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- /*
- * Copyright The OpenTelemetry Authors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- import { validateKey, validateValue } from './tracestate-validators';
- const MAX_TRACE_STATE_ITEMS = 32;
- const MAX_TRACE_STATE_LEN = 512;
- const LIST_MEMBERS_SEPARATOR = ',';
- const LIST_MEMBER_KEY_VALUE_SPLITTER = '=';
- /**
- * TraceState must be a class and not a simple object type because of the spec
- * requirement (https://www.w3.org/TR/trace-context/#tracestate-field).
- *
- * Here is the list of allowed mutations:
- * - New key-value pair should be added into the beginning of the list
- * - The value of any key can be updated. Modified keys MUST be moved to the
- * beginning of the list.
- */
- export class TraceStateImpl {
- constructor(rawTraceState) {
- this._internalState = new Map();
- if (rawTraceState)
- this._parse(rawTraceState);
- }
- set(key, value) {
- // TODO: Benchmark the different approaches(map vs list) and
- // use the faster one.
- const traceState = this._clone();
- if (traceState._internalState.has(key)) {
- traceState._internalState.delete(key);
- }
- traceState._internalState.set(key, value);
- return traceState;
- }
- unset(key) {
- const traceState = this._clone();
- traceState._internalState.delete(key);
- return traceState;
- }
- get(key) {
- return this._internalState.get(key);
- }
- serialize() {
- return this._keys()
- .reduce((agg, key) => {
- agg.push(key + LIST_MEMBER_KEY_VALUE_SPLITTER + this.get(key));
- return agg;
- }, [])
- .join(LIST_MEMBERS_SEPARATOR);
- }
- _parse(rawTraceState) {
- if (rawTraceState.length > MAX_TRACE_STATE_LEN)
- return;
- this._internalState = rawTraceState
- .split(LIST_MEMBERS_SEPARATOR)
- .reverse() // Store in reverse so new keys (.set(...)) will be placed at the beginning
- .reduce((agg, part) => {
- const listMember = part.trim(); // Optional Whitespace (OWS) handling
- const i = listMember.indexOf(LIST_MEMBER_KEY_VALUE_SPLITTER);
- if (i !== -1) {
- const key = listMember.slice(0, i);
- const value = listMember.slice(i + 1, part.length);
- if (validateKey(key) && validateValue(value)) {
- agg.set(key, value);
- }
- else {
- // TODO: Consider to add warning log
- }
- }
- return agg;
- }, new Map());
- // Because of the reverse() requirement, trunc must be done after map is created
- if (this._internalState.size > MAX_TRACE_STATE_ITEMS) {
- this._internalState = new Map(Array.from(this._internalState.entries())
- .reverse() // Use reverse same as original tracestate parse chain
- .slice(0, MAX_TRACE_STATE_ITEMS));
- }
- }
- _keys() {
- return Array.from(this._internalState.keys()).reverse();
- }
- _clone() {
- const traceState = new TraceStateImpl();
- traceState._internalState = new Map(this._internalState);
- return traceState;
- }
- }
- //# sourceMappingURL=tracestate-impl.js.map
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