-
Notifications
You must be signed in to change notification settings - Fork 1k
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Add delegating global propagator (#1258)
* Add delegating global propagator * Add Changes to CHANGELOG * Add PR number to CHANGELOG * Add tests using new test framework * Revert "Add tests using new test framework" This reverts commit af7ae17.
- Loading branch information
Showing
3 changed files
with
107 additions
and
9 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,86 @@ | ||
// 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 | ||
// | ||
// http://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. | ||
|
||
package internal | ||
|
||
import ( | ||
"context" | ||
"sync" | ||
|
||
"go.opentelemetry.io/otel" | ||
) | ||
|
||
// textMapPropagator is a default TextMapPropagator that delegates calls to a | ||
// registered delegate if one is set, otherwise it defaults to delegating the | ||
// calls to a the default no-op otel.TextMapPropagator. | ||
type textMapPropagator struct { | ||
mtx sync.Mutex | ||
once sync.Once | ||
delegate otel.TextMapPropagator | ||
noop otel.TextMapPropagator | ||
} | ||
|
||
// Compile-time guarantee that textMapPropagator implements the | ||
// otel.TextMapPropagator interface. | ||
var _ otel.TextMapPropagator = (*textMapPropagator)(nil) | ||
|
||
func newTextMapPropagator() *textMapPropagator { | ||
return &textMapPropagator{ | ||
noop: otel.NewCompositeTextMapPropagator(), | ||
} | ||
} | ||
|
||
// SetDelegate sets a delegate otel.TextMapPropagator that all calls are | ||
// forwarded to. Delegation can only be performed once, all subsequent calls | ||
// perform no delegation. | ||
func (p *textMapPropagator) SetDelegate(delegate otel.TextMapPropagator) { | ||
if delegate == nil { | ||
return | ||
} | ||
|
||
p.mtx.Lock() | ||
p.once.Do(func() { p.delegate = delegate }) | ||
p.mtx.Unlock() | ||
} | ||
|
||
// HasDelegate returns if a delegate is set for p. | ||
func (p *textMapPropagator) HasDelegate() bool { | ||
p.mtx.Lock() | ||
defer p.mtx.Unlock() | ||
return p.delegate != nil | ||
} | ||
|
||
// Inject set cross-cutting concerns from the Context into the carrier. | ||
func (p *textMapPropagator) Inject(ctx context.Context, carrier otel.TextMapCarrier) { | ||
if p.HasDelegate() { | ||
p.delegate.Inject(ctx, carrier) | ||
} | ||
p.noop.Inject(ctx, carrier) | ||
} | ||
|
||
// Extract reads cross-cutting concerns from the carrier into a Context. | ||
func (p *textMapPropagator) Extract(ctx context.Context, carrier otel.TextMapCarrier) context.Context { | ||
if p.HasDelegate() { | ||
return p.delegate.Extract(ctx, carrier) | ||
} | ||
return p.noop.Extract(ctx, carrier) | ||
} | ||
|
||
// Fields returns the keys who's values are set with Inject. | ||
func (p *textMapPropagator) Fields() []string { | ||
if p.HasDelegate() { | ||
return p.delegate.Fields() | ||
} | ||
return p.noop.Fields() | ||
} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters