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types.go
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/
types.go
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// Copyright 2015 Netflix, Inc.
//
// 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 chunked
import (
"encoding/binary"
"io"
"github.com/netflix/rend/common"
"github.com/netflix/rend/metrics"
)
const metadataSize = 24 + tokenSize
type metadata struct {
Length uint32
OrigFlags uint32
NumChunks uint32
ChunkSize uint32
Instime uint32
Exptime uint32
Token [tokenSize]byte
}
func readMetadata(r io.Reader) (metadata, error) {
buf := make([]byte, metadataSize)
n, err := io.ReadAtLeast(r, buf, metadataSize)
metrics.IncCounterBy(common.MetricBytesReadLocal, uint64(n))
if err != nil {
return emptyMeta, nil
}
m := metadata{}
m.Length = binary.BigEndian.Uint32(buf[0:4])
m.OrigFlags = binary.BigEndian.Uint32(buf[4:8])
m.NumChunks = binary.BigEndian.Uint32(buf[8:12])
m.ChunkSize = binary.BigEndian.Uint32(buf[12:16])
m.Instime = binary.BigEndian.Uint32(buf[16:20])
m.Exptime = binary.BigEndian.Uint32(buf[20:24])
copy(m.Token[:], buf[24:])
return m, nil
}
func writeMetadata(w io.Writer, md metadata) error {
buf := make([]byte, metadataSize-tokenSize)
binary.BigEndian.PutUint32(buf[0:4], md.Length)
binary.BigEndian.PutUint32(buf[4:8], md.OrigFlags)
binary.BigEndian.PutUint32(buf[8:12], md.NumChunks)
binary.BigEndian.PutUint32(buf[12:16], md.ChunkSize)
binary.BigEndian.PutUint32(buf[16:20], md.Instime)
binary.BigEndian.PutUint32(buf[20:24], md.Exptime)
n, err := w.Write(buf)
metrics.IncCounterBy(common.MetricBytesWrittenLocal, uint64(n))
if err != nil {
return err
}
n, err = w.Write(md.Token[:])
metrics.IncCounterBy(common.MetricBytesWrittenLocal, uint64(n))
return err
}