownTagCodec.keyOf(tag) : 0L; + if (KnownTagCodec.isStored(id)) { + Object known = this.knownRawValue(id); + return known == null ? null : Entry.newAnyEntry(tag, known); + } Object[] thisBuckets = this.buckets; int hash = TagMap.Entry._hash(tag); return findInBucket(thisBuckets[hash & (thisBuckets.length - 1)], hash, tag); @@ -1319,10 +1367,102 @@ private boolean parentEntryVisible(Entry parentEntry, TagMap fromAncestor) { return true; } + // ---- dense known-tag store (see the knownIds field doc) + // ---------------------------------------- + + /** + * Linear scan of the dense store for {@code tagId}, returning its index or -1. Ids are canonical + * (the only way one enters is {@link KnownTagCodec#keyOf} or a {@code KnownTags} constant, both + * canonical), so a full {@code long} compare is exact and cheaper than extracting globalSerial. + */ + private int knownIndexOf(long tagId) { + long[] ids = this.knownIds; + int n = this.knownCount; + for (int i = 0; i < n; ++i) { + if (ids[i] == tagId) return i; + } + return -1; + } + + private void ensureKnownCapacity() { + if (this.knownIds == null) { + this.knownIds = new long[KNOWN_INIT_CAP]; + this.knownValues = new Object[KNOWN_INIT_CAP]; + } else if (this.knownCount == this.knownIds.length) { + int newCap = this.knownIds.length << 1; + this.knownIds = Arrays.copyOf(this.knownIds, newCap); + this.knownValues = Arrays.copyOf(this.knownValues, newCap); + } + } + + /** + * Stores a known tag's value densely (no {@link Entry} alloc). Overwrites in place when present + * (returning the prior value materialized as an Entry, per the {@code Map} contract — usually + * discarded by {@code set}); otherwise appends, growing x2 as needed. + */ + private Entry putKnownValue(long tagId, Object value) { + int i = this.knownIndexOf(tagId); + if (i >= 0) { + Object prior = this.knownValues[i]; + this.knownValues[i] = value; + return materializeKnown(tagId, prior); + } + this.ensureKnownCapacity(); + int slot = this.knownCount++; + this.knownIds[slot] = tagId; + this.knownValues[slot] = value; + return null; + } + + /** Raw dense value for {@code tagId}, or {@code null} when absent (no Entry, no boxing). */ + private Object knownRawValue(long tagId) { + int i = this.knownIndexOf(tagId); + return i < 0 ? null : this.knownValues[i]; + } + + /** + * Removes a known tag from the dense store (swap-with-last), returning the prior Entry or null. + */ + private Entry removeKnown(long tagId) { + int i = this.knownIndexOf(tagId); + if (i < 0) return null; + Object prior = this.knownValues[i]; + int last = --this.knownCount; + this.knownIds[i] = this.knownIds[last]; + this.knownValues[i] = this.knownValues[last]; + this.knownIds[last] = 0L; + this.knownValues[last] = null; + return materializeKnown(tagId, prior); + } + + /** Materializes a transient Entry for a dense (id, value) pair — only on explicit get/iterate. */ + private static Entry materializeKnown(long tagId, Object value) { + return Entry.newAnyEntry(KnownTagCodec.nameOf(tagId), value); + } + + /** + * Whether an ancestor dense entry ({@code tagId}, declared at level {@code fromAncestor}) is + * visible from this leaf under read-through: not shadowed by a nearer level's dense entry of the + * same id and not tombstoned by a nearer level. Chain-aware mirror of {@link #parentEntryVisible} + * for the dense store. (Disjointness: a known tag never buckets, so no bucket shadow check is + * needed.) + */ + private boolean parentDenseVisible(long tagId, TagMap fromAncestor) { + String tag = null; // resolved lazily, only if a nearer level carries tombstones + for (TagMap nearer = this; nearer != fromAncestor; nearer = nearer.parent) { + if (nearer.knownIndexOf(tagId) >= 0) return false; // shadowed by a nearer dense entry + if (nearer.removedFromParent != null) { + if (tag == null) tag = KnownTagCodec.nameOf(tagId); + if (nearer.removedFromParent.contains(tag)) return false; // tombstoned by a nearer level + } + } + return true; + } + @Deprecated @Override public Object put(@Nonnull String tag, Object value) { - TagMap.Entry entry = this.getAndSet(Entry.newAnyEntry(tag, value)); + TagMap.Entry entry = this.getAndSet(tag, value); return entry == null ? null : entry.objectValue(); } @@ -1337,32 +1477,70 @@ public void set(@Nullable TagMap.EntryReader newEntryReader) { } } + // The set(String, ...) family resolves keyOf FIRST: a known tag stores its value densely with no + // Entry (boxing the primitive only on that branch) and no parent-fallback lookup (set discards + // the prior value); a custom tag takes the typed bucket insert (no boxing for primitives). public void set(@Nonnull String tag, @Nonnull Object value) { - this.putEntry(Entry.newAnyEntry(tag, value)); + long id = KnownTagCodec.DENSE_STORE ? KnownTagCodec.keyOf(tag) : 0L; + if (KnownTagCodec.isStored(id)) { + this.putKnownLocal(id, tag, value); + } else { + this.putBucketEntry(Entry.newAnyEntry(tag, value)); + } } public void set(@Nonnull String tag, @Nonnull CharSequence value) { - this.putEntry(Entry.newObjectEntry(tag, value)); + long id = KnownTagCodec.DENSE_STORE ? KnownTagCodec.keyOf(tag) : 0L; + if (KnownTagCodec.isStored(id)) { + this.putKnownLocal(id, tag, value); + } else { + this.putBucketEntry(Entry.newObjectEntry(tag, value)); + } } public void set(@Nonnull String tag, boolean value) { - this.putEntry(Entry.newBooleanEntry(tag, value)); + long id = KnownTagCodec.DENSE_STORE ? KnownTagCodec.keyOf(tag) : 0L; + if (KnownTagCodec.isStored(id)) { + this.putKnownLocal(id, tag, Boolean.valueOf(value)); + } else { + this.putBucketEntry(Entry.newBooleanEntry(tag, value)); + } } public void set(@Nonnull String tag, int value) { - this.putEntry(Entry.newIntEntry(tag, value)); + long id = KnownTagCodec.DENSE_STORE ? KnownTagCodec.keyOf(tag) : 0L; + if (KnownTagCodec.isStored(id)) { + this.putKnownLocal(id, tag, Integer.valueOf(value)); + } else { + this.putBucketEntry(Entry.newIntEntry(tag, value)); + } } public void set(@Nonnull String tag, long value) { - this.putEntry(Entry.newLongEntry(tag, value)); + long id = KnownTagCodec.DENSE_STORE ? KnownTagCodec.keyOf(tag) : 0L; + if (KnownTagCodec.isStored(id)) { + this.putKnownLocal(id, tag, Long.valueOf(value)); + } else { + this.putBucketEntry(Entry.newLongEntry(tag, value)); + } } public void set(@Nonnull