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