/usr/share/gocode/src/github.com/Shopify/sarama/message.go is in golang-github-shopify-sarama-dev 1.9.0-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 | package sarama
import (
"bytes"
"compress/gzip"
"fmt"
"io/ioutil"
)
// CompressionCodec represents the various compression codecs recognized by Kafka in messages.
type CompressionCodec int8
// only the last two bits are really used
const compressionCodecMask int8 = 0x03
const (
CompressionNone CompressionCodec = 0
CompressionGZIP CompressionCodec = 1
CompressionSnappy CompressionCodec = 2
)
// The spec just says: "This is a version id used to allow backwards compatible evolution of the message
// binary format." but it doesn't say what the current value is, so presumably 0...
const messageFormat int8 = 0
type Message struct {
Codec CompressionCodec // codec used to compress the message contents
Key []byte // the message key, may be nil
Value []byte // the message contents
Set *MessageSet // the message set a message might wrap
compressedCache []byte
}
func (m *Message) encode(pe packetEncoder) error {
pe.push(&crc32Field{})
pe.putInt8(messageFormat)
attributes := int8(m.Codec) & compressionCodecMask
pe.putInt8(attributes)
err := pe.putBytes(m.Key)
if err != nil {
return err
}
var payload []byte
if m.compressedCache != nil {
payload = m.compressedCache
m.compressedCache = nil
} else {
switch m.Codec {
case CompressionNone:
payload = m.Value
case CompressionGZIP:
var buf bytes.Buffer
writer := gzip.NewWriter(&buf)
if _, err = writer.Write(m.Value); err != nil {
return err
}
if err = writer.Close(); err != nil {
return err
}
m.compressedCache = buf.Bytes()
payload = m.compressedCache
case CompressionSnappy:
tmp := snappyEncode(m.Value)
m.compressedCache = tmp
payload = m.compressedCache
default:
return PacketEncodingError{fmt.Sprintf("unsupported compression codec (%d)", m.Codec)}
}
}
if err = pe.putBytes(payload); err != nil {
return err
}
return pe.pop()
}
func (m *Message) decode(pd packetDecoder) (err error) {
err = pd.push(&crc32Field{})
if err != nil {
return err
}
format, err := pd.getInt8()
if err != nil {
return err
}
if format != messageFormat {
return PacketDecodingError{"unexpected messageFormat"}
}
attribute, err := pd.getInt8()
if err != nil {
return err
}
m.Codec = CompressionCodec(attribute & compressionCodecMask)
m.Key, err = pd.getBytes()
if err != nil {
return err
}
m.Value, err = pd.getBytes()
if err != nil {
return err
}
switch m.Codec {
case CompressionNone:
// nothing to do
case CompressionGZIP:
if m.Value == nil {
return PacketDecodingError{"GZIP compression specified, but no data to uncompress"}
}
reader, err := gzip.NewReader(bytes.NewReader(m.Value))
if err != nil {
return err
}
if m.Value, err = ioutil.ReadAll(reader); err != nil {
return err
}
if err := m.decodeSet(); err != nil {
return err
}
case CompressionSnappy:
if m.Value == nil {
return PacketDecodingError{"Snappy compression specified, but no data to uncompress"}
}
if m.Value, err = snappyDecode(m.Value); err != nil {
return err
}
if err := m.decodeSet(); err != nil {
return err
}
default:
return PacketDecodingError{fmt.Sprintf("invalid compression specified (%d)", m.Codec)}
}
return pd.pop()
}
// decodes a message set from a previousy encoded bulk-message
func (m *Message) decodeSet() (err error) {
pd := realDecoder{raw: m.Value}
m.Set = &MessageSet{}
return m.Set.decode(&pd)
}
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