mirror of https://github.com/restic/restic.git
32 lines
645 B
Go
32 lines
645 B
Go
|
package hashing
|
||
|
|
|
||
|
|
import (
|
||
|
|
"hash"
|
||
|
|
"io"
|
||
|
|
)
|
||
|
|
|
||
|
|
// Writer transparently hashes all data while writing it to the underlying writer.
|
||
|
|
type Writer struct {
|
||
|
|
w io.Writer
|
||
|
|
h hash.Hash
|
||
|
|
}
|
||
|
|
|
||
|
|
// NewWriter wraps the writer w and feeds all data written to the hash h.
|
||
|
|
func NewWriter(w io.Writer, h hash.Hash) *Writer {
|
||
|
|
return &Writer{
|
||
|
|
h: h,
|
||
|
|
w: io.MultiWriter(w, h),
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Write wraps the write method of the underlying writer and also hashes all data.
|
||
|
|
func (h *Writer) Write(p []byte) (int, error) {
|
||
|
|
n, err := h.w.Write(p)
|
||
|
|
return n, err
|
||
|
|
}
|
||
|
|
|
||
|
|
// Sum returns the hash of all data written so far.
|
||
|
|
func (h *Writer) Sum(d []byte) []byte {
|
||
|
|
return h.h.Sum(d)
|
||
|
|
}
|