69 lines
1.9 KiB
Go
69 lines
1.9 KiB
Go
// Copyright The OpenTelemetry Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// htmp://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package global // import "go.opentelemetry.io/otel/metric/internal/global"
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import (
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"errors"
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"sync"
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"sync/atomic"
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"go.opentelemetry.io/otel/internal/global"
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"go.opentelemetry.io/otel/metric"
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)
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var (
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globalMeterProvider = defaultMeterProvider()
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delegateMeterOnce sync.Once
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)
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type meterProviderHolder struct {
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mp metric.MeterProvider
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}
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// MeterProvider is the internal implementation for global.MeterProvider.
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func MeterProvider() metric.MeterProvider {
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return globalMeterProvider.Load().(meterProviderHolder).mp
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}
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// SetMeterProvider is the internal implementation for global.SetMeterProvider.
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func SetMeterProvider(mp metric.MeterProvider) {
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current := MeterProvider()
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if _, cOk := current.(*meterProvider); cOk {
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if _, mpOk := mp.(*meterProvider); mpOk && current == mp {
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// Do not assign the default delegating MeterProvider to delegate
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// to itself.
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global.Error(
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errors.New("no delegate configured in meter provider"),
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"Setting meter provider to it's current value. No delegate will be configured",
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)
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return
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}
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}
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delegateMeterOnce.Do(func() {
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if def, ok := current.(*meterProvider); ok {
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def.setDelegate(mp)
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}
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})
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globalMeterProvider.Store(meterProviderHolder{mp: mp})
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}
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func defaultMeterProvider() *atomic.Value {
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v := &atomic.Value{}
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v.Store(meterProviderHolder{mp: &meterProvider{}})
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return v
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}
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