refactor(propagation): Parse OpenTelemetry tracestate member #12405
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,30 @@ | ||
| package datadog.trace.core.propagation.ptags; | ||
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| final class OtelTraceState { | ||
| private final String value; | ||
| private final int inheritedPosition; | ||
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| private OtelTraceState(String value, int inheritedPosition) { | ||
| this.value = value; | ||
| this.inheritedPosition = inheritedPosition; | ||
| } | ||
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| static OtelTraceState parse(String raw, int inheritedPosition) { | ||
| if (raw == null || raw.isEmpty()) { | ||
| return null; | ||
| } | ||
| return new OtelTraceState(raw, inheritedPosition); | ||
| } | ||
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| String getValue() { | ||
| return value; | ||
| } | ||
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| int length() { | ||
| return value.length(); | ||
| } | ||
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| int getInheritedPosition() { | ||
| return inheritedPosition; | ||
| } | ||
| } |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
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@@ -21,6 +21,7 @@ public class W3CPTagsCodec extends PTagsCodec { | |
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| private static final int MAX_HEADER_SIZE = 256; | ||
| private static final String DATADOG_MEMBER_KEY = "dd="; | ||
| private static final String OTEL_MEMBER_KEY = "ot="; | ||
| private static final int EMPTY_SIZE = DATADOG_MEMBER_KEY.length(); // 3 | ||
| private static final char MEMBER_SEPARATOR = ','; | ||
| private static final char ELEMENT_SEPARATOR = ';'; | ||
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@@ -49,13 +50,19 @@ PropagationTags fromHeaderValue(PTagsFactory tagsFactory, String value) { | |
| int ddMemberValueEnd = -1; // dd member value end position including OWS (exclusive) | ||
| int memberIndex = 0; | ||
| int ddMemberIndex = -1; | ||
| int otelMemberValueStart = -1; | ||
| int otelMemberValueEnd = -1; | ||
| int otelMemberPosition = 0; | ||
| int otherMemberPosition = 0; | ||
| while (memberStart < len) { | ||
| if (memberIndex == MAX_MEMBER_COUNT) { | ||
| // TODO should we return one with an error? | ||
| // TODO should we try to pick up the `dd` member anyway? | ||
| return tagsFactory.empty(); | ||
| } | ||
| boolean datadogMember = value.startsWith(DATADOG_MEMBER_KEY, memberStart); | ||
| boolean otelMember = value.startsWith(OTEL_MEMBER_KEY, memberStart); | ||
| if (ddMemberIndex == -1 && datadogMember) { | ||
| ddMemberStart = memberStart; | ||
| ddMemberIndex = memberIndex; | ||
| } | ||
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@@ -68,6 +75,7 @@ PropagationTags fromHeaderValue(PTagsFactory tagsFactory, String value) { | |
| if (ddMemberValueStart == -1 && ddMemberIndex != -1) { | ||
| ddMemberValueStart = pos; | ||
| } | ||
| int memberValueStart = pos; | ||
| pos = validateMemberValue(value, pos); | ||
| if (pos < 0) { | ||
| // TODO should we return one with an error? | ||
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@@ -76,6 +84,15 @@ PropagationTags fromHeaderValue(PTagsFactory tagsFactory, String value) { | |
| if (ddMemberValueEnd == -1 && ddMemberIndex != -1) { | ||
| ddMemberValueEnd = pos; | ||
| } | ||
| if (otelMemberValueStart == -1) { | ||
| if (otelMember) { | ||
| otelMemberValueStart = memberValueStart; | ||
| otelMemberValueEnd = stripTrailingOWC(value, memberValueStart, pos); | ||
| otelMemberPosition = otherMemberPosition; | ||
| } else if (!datadogMember) { | ||
| otherMemberPosition++; | ||
| } | ||
| } | ||
| memberStart = findNextMember(value, pos); | ||
| if (memberStart < 0) { | ||
| // TODO should we return one with an error? | ||
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@@ -84,9 +101,15 @@ PropagationTags fromHeaderValue(PTagsFactory tagsFactory, String value) { | |
| memberIndex++; | ||
| } | ||
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| OtelTraceState otelTraceState = | ||
| otelMemberValueStart < 0 | ||
| ? null | ||
| : OtelTraceState.parse( | ||
| value.substring(otelMemberValueStart, otelMemberValueEnd), otelMemberPosition); | ||
