Emit span IDs in profiles as 64-bit numbers instead of as strings. (#6281)

This significantly reduces the maximum memory use of profile serializations.

Author: szegedi

integration-tests/profiler/profiler.spec.js

@@ -389,8 +389,8 @@ describe('profiler', () => {
         for (const label of sample.label) {
           switch (label.key) {
             case tsKey: ts = label.num; break
-            case spanKey: spanId = label.str; break
-            case rootSpanKey: rootSpanId = label.str; break
+            case spanKey: spanId = label.num; break
+            case rootSpanKey: rootSpanId = label.num; break
             case endpointKey: endpoint = label.str; break
             case threadNameKey: threadName = label.str; break
             case threadIdKey: threadId = label.str; break

packages/dd-trace/src/opentracing/span_context.js

@@ -59,6 +59,10 @@ class DatadogSpanContext {
     return this._spanId.toString(10)
   }
 
+  toBigIntSpanId () {
+    return this._spanId.toBigInt()
+  }
+
   toTraceparent () {
     const flags = this._sampling.priority >= AUTO_KEEP ? '01' : '00'
     const traceId = this.toTraceId(true)

packages/dd-trace/src/profiling/profilers/event_plugins/event.js

@@ -52,8 +52,8 @@ class EventPlugin extends TracingPlugin {
     }
 
     const context = (ctx.currentStore?.span || this.activeSpan)?.context()
-    event._ddSpanId = context?.toSpanId()
-    event._ddRootSpanId = context?._trace.started[0]?.context().toSpanId() || event._ddSpanId
+    event._ddSpanId = context?.toBigIntSpanId()
+    event._ddRootSpanId = context?._trace.started[0]?.context().toBigIntSpanId() || event._ddSpanId
 
     this.#eventHandler(this.extendEvent(event, ctx))
   }

packages/dd-trace/src/profiling/profilers/events.js

@@ -273,10 +273,11 @@ class EventSerializer {
       new Label({ key: this.timestampLabelKey, num: dateOffset + BigInt(Math.round(endTime * MS_TO_NS)) })
     ]
     if (_ddSpanId) {
-      label.push(labelFromStr(this.stringTable, this.spanIdKey, _ddSpanId))
+      label.push(
+        new Label({ key: this.spanIdKey, num: _ddSpanId }))
     }
     if (_ddRootSpanId) {
-      label.push(labelFromStr(this.stringTable, this.rootSpanIdKey, _ddRootSpanId))
+      label.push(new Label({ key: this.rootSpanIdKey, num: _ddRootSpanId }))
     }
 
     const sampleInput = {

packages/dd-trace/src/profiling/profilers/wall.js

@@ -215,10 +215,10 @@ class NativeWallProfiler {
 
   _updateContext (context) {
     if (context.spanId !== null && typeof context.spanId === 'object') {
-      context.spanId = context.spanId.toString(10)
+      context.spanId = context.spanId.toBigInt()
     }
     if (context.rootSpanId !== null && typeof context.rootSpanId === 'object') {
-      context.rootSpanId = context.rootSpanId.toString(10)
+      context.rootSpanId = context.rootSpanId.toBigInt()
     }
     if (context.webTags !== undefined && context.endpoint === undefined) {
       // endpoint may not be determined yet, but keep it as fallback

packages/dd-trace/test/profiling/profilers/events.spec.js

@@ -17,7 +17,7 @@ describe('profilers/events', () => {
     // Set up a mock span to simulate tracing context
     const span = {
       context: () => ({
-        toSpanId: () => '1234',
+        toBigIntSpanId: () => 1234n,
         _trace: {
           started: [span]
         }