String tag, float value) { - this.putEntry(Entry.newFloatEntry(tag, value)); + long id = KnownTagCodec.DENSE_STORE ? KnownTagCodec.keyOf(tag) : 0L; + if (KnownTagCodec.isStored(id)) { + this.putKnownLocal(id, tag, Float.valueOf(value)); + } else { + this.putBucketEntry(Entry.newFloatEntry(tag, value)); + } } public void set(@Nonnull String tag, double value) { - this.putEntry(Entry.newDoubleEntry(tag, value)); + long id = KnownTagCodec.DENSE_STORE ? KnownTagCodec.keyOf(tag) : 0L; + if (KnownTagCodec.isStored(id)) { + this.putKnownLocal(id, tag, Double.valueOf(value)); + } else { + this.putBucketEntry(Entry.newDoubleEntry(tag, value)); + } } /** @@ -1375,6 +1553,17 @@ public Entry getAndSet(@Nullable Entry newEntry) { if (newEntry == null) { return null; } + return this.getAndSetWithFallback(newEntry); + } + + /** + * Local insert (via {@link #putEntry}) plus the read-through parent fallback for the prior + * visible value (Map contract). When no local entry was replaced and the key was not tombstoned, + * the prior visible value is the nearest ancestor's, resolved through {@link #getEntry} (which + * handles both dense known tags and bucketed custom tags). Shared by {@link #getAndSet(Entry)} + * and the {@code getAndSet(String, ...)} overloads. + */ + private Entry getAndSetWithFallback(@Nonnull Entry newEntry) { // Capture whether the key was tombstoned BEFORE putEntry clears it: a tombstoned key had no // visible prior value (it was removed), so getAndSet must report null rather than the parent's. boolean wasTombstoned = @@ -1395,10 +1584,44 @@ public Entry getAndSet(@Nullable Entry newEntry) { /** * Inserts or replaces a local entry, returning the replaced local Entry (or null if none). Does * NOT consult the read-through parent -- the {@code set(...)} methods use this so they never pay - * for a prior-value lookup they discard; {@link #getAndSet(Entry)} layers the parent fallback on - * top. + * for a prior-value lookup they discard; {@link #getAndSetWithFallback} layers the parent + * fallback on top. Routes a known tag to the dense store, a custom tag to the hash buckets. */ private Entry putEntry(@Nonnull Entry newEntry) { + long id = KnownTagCodec.DENSE_STORE ? KnownTagCodec.keyOf(newEntry.tag) : 0L; + if (KnownTagCodec.isStored(id)) { + return this.putKnownLocal(id, newEntry.tag, newEntry.objectValue()); + } + return this.putBucketEntry(newEntry); + } + + /** + * Stores a known tag's value densely with NO Entry retained (the alloc win) and NO parent + * fallback — the local-only counterpart used by {@code set} and {@link #putEntry}. Returns the + * prior LOCAL dense value materialized as an Entry (Map contract); usually discarded. + */ + private Entry putKnownLocal(long id, String tag, Object value) { + this.checkWriteAccess(); + if (this.removedFromParent != null) { + this.removedFromParent.remove(tag); + } + return this.putKnownValue(id, value); + } + + /** Copy-on-write the shared empty buckets to a private array on the first bucket write. */ + private Object[] materializeBuckets() { + Object[] b = this.buckets; + if (b == EMPTY_BUCKETS) { + b = new Object[1 << 4]; + this.buckets = b; + } + return b; + } + + /** + * Stores an entry in the hash buckets — the unknown/custom-tag local path (no parent fallback). + */ + private Entry putBucketEntry(@Nonnull Entry newEntry) { this.checkWriteAccess(); // Re-setting a key clears any read-through tombstone for it (the new value overrides the @@ -1407,7 +1630,7 @@ private Entry putEntry(@Nonnull Entry newEntry) { this.removedFromParent.remove(newEntry.tag); } - Object[] thisBuckets = this.buckets; + Object[] thisBuckets = this.materializeBuckets(); int newHash = newEntry.hash(); int bucketIndex = newHash & (thisBuckets.length - 1); @@ -1452,32 +1675,36 @@ private Entry putEntry(@Nonnull Entry newEntry) { return null; } + // Each getAndSet(String, ...) builds the typed Entry (no boxing for primitives) then funnels + // through getAndSetWithFallback, which routes a known tag to the dense store (dropping the Entry) + // and a custom tag to the buckets, layering the read-through parent fallback on top. The Entry- + // free hot path is set(String, ...), which discards the prior value; getAndSet returns it. public Entry getAndSet(@Nonnull String tag, Object value) { - return this.getAndSet(Entry.newAnyEntry(tag, value)); + return this.getAndSetWithFallback(Entry.newAnyEntry(tag, value)); } public Entry getAndSet(@Nonnull String tag, CharSequence value) { - return this.getAndSet(Entry.newObjectEntry(tag, value)); + return this.getAndSetWithFallback(Entry.newObjectEntry(tag, value)); } public TagMap.Entry getAndSet(@Nonnull String tag, boolean value) { - return this.getAndSet(Entry.newBooleanEntry(tag, value)); + return this.getAndSetWithFallback(Entry.newBooleanEntry(tag, value)); } public TagMap.Entry getAndSet(@Nonnull String tag, int value) { - return this.getAndSet(Entry.newIntEntry(tag, value)); + return this.getAndSetWithFallback(Entry.newIntEntry(tag, value)); } public TagMap.Entry getAndSet(@Nonnull String tag, long value) { - return this.getAndSet(Entry.newLongEntry(tag, value)); + return this.getAndSetWithFallback(Entry.newLongEntry(tag, value)); } public TagMap.Entry getAndSet(@Nonnull String tag, float value) { - return this.getAndSet(Entry.newFloatEntry(tag, value)); + return this.getAndSetWithFallback(Entry.newFloatEntry(tag, value)); } public TagMap.Entry getAndSet(@Nonnull String tag, double value) { - return this.getAndSet(Entry.newDoubleEntry(tag, value)); + return this.getAndSetWithFallback(Entry.newDoubleEntry(tag, value)); } public void putAll(Map map) { @@ -1518,7 +1745,9 @@ private void putAllOptimizedMap(TagMap that) { that.forEach(this, (self, entry) -> self.set(entry)); return; } - if (this.size == 0) { + // "empty" must consider BOTH local regions — a map with only dense entries has size == 0 but is + // not empty, and putAllIntoEmptyMap would clobber its dense store. + if (this.size == 0 && this.knownCount == 0) { this.putAllIntoEmptyMap(that); } else { this.putAllMerge(that); @@ -1526,7 +1755,9 @@ private void putAllOptimizedMap(TagMap that) { } private void putAllMerge(TagMap that) { - Object[] thisBuckets = this.buckets; + // COW our buckets only if the source has bucket entries to merge in; otherwise the loop below + // writes nothing and the shared empty buckets stay shared. + Object[] thisBuckets = (that.size > 0) ? this.materializeBuckets() : this.buckets; Object[] thatBuckets = that.buckets; // Since TagMap-s don't support expansion, buckets are perfectly aligned @@ -1637,33 +1868,49 @@ private void putAllMerge(TagMap that) { } } } + + // merge the source's dense known-tag entries; incoming clobbers existing (same as buckets) + for (int i = 0; i < that.knownCount; ++i) { + this.putKnownValue(that.knownIds[i], that.knownValues[i]); + } } /* * Specially optimized version of putAll for the common case of destination map being empty */ private void putAllIntoEmptyMap(TagMap that) { - Object[] thisBuckets = this.buckets; - Object[] thatBuckets = that.buckets; - - // Check against both thisBuckets.length && thatBuckets.length is to help the JIT do bound check - // elimination - for (int i = 0; i < thisBuckets.length && i < thatBuckets.length; ++i) { - Object thatBucket = thatBuckets[i]; - - // faster to explicitly null check first, then do instanceof - if (thatBucket == null) { - // do nothing - } else if (thatBucket instanceof BucketGroup) { - // if it is a BucketGroup, then need to clone - BucketGroup thatGroup = (BucketGroup) thatBucket; + // Only copy buckets (and COW ours) when the source actually has bucket entries; an all-known + // source leaves us on the shared empty buckets. + if (that.size > 0) { + Object[] thisBuckets = this.materializeBuckets(); + Object[] thatBuckets = that.buckets; + + // Check against both thisBuckets.length && thatBuckets.length is to help the JIT do bound + // check elimination + for (int i = 0; i < thisBuckets.length && i < thatBuckets.length; ++i) { + Object thatBucket = thatBuckets[i]; + + // faster to explicitly null check first, then do instanceof + if (thatBucket == null) { + // do nothing + } else if (thatBucket instanceof BucketGroup) { + // if it is a BucketGroup, then need to clone + BucketGroup thatGroup = (BucketGroup) thatBucket; - thisBuckets[i] = thatGroup.cloneChain(); - } else { // if ( thatBucket instanceof Entry ) - thisBuckets[i] = thatBucket; + thisBuckets[i] = thatGroup.cloneChain(); + } else { // if ( thatBucket instanceof Entry ) + thisBuckets[i] = thatBucket; + } } + this.size = that.size; + } + + // clone the dense known-tag store (values are immutable boxes/objects -> safe to share refs) + if (that.knownCount > 0) { + this.knownIds = Arrays.copyOf(that.knownIds, that.knownIds.length); + this.knownValues = Arrays.copyOf(that.knownValues, that.knownValues.length); + this.knownCount = that.knownCount; } - this.size = that.size; } public void fillMap(Map map) { @@ -1690,6 +1937,9 @@ public void fillMap(Map map) { thisGroup.fillMapFromChain(map); } } + for (int i = 0; i < this.knownCount; ++i) { + map.put(KnownTagCodec.nameOf(this.knownIds[i]), this.knownValues[i]); + } } public void fillStringMap(Map stringMap) { @@ -1715,6 +1965,11 @@ public void fillStringMap(Map stringMap) { thisGroup.fillStringMapFromChain(stringMap); } } + for (int i = 0; i < this.knownCount; ++i) { + stringMap.put( + KnownTagCodec.nameOf(this.knownIds[i]), + TagValueConversions.toString(this.knownValues[i])); + } } @Override @@ -1758,8 +2013,13 @@ public Entry getAndRemove(String tag) { return localRemoved; } - /** Removes an entry from this map's own buckets only — no parent/tombstone handling. */ + /** Removes an entry from this map's own storage only — no parent/tombstone handling. */ private Entry removeLocal(String tag) { + long id = KnownTagCodec.DENSE_STORE ? KnownTagCodec.keyOf(tag) : 0L; + if (KnownTagCodec.isStored(id)) { + return this.removeKnown(id); + } + Object[] thisBuckets = this.buckets; int hash = TagMap.Entry._hash(tag); @@ -1827,6 +2087,15 @@ public Stream stream() { @Override public void forEach(Consumer consumer) { + // local dense known tags via a reused flyweight (no per-entry Entry alloc — the serialize win) + if (this.knownCount > 0) { + EntryReadingHelper reader = new EntryReadingHelper(); + for (int i = 0; i < this.knownCount; ++i) { + reader.set(KnownTagCodec.nameOf(this.knownIds[i]), this.knownValues[i]); + consumer.accept(reader); + } + } + Object[] thisBuckets = this.buckets; for (int i = 0; i < thisBuckets.length; ++i) { @@ -1852,8 +2121,23 @@ public void forEach(Consumer consumer) { private void forEachParent(Consumer consumer) { // Walk the ancestor chain, nearest first. Each entry is emitted once, by the nearest level that - // defines its key, when not shadowed by a nearer level and not tombstoned. + // defines its key, when not shadowed by a nearer level and not tombstoned. Dense known tags are + // emitted via a reused flyweight (no per-entry Entry alloc — the serialize win). + EntryReadingHelper reader = null; for (TagMap ancestor = this.parent; ancestor != null; ancestor = ancestor.parent) { + long[] ancestorIds = ancestor.knownIds; + int ancestorKnownCount = ancestor.knownCount; + if (ancestorKnownCount > 0) { + Object[] ancestorValues = ancestor.knownValues; + if (reader == null) reader = new EntryReadingHelper(); + for (int i = 0; i < ancestorKnownCount; ++i) { + long id = ancestorIds[i]; + if (this.parentDenseVisible(id, ancestor)) { + reader.set(KnownTagCodec.nameOf(id), ancestorValues[i]); + consumer.accept(reader); + } + } + } Object[] parentBuckets = ancestor.buckets; for (int i = 0; i < parentBuckets.length; ++i) { Object parentBucket = parentBuckets[i]; @@ -1876,6 +2160,14 @@ private void forEachParent(Consumer consumer) { } public void forEach(T thisObj, BiConsumer consumer) { + if (this.knownCount > 0) { + EntryReadingHelper reader = new EntryReadingHelper(); + for (int i = 0; i < this.knownCount; ++i) { + reader.set(KnownTagCodec.nameOf(this.knownIds[i]), this.knownValues[i]); + consumer.accept(thisObj, reader); + } + } + Object[] thisBuckets = this.buckets; for (int i = 0; i < thisBuckets.length; ++i) { @@ -1899,7 +2191,21 @@ public void forEach(T thisObj, BiConsumer con } private void forEachParent(T thisObj, BiConsumer consumer) { + EntryReadingHelper reader = null; for (TagMap ancestor = this.parent; ancestor != null; ancestor = ancestor.parent) { + int ancestorKnownCount = ancestor.knownCount; + if (ancestorKnownCount > 0) { + long[] ancestorIds = ancestor.knownIds; + Object[] ancestorValues = ancestor.knownValues; + if (reader == null) reader = new EntryReadingHelper(); + for (int i = 0; i < ancestorKnownCount; ++i) { + long id = ancestorIds[i]; + if (this.parentDenseVisible(id, ancestor)) { + reader.set(KnownTagCodec.nameOf(id), ancestorValues[i]); + consumer.accept(thisObj, reader); + } + } + } Object[] parentBuckets = ancestor.buckets; for (int i = 0; i < parentBuckets.length; ++i) { Object parentBucket = parentBuckets[i]; @@ -1924,6 +2230,14 @@ private void forEachParent(T thisObj, BiConsumer void forEach( T thisObj, U otherObj, TriConsumer consumer) { + if (this.knownCount > 0) { + EntryReadingHelper reader = new EntryReadingHelper(); + for (int i = 0; i < this.knownCount; ++i) { + reader.set(KnownTagCodec.nameOf(this.knownIds[i]), this.knownValues[i]); + consumer.accept(thisObj, otherObj, reader); + } + } + Object[] thisBuckets = this.buckets; for (int i = 0; i < thisBuckets.length; ++i) { @@ -1948,7 +2262,21 @@ public void forEach( private void forEachParent( T thisObj, U otherObj, TriConsumer consumer) { + EntryReadingHelper reader = null; for (TagMap ancestor = this.parent; ancestor != null; ancestor = ancestor.parent) { + int ancestorKnownCount = ancestor.knownCount; + if (ancestorKnownCount > 0) { + long[] ancestorIds = ancestor.knownIds; + Object[] ancestorValues = ancestor.knownValues; + if (reader == null) reader = new EntryReadingHelper(); + for (int i = 0; i < ancestorKnownCount; ++i) { + long id = ancestorIds[i]; + if (this.parentDenseVisible(id, ancestor)) { + reader.set(KnownTagCodec.nameOf(id), ancestorValues[i]); + consumer.accept(thisObj, otherObj, reader); + } + } + } Object[] parentBuckets = ancestor.buckets; for (int i = 0; i < parentBuckets.length; ++i) { Object parentBucket = parentBuckets[i]; @@ -1975,13 +2303,17 @@ private void forEachParent( public void clear() { this.checkWriteAccess(); - Arrays.fill(this.buckets, null); + // Drop the private bucket array back to the shared empty sentinel (also avoids mutating it). + this.buckets = EMPTY_BUCKETS; this.size = 0; // clear() removes ALL mappings, including any inherited through read-through. Detaching the // parent (rather than tombstoning every inherited key) is simpler and cheaper, and leaves an // empty, parent-less map. Detach is one-way -- the parent is never re-pointed. this.parent = null; this.removedFromParent = null; + this.knownIds = null; + this.knownValues = null; + this.knownCount = 0; } public TagMap freeze() { @@ -2036,6 +2368,20 @@ void checkIntegrity() { } } + // dense store: ids must be unique (no tag stored twice) and the count within array bounds. + if (this.knownCount > 0) { + if (this.knownIds == null || this.knownCount > this.knownIds.length) { + throw new IllegalStateException("incorrect known count"); + } + for (int i = 0; i < this.knownCount; ++i) { + for (int j = i + 1; j < this.knownCount; ++j) { + if (this.knownIds[i] == this.knownIds[j]) { + throw new IllegalStateException("duplicate known id"); + } + } + } + } + if (this.size != this.computeSize()) { throw new IllegalStateException("incorrect size"); } @@ -2166,13 +2512,23 @@ abstract static class IteratorBase { private TagMap level; private Object[] buckets; - private Entry nextEntry; + // Currency is EntryReader, not Entry: a BUCKET entry is its own (real, retain-safe) Entry, but + // a + // DENSE entry is emitted via the reused denseReader flyweight (alloc-free, "use now"). This is + // the contract of TagMap.iterator()/keySet()/values(). entrySet() (Iterator) sits on + // top and calls .entry() per next() to get a real retain-safe Entry (see EntriesIterator). + private EntryReader nextEntry; + private EntryReadingHelper denseReader; // lazily created on the first dense emit private int bucketIndex = -1; private BucketGroup group = null; private int groupIndex = 0; + // dense-store cursor for the current level's known tags; advance() resets it when it moves to + // the next ancestor level (read-through union). + private int knownIndex = 0; + IteratorBase(TagMap map) { this.map = map; this.level = map; @@ -2186,9 +2542,9 @@ public final boolean hasNext() { return this.nextEntry != null; } - final Entry nextEntryOrThrowNoSuchElement() { + final EntryReader nextEntryOrThrowNoSuchElement() { if (this.nextEntry != null) { - Entry nextEntry = this.nextEntry; + EntryReader nextEntry = this.nextEntry; this.nextEntry = null; return nextEntry; } @@ -2200,9 +2556,9 @@ final Entry nextEntryOrThrowNoSuchElement() { } } - final Entry nextEntryOrNull() { + final EntryReader nextEntryOrNull() { if (this.nextEntry != null) { - Entry nextEntry = this.nextEntry; + EntryReader nextEntry = this.nextEntry; this.nextEntry = null; return nextEntry; } @@ -2210,8 +2566,22 @@ final Entry nextEntryOrNull() { return this.hasNext() ? this.nextEntry : null; } - private final Entry advance() { + private final EntryReader advance() { while (true) { + // phase 1: drain the current level's dense known tags before its buckets. Leaf dense always + // emits; ancestor dense only if visible from the leaf (not shadowed by a nearer dense entry + // and not tombstoned). Emitted via the reused denseReader flyweight -- NO per-entry Entry + // alloc (the read/serialize alloc win). + if (this.knownIndex < this.level.knownCount) { + int i = this.knownIndex++; + long id = this.level.knownIds[i]; + if (this.level == this.map || this.map.parentDenseVisible(id, this.level)) { + return this.emitDense(id, this.level.knownValues[i]); + } + continue; // ancestor dense entry shadowed/tombstoned -> skip + } + + // phase 2: the current level's buckets. Entry tagEntry = this.rawAdvance(); if (tagEntry != null) { // leaf entries emit as-is; ancestor entries only if visible from the leaf -- not shadowed @@ -2222,9 +2592,12 @@ private final Entry advance() { continue; // ancestor entry shadowed/tombstoned -> skip } - // current level exhausted; advance to the next ancestor's buckets (read-through union) + // current level exhausted; advance to the next ancestor (read-through union), resetting + // both + // the per-level dense cursor and the bucket cursor for the new level. if (this.level.parent != null) { this.level = this.level.parent; + this.knownIndex = 0; this.buckets = this.level.buckets; this.bucketIndex = -1; this.group = null; @@ -2235,6 +2608,16 @@ private final Entry