seaweedfs/weed/util/buffered_writer/buffered_writer.go
2020-12-01 15:32:27 -08:00

53 lines
1,014 B
Go

package buffered_writer
import (
"bytes"
"io"
)
var _ = io.WriteCloser(&BufferedWriteCloser{})
type BufferedWriteCloser struct {
buffer bytes.Buffer
bufferLimit int
position int64
nextFlushOffset int64
FlushFunc func([]byte, int64) error
CloseFunc func() error
}
func NewBufferedWriteCloser(bufferLimit int) *BufferedWriteCloser {
return &BufferedWriteCloser{
bufferLimit: bufferLimit,
}
}
func (b *BufferedWriteCloser) Write(p []byte) (n int, err error) {
if b.buffer.Len()+len(p) >= b.bufferLimit {
if err := b.FlushFunc(b.buffer.Bytes(), b.nextFlushOffset); err != nil {
return 0, err
}
b.nextFlushOffset += int64(b.buffer.Len())
b.buffer.Reset()
}
return b.buffer.Write(p)
}
func (b *BufferedWriteCloser) Close() error {
if b.buffer.Len() > 0 {
if err := b.FlushFunc(b.buffer.Bytes(), b.nextFlushOffset); err != nil {
return err
}
}
if b.CloseFunc != nil {
if err := b.CloseFunc(); err != nil {
return err
}
}
return nil
}