85 lines
1.8 KiB
Go
85 lines
1.8 KiB
Go
package wsflate
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import (
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"io"
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)
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// Decompressor is an interface holding deflate decompression implementation.
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type Decompressor interface {
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io.Reader
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}
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// ReadResetter is an optional interface that Decompressor can implement.
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type ReadResetter interface {
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Reset(io.Reader)
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}
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// Reader implements decompression from an io.Reader object using Decompressor.
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// Essentially Reader is a thin wrapper around Decompressor interface to meet
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// PMCE specs.
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//
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// After all data has been written client should call Flush() method.
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// If any error occurs after reading from Reader, all subsequent calls to
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// Read() or Close() will return the error.
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//
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// Reader might be reused for different io.Reader objects after its Reset()
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// method has been called.
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type Reader struct {
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src io.Reader
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ctor func(io.Reader) Decompressor
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d Decompressor
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sr suffixedReader
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err error
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}
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// NewReader returns a new Reader.
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func NewReader(r io.Reader, ctor func(io.Reader) Decompressor) *Reader {
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ret := &Reader{
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src: r,
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ctor: ctor,
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sr: suffixedReader{
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suffix: compressionReadTail,
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},
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}
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ret.Reset(r)
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return ret
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}
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// Reset resets Reader to decompress data from src.
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func (r *Reader) Reset(src io.Reader) {
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r.err = nil
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r.src = src
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r.sr.reset(src)
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if x, ok := r.d.(ReadResetter); ok {
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x.Reset(r.sr.iface())
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} else {
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r.d = r.ctor(r.sr.iface())
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}
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}
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// Read implements io.Reader.
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func (r *Reader) Read(p []byte) (n int, err error) {
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if r.err != nil {
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return 0, r.err
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}
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return r.d.Read(p)
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}
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// Close closes Reader and a Decompressor instance used under the hood (if it
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// implements io.Closer interface).
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func (r *Reader) Close() error {
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if r.err != nil {
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return r.err
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}
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if c, ok := r.d.(io.Closer); ok {
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r.err = c.Close()
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}
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return r.err
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}
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// Err returns an error happened during any operation.
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func (r *Reader) Err() error {
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return r.err
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}
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