chore: rename CorrelationContext to Baggage (open-telemetry#1687)

* chore: rename CorrelationContext to Baggage

* chore: lint

api/src/correlation_context/CorrelationContext.ts → api/src/baggage/Baggage.ts

@@ -17,13 +17,13 @@
 import { EntryValue } from './EntryValue';
 
 /**
- * CorrelationContext represents collection of entries. Each key of
- * CorrelationContext is associated with exactly one value. CorrelationContext
+ * Baggage represents collection of entries. Each key of
+ * Baggage is associated with exactly one value. Baggage
  * is serializable, to facilitate propagating it not only inside the process
- * but also across process boundaries. CorrelationContext is used to annotate
+ * but also across process boundaries. Baggage is used to annotate
  * telemetry with the name:value pair Entry. Those values can be used to add
  * dimension to the metric or additional contest properties to logs and traces.
  */
-export interface CorrelationContext {
+export interface Baggage {
   [entryKey: string]: EntryValue;
 }

api/src/context/context.ts

@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-import { NoopSpan, Span, SpanContext } from '../';
 import { Context, createContextKey } from '@opentelemetry/context-base';
+import { Baggage, NoopSpan, Span, SpanContext } from '../';
 
 /**
  * Active span key
@@ -32,6 +32,11 @@ const SUPPRESS_INSTRUMENTATION_KEY = createContextKey(
   'OpenTelemetry Context Key SUPPRESS_INSTRUMENTATION'
 );
 
+/**
+ * Baggage key
+ */
+const BAGGAGE_KEY = createContextKey('OpenTelemetry Baggage Key');
+
 /**
  * Return the active span if one exists
  *
@@ -107,3 +112,19 @@ export function unsuppressInstrumentation(context: Context): Context {
 export function isInstrumentationSuppressed(context: Context): boolean {
   return Boolean(context.getValue(SUPPRESS_INSTRUMENTATION_KEY));
 }
+
+/**
+ * @param {Context} Context that manage all context values
+ * @returns {Baggage} Extracted baggage from the context
+ */
+export function getBaggage(context: Context): Baggage | undefined {
+  return (context.getValue(BAGGAGE_KEY) as Baggage) || undefined;
+}
+
+/**
+ * @param {Context} Context that manage all context values
+ * @param {Baggage} baggage that will be set in the actual context
+ */
+export function setBaggage(context: Context, baggage: Baggage): Context {
+  return context.setValue(BAGGAGE_KEY, baggage);
+}

api/src/index.ts

@@ -20,8 +20,8 @@ export * from './common/Time';
 export * from './context/context';
 export * from './context/propagation/TextMapPropagator';
 export * from './context/propagation/NoopTextMapPropagator';
-export * from './correlation_context/CorrelationContext';
-export * from './correlation_context/EntryValue';
+export * from './baggage/Baggage';
+export * from './baggage/EntryValue';
 export * from './metrics/BatchObserverResult';
 export * from './metrics/BoundInstrument';
 export * from './metrics/Meter';

api/src/metrics/NoopMeter.ts

@@ -33,7 +33,7 @@ import {
   BoundCounter,
   BoundBaseObserver,
 } from './BoundInstrument';
-import { CorrelationContext } from '../correlation_context/CorrelationContext';
+import { Baggage } from '../baggage/Baggage';
 import { SpanContext } from '../trace/span_context';
 import { ObserverResult } from './ObserverResult';
 
@@ -198,11 +198,7 @@ export class NoopBoundCounter implements BoundCounter {
 }
 
 export class NoopBoundValueRecorder implements BoundValueRecorder {
-  record(
-    _value: number,
-    _correlationContext?: CorrelationContext,
-    _spanContext?: SpanContext
-  ): void {
+  record(_value: number, _baggage?: Baggage, _spanContext?: SpanContext): void {
     return;
   }
 }

api/src/trace/span_context.ts

@@ -18,7 +18,7 @@ import { TraceState } from './trace_state';
 
 /**
  * A SpanContext represents the portion of a {@link Span} which must be
- * serialized and propagated along side of a {@link CorrelationContext}.
+ * serialized and propagated along side of a {@link Baggage}.
  */
 export interface SpanContext {
   /**