diff options
Diffstat (limited to 'vendor/github.com/opentracing/opentracing-go/noop.go')
-rw-r--r-- | vendor/github.com/opentracing/opentracing-go/noop.go | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/vendor/github.com/opentracing/opentracing-go/noop.go b/vendor/github.com/opentracing/opentracing-go/noop.go new file mode 100644 index 00000000..f9b680a2 --- /dev/null +++ b/vendor/github.com/opentracing/opentracing-go/noop.go @@ -0,0 +1,64 @@ +package opentracing + +import "github.com/opentracing/opentracing-go/log" + +// A NoopTracer is a trivial, minimum overhead implementation of Tracer +// for which all operations are no-ops. +// +// The primary use of this implementation is in libraries, such as RPC +// frameworks, that make tracing an optional feature controlled by the +// end user. A no-op implementation allows said libraries to use it +// as the default Tracer and to write instrumentation that does +// not need to keep checking if the tracer instance is nil. +// +// For the same reason, the NoopTracer is the default "global" tracer +// (see GlobalTracer and SetGlobalTracer functions). +// +// WARNING: NoopTracer does not support baggage propagation. +type NoopTracer struct{} + +type noopSpan struct{} +type noopSpanContext struct{} + +var ( + defaultNoopSpanContext SpanContext = noopSpanContext{} + defaultNoopSpan Span = noopSpan{} + defaultNoopTracer Tracer = NoopTracer{} +) + +const ( + emptyString = "" +) + +// noopSpanContext: +func (n noopSpanContext) ForeachBaggageItem(handler func(k, v string) bool) {} + +// noopSpan: +func (n noopSpan) Context() SpanContext { return defaultNoopSpanContext } +func (n noopSpan) SetBaggageItem(key, val string) Span { return n } +func (n noopSpan) BaggageItem(key string) string { return emptyString } +func (n noopSpan) SetTag(key string, value interface{}) Span { return n } +func (n noopSpan) LogFields(fields ...log.Field) {} +func (n noopSpan) LogKV(keyVals ...interface{}) {} +func (n noopSpan) Finish() {} +func (n noopSpan) FinishWithOptions(opts FinishOptions) {} +func (n noopSpan) SetOperationName(operationName string) Span { return n } +func (n noopSpan) Tracer() Tracer { return defaultNoopTracer } +func (n noopSpan) LogEvent(event string) {} +func (n noopSpan) LogEventWithPayload(event string, payload interface{}) {} +func (n noopSpan) Log(data LogData) {} + +// StartSpan belongs to the Tracer interface. +func (n NoopTracer) StartSpan(operationName string, opts ...StartSpanOption) Span { + return defaultNoopSpan +} + +// Inject belongs to the Tracer interface. +func (n NoopTracer) Inject(sp SpanContext, format interface{}, carrier interface{}) error { + return nil +} + +// Extract belongs to the Tracer interface. +func (n NoopTracer) Extract(format interface{}, carrier interface{}) (SpanContext, error) { + return nil, ErrSpanContextNotFound +} |