72 lines
1.1 KiB
Go
72 lines
1.1 KiB
Go
package fscache
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import (
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"encoding/json"
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"errors"
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"io"
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)
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type decoder interface {
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Decode(interface{}) error
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}
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type encoder interface {
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Encode(interface{}) error
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}
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type pktReader struct {
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dec decoder
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}
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type pktWriter struct {
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enc encoder
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}
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type packet struct {
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Err int
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Data []byte
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}
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const eof = 1
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func (t *pktReader) ReadAt(p []byte, off int64) (n int, err error) {
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// TODO not implemented
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return 0, errors.New("not implemented")
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}
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func (t *pktReader) Read(p []byte) (int, error) {
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var pkt packet
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err := t.dec.Decode(&pkt)
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if err != nil {
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return 0, err
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}
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if pkt.Err == eof {
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return 0, io.EOF
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}
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return copy(p, pkt.Data), nil
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}
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func (t *pktReader) Close() error {
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return nil
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}
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func (t *pktWriter) Write(p []byte) (int, error) {
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pkt := packet{Data: p}
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err := t.enc.Encode(pkt)
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if err != nil {
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return 0, err
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}
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return len(p), nil
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}
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func (t *pktWriter) Close() error {
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return t.enc.Encode(packet{Err: eof})
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}
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func newEncoder(w io.Writer) io.WriteCloser {
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return &pktWriter{enc: json.NewEncoder(w)}
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}
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func newDecoder(r io.Reader) ReadAtCloser {
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return &pktReader{dec: json.NewDecoder(r)}
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}
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