advance() { } } + /** Sets and returns the reused dense flyweight (lazily created); "use now", do not retain. */ + private EntryReader emitDense(long tagId, Object value) { + EntryReadingHelper reader = this.denseReader; + if (reader == null) { + reader = this.denseReader = new EntryReadingHelper(); + } + reader.set(KnownTagCodec.nameOf(tagId), value); + return reader; + } + /** Next raw entry in the current bucket array, ignoring shadowing/tombstones. */ private final Entry rawAdvance() { while (this.bucketIndex < this.buckets.length) { @@ -2764,9 +3147,26 @@ public boolean isEmpty() { @Override public Iterator> iterator() { - @SuppressWarnings({"rawtypes", "unchecked"}) - Iterator> iter = (Iterator) this.map.iterator(); - return iter; + return new EntriesIterator(this.map); + } + } + + /** + * entrySet() yields real, retain-safe {@code Map.Entry} objects. It sits on top of the + * EntryReader iterator and materializes each via {@code .entry()}: a bucket entry's reader IS the + * real stored Entry (returns {@code this}, free); a dense entry's flyweight materializes a fresh + * Entry. Deliberately NOT alloc-optimized for dense — bulk reads use {@code forEach}/EntryReader, + * and manual instrumentation does point get/set, not bulk entrySet iteration. + */ + static final class EntriesIterator extends IteratorBase + implements Iterator> { + EntriesIterator(TagMap map) { + super(map); + } + + @Override + public Map.Entry next() { + return this.nextEntryOrThrowNoSuchElement().entry(); } } diff --git a/internal-api/src/test/java/datadog/trace/api/KnownTagsTest.java b/internal-api/src/test/java/datadog/trace/api/KnownTagsTest.java new file mode 100644 index 00000000000..11d01bc7ec8 --- /dev/null +++ b/internal-api/src/test/java/datadog/trace/api/KnownTagsTest.java @@ -0,0 +1,152 @@ +package datadog.trace.api; + +import static org.junit.jupiter.api.Assertions.assertEquals; +import static org.junit.jupiter.api.Assertions.assertFalse; +import static org.junit.jupiter.api.Assertions.assertNull; +import static org.junit.jupiter.api.Assertions.assertTrue; + +import datadog.trace.bootstrap.instrumentation.api.Tags; +import java.util.ArrayList; +import java.util.HashSet; +import java.util.List; +import java.util.Set; +import java.util.stream.Stream; +import org.junit.jupiter.api.Test; +import org.junit.jupiter.params.ParameterizedTest; +import org.junit.jupiter.params.provider.Arguments; +import org.junit.jupiter.params.provider.MethodSource; + +/** + * Parity test for the keyOf substrate (slice 1): the {@link KnownTags} registry + the {@link + * KnownTagCodec.Resolver} it registers. Verifies name ↔ id resolution without any dense store + * — {@code keyOf}/{@code nameOf} depend only on globalSerial + name, not on the (dormant) + * positional layout. + */ +class KnownTagsTest { + + /** (name, id) pairs — the full registry. keyOf returns the id verbatim (incl. INTERCEPTED). */ + static Stream knownTags() { + return Stream.of( + Arguments.of(Tags.ERROR, KnownTags.ERROR_ID), + Arguments.of(DDTags.PARENT_ID, KnownTags.PARENT_ID), + Arguments.of(DDTags.BASE_SERVICE, KnownTags.BASE_SERVICE_ID), + Arguments.of(Tags.VERSION, KnownTags.VERSION_ID), + Arguments.of(KnownTags.ENV, KnownTags.ENV_ID), + Arguments.of(DDTags.DJM_ENABLED, KnownTags.DJM_ENABLED_ID), + Arguments.of(DDTags.DSM_ENABLED, KnownTags.DSM_ENABLED_ID), + Arguments.of(DDTags.TRACER_HOST, KnownTags.TRACER_HOST_ID), + Arguments.of(DDTags.DD_INTEGRATION, KnownTags.INTEGRATION_ID), + Arguments.of(DDTags.DD_SVC_SRC, KnownTags.SVC_SRC_ID), + Arguments.of(Tags.PEER_SERVICE, KnownTags.PEER_SERVICE_ID), + Arguments.of(DDTags.PEER_SERVICE_REMAPPED_FROM, KnownTags.PEER_SERVICE_REMAPPED_FROM_ID), + Arguments.of(Tags.HTTP_METHOD, KnownTags.HTTP_METHOD_ID), + Arguments.of(Tags.HTTP_ROUTE, KnownTags.HTTP_ROUTE_ID), + Arguments.of(Tags.HTTP_URL, KnownTags.HTTP_URL_ID), + Arguments.of(Tags.PEER_HOSTNAME, KnownTags.PEER_HOSTNAME_ID), + Arguments.of(Tags.PEER_HOST_IPV4, KnownTags.PEER_HOST_IPV4_ID), + Arguments.of(Tags.PEER_HOST_IPV6, KnownTags.PEER_HOST_IPV6_ID), + Arguments.of(Tags.PEER_PORT, KnownTags.PEER_PORT_ID), + Arguments.of(Tags.COMPONENT, KnownTags.COMPONENT_ID), + Arguments.of(Tags.SPAN_KIND, KnownTags.SPAN_KIND_ID), + Arguments.of(DDTags.LANGUAGE_TAG_KEY, KnownTags.LANGUAGE_ID), + Arguments.of(Tags.DB_TYPE, KnownTags.DB_TYPE_ID), + Arguments.of(Tags.DB_INSTANCE, KnownTags.DB_INSTANCE_ID), + Arguments.of(Tags.DB_USER, KnownTags.DB_USER_ID), + Arguments.of(Tags.DB_OPERATION, KnownTags.DB_OPERATION_ID), + Arguments.of(Tags.DB_POOL_NAME, KnownTags.DB_POOL_NAME_ID)); + } + + /** + * The subset flagged INTERCEPTED (sign bit) — must agree with the interceptor's needsIntercept. + */ + static Stream interceptedTags() { + return Stream.of( + Arguments.of(KnownTags.ERROR_ID), + Arguments.of(KnownTags.PEER_SERVICE_ID), + Arguments.of(KnownTags.HTTP_METHOD_ID), + Arguments.of(KnownTags.HTTP_URL_ID), + Arguments.of(KnownTags.SPAN_KIND_ID)); + } + + @Test + void resolverIsActiveOnceReferenced() { + // referencing any constant triggers KnownTags. -> KnownTagCodec.register + assertTrue(KnownTags.ERROR_ID != 0L); + assertTrue(KnownTagCodec.isActive()); + assertEquals(KnownTags.SLOT_COUNT, KnownTagCodec.slotCount()); + } + + @ParameterizedTest + @MethodSource("knownTags") + void keyOfResolvesNameToId(String name, long id) { + assertEquals(id, KnownTagCodec.keyOf(name), "keyOf(" + name + ")"); + } + + @ParameterizedTest + @MethodSource("knownTags") + void nameOfResolvesIdToName(String name, long id) { + assertEquals(name, KnownTagCodec.nameOf(id), "nameOf(" + name + ")"); + } + + @ParameterizedTest + @MethodSource("knownTags") + void nameHashMatchesEntryHash(String name, long id) { + assertEquals( + (int) TagMap.Entry._hash(name), KnownTagCodec.nameHash(id), "nameHash(" + name + ")"); + } + + @ParameterizedTest + @MethodSource("interceptedTags") + void interceptedTagsCarryFlag(long id) { + assertTrue(KnownTagCodec.isIntercepted(id), "isIntercepted"); + } + + @Test + void nonInterceptedTagsDoNotCarryFlag() { + Set intercepted = new HashSet<>(); + interceptedTags().forEach(a -> intercepted.add((Long) a.get()[0])); + knownTags() + .forEach( + a -> { + long id = (Long) a.get()[1]; + if (!intercepted.contains(id)) { + assertFalse(KnownTagCodec.isIntercepted(id), "not