remove root tag logic from format.js

Author: bengl

packages/dd-trace/src/format.js

@@ -7,17 +7,13 @@ const { isError } = require('./util')
 const { registerExtraService } = require('./service-naming/extra-services')
 
 const SAMPLING_PRIORITY_KEY = constants.SAMPLING_PRIORITY_KEY
-const SAMPLING_RULE_DECISION = constants.SAMPLING_RULE_DECISION
-const SAMPLING_LIMIT_DECISION = constants.SAMPLING_LIMIT_DECISION
-const SAMPLING_AGENT_DECISION = constants.SAMPLING_AGENT_DECISION
 const SPAN_SAMPLING_MECHANISM = constants.SPAN_SAMPLING_MECHANISM
 const SPAN_SAMPLING_RULE_RATE = constants.SPAN_SAMPLING_RULE_RATE
 const SPAN_SAMPLING_MAX_PER_SECOND = constants.SPAN_SAMPLING_MAX_PER_SECOND
 const SAMPLING_MECHANISM_SPAN = constants.SAMPLING_MECHANISM_SPAN
 const { MEASURED, BASE_SERVICE, ANALYTICS } = tags
 const ORIGIN_KEY = constants.ORIGIN_KEY
 const HOSTNAME_KEY = constants.HOSTNAME_KEY
-const TOP_LEVEL_KEY = constants.TOP_LEVEL_KEY
 const PROCESS_ID = constants.PROCESS_ID
 const ERROR_MESSAGE = constants.ERROR_MESSAGE
 const ERROR_STACK = constants.ERROR_STACK
@@ -37,7 +33,6 @@ function format (span) {
 
   extractSpanLinks(formatted, span)
   extractSpanEvents(formatted, span)
-  extractRootTags(formatted, span)
   extractTags(formatted, span)
 
   return formatted
@@ -178,19 +173,6 @@ function extractTags (formattedSpan, span) {
   addTag(formattedSpan.meta, formattedSpan.metrics, HOSTNAME_KEY, hostname)
 }
 
-function extractRootTags (formattedSpan, span) {
-  const context = span.context()
-  const isLocalRoot = span === context._trace.started[0]
-  const parentId = context._parentId
-
-  if (!isLocalRoot || (parentId && parentId.toString(10) !== '0')) return
-
-  addTag({}, formattedSpan.metrics, SAMPLING_RULE_DECISION, context._trace[SAMPLING_RULE_DECISION])
-  addTag({}, formattedSpan.metrics, SAMPLING_LIMIT_DECISION, context._trace[SAMPLING_LIMIT_DECISION])
-  addTag({}, formattedSpan.metrics, SAMPLING_AGENT_DECISION, context._trace[SAMPLING_AGENT_DECISION])
-  addTag({}, formattedSpan.metrics, TOP_LEVEL_KEY, 1)
-}
-
 function extractError (formattedSpan, error) {
   if (!error) return
 

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

@@ -3,9 +3,28 @@
 const util = require('util')
 const { AUTO_KEEP } = require('../../../../ext/priority')
 
+const {
+  SAMPLING_RULE_DECISION,
+  SAMPLING_LIMIT_DECISION,
+  SAMPLING_AGENT_DECISION,
+  TOP_LEVEL_KEY
+} = require('../constants');
+
 // the lowercase, hex encoded upper 64 bits of a 128-bit trace id, if present
 const TRACE_ID_128 = '_dd.p.tid'
 
+function getChunkRoot (self) {
+  return self._trace.started[0]?.context() || self
+}
+
+function assignRootTag (self, prop, val) {
+  const chunkRoot = getChunkRoot(self)
+  if (!chunkRoot._parentId || chunkRoot._parentId.toString(10) === '0') {
+    chunkRoot._tags[SAMPLING_RULE_DECISION] = val
+    chunkRoot._tags[TOP_LEVEL_KEY] = 1
+  }
+}
+
 class DatadogSpanContext {
   constructor (props) {
     props = props || {}
@@ -27,7 +46,16 @@ class DatadogSpanContext {
     const self = this
     this._trace = props.trace || {
       started: [],
-      finished: []
+      finished: [],
+      set [SAMPLING_RULE_DECISION] (val) {
+        assignRootTag(self, SAMPLING_RULE_DECISION, val)
+      },
+      set [SAMPLING_LIMIT_DECISION] (val) {
+        assignRootTag(self, SAMPLING_LIMIT_DECISION, val)
+      },
+      set [SAMPLING_AGENT_DECISION] (val) {
+        assignRootTag(self, SAMPLING_AGENT_DECISION, val)
+      }
     }
     if (!props.trace) {
       Object.defineProperty(this._trace, 'tags', {

packages/dd-trace/test/format.spec.js

@@ -180,35 +180,6 @@ describe('format', () => {
       expect(trace.resource).to.equal('resource')
     })
 
-    it('should extract Datadog specific root tags', () => {
-      spanContext._parentId = null
-      spanContext._trace[SAMPLING_AGENT_DECISION] = 0.8
-      spanContext._trace[SAMPLING_LIMIT_DECISION] = 0.2
-      spanContext._trace[SAMPLING_RULE_DECISION] = 0.5
-
-      trace = format(span)
-
-      expect(trace.metrics).to.include({
-        [SAMPLING_AGENT_DECISION]: 0.8,
-        [SAMPLING_LIMIT_DECISION]: 0.2,
-        [SAMPLING_RULE_DECISION]: 0.5
-      })
-    })
-
-    it('should not extract Datadog specific root tags from non-root spans', () => {
-      spanContext._trace[SAMPLING_AGENT_DECISION] = 0.8
-      spanContext._trace[SAMPLING_LIMIT_DECISION] = 0.2
-      spanContext._trace[SAMPLING_RULE_DECISION] = 0.5
-
-      trace = format(span)
-
-      expect(trace.metrics).to.not.have.keys(
-        SAMPLING_AGENT_DECISION,
-        SAMPLING_LIMIT_DECISION,
-        SAMPLING_RULE_DECISION
-      )
-    })
-
     it('should always add single span ingestion tags from options if present', () => {
       spanContext._spanSampling = {
         maxPerSecond: 5,

packages/dd-trace/test/opentracing/span_context.spec.js

@@ -70,6 +70,7 @@ describe('SpanContext', () => {
       spanId: '456'
     })
 
+    const tags = {}
     expect(spanContext).to.deep.equal({
       _traceId: '123',
       _spanId: '456',
@@ -86,6 +87,9 @@ describe('SpanContext', () => {
       _trace: {
         started: [],
         finished: [],
+        '_dd.rule_psr': undefined,
+        '_dd.limit_psr': undefined,
+        '_dd.agent_psr': undefined,
         tags: {}
       },
       _traceparent: undefined,