mirror of https://github.com/octoleo/restic.git
85 lines
1.5 KiB
Go
85 lines
1.5 KiB
Go
package khepri
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import (
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"hash"
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"io"
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)
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// HashingReader is the interfaces that wraps a normal reader. When Hash() is called,
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// it returns the hash for all data that has been read so far.
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type HashingReader interface {
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io.Reader
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Hash() []byte
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}
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// HashingWriter is the interfaces that wraps a normal writer. When Hash() is called,
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// it returns the hash for all data that has been written so far.
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type HashingWriter interface {
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io.Writer
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Hash() []byte
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}
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type reader struct {
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reader io.Reader
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hash hash.Hash
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}
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// NewHashingReader wraps an io.Reader and in addition feeds all data read through the
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// given hash.
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func NewHashingReader(r io.Reader, h func() hash.Hash) *reader {
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return &reader{
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reader: r,
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hash: h(),
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}
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}
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func (h *reader) Read(p []byte) (int, error) {
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// call original reader
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n, err := h.reader.Read(p)
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// hash bytes
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if n > 0 {
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// hash
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h.hash.Write(p[0:n])
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}
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// return result
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return n, err
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}
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func (h *reader) Hash() []byte {
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return h.hash.Sum([]byte{})
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}
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type writer struct {
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writer io.Writer
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hash hash.Hash
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}
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// NewHashingWriter wraps an io.Reader and in addition feeds all data written through
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// the given hash.
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func NewHashingWriter(w io.Writer, h func() hash.Hash) *writer {
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return &writer{
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writer: w,
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hash: h(),
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}
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}
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func (h *writer) Write(p []byte) (int, error) {
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// call original writer
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n, err := h.writer.Write(p)
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// hash bytes
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if n > 0 {
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// hash
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h.hash.Write(p[0:n])
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}
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// return result
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return n, err
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}
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func (h *writer) Hash() []byte {
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return h.hash.Sum([]byte{})
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}
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