intercepted: " + a.get()[0]); + } + }); + } + + @Test + void unknownNamesResolveToZero() { + assertEquals(0L, KnownTagCodec.keyOf("definitely.not.a.known.tag")); + assertEquals(0L, KnownTagCodec.keyOf("http.statuscode")); // close-but-not-listed + assertEquals(0L, KnownTagCodec.keyOf("")); + } + + @Test + void unknownIdsResolveToNullName() { + assertNull(KnownTagCodec.nameOf(0L)); + assertNull(KnownTagCodec.nameOf(KnownTagCodec.tagId(9999, "made.up"))); + } + + @Test + void errorIsReservedTheRestAreStored() { + assertTrue(KnownTagCodec.isReserved(KnownTags.ERROR_ID), "ERROR reserved"); + assertFalse(KnownTagCodec.isStored(KnownTags.ERROR_ID), "ERROR not stored"); + knownTags() + .forEach( + a -> { + long id = (Long) a.get()[1]; + if (id != KnownTags.ERROR_ID) { + assertTrue(KnownTagCodec.isStored(id), "stored: " + a.get()[0]); + assertFalse(KnownTagCodec.isReserved(id), "not reserved: " + a.get()[0]); + } + }); + } + + @Test + void globalSerialsAreUnique() { + List serials = new ArrayList<>(); + knownTags().forEach(a -> serials.add((long) KnownTagCodec.globalSerial((Long) a.get()[1]))); + assertEquals(serials.size(), new HashSet<>(serials).size(), "globalSerials must be unique"); + } +} diff --git a/internal-api/src/test/java/datadog/trace/api/TagMapDenseForkedTest.java b/internal-api/src/test/java/datadog/trace/api/TagMapDenseForkedTest.java new file mode 100644 index 00000000000..c653bd8b33a --- /dev/null +++ b/internal-api/src/test/java/datadog/trace/api/TagMapDenseForkedTest.java @@ -0,0 +1,283 @@ +package datadog.trace.api; + +import static org.junit.jupiter.api.Assertions.assertEquals; +import static org.junit.jupiter.api.Assertions.assertFalse; +import static org.junit.jupiter.api.Assertions.assertNull; +import static org.junit.jupiter.api.Assertions.assertTrue; + +import datadog.trace.bootstrap.instrumentation.api.Tags; +import java.util.HashMap; +import java.util.Map; +import org.junit.jupiter.api.BeforeAll; +import org.junit.jupiter.api.Test; + +/** + * Exercises the dense known-tag store with a LIVE resolver. Registration ({@link KnownTagCodec}) is + * a global static with no un-register, so this lives in a {@code ForkedTest} (isolated JVM) to keep + * dense routing from leaking into the bucket-only tests in the shared JVM. The dense store is + * dormant in production (no resolver) — this is where it actually executes. + * + *

Stored tags (globalSerial ≥ {@code FIRST_STORED_SERIAL}) route to the dense store; reserved + * tags (e.g. {@code error}) and arbitrary tags stay in the hash buckets. Behavior must be + * observationally identical to the bucket store. + */ +class TagMapDenseForkedTest { + + static { + // Dense routing is a const-folded gate (KnownTagCodec.DENSE_STORE, captured from Config at + // KnownTagCodec's class-init). Set the flag before anything touches Config/KnownTagCodec so the + // gate reads true in this forked JVM. Registering the resolver alone no longer engages dense. + System.setProperty("dd.trace.experimental.dense.tags.enabled", "true"); + } + + // stored (dense-routed) tags + static final String BASE_SERVICE = DDTags.BASE_SERVICE; + static final String COMPONENT = Tags.COMPONENT; + static final String DB_TYPE = Tags.DB_TYPE; + static final String HTTP_METHOD = Tags.HTTP_METHOD; // stored + intercepted + static final String DB_INSTANCE = Tags.DB_INSTANCE; + // arbitrary (bucket-routed) tags + static final String CUSTOM_A = "custom.tag.a"; + static final String CUSTOM_B = "custom.tag.b"; + + @BeforeAll + static void registerResolver() { + // referencing any KnownTags constant triggers its -> KnownTagCodec.register + assertTrue(KnownTags.BASE_SERVICE_ID != 0L); + assertTrue(KnownTagCodec.isActive(), "resolver must be live for the dense store to engage"); + assertTrue(KnownTagCodec.DENSE_STORE, "dense store must be enabled in this forked JVM"); + assertTrue( + KnownTagCodec.routesToDense(KnownTagCodec.keyOf(BASE_SERVICE)), + "base_service routes dense"); + assertFalse( + KnownTagCodec.routesToDense(KnownTagCodec.keyOf(CUSTOM_A)), "custom tag stays in buckets"); + assertFalse( + KnownTagCodec.routesToDense(KnownTagCodec.keyOf(Tags.ERROR)), + "error is reserved, not stored"); + } + + private static TagMap map() { + return (TagMap) TagMap.create(); + } + + @Test + void knownTagRoundTripsThroughDenseStore() { + TagMap map = map(); + map.set(BASE_SERVICE, "billing"); + map.set(COMPONENT, "spring-web"); + + assertEquals("billing", map.getObject(BASE_SERVICE)); + assertEquals("spring-web", map.getString(COMPONENT)); + assertEquals("billing", map.getEntry(BASE_SERVICE).objectValue()); + assertTrue(map.containsKey(BASE_SERVICE)); + assertEquals(2, map.size()); + map.checkIntegrity(); + } + + @Test + void typedKnownValuesRoundTrip() { + TagMap map = map(); + map.set(DB_TYPE, "postgresql"); + map.set(HTTP_METHOD, "GET"); + map.set(Tags.PEER_PORT, 5432); + + assertEquals("postgresql", map.getString(DB_TYPE)); + assertEquals("GET", map.getString(HTTP_METHOD)); + assertEquals(5432, map.getInt(Tags.PEER_PORT)); + assertEquals(3, map.size()); + map.checkIntegrity(); + } + + @Test + void knownAndUnknownCoexist() { + TagMap map = map(); + map.set(BASE_SERVICE, "billing"); // dense + map.set(CUSTOM_A, "alpha"); // bucket + map.set(DB_TYPE, "h2"); // dense + map.set(CUSTOM_B, "beta"); // bucket + + assertEquals("billing", map.getObject(BASE_SERVICE)); + assertEquals("alpha", map.getObject(CUSTOM_A)); + assertEquals("h2", map.getObject(DB_TYPE)); + assertEquals("beta", map.getObject(CUSTOM_B)); + assertEquals(4, map.size()); + assertFalse(map.isEmpty()); + map.checkIntegrity(); + + Map collected = new HashMap<>(); + map.fillMap(collected); + assertEquals(4, collected.size()); + assertEquals("billing", collected.get(BASE_SERVICE)); + assertEquals("alpha", collected.get(CUSTOM_A)); + assertEquals("h2", collected.get(DB_TYPE)); + assertEquals("beta", collected.get(CUSTOM_B)); + } + + @Test + void overwriteKnownReplacesInPlace() { + TagMap map = map(); + map.set(COMPONENT, "first"); + assertEquals("first", map.getObject(COMPONENT)); + map.set(COMPONENT, "second"); + assertEquals("second", map.getObject(COMPONENT)); + assertEquals(1, map.size()); // overwrite, not append + map.checkIntegrity(); + } + + @Test + void removeKnownClearsIt() { + TagMap map = map(); + map.set(BASE_SERVICE, "billing"); + map.set(DB_TYPE, "h2"); + map.set(CUSTOM_A, "alpha"); + assertEquals(3, map.size()); + + TagMap.Entry removed = map.getAndRemove(BASE_SERVICE); + assertEquals("billing", removed.objectValue()); + assertNull(map.getObject(BASE_SERVICE)); + assertEquals("h2", map.getObject(DB_TYPE)); // sibling dense entry intact + assertEquals("alpha", map.getObject(CUSTOM_A)); + assertEquals(2, map.size()); + map.checkIntegrity(); + } + + @Test + void forEachAndIteratorEmitDenseAndBucketEntries() { + TagMap map = map(); + map.set(BASE_SERVICE, "billing"); + map.set(COMPONENT, "web"); + map.set(CUSTOM_A, "alpha"); + + Map viaForEach = new HashMap<>(); + map.forEach(reader -> viaForEach.put(reader.tag(), reader.objectValue())); + assertEquals(3, viaForEach.size()); + assertEquals("billing", viaForEach.get(BASE_SERVICE)); + assertEquals("web", viaForEach.get(COMPONENT)); + assertEquals("alpha", viaForEach.get(CUSTOM_A)); + + Map viaIterator = new HashMap<>(); + for (TagMap.EntryReader reader : map) { + viaIterator.put(reader.tag(), reader.objectValue()); + } + assertEquals(viaForEach, viaIterator); + } + + @Test + void copyPreservesDenseStore() { + TagMap map = map(); + map.set(BASE_SERVICE, "billing"); + map.set(CUSTOM_A, "alpha"); + + TagMap copy = (TagMap) map.copy(); + assertEquals("billing", copy.getObject(BASE_SERVICE)); + assertEquals("alpha", copy.getObject(CUSTOM_A)); + assertEquals(2, copy.size()); + + // independence: mutating the copy doesn't touch the original's dense store + copy.set(BASE_SERVICE, "shipping"); + assertEquals("shipping", copy.getObject(BASE_SERVICE)); + assertEquals("billing", map.getObject(BASE_SERVICE)); + copy.checkIntegrity(); + map.checkIntegrity(); + } + + @Test + void clearEmptiesDenseStore() { + TagMap map = map(); + map.set(BASE_SERVICE, "billing"); + map.set(CUSTOM_A, "alpha"); + map.clear(); + assertEquals(0, map.size()); + assertTrue(map.isEmpty()); + assertNull(map.getObject(BASE_SERVICE)); + map.checkIntegrity(); + } + + @Test + void putAllMergesDenseStore() { + TagMap src = map(); + src.set(BASE_SERVICE, "billing"); + src.set(DB_TYPE, "h2"); + src.set(CUSTOM_A, "alpha"); + + TagMap dst = map(); + dst.set(COMPONENT, "web"); // dense, distinct + dst.set(BASE_SERVICE, "old"); // dense, clobbered by src + dst.putAll((TagMap) src); + + assertEquals("billing", dst.getObject(BASE_SERVICE)); // src clobbers + assertEquals("h2", dst.getObject(DB_TYPE)); + assertEquals("web", dst.getObject(COMPONENT)); + assertEquals("alpha", dst.getObject(CUSTOM_A)); + assertEquals(4, dst.size()); + dst.checkIntegrity(); + } + + // ---- read-through union (dense parent + dense child) ---- + + private static TagMap frozenParent() { + TagMap parent = map(); + parent.set(BASE_SERVICE, "billing"); // dense + parent.set(COMPONENT, "web"); // dense + parent.set(CUSTOM_A, "alpha"); // bucket + parent.freeze(); + return parent; + } + + @Test + void childReadsThroughToParentDense() { + TagMap child = TagMap.createFromParent(frozenParent()); + child.set(DB_TYPE, "h2"); // child-only dense + child.set(CUSTOM_B, "beta"); // child-only bucket + + // inherited from parent + assertEquals("billing", child.getObject(BASE_SERVICE)); + assertEquals("web", child.getObject(COMPONENT)); + assertEquals("alpha", child.getObject(CUSTOM_A)); + // own + assertEquals("h2", child.getObject(DB_TYPE)); + assertEquals("beta", child.getObject(CUSTOM_B)); + // union size: 3 parent + 2 child + assertEquals(5, child.size()); + assertFalse(child.isEmpty()); + + Map union = new HashMap<>(); + child.forEach(reader -> union.put(reader.tag(), reader.objectValue())); + assertEquals(5, union.size()); + assertEquals("billing", union.get(BASE_SERVICE)); + assertEquals("h2", union.get(DB_TYPE)); + child.checkIntegrity(); + } + + @Test + void childDenseShadowsParentDense() { + TagMap child = TagMap.createFromParent(frozenParent()); + child.set(BASE_SERVICE, "shipping"); // shadows parent's dense base_service + + assertEquals("shipping", child.getObject(BASE_SERVICE)); // local wins + assertEquals("web", child.getObject(COMPONENT)); // still inherited + assertEquals(3, child.size()); // base_service counted once (shadowed, not doubled) + + Map union = new HashMap<>(); + child.forEach(reader -> union.put(reader.tag(), reader.objectValue())); + assertEquals(3, union.size()); + assertEquals("shipping", union.get(BASE_SERVICE)); // shadow value, parent suppressed + } + + @Test + void removingParentDenseKeyTombstonesIt() { + TagMap child = TagMap.createFromParent(frozenParent()); + + TagMap.Entry removed = child.getAndRemove(BASE_SERVICE); // parent-only dense key + assertEquals("billing", removed.objectValue()); // prior visible value was the parent's + assertNull(child.getObject(BASE_SERVICE)); // tombstoned: no read-through + assertEquals("web", child.getObject(COMPONENT)); // sibling still inherited + assertEquals(2, child.size()); // 3 parent - 1 tombstoned + + Map union = new HashMap<>(); + child.forEach(reader -> union.put(reader.tag(), reader.objectValue())); + assertEquals(2, union.size()); + assertFalse(union.containsKey(BASE_SERVICE)); + child.checkIntegrity(); + } +} diff --git a/internal-api/src/test/java/datadog/trace/api/TagMapDenseFuzzForkedTest.java b/internal-api/src/test/java/datadog/trace/api/TagMapDenseFuzzForkedTest.java new file mode 100644 index 00000000000..f890ca7bdf1 --- /dev/null +++ b/internal-api/src/test/java/datadog/trace/api/TagMapDenseFuzzForkedTest.java @@ -0,0 +1,210 @@ +package datadog.trace.api; + +import static org.junit.jupiter.api.Assertions.assertFalse; +import static org.junit.jupiter.api.Assertions.assertTrue; + +import datadog.trace.api.TagMapFuzzTest.MapAction; +import datadog.trace.api.TagMapFuzzTest.TestCase; +import java.util.ArrayList; +import java.util.HashMap; +import java.util.List; +import java.util.concurrent.ThreadLocalRandom; +import java.util.function.Supplier; +import org.junit.jupiter.api.BeforeAll; +import org.junit.jupiter.api.Test; + +/** + * Fuzz test for the dense store under a LIVE resolver, across three key regimes. Reuses {@link + * TagMapFuzzTest}'s oracle machinery ({@code test(TestCase)} replays a random action sequence + * against a {@code HashMap}, verifying each step + {@code checkIntegrity}). + * + *

