forked from Sreevani871/opentelemetry-go-contrib
/
message.go
65 lines (57 loc) · 1.68 KB
/
message.go
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// Copyright The OpenTelemetry Authors
//
// 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 otelkafka
import (
"github.com/confluentinc/confluent-kafka-go/kafka"
"go.opentelemetry.io/otel/propagation"
)
// A MessageCarrier injects and extracts traces from a kafka.Message.
type MessageCarrier struct {
msg *kafka.Message
keys []string
}
var _ propagation.TextMapCarrier = (*MessageCarrier)(nil)
// NewMessageCarrier creates a new MessageCarrier.
func NewMessageCarrier(msg *kafka.Message) MessageCarrier {
return MessageCarrier{
msg: msg,
}
}
// Set sets a header.
func (c MessageCarrier) Set(key, val string) {
// ensure uniqueness of keys
for i := 0; i < len(c.msg.Headers); i++ {
if c.msg.Headers[i].Key == key {
c.msg.Headers = append(c.msg.Headers[:i], c.msg.Headers[i+1:]...)
i--
}
}
c.msg.Headers = append(c.msg.Headers, kafka.Header{
Key: key,
Value: []byte(val),
})
c.keys = append(c.keys, key)
}
// Get retrieves a single value for a given key.
func (c MessageCarrier) Get(key string) string {
for _, h := range c.msg.Headers {
if h.Key == key {
return string(h.Value)
}
}
return ""
}
func (c MessageCarrier) Keys() []string {
return c.keys
}