DockerCLI/vendor/github.com/emicklei/go-restful/compressor_pools.go

92 lines
2.3 KiB
Go

package restful
// Copyright 2015 Ernest Micklei. All rights reserved.
// Use of this source code is governed by a license
// that can be found in the LICENSE file.
import (
"bytes"
"compress/gzip"
"compress/zlib"
"sync"
)
// SyncPoolCompessors is a CompressorProvider that use the standard sync.Pool.
type SyncPoolCompessors struct {
GzipWriterPool *sync.Pool
GzipReaderPool *sync.Pool
ZlibWriterPool *sync.Pool
}
// NewSyncPoolCompessors returns a new ("empty") SyncPoolCompessors.
func NewSyncPoolCompessors() *SyncPoolCompessors {
return &SyncPoolCompessors{
GzipWriterPool: &sync.Pool{
New: func() interface{} { return newGzipWriter() },
},
GzipReaderPool: &sync.Pool{
New: func() interface{} { return newGzipReader() },
},
ZlibWriterPool: &sync.Pool{
New: func() interface{} { return newZlibWriter() },
},
}
}
func (s *SyncPoolCompessors) AcquireGzipWriter() *gzip.Writer {
return s.GzipWriterPool.Get().(*gzip.Writer)
}
func (s *SyncPoolCompessors) ReleaseGzipWriter(w *gzip.Writer) {
s.GzipWriterPool.Put(w)
}
func (s *SyncPoolCompessors) AcquireGzipReader() *gzip.Reader {
return s.GzipReaderPool.Get().(*gzip.Reader)
}
func (s *SyncPoolCompessors) ReleaseGzipReader(r *gzip.Reader) {
s.GzipReaderPool.Put(r)
}
func (s *SyncPoolCompessors) AcquireZlibWriter() *zlib.Writer {
return s.ZlibWriterPool.Get().(*zlib.Writer)
}
func (s *SyncPoolCompessors) ReleaseZlibWriter(w *zlib.Writer) {
s.ZlibWriterPool.Put(w)
}
func newGzipWriter() *gzip.Writer {
// create with an empty bytes writer; it will be replaced before using the gzipWriter
writer, err := gzip.NewWriterLevel(new(bytes.Buffer), gzip.BestSpeed)
if err != nil {
panic(err.Error())
}
return writer
}
func newGzipReader() *gzip.Reader {
// create with an empty reader (but with GZIP header); it will be replaced before using the gzipReader
// we can safely use currentCompressProvider because it is set on package initialization.
w := currentCompressorProvider.AcquireGzipWriter()
defer currentCompressorProvider.ReleaseGzipWriter(w)
b := new(bytes.Buffer)
w.Reset(b)
w.Flush()
w.Close()
reader, err := gzip.NewReader(bytes.NewReader(b.Bytes()))
if err != nil {
panic(err.Error())
}
return reader
}
func newZlibWriter() *zlib.Writer {
writer, err := zlib.NewWriterLevel(new(bytes.Buffer), gzip.BestSpeed)
if err != nil {
panic(err.Error())
}
return writer
}