mirror of
https://github.com/astaxie/beego.git
synced 2024-11-16 04:50:55 +00:00
68 lines
1.0 KiB
Go
68 lines
1.0 KiB
Go
package rdb
|
|
|
|
import (
|
|
"errors"
|
|
"io"
|
|
)
|
|
|
|
type sliceBuffer struct {
|
|
s []byte
|
|
i int
|
|
}
|
|
|
|
func newSliceBuffer(s []byte) *sliceBuffer {
|
|
return &sliceBuffer{s, 0}
|
|
}
|
|
|
|
func (s *sliceBuffer) Slice(n int) ([]byte, error) {
|
|
if s.i+n > len(s.s) {
|
|
return nil, io.EOF
|
|
}
|
|
b := s.s[s.i : s.i+n]
|
|
s.i += n
|
|
return b, nil
|
|
}
|
|
|
|
func (s *sliceBuffer) ReadByte() (byte, error) {
|
|
if s.i >= len(s.s) {
|
|
return 0, io.EOF
|
|
}
|
|
b := s.s[s.i]
|
|
s.i++
|
|
return b, nil
|
|
}
|
|
|
|
func (s *sliceBuffer) Read(b []byte) (int, error) {
|
|
if len(b) == 0 {
|
|
return 0, nil
|
|
}
|
|
if s.i >= len(s.s) {
|
|
return 0, io.EOF
|
|
}
|
|
n := copy(b, s.s[s.i:])
|
|
s.i += n
|
|
return n, nil
|
|
}
|
|
|
|
func (s *sliceBuffer) Seek(offset int64, whence int) (int64, error) {
|
|
var abs int64
|
|
switch whence {
|
|
case 0:
|
|
abs = offset
|
|
case 1:
|
|
abs = int64(s.i) + offset
|
|
case 2:
|
|
abs = int64(len(s.s)) + offset
|
|
default:
|
|
return 0, errors.New("invalid whence")
|
|
}
|
|
if abs < 0 {
|
|
return 0, errors.New("negative position")
|
|
}
|
|
if abs >= 1<<31 {
|
|
return 0, errors.New("position out of range")
|
|
}
|
|
s.i = int(abs)
|
|
return abs, nil
|
|
}
|