Opentracing support

vendor/github.com/openzipkin/zipkin-go-opentracing/log-materializers.go

@@ -0,0 +1,113 @@
+// Copyright (c) 2016 Uber Technologies, Inc.
+// Copyright (c) 2016 Bas van Beek
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zipkintracer
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+
+	"github.com/go-logfmt/logfmt"
+	"github.com/opentracing/opentracing-go/log"
+)
+
+var errEventLogNotFound = errors.New("event log field not found")
+
+type fieldsAsMap map[string]string
+
+// MaterializeWithJSON converts log Fields into JSON string
+func MaterializeWithJSON(logFields []log.Field) ([]byte, error) {
+	fields := fieldsAsMap(make(map[string]string, len(logFields)))
+	for _, field := range logFields {
+		field.Marshal(fields)
+	}
+	return json.Marshal(fields)
+}
+
+// MaterializeWithLogFmt converts log Fields into LogFmt string
+func MaterializeWithLogFmt(logFields []log.Field) ([]byte, error) {
+	var (
+		buffer  = bytes.NewBuffer(nil)
+		encoder = logfmt.NewEncoder(buffer)
+	)
+	for _, field := range logFields {
+		if err := encoder.EncodeKeyval(field.Key(), field.Value()); err != nil {
+			encoder.EncodeKeyval(field.Key(), err.Error())
+		}
+	}
+	return buffer.Bytes(), nil
+}
+
+// StrictZipkinMaterializer will only record a log.Field of type "event".
+func StrictZipkinMaterializer(logFields []log.Field) ([]byte, error) {
+	for _, field := range logFields {
+		if field.Key() == "event" {
+			return []byte(fmt.Sprintf("%+v", field.Value())), nil
+		}
+	}
+	return nil, errEventLogNotFound
+}
+
+func (ml fieldsAsMap) EmitString(key, value string) {
+	ml[key] = value
+}
+
+func (ml fieldsAsMap) EmitBool(key string, value bool) {
+	ml[key] = fmt.Sprintf("%t", value)
+}
+
+func (ml fieldsAsMap) EmitInt(key string, value int) {
+	ml[key] = fmt.Sprintf("%d", value)
+}
+
+func (ml fieldsAsMap) EmitInt32(key string, value int32) {
+	ml[key] = fmt.Sprintf("%d", value)
+}
+
+func (ml fieldsAsMap) EmitInt64(key string, value int64) {
+	ml[key] = fmt.Sprintf("%d", value)
+}
+
+func (ml fieldsAsMap) EmitUint32(key string, value uint32) {
+	ml[key] = fmt.Sprintf("%d", value)
+}
+
+func (ml fieldsAsMap) EmitUint64(key string, value uint64) {
+	ml[key] = fmt.Sprintf("%d", value)
+}
+
+func (ml fieldsAsMap) EmitFloat32(key string, value float32) {
+	ml[key] = fmt.Sprintf("%f", value)
+}
+
+func (ml fieldsAsMap) EmitFloat64(key string, value float64) {
+	ml[key] = fmt.Sprintf("%f", value)
+}
+
+func (ml fieldsAsMap) EmitObject(key string, value interface{}) {
+	ml[key] = fmt.Sprintf("%+v", value)
+}
+
+func (ml fieldsAsMap) EmitLazyLogger(value log.LazyLogger) {
+	value(ml)
+}