mirror of
https://github.com/ceph/ceph-csi.git
synced 2024-11-10 00:10:20 +00:00
118 lines
2.8 KiB
Go
118 lines
2.8 KiB
Go
/*
|
|
*
|
|
* Copyright 2017 gRPC authors.
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*
|
|
*/
|
|
|
|
// Package gzip implements and registers the gzip compressor
|
|
// during the initialization.
|
|
// This package is EXPERIMENTAL.
|
|
package gzip
|
|
|
|
import (
|
|
"compress/gzip"
|
|
"fmt"
|
|
"io"
|
|
"io/ioutil"
|
|
"sync"
|
|
|
|
"google.golang.org/grpc/encoding"
|
|
)
|
|
|
|
// Name is the name registered for the gzip compressor.
|
|
const Name = "gzip"
|
|
|
|
func init() {
|
|
c := &compressor{}
|
|
c.poolCompressor.New = func() interface{} {
|
|
return &writer{Writer: gzip.NewWriter(ioutil.Discard), pool: &c.poolCompressor}
|
|
}
|
|
encoding.RegisterCompressor(c)
|
|
}
|
|
|
|
type writer struct {
|
|
*gzip.Writer
|
|
pool *sync.Pool
|
|
}
|
|
|
|
// SetLevel updates the registered gzip compressor to use the compression level specified (gzip.HuffmanOnly is not supported).
|
|
// NOTE: this function must only be called during initialization time (i.e. in an init() function),
|
|
// and is not thread-safe.
|
|
//
|
|
// The error returned will be nil if the specified level is valid.
|
|
func SetLevel(level int) error {
|
|
if level < gzip.DefaultCompression || level > gzip.BestCompression {
|
|
return fmt.Errorf("grpc: invalid gzip compression level: %d", level)
|
|
}
|
|
c := encoding.GetCompressor(Name).(*compressor)
|
|
c.poolCompressor.New = func() interface{} {
|
|
w, err := gzip.NewWriterLevel(ioutil.Discard, level)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
return &writer{Writer: w, pool: &c.poolCompressor}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (c *compressor) Compress(w io.Writer) (io.WriteCloser, error) {
|
|
z := c.poolCompressor.Get().(*writer)
|
|
z.Writer.Reset(w)
|
|
return z, nil
|
|
}
|
|
|
|
func (z *writer) Close() error {
|
|
defer z.pool.Put(z)
|
|
return z.Writer.Close()
|
|
}
|
|
|
|
type reader struct {
|
|
*gzip.Reader
|
|
pool *sync.Pool
|
|
}
|
|
|
|
func (c *compressor) Decompress(r io.Reader) (io.Reader, error) {
|
|
z, inPool := c.poolDecompressor.Get().(*reader)
|
|
if !inPool {
|
|
newZ, err := gzip.NewReader(r)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &reader{Reader: newZ, pool: &c.poolDecompressor}, nil
|
|
}
|
|
if err := z.Reset(r); err != nil {
|
|
c.poolDecompressor.Put(z)
|
|
return nil, err
|
|
}
|
|
return z, nil
|
|
}
|
|
|
|
func (z *reader) Read(p []byte) (n int, err error) {
|
|
n, err = z.Reader.Read(p)
|
|
if err == io.EOF {
|
|
z.pool.Put(z)
|
|
}
|
|
return n, err
|
|
}
|
|
|
|
func (c *compressor) Name() string {
|
|
return Name
|
|
}
|
|
|
|
type compressor struct {
|
|
poolCompressor sync.Pool
|
|
poolDecompressor sync.Pool
|
|
}
|