forked from TrueCloudLab/restic
70 lines
1.1 KiB
Go
70 lines
1.1 KiB
Go
package backend
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import (
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"errors"
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"hash"
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"io"
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)
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type HashAppendWriter struct {
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w io.Writer
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origWr io.Writer
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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 NewHashAppendWriter(w io.Writer, h hash.Hash) *HashAppendWriter {
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return &HashAppendWriter{
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h: h,
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w: io.MultiWriter(w, h),
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origWr: w,
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sum: make([]byte, 0, h.Size()),
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}
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}
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func (h *HashAppendWriter) Close() error {
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if !h.closed {
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h.closed = true
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_, err := h.origWr.Write(h.h.Sum(nil))
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return err
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}
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return nil
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}
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func (h *HashAppendWriter) Write(p []byte) (n int, err error) {
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if !h.closed {
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return h.w.Write(p)
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}
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return 0, errors.New("Write() called on closed HashAppendWriter")
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}
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type HashingWriter struct {
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w io.Writer
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h hash.Hash
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size int
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}
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func NewHashingWriter(w io.Writer, h hash.Hash) *HashingWriter {
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return &HashingWriter{
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h: h,
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w: io.MultiWriter(w, h),
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}
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}
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func (h *HashingWriter) Write(p []byte) (int, error) {
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n, err := h.w.Write(p)
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h.size += n
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return n, err
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}
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func (h *HashingWriter) Sum(d []byte) []byte {
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return h.h.Sum(d)
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}
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func (h *HashingWriter) Size() int {
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return h.size
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}
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