mirror of
https://github.com/restic/restic.git
synced 2024-12-23 00:07:25 +00:00
Add hashing package
This commit is contained in:
parent
30ff7413be
commit
c93f79f0f3
4 changed files with 207 additions and 0 deletions
29
src/restic/hashing/reader.go
Normal file
29
src/restic/hashing/reader.go
Normal file
|
@ -0,0 +1,29 @@
|
|||
package hashing
|
||||
|
||||
import (
|
||||
"hash"
|
||||
"io"
|
||||
)
|
||||
|
||||
// Reader hashes all data read from the underlying reader.
|
||||
type Reader struct {
|
||||
r io.Reader
|
||||
h hash.Hash
|
||||
}
|
||||
|
||||
// NewReader returns a new Reader that uses the hash h.
|
||||
func NewReader(r io.Reader, h hash.Hash) *Reader {
|
||||
return &Reader{
|
||||
h: h,
|
||||
r: io.TeeReader(r, h),
|
||||
}
|
||||
}
|
||||
|
||||
func (h *Reader) Read(p []byte) (int, error) {
|
||||
return h.r.Read(p)
|
||||
}
|
||||
|
||||
// Sum returns the hash of the data read so far.
|
||||
func (h *Reader) Sum(d []byte) []byte {
|
||||
return h.h.Sum(d)
|
||||
}
|
73
src/restic/hashing/reader_test.go
Normal file
73
src/restic/hashing/reader_test.go
Normal file
|
@ -0,0 +1,73 @@
|
|||
package hashing
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"crypto/rand"
|
||||
"crypto/sha256"
|
||||
"io"
|
||||
"io/ioutil"
|
||||
"testing"
|
||||
)
|
||||
|
||||
func TestReader(t *testing.T) {
|
||||
tests := []int{5, 23, 2<<18 + 23, 1 << 20}
|
||||
|
||||
for _, size := range tests {
|
||||
data := make([]byte, size)
|
||||
_, err := io.ReadFull(rand.Reader, data)
|
||||
if err != nil {
|
||||
t.Fatalf("ReadFull: %v", err)
|
||||
}
|
||||
|
||||
expectedHash := sha256.Sum256(data)
|
||||
|
||||
rd := NewReader(bytes.NewReader(data), sha256.New())
|
||||
n, err := io.Copy(ioutil.Discard, rd)
|
||||
if err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
|
||||
if n != int64(size) {
|
||||
t.Errorf("Reader: invalid number of bytes written: got %d, expected %d",
|
||||
n, size)
|
||||
}
|
||||
|
||||
resultingHash := rd.Sum(nil)
|
||||
|
||||
if !bytes.Equal(expectedHash[:], resultingHash) {
|
||||
t.Errorf("Reader: hashes do not match: expected %02x, got %02x",
|
||||
expectedHash, resultingHash)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkReader(b *testing.B) {
|
||||
buf := make([]byte, 1<<22)
|
||||
_, err := io.ReadFull(rand.Reader, buf)
|
||||
if err != nil {
|
||||
b.Fatal(err)
|
||||
}
|
||||
|
||||
expectedHash := sha256.Sum256(buf)
|
||||
|
||||
b.SetBytes(int64(len(buf)))
|
||||
b.ResetTimer()
|
||||
for i := 0; i < b.N; i++ {
|
||||
rd := NewReader(bytes.NewReader(buf), sha256.New())
|
||||
n, err := io.Copy(ioutil.Discard, rd)
|
||||
if err != nil {
|
||||
b.Fatal(err)
|
||||
}
|
||||
|
||||
if n != int64(len(buf)) {
|
||||
b.Errorf("Reader: invalid number of bytes written: got %d, expected %d",
|
||||
n, len(buf))
|
||||
}
|
||||
|
||||
resultingHash := rd.Sum(nil)
|
||||
if !bytes.Equal(expectedHash[:], resultingHash) {
|
||||
b.Errorf("Reader: hashes do not match: expected %02x, got %02x",
|
||||
expectedHash, resultingHash)
|
||||
}
|
||||
}
|
||||
}
|
31
src/restic/hashing/writer.go
Normal file
31
src/restic/hashing/writer.go
Normal file
|
@ -0,0 +1,31 @@
|
|||
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)
|
||||
}
|
74
src/restic/hashing/writer_test.go
Normal file
74
src/restic/hashing/writer_test.go
Normal file
|
@ -0,0 +1,74 @@
|
|||
package hashing
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"crypto/rand"
|
||||
"crypto/sha256"
|
||||
"io"
|
||||
"io/ioutil"
|
||||
"testing"
|
||||
)
|
||||
|
||||
func TestWriter(t *testing.T) {
|
||||
tests := []int{5, 23, 2<<18 + 23, 1 << 20}
|
||||
|
||||
for _, size := range tests {
|
||||
data := make([]byte, size)
|
||||
_, err := io.ReadFull(rand.Reader, data)
|
||||
if err != nil {
|
||||
t.Fatalf("ReadFull: %v", err)
|
||||
}
|
||||
|
||||
expectedHash := sha256.Sum256(data)
|
||||
|
||||
wr := NewWriter(ioutil.Discard, sha256.New())
|
||||
|
||||
n, err := io.Copy(wr, bytes.NewReader(data))
|
||||
if err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
|
||||
if n != int64(size) {
|
||||
t.Errorf("Writer: invalid number of bytes written: got %d, expected %d",
|
||||
n, size)
|
||||
}
|
||||
|
||||
resultingHash := wr.Sum(nil)
|
||||
|
||||
if !bytes.Equal(expectedHash[:], resultingHash) {
|
||||
t.Errorf("Writer: hashes do not match: expected %02x, got %02x",
|
||||
expectedHash, resultingHash)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkWriter(b *testing.B) {
|
||||
buf := make([]byte, 1<<22)
|
||||
_, err := io.ReadFull(rand.Reader, buf)
|
||||
if err != nil {
|
||||
b.Fatal(err)
|
||||
}
|
||||
|
||||
expectedHash := sha256.Sum256(buf)
|
||||
|
||||
b.SetBytes(int64(len(buf)))
|
||||
b.ResetTimer()
|
||||
for i := 0; i < b.N; i++ {
|
||||
wr := NewWriter(ioutil.Discard, sha256.New())
|
||||
n, err := io.Copy(wr, bytes.NewReader(buf))
|
||||
if err != nil {
|
||||
b.Fatal(err)
|
||||
}
|
||||
|
||||
if n != int64(len(buf)) {
|
||||
b.Errorf("Writer: invalid number of bytes written: got %d, expected %d",
|
||||
n, len(buf))
|
||||
}
|
||||
|
||||
resultingHash := wr.Sum(nil)
|
||||
if !bytes.Equal(expectedHash[:], resultingHash) {
|
||||
b.Errorf("Writer: hashes do not match: expected %02x, got %02x",
|
||||
expectedHash, resultingHash)
|
||||
}
|
||||
}
|
||||
}
|
Loading…
Reference in a new issue