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// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you 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 compress
import (
"bytes"
"fmt"
"io"
"github.com/klauspost/compress/gzip"
)
type gzipCodec struct{}
func (gzipCodec) NewReader(r io.Reader) io.ReadCloser {
ret, err := gzip.NewReader(r)
if err != nil {
panic(fmt.Errorf("codec: gzip: %w", err))
}
return ret
}
func (gzipCodec) Decode(dst, src []byte) []byte {
rdr, err := gzip.NewReader(bytes.NewReader(src))
if err != nil {
panic(err)
}
if dst != nil {
n, err := io.ReadFull(rdr, dst)
if err != nil {
panic(err)
}
return dst[:n]
}
dst, err = io.ReadAll(rdr)
if err != nil {
panic(err)
}
return dst
}
func (g gzipCodec) EncodeLevel(dst, src []byte, level int) []byte {
maxlen := int(g.CompressBound(int64(len(src))))
if dst == nil || cap(dst) < maