forked from open-telemetry/opentelemetry-go-contrib
/
parent.go
67 lines (55 loc) · 2.17 KB
/
parent.go
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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
//
// 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 consistent // import "go.opentelemetry.io/contrib/samplers/probability/consistent"
import (
"strings"
"go.opentelemetry.io/otel"
sdktrace "go.opentelemetry.io/otel/sdk/trace"
"go.opentelemetry.io/otel/trace"
)
type (
parentProbabilitySampler struct {
delegate sdktrace.Sampler
}
)
func ParentProbabilityBased(root sdktrace.Sampler, samplers ...sdktrace.ParentBasedSamplerOption) sdktrace.Sampler {
return &parentProbabilitySampler{
delegate: sdktrace.ParentBased(root, samplers...),
}
}
func (p *parentProbabilitySampler) ShouldSample(params sdktrace.SamplingParameters) sdktrace.SamplingResult {
psc := trace.SpanContextFromContext(params.ParentContext)
// Note: We do not check psc.IsValid(), i.e., we repair the tracestate
// with or without a parent TraceId and SpanId.
state := psc.TraceState()
otts, err := parseOTelTraceState(state.Get(traceStateKey), psc.IsSampled())
if err != nil {
otel.Handle(err)
value := otts.serialize()
if len(value) > 0 {
// Note: see the note in
// "go.opentelemetry.io/otel/trace".TraceState.Insert(). The
// error below is not a condition we're supposed to handle.
state, _ = state.Insert(traceStateKey, value)
} else {
state = state.Delete(traceStateKey)
}
// Fix the broken tracestate before calling the delegate.
params.ParentContext = trace.ContextWithSpanContext(params.ParentContext, psc.WithTraceState(state))
}
return p.delegate.ShouldSample(params)
}
func (p *parentProbabilitySampler) Description() string {
return "ParentProbabilityBased" + strings.TrimPrefix(p.delegate.Description(), "ParentBased")
}