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-rw-r--r--vendor/github.com/opentracing/opentracing-go/noop.go64
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 000000000..0d32f692c
--- /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 = noopSpanContext{}
+ defaultNoopSpan = noopSpan{}
+ defaultNoopTracer = 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 defaultNoopSpan }
+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
+}