You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

75 lines
1.4 KiB

package common
import (
"bytes"
"errors"
"io"
)
type PrefixedReader struct {
Prefix []byte
reader io.Reader
}
func NewPrefixedReader(prefix []byte, reader io.Reader) *PrefixedReader {
return &PrefixedReader{prefix, reader}
}
func (pr *PrefixedReader) Read(p []byte) (n int, err error) {
if len(pr.Prefix) > 0 {
read := copy(p, pr.Prefix)
pr.Prefix = pr.Prefix[read:]
return read, nil
} else {
return pr.reader.Read(p)
}
}
// NOTE: Not goroutine safe
type BufferCloser struct {
bytes.Buffer
Closed bool
}
func NewBufferCloser(buf []byte) *BufferCloser {
return &BufferCloser{
*bytes.NewBuffer(buf),
false,
}
}
func (bc *BufferCloser) Close() error {
if bc.Closed {
return errors.New("BufferCloser already closed")
}
bc.Closed = true
return nil
}
func (bc *BufferCloser) Write(p []byte) (n int, err error) {
if bc.Closed {
return 0, errors.New("Cannot write to closed BufferCloser")
}
return bc.Buffer.Write(p)
}
func (bc *BufferCloser) WriteByte(c byte) error {
if bc.Closed {
return errors.New("Cannot write to closed BufferCloser")
}
return bc.Buffer.WriteByte(c)
}
func (bc *BufferCloser) WriteRune(r rune) (n int, err error) {
if bc.Closed {
return 0, errors.New("Cannot write to closed BufferCloser")
}
return bc.Buffer.WriteRune(r)
}
func (bc *BufferCloser) WriteString(s string) (n int, err error) {
if bc.Closed {
return 0, errors.New("Cannot write to closed BufferCloser")
}
return bc.Buffer.WriteString(s)
}