Uses a synthetic prefix resolver ({@code known-N} -> stored / dense, anything else -> bucket) + * rather than the real {@link KnownTags}: it gives an UNBOUNDED known key space, so the dense array + * actually grows past its initial capacity and the linear scan gets long, and it lets each test pin + * the known/custom ratio. The three regimes exercise paths the mixed run alone would miss: + * + *

+ * + *

Forked (isolated JVM) because resolver registration is a global static with no un-register. + */ +class TagMapDenseFuzzForkedTest { + static { + // Dense routing is a const-folded gate (KnownTagCodec.DENSE_STORE, captured from Config at + // KnownTagCodec's class-init). Set the flag before anything touches Config/KnownTagCodec so the + // gate reads true in this forked JVM. Registering the resolver alone no longer engages dense. + System.setProperty("dd.trace.experimental.dense.tags.enabled", "true"); + } + + static final int SINGLE_MAP_CASES = 1500; + static final int MERGE_CASES = 400; + static final int MAX_ACTIONS = 40; + static final int MIN_ACTIONS = 8; + + // unbounded synthetic key spaces — large enough to grow the dense array past cap-8 several times + static final int KNOWN_SPACE = 48; + static final int CUSTOM_SPACE = 48; + + enum Regime { + KNOWN_ONLY, + CUSTOM_ONLY, + MIXED + } + + /** + * Synthetic resolver: {@code known-N} -> stored id (serial = FIRST_STORED_SERIAL + N); else 0. + */ + static final KnownTagCodec.Resolver FUZZ_RESOLVER = + new KnownTagCodec.Resolver() { + @Override + public long keyOf(String name) { + if (name.startsWith("known-")) { + int n = Integer.parseInt(name.substring("known-".length())); + return KnownTagCodec.tagId(KnownTagCodec.FIRST_STORED_SERIAL + n, name); + } + return 0L; + } + + @Override + public String nameOf(long tagId) { + int serial = KnownTagCodec.globalSerial(tagId); + return serial >= KnownTagCodec.FIRST_STORED_SERIAL + ? "known-" + (serial - KnownTagCodec.FIRST_STORED_SERIAL) + : null; + } + + @Override + public int slotCount() { + return 0; // positional unused + } + }; + + @BeforeAll + static void registerResolver() { + KnownTagCodec.register(FUZZ_RESOLVER); + assertTrue(KnownTagCodec.isActive(), "resolver must be live"); + assertTrue(KnownTagCodec.DENSE_STORE, "dense store must be enabled in this forked JVM"); + assertTrue(KnownTagCodec.routesToDense(KnownTagCodec.keyOf("known-0")), "known- routes dense"); + assertFalse( + KnownTagCodec.routesToDense(KnownTagCodec.keyOf("custom-0")), "custom- stays in buckets"); + // round-trip the synthetic encoding + long id = KnownTagCodec.keyOf("known-7"); + assertTrue("known-7".equals(KnownTagCodec.nameOf(id)), "name<->id round-trips"); + } + + @Test + void knownOnlyFuzz() { + runRegime(Regime.KNOWN_ONLY); + } + + @Test + void customOnlyFuzz() { + runRegime(Regime.CUSTOM_ONLY); + } + + @Test + void mixedFuzz() { + runRegime(Regime.MIXED); + } + + private static void runRegime(Regime regime) { + for (int i = 0; i < SINGLE_MAP_CASES; ++i) { + TagMapFuzzTest.test(generateTest(regime)); + } + for (int i = 0; i < MERGE_CASES; ++i) { + TagMap mapA = TagMapFuzzTest.test(generateTest(regime)); + TagMap mapB = TagMapFuzzTest.test(generateTest(regime)); + + HashMap hashA = new HashMap<>(mapA); + HashMap hashB = new HashMap<>(mapB); + + mapA.putAll(mapB); + hashA.putAll(hashB); + + TagMapFuzzTest.assertMapEquals(hashA, mapA); + } + } + + // --- action generation (mirrors TagMapFuzzTest.randomAction, regime-driven key pool) --- + + private static TestCase generateTest(Regime regime) { + ThreadLocalRandom r = ThreadLocalRandom.current(); + int numActions = r.nextInt(MAX_ACTIONS - MIN_ACTIONS) + MIN_ACTIONS; + List actions = new ArrayList<>(numActions); + for (int i = 0; i < numActions; ++i) { + actions.add(randomAction(regime)); + } + return new TestCase(actions); + } + + private static MapAction randomAction(Regime regime) { + switch (randomChoice(0.02, 0.1, 0.2)) { + case 0: + return TagMapFuzzTest.clear(); + case 1: + return choose( + () -> TagMapFuzzTest.putAll(randomKeysAndValues(regime)), + () -> TagMapFuzzTest.putAllTagMap(randomKeysAndValues(regime)), + () -> TagMapFuzzTest.putAllLedger(randomKeysAndValues(regime))); + case 2: + return choose( + () -> TagMapFuzzTest.remove(randomKey(regime)), + () -> TagMapFuzzTest.removeLight(randomKey(regime)), + () -> TagMapFuzzTest.getAndRemove(randomKey(regime))); + default: + return choose( + () -> TagMapFuzzTest.put(randomKey(regime), randomValue()), + () -> TagMapFuzzTest.set(randomKey(regime), randomValue()), + () -> TagMapFuzzTest.getAndSet(randomKey(regime), randomValue())); + } + } + + private static String randomKey(Regime regime) { + ThreadLocalRandom r = ThreadLocalRandom.current(); + boolean known; + switch (regime) { + case KNOWN_ONLY: + known = true; + break; + case CUSTOM_ONLY: + known = false; + break; + default: + known = r.nextBoolean(); + } + return known ? "known-" + r.nextInt(KNOWN_SPACE) : "custom-" + r.nextInt(CUSTOM_SPACE); + } + + private static String randomValue() { + return "values-" + ThreadLocalRandom.current().nextInt(); + } + + private static String[] randomKeysAndValues(Regime regime) { + int numEntries = ThreadLocalRandom.current().nextInt(KNOWN_SPACE + CUSTOM_SPACE); + String[] keysAndValues = new String[numEntries << 1]; + for (int i = 0; i < keysAndValues.length; i += 2) { + keysAndValues[i] = randomKey(regime); + keysAndValues[i + 1] = randomValue(); + } + return keysAndValues; + } + + private static int randomChoice(double... proportions) { + double selector = ThreadLocalRandom.current().nextDouble(); + for (int i = 0; i < proportions.length; ++i) { + if (selector < proportions[i]) return i; + selector -= proportions[i]; + } + return proportions.length; + } + + @SafeVarargs + private static MapAction choose(Supplier... choices) { + return choices[ThreadLocalRandom.current().nextInt(choices.length)].get(); + } +} diff --git a/metadata/supported-configurations.json b/metadata/supported-configurations.json index 6c3fe354b68..9036de0703d 100644 --- a/metadata/supported-configurations.json +++ b/metadata/supported-configurations.json @@ -5780,6 +5780,14 @@ "aliases": [] } ], + "DD_TRACE_EXPERIMENTAL_DENSE_TAGS_ENABLED": [ + { + "version": "A", + "type": "boolean", + "default": "false", + "aliases": [] + } + ], "DD_TRACE_EXPERIMENTAL_FEATURES_ENABLED": [ { "version": "A",