mirror of https://github.com/restic/restic.git
74 lines
1.0 KiB
Go
74 lines
1.0 KiB
Go
package backend
|
|
|
|
import (
|
|
"hash"
|
|
"io"
|
|
)
|
|
|
|
type HashAppendReader struct {
|
|
r io.Reader
|
|
h hash.Hash
|
|
sum []byte
|
|
closed bool
|
|
}
|
|
|
|
func NewHashAppendReader(r io.Reader, h hash.Hash) *HashAppendReader {
|
|
return &HashAppendReader{
|
|
h: h,
|
|
r: io.TeeReader(r, h),
|
|
sum: make([]byte, 0, h.Size()),
|
|
}
|
|
}
|
|
|
|
func (h *HashAppendReader) Read(p []byte) (n int, err error) {
|
|
if !h.closed {
|
|
n, err = h.r.Read(p)
|
|
|
|
if err == io.EOF {
|
|
h.closed = true
|
|
h.sum = h.h.Sum(h.sum)
|
|
} else if err != nil {
|
|
return
|
|
}
|
|
}
|
|
|
|
if h.closed {
|
|
// output hash
|
|
r := len(p) - n
|
|
|
|
if r > 0 {
|
|
c := copy(p[n:], h.sum)
|
|
h.sum = h.sum[c:]
|
|
|
|
n += c
|
|
err = nil
|
|
}
|
|
|
|
if len(h.sum) == 0 {
|
|
err = io.EOF
|
|
}
|
|
}
|
|
|
|
return
|
|
}
|
|
|
|
type HashingReader struct {
|
|
r io.Reader
|
|
h hash.Hash
|
|
}
|
|
|
|
func NewHashingReader(r io.Reader, h hash.Hash) *HashingReader {
|
|
return &HashingReader{
|
|
h: h,
|
|
r: io.TeeReader(r, h),
|
|
}
|
|
}
|
|
|
|
func (h *HashingReader) Read(p []byte) (int, error) {
|
|
return h.r.Read(p)
|
|
}
|
|
|
|
func (h *HashingReader) Sum(d []byte) []byte {
|
|
return h.h.Sum(d)
|
|
}
|