github.com/hasnat/dolt/go@v0.0.0-20210628190320-9eb5d843fbb7/libraries/utils/tracing/tracing.go (about) 1 // Copyright 2020 Dolthub, Inc. 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 tracing 16 17 import ( 18 "context" 19 20 "github.com/opentracing/opentracing-go" 21 ) 22 23 // Called throughout dolt to get the tracer. Default implementation returns 24 // opentracing.GlobalTracer(), but another implementation could be installed to 25 // return a context-specific tracer. 26 var Tracer func(ctx context.Context) opentracing.Tracer 27 28 func init() { 29 Tracer = func(ctx context.Context) opentracing.Tracer { 30 return opentracing.GlobalTracer() 31 } 32 } 33 34 // Start a new span, named `name`, as a child of the current span associated 35 // with `ctx`. Starts a root span if there is no Span associated with `ctx`. 36 // Returns the newly created Span and a new `ctx` associated with the Span. 37 func StartSpan(ctx context.Context, name string) (opentracing.Span, context.Context) { 38 parentSpan := opentracing.SpanFromContext(ctx) 39 var opts []opentracing.StartSpanOption 40 if parentSpan != nil { 41 opts = append(opts, opentracing.ChildOf(parentSpan.Context())) 42 } 43 span := Tracer(ctx).StartSpan(name, opts...) 44 ctx = opentracing.ContextWithSpan(ctx, span) 45 return span, ctx 46 }