142 lines
3.4 KiB
Go
142 lines
3.4 KiB
Go
// Copyright 2019+ Klaus Post. All rights reserved.
|
|
// License information can be found in the LICENSE file.
|
|
|
|
package zstd
|
|
|
|
import (
|
|
"errors"
|
|
"io"
|
|
"sync"
|
|
)
|
|
|
|
// ZipMethodWinZip is the method for Zstandard compressed data inside Zip files for WinZip.
|
|
// See https://www.winzip.com/win/en/comp_info.html
|
|
const ZipMethodWinZip = 93
|
|
|
|
// ZipMethodPKWare is the original method number used by PKWARE to indicate Zstandard compression.
|
|
// Deprecated: This has been deprecated by PKWARE, use ZipMethodWinZip instead for compression.
|
|
// See https://pkware.cachefly.net/webdocs/APPNOTE/APPNOTE-6.3.9.TXT
|
|
const ZipMethodPKWare = 20
|
|
|
|
// zipReaderPool is the default reader pool.
|
|
var zipReaderPool = sync.Pool{New: func() interface{} {
|
|
z, err := NewReader(nil, WithDecoderLowmem(true), WithDecoderMaxWindow(128<<20), WithDecoderConcurrency(1))
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
return z
|
|
}}
|
|
|
|
// newZipReader creates a pooled zip decompressor.
|
|
func newZipReader(opts ...DOption) func(r io.Reader) io.ReadCloser {
|
|
pool := &zipReaderPool
|
|
if len(opts) > 0 {
|
|
opts = append([]DOption{WithDecoderLowmem(true), WithDecoderMaxWindow(128 << 20)}, opts...)
|
|
// Force concurrency 1
|
|
opts = append(opts, WithDecoderConcurrency(1))
|
|
// Create our own pool
|
|
pool = &sync.Pool{}
|
|
}
|
|
return func(r io.Reader) io.ReadCloser {
|
|
dec, ok := pool.Get().(*Decoder)
|
|
if ok {
|
|
dec.Reset(r)
|
|
} else {
|
|
d, err := NewReader(r, opts...)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
dec = d
|
|
}
|
|
return &pooledZipReader{dec: dec, pool: pool}
|
|
}
|
|
}
|
|
|
|
type pooledZipReader struct {
|
|
mu sync.Mutex // guards Close and Read
|
|
pool *sync.Pool
|
|
dec *Decoder
|
|
}
|
|
|
|
func (r *pooledZipReader) Read(p []byte) (n int, err error) {
|
|
r.mu.Lock()
|
|
defer r.mu.Unlock()
|
|
if r.dec == nil {
|
|
return 0, errors.New("read after close or EOF")
|
|
}
|
|
dec, err := r.dec.Read(p)
|
|
if err == io.EOF {
|
|
r.dec.Reset(nil)
|
|
r.pool.Put(r.dec)
|
|
r.dec = nil
|
|
}
|
|
return dec, err
|
|
}
|
|
|
|
func (r *pooledZipReader) Close() error {
|
|
r.mu.Lock()
|
|
defer r.mu.Unlock()
|
|
var err error
|
|
if r.dec != nil {
|
|
err = r.dec.Reset(nil)
|
|
r.pool.Put(r.dec)
|
|
r.dec = nil
|
|
}
|
|
return err
|
|
}
|
|
|
|
type pooledZipWriter struct {
|
|
mu sync.Mutex // guards Close and Read
|
|
enc *Encoder
|
|
pool *sync.Pool
|
|
}
|
|
|
|
func (w *pooledZipWriter) Write(p []byte) (n int, err error) {
|
|
w.mu.Lock()
|
|
defer w.mu.Unlock()
|
|
if w.enc == nil {
|
|
return 0, errors.New("Write after Close")
|
|
}
|
|
return w.enc.Write(p)
|
|
}
|
|
|
|
func (w *pooledZipWriter) Close() error {
|
|
w.mu.Lock()
|
|
defer w.mu.Unlock()
|
|
var err error
|
|
if w.enc != nil {
|
|
err = w.enc.Close()
|
|
w.pool.Put(w.enc)
|
|
w.enc = nil
|
|
}
|
|
return err
|
|
}
|
|
|
|
// ZipCompressor returns a compressor that can be registered with zip libraries.
|
|
// The provided encoder options will be used on all encodes.
|
|
func ZipCompressor(opts ...EOption) func(w io.Writer) (io.WriteCloser, error) {
|
|
var pool sync.Pool
|
|
return func(w io.Writer) (io.WriteCloser, error) {
|
|
enc, ok := pool.Get().(*Encoder)
|
|
if ok {
|
|
enc.Reset(w)
|
|
} else {
|
|
var err error
|
|
enc, err = NewWriter(w, opts...)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
return &pooledZipWriter{enc: enc, pool: &pool}, nil
|
|
}
|
|
}
|
|
|
|
// ZipDecompressor returns a decompressor that can be registered with zip libraries.
|
|
// See ZipCompressor for example.
|
|
// Options can be specified. WithDecoderConcurrency(1) is forced,
|
|
// and by default a 128MB maximum decompression window is specified.
|
|
// The window size can be overridden if required.
|
|
func ZipDecompressor(opts ...DOption) func(r io.Reader) io.ReadCloser {
|
|
return newZipReader(opts...)
|
|
}
|