@opentelemetry/core
Version:
OpenTelemetry Core provides constants and utilities shared by all OpenTelemetry SDK packages.
88 lines • 3.84 kB
JavaScript
/*
* Copyright The OpenTelemetry Authors
* SPDX-License-Identifier: Apache-2.0
*/
import { isSpanContextValid, trace, TraceFlags } from '@opentelemetry/api';
import { isTracingSuppressed } from './suppress-tracing';
import { TraceState } from './TraceState';
export const TRACE_PARENT_HEADER = 'traceparent';
export const TRACE_STATE_HEADER = 'tracestate';
const VERSION = '00';
const VERSION_PART = '(?!ff)[\\da-f]{2}';
const TRACE_ID_PART = '(?![0]{32})[\\da-f]{32}';
const PARENT_ID_PART = '(?![0]{16})[\\da-f]{16}';
const FLAGS_PART = '[\\da-f]{2}';
const TRACE_PARENT_REGEX = new RegExp(`^\\s?(${VERSION_PART})-(${TRACE_ID_PART})-(${PARENT_ID_PART})-(${FLAGS_PART})(-.*)?\\s?$`);
/**
* Parses information from the [traceparent] span tag and converts it into {@link SpanContext}
* @param traceParent - A meta property that comes from server.
* It should be dynamically generated server side to have the server's request trace Id,
* a parent span Id that was set on the server's request span,
* and the trace flags to indicate the server's sampling decision
* (01 = sampled, 00 = not sampled).
* for example: '{version}-{traceId}-{spanId}-{sampleDecision}'
* For more information see {@link https://www.w3.org/TR/trace-context/}
*/
export function parseTraceParent(traceParent) {
const match = TRACE_PARENT_REGEX.exec(traceParent);
if (!match)
return null;
// According to the specification the implementation should be compatible
// with future versions. If there are more parts, we only reject it if it's using version 00
// See https://www.w3.org/TR/trace-context/#versioning-of-traceparent
if (match[1] === '00' && match[5])
return null;
return {
traceId: match[2],
spanId: match[3],
traceFlags: parseInt(match[4], 16),
};
}
/**
* Propagates {@link SpanContext} through Trace Context format propagation.
*
* Based on the Trace Context specification:
* https://www.w3.org/TR/trace-context/
*/
export class W3CTraceContextPropagator {
inject(context, carrier, setter) {
const spanContext = trace.getSpanContext(context);
if (!spanContext ||
isTracingSuppressed(context) ||
!isSpanContextValid(spanContext))
return;
const traceParent = `${VERSION}-${spanContext.traceId}-${spanContext.spanId}-0${Number(spanContext.traceFlags || TraceFlags.NONE).toString(16)}`;
setter.set(carrier, TRACE_PARENT_HEADER, traceParent);
if (spanContext.traceState) {
setter.set(carrier, TRACE_STATE_HEADER, spanContext.traceState.serialize());
}
}
extract(context, carrier, getter) {
const traceParentHeader = getter.get(carrier, TRACE_PARENT_HEADER);
if (!traceParentHeader)
return context;
const traceParent = Array.isArray(traceParentHeader)
? traceParentHeader[0]
: traceParentHeader;
if (typeof traceParent !== 'string')
return context;
const spanContext = parseTraceParent(traceParent);
if (!spanContext)
return context;
spanContext.isRemote = true;
const traceStateHeader = getter.get(carrier, TRACE_STATE_HEADER);
if (traceStateHeader) {
// If more than one `tracestate` header is found, we merge them into a
// single header.
const state = Array.isArray(traceStateHeader)
? traceStateHeader.join(',')
: traceStateHeader;
spanContext.traceState = new TraceState(typeof state === 'string' ? state : undefined);
}
return trace.setSpanContext(context, spanContext);
}
fields() {
return [TRACE_PARENT_HEADER, TRACE_STATE_HEADER];
}
}
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