1 // Copyright The OpenTelemetry Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package trace // import "go.opentelemetry.io/otel/sdk/trace" 16 17 import ( 18 "context" 19 "sync" 20 ) 21 22 // SpanProcessor is a processing pipeline for spans in the trace signal. 23 // SpanProcessors registered with a TracerProvider and are called at the start 24 // and end of a Span's lifecycle, and are called in the order they are 25 // registered. 26 type SpanProcessor interface { 27 // DO NOT CHANGE: any modification will not be backwards compatible and 28 // must never be done outside of a new major release. 29 30 // OnStart is called when a span is started. It is called synchronously 31 // and should not block. 32 OnStart(parent context.Context, s ReadWriteSpan) 33 // DO NOT CHANGE: any modification will not be backwards compatible and 34 // must never be done outside of a new major release. 35 36 // OnEnd is called when span is finished. It is called synchronously and 37 // hence not block. 38 OnEnd(s ReadOnlySpan) 39 // DO NOT CHANGE: any modification will not be backwards compatible and 40 // must never be done outside of a new major release. 41 42 // Shutdown is called when the SDK shuts down. Any cleanup or release of 43 // resources held by the processor should be done in this call. 44 // 45 // Calls to OnStart, OnEnd, or ForceFlush after this has been called 46 // should be ignored. 47 // 48 // All timeouts and cancellations contained in ctx must be honored, this 49 // should not block indefinitely. 50 Shutdown(ctx context.Context) error 51 // DO NOT CHANGE: any modification will not be backwards compatible and 52 // must never be done outside of a new major release. 53 54 // ForceFlush exports all ended spans to the configured Exporter that have not yet 55 // been exported. It should only be called when absolutely necessary, such as when 56 // using a FaaS provider that may suspend the process after an invocation, but before 57 // the Processor can export the completed spans. 58 ForceFlush(ctx context.Context) error 59 // DO NOT CHANGE: any modification will not be backwards compatible and 60 // must never be done outside of a new major release. 61 } 62 63 type spanProcessorState struct { 64 sp SpanProcessor 65 state sync.Once 66 } 67 68 func newSpanProcessorState(sp SpanProcessor) *spanProcessorState { 69 return &spanProcessorState{sp: sp} 70 } 71 72 type spanProcessorStates []*spanProcessorState 73