Added support for Haystack tracing

vendor/github.com/ExpediaDotCom/haystack-client-go/span.go

@@ -0,0 +1,164 @@
+/*
+ *  Copyright 2018 Expedia Group.
+ *
+ *     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 haystack
+
+import (
+	"encoding/json"
+	"time"
+
+	"github.com/opentracing/opentracing-go"
+	"github.com/opentracing/opentracing-go/log"
+)
+
+/*_Span implements opentracing.Span*/
+type _Span struct {
+	tracer  *Tracer
+	context *SpanContext
+
+	operationName string
+
+	// startTime is the timestamp indicating when the span began, with microseconds precision.
+	startTime time.Time
+	// duration returns duration of the span with microseconds precision.
+	duration time.Duration
+
+	tags []opentracing.Tag
+	logs []opentracing.LogRecord
+}
+
+// SetOperationName sets or changes the operation name.
+func (span *_Span) SetOperationName(operationName string) opentracing.Span {
+	span.operationName = operationName
+	return span
+}
+
+// SetTag implements SetTag() of opentracing.Span
+func (span *_Span) SetTag(key string, value interface{}) opentracing.Span {
+	span.tags = append(span.tags,
+		opentracing.Tag{
+			Key:   key,
+			Value: value,
+		})
+	return span
+}
+
+// LogFields implements opentracing.Span API
+func (span *_Span) LogFields(fields ...log.Field) {
+	log := opentracing.LogRecord{
+		Fields:    fields,
+		Timestamp: time.Now(),
+	}
+	span.logs = append(span.logs, log)
+}
+
+// LogKV implements opentracing.Span API
+func (span *_Span) LogKV(alternatingKeyValues ...interface{}) {
+	fields, err := log.InterleavedKVToFields(alternatingKeyValues...)
+	if err != nil {
+		span.LogFields(log.Error(err), log.String("function", "LogKV"))
+		return
+	}
+	span.LogFields(fields...)
+}
+
+// LogEvent implements opentracing.Span API
+func (span *_Span) LogEvent(event string) {
+	span.Log(opentracing.LogData{Event: event})
+}
+
+// LogEventWithPayload implements opentracing.Span API
+func (span *_Span) LogEventWithPayload(event string, payload interface{}) {
+	span.Log(opentracing.LogData{Event: event, Payload: payload})
+}
+
+// Log implements opentracing.Span API
+func (span *_Span) Log(ld opentracing.LogData) {
+	span.logs = append(span.logs, ld.ToLogRecord())
+}
+
+// SetBaggageItem implements SetBaggageItem() of opentracing.SpanContext
+func (span *_Span) SetBaggageItem(key, value string) opentracing.Span {
+	span.context = span.context.WithBaggageItem(key, value)
+	span.LogFields(log.String("event", "baggage"), log.String("payload", key), log.String("payload", value))
+	return span
+}
+
+// BaggageItem implements BaggageItem() of opentracing.SpanContext
+func (span *_Span) BaggageItem(key string) string {
+	return span.context.Baggage[key]
+}
+
+// Finish implements opentracing.Span API
+func (span *_Span) Finish() {
+	span.FinishWithOptions(opentracing.FinishOptions{})
+}
+
+// FinishWithOptions implements opentracing.Span API
+func (span *_Span) FinishWithOptions(options opentracing.FinishOptions) {
+	if options.FinishTime.IsZero() {
+		options.FinishTime = span.tracer.timeNow()
+	}
+	span.duration = options.FinishTime.Sub(span.startTime)
+	if options.LogRecords != nil {
+		span.logs = append(span.logs, options.LogRecords...)
+	}
+	for _, ld := range options.BulkLogData {
+		span.logs = append(span.logs, ld.ToLogRecord())
+	}
+	span.tracer.DispatchSpan(span)
+}
+
+// Context implements opentracing.Span API
+func (span *_Span) Context() opentracing.SpanContext {
+	return span.context
+}
+
+/*Tracer returns the tracer*/
+func (span *_Span) Tracer() opentracing.Tracer {
+	return span.tracer
+}
+
+/*OperationName allows retrieving current operation name*/
+func (span *_Span) OperationName() string {
+	return span.operationName
+}
+
+/*ServiceName returns the name of the service*/
+func (span *_Span) ServiceName() string {
+	return span.tracer.serviceName
+}
+
+func (span *_Span) String() string {
+	data, err := json.Marshal(map[string]interface{}{
+		"traceId":       span.context.TraceID,
+		"spanId":        span.context.SpanID,
+		"parentSpanId":  span.context.ParentID,
+		"operationName": span.OperationName(),
+		"serviceName":   span.ServiceName(),
+		"tags":          span.Tags(),
+		"logs":          span.logs,
+	})
+	if err != nil {
+		panic(err)
+	}
+	return string(data)
+}
+
+func (span *_Span) Tags() []opentracing.Tag {
+	return span.tags
+}