forgejo/vendor/go.opentelemetry.io/otel/internal/global/propagator.go
6543 ac97ea573c
[Vendor] Update go-redis to v8.5.0 (#13749)
* Update go-redis to v8.4.0

* github.com/go-redis/redis/v8  v8.4.0 -> v8.5.0

* Apply suggestions from code review

Co-authored-by: zeripath <art27@cantab.net>

* TODO

* Use the Queue termination channel as the default context for pushes

Signed-off-by: Andrew Thornton <art27@cantab.net>

* missed one

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: zeripath <art27@cantab.net>
2021-02-10 21:28:32 +00:00

83 lines
2.6 KiB
Go
Vendored

// 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 global
import (
"context"
"sync"
"go.opentelemetry.io/otel/propagation"
)
// 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 propagation.TextMapPropagator.
type textMapPropagator struct {
mtx sync.Mutex
once sync.Once
delegate propagation.TextMapPropagator
noop propagation.TextMapPropagator
}
// Compile-time guarantee that textMapPropagator implements the
// propagation.TextMapPropagator interface.
var _ propagation.TextMapPropagator = (*textMapPropagator)(nil)
func newTextMapPropagator() *textMapPropagator {
return &textMapPropagator{
noop: propagation.NewCompositeTextMapPropagator(),
}
}
// SetDelegate sets a delegate propagation.TextMapPropagator that all calls are
// forwarded to. Delegation can only be performed once, all subsequent calls
// perform no delegation.
func (p *textMapPropagator) SetDelegate(delegate propagation.TextMapPropagator) {
if delegate == nil {
return
}
p.mtx.Lock()
p.once.Do(func() { p.delegate = delegate })
p.mtx.Unlock()
}
// effectiveDelegate returns the current delegate of p if one is set,
// otherwise the default noop TextMapPropagator is returned. This method
// can be called concurrently.
func (p *textMapPropagator) effectiveDelegate() propagation.TextMapPropagator {
p.mtx.Lock()
defer p.mtx.Unlock()
if p.delegate != nil {
return p.delegate
}
return p.noop
}
// Inject set cross-cutting concerns from the Context into the carrier.
func (p *textMapPropagator) Inject(ctx context.Context, carrier propagation.TextMapCarrier) {
p.effectiveDelegate().Inject(ctx, carrier)
}
// Extract reads cross-cutting concerns from the carrier into a Context.
func (p *textMapPropagator) Extract(ctx context.Context, carrier propagation.TextMapCarrier) context.Context {
return p.effectiveDelegate().Extract(ctx, carrier)
}
// Fields returns the keys whose values are set with Inject.
func (p *textMapPropagator) Fields() []string {
return p.effectiveDelegate().Fields()
}