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| if (ddMemberIndex == -1) { | ||
| // There was no dd member, so create an empty one with the _suffix_ | ||
| return empty(tagsFactory, value, otelTraceState); | ||
| } | ||
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| List<TagElement> tagPairs = null; | ||
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@@ -158,7 +181,13 @@ PropagationTags fromHeaderValue(PTagsFactory tagsFactory, String value) { | |
| if (tagKey.equals(TRACE_ID_TAG)) { | ||
| return tagsFactory.createInvalid(PROPAGATION_ERROR_MALFORMED_TID + tagValue); | ||
| } | ||
| return empty( | ||
| tagsFactory, | ||
| value, | ||
| firstMemberStart, | ||
| ddMemberStart, | ||
| ddMemberValueEnd, | ||
| otelTraceState); | ||
| } | ||
| if (tagKey.equals(DECISION_MAKER_TAG)) { | ||
| decisionMakerTagValue = tagValue; | ||
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@@ -201,7 +230,8 @@ PropagationTags fromHeaderValue(PTagsFactory tagsFactory, String value) { | |
| ddMemberValueEnd, | ||
| maxUnknownSize, | ||
| lastParentId, | ||
| orgPropagationMarkerTagValue, | ||
| otelTraceState); | ||
| } | ||
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| @Override | ||
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@@ -226,6 +256,10 @@ protected int estimateHeaderSize(PTags pTags) { | |
| // We assume there is no Datadog list-member | ||
| size += pTags.tracestate.length(); | ||
| } | ||
| OtelTraceState otelTraceState = pTags.getOtelTraceState(); | ||
| if (otelTraceState != null) { | ||
| size += OTEL_MEMBER_KEY.length() + otelTraceState.length() + 1; | ||
|
Comment on lines
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perf: When the original tracestate length is already included above—either for a parsed AGENTS.md reference: AGENTS.md:L76-L79 Useful? React with 👍 / 👎. |
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| } | ||
| return size; | ||
| } | ||
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@@ -290,9 +324,8 @@ protected int appendSuffix(StringBuilder sb, PTags ptags, int size) { | |
| sb.setLength(0); | ||
| size = 0; | ||
| } | ||
| // Append the managed OTel member and all other non-Datadog list-members | ||
| if (appendOtelAndVendorMembers(sb, ptags, size != 0)) { | ||
| // We don't care about the total size in bytes here, but only the fact that we added something | ||
| // that should be returned | ||
| size = Math.max(size, EMPTY_SIZE + 1); | ||
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@@ -698,58 +731,113 @@ private static int cleanUpAndAppendUnknown(StringBuilder sb, W3CPTags w3CPTags, | |
| return size; | ||
| } | ||
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| private static boolean appendOtelAndVendorMembers( | ||
| StringBuilder sb, PTags ptags, boolean hasDatadogMember) { | ||
| String original = ptags.tracestate; | ||
| OtelTraceState otelTraceState = ptags.getOtelTraceState(); | ||
| int remainingMembers = MAX_MEMBER_COUNT - (hasDatadogMember ? 1 : 0); | ||
| int otherMemberPosition = 0; | ||
| boolean otelTraceStateAppended = false; | ||
| boolean memberAppended = false; | ||
| int len = original == null ? 0 : original.length(); | ||
| int memberStart = original == null ? 0 : findNextMember(original, 0); | ||
| while (memberStart < len && remainingMembers > 0) { | ||
| // Look for member end position | ||
| int memberEnd = original.indexOf(MEMBER_SEPARATOR, memberStart); | ||
| if (memberEnd < 0) { | ||
| memberEnd = len; | ||
| } | ||
| boolean managedMember = | ||
| original.startsWith(DATADOG_MEMBER_KEY, memberStart) | ||
| || original.startsWith(OTEL_MEMBER_KEY, memberStart); | ||
| if (!managedMember) { | ||
| if (otelTraceState != null | ||
| && !otelTraceStateAppended | ||
| && otelTraceState.getInheritedPosition() == otherMemberPosition) { | ||
| appendMember(sb, OTEL_MEMBER_KEY, otelTraceState.getValue()); | ||
| remainingMembers--; | ||
| otelTraceStateAppended = true; | ||
| memberAppended = true; | ||
| if (remainingMembers == 0) { | ||
| break; | ||
| } | ||
| } | ||
| int end = stripTrailingOWC(original, memberStart, memberEnd); | ||
| appendMember(sb, original, memberStart, end); | ||
| remainingMembers--; | ||
| otherMemberPosition++; | ||
| memberAppended = true; | ||
| } | ||
| memberStart = findNextMember(original, memberEnd + 1); | ||
| } | ||
| if (otelTraceState != null | ||
| && !otelTraceStateAppended | ||
| && remainingMembers > 0 | ||
| && otelTraceState.getInheritedPosition() == otherMemberPosition) { | ||
| appendMember(sb, OTEL_MEMBER_KEY, otelTraceState.getValue()); | ||
| memberAppended = true; | ||
| } | ||
| return memberAppended; | ||
| } | ||
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| private static void appendMember(StringBuilder sb, String member, int start, int end) { | ||
| if (sb.length() != 0) { | ||
| sb.append(MEMBER_SEPARATOR); | ||
| } | ||
| sb.append(member, start, end); | ||
| } | ||
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| private static void appendMember(StringBuilder sb, String key, String value) { | ||
| if (sb.length() != 0) { | ||
| sb.append(MEMBER_SEPARATOR); | ||
| } | ||
| sb.append(key).append(value); | ||
| } | ||
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| static OtelTraceState extractOtelTraceState(String tracestate) { | ||
| if (tracestate == null || tracestate.isEmpty()) { | ||
| return null; | ||
| } | ||
| int otherMemberPosition = 0; | ||
| int memberStart = findNextMember(tracestate, 0); | ||
| while (memberStart < tracestate.length()) { | ||
| int memberValueStart = validateMemberKey(tracestate, memberStart); | ||
| if (memberValueStart < 0) { | ||
| return null; | ||
| } | ||
| int memberValueEnd = validateMemberValue(tracestate, memberValueStart); | ||
| if (memberValueEnd < 0) { | ||
| return null; | ||
| } | ||
| if (tracestate.startsWith(OTEL_MEMBER_KEY, memberStart)) { | ||
| int end = stripTrailingOWC(tracestate, memberValueStart, memberValueEnd); | ||
| return OtelTraceState.parse( | ||
| tracestate.substring(memberValueStart, end), otherMemberPosition); | ||
| } | ||
| if (!tracestate.startsWith(DATADOG_MEMBER_KEY, memberStart)) { | ||
| otherMemberPosition++; | ||
| } | ||
| memberStart = findNextMember(tracestate, memberValueEnd); | ||
| } | ||
| return null; | ||
| } | ||
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| static W3CPTags empty(PTagsFactory factory, String original) { | ||
| return empty(factory, original, extractOtelTraceState(original)); | ||
| } | ||
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| private static W3CPTags empty( | ||
| PTagsFactory factory, String original, OtelTraceState otelTraceState) { | ||
| return empty(factory, original, 0, -1, -1, otelTraceState); | ||
| } | ||
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| private static W3CPTags empty( | ||
| PTagsFactory factory, | ||
| String original, | ||
| int firstMemberStart, | ||
| int ddMemberStart, | ||
| int ddMemberValueEnd, | ||
| OtelTraceState otelTraceState) { | ||
| return new W3CPTags( | ||
| factory, | ||
| null, | ||
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@@ -764,7 +852,8 @@ private static W3CPTags empty( | |
| ddMemberValueEnd, | ||
| 0, | ||
| null, | ||
| null, | ||
| otelTraceState); | ||
| } | ||
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| private static class W3CPTags extends PTags { | ||
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@@ -799,7 +888,8 @@ public W3CPTags( | |
| int ddMemberValueEnd, | ||
| int maxUnknownSize, | ||
| CharSequence lastParentId, | ||
| TagValue orgPropagationMarkerTagValue, | ||
| OtelTraceState otelTraceState) { | ||
| super( | ||
| factory, | ||
| tagPairs, | ||
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@@ -815,6 +905,7 @@ public W3CPTags( | |
| this.ddMemberStart = ddMemberStart; | ||
| this.ddMemberValueEnd = ddMemberValueEnd; | ||
| this.maxUnknownSize = maxUnknownSize; | ||
| setOtelTraceState(otelTraceState); | ||
| } | ||
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| @Override | ||
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perf: With the default
DATADOG,TRACECONTEXTextraction order, matching Datadog and W3C headers causefromHeaderValueto parse the tracestate beforeHttpCodec.applyTraceContextToFirstContextpasses the same string here. CallingextractOtelTraceStatethen validates and scans it again—and allocates another substring/state whenotis present—on the inbound request path. Transfer the already-parsed state with the propagation tags instead of reparsing the raw header.AGENTS.md reference: AGENTS.md:L76-L79
Useful? React with 👍 / 👎.