zapjournald/encoder.go
Evgenii Stratonikov 2b6d84de9a [#12] Optimize field encoding a bit
No need to clone a map if it is empty.

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>
2023-10-18 11:30:19 +03:00

70 lines
1.6 KiB
Go

package zapjournald
import (
"bytes"
"fmt"
"strings"
"go.uber.org/zap/buffer"
)
var pool = buffer.NewPool()
func encodeJournaldField(buf *buffer.Buffer, key string, value any) {
switch v := value.(type) {
case string:
writeField(buf, key, v)
case []byte:
writeFieldBytes(buf, key, v)
default:
writeField(buf, key, fmt.Sprint(v))
}
}
func writeFieldBytes(buf *buffer.Buffer, name string, value []byte) {
buf.Write([]byte(name))
if bytes.ContainsRune(value, '\n') {
// According to the format, if the value includes a newline
// need to write the field name, plus a newline, then the
// size (64bit LE), the field data and a final newline.
buf.Write([]byte{'\n'})
appendUint64Binary(buf, uint64(len(value)))
} else {
buf.Write([]byte{'='})
}
buf.Write(value)
buf.Write([]byte{'\n'})
}
func writeField(buf *buffer.Buffer, name string, value string) {
buf.Write([]byte(name))
if strings.ContainsRune(value, '\n') {
// According to the format, if the value includes a newline
// need to write the field name, plus a newline, then the
// size (64bit LE), the field data and a final newline.
buf.Write([]byte{'\n'})
// 1 allocation here.
// binary.Write(w, binary.LittleEndian, uint64(len(value)))
appendUint64Binary(buf, uint64(len(value)))
} else {
buf.Write([]byte{'='})
}
buf.WriteString(value)
buf.Write([]byte{'\n'})
}
func appendUint64Binary(buf *buffer.Buffer, v uint64) {
// Copied from https://github.com/golang/go/blob/go1.21.3/src/encoding/binary/binary.go#L119
buf.Write([]byte{
byte(v),
byte(v >> 8),
byte(v >> 16),
byte(v >> 24),
byte(v >> 32),
byte(v >> 40),
byte(v >> 48),
byte(v >> 56),
})
}