prometheus/scrape/clientprotobuf.go
Jeanette Tan 40240c9c1c Update according to code review
Signed-off-by: Jeanette Tan <jeanette.tan@grafana.com>
2023-05-05 02:33:00 +08:00

55 lines
1.7 KiB
Go

// Copyright 2023 The Prometheus 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 scrape
import (
"bytes"
"encoding/binary"
"github.com/gogo/protobuf/proto"
// Intentionally using client model to simulate client in tests.
dto "github.com/prometheus/client_model/go"
)
// Write a MetricFamily into a protobuf.
// This function is intended for testing scraping by providing protobuf serialized input.
func MetricFamilyToProtobuf(metricFamily *dto.MetricFamily) ([]byte, error) {
buffer := &bytes.Buffer{}
err := AddMetricFamilyToProtobuf(buffer, metricFamily)
if err != nil {
return nil, err
}
return buffer.Bytes(), nil
}
// Append a MetricFamily protobuf representation to a buffer.
// This function is intended for testing scraping by providing protobuf serialized input.
func AddMetricFamilyToProtobuf(buffer *bytes.Buffer, metricFamily *dto.MetricFamily) error {
protoBuf, err := proto.Marshal(metricFamily)
if err != nil {
return err
}
varintBuf := make([]byte, binary.MaxVarintLen32)
varintLength := binary.PutUvarint(varintBuf, uint64(len(protoBuf)))
_, err = buffer.Write(varintBuf[:varintLength])
if err != nil {
return err
}
_, err = buffer.Write(protoBuf)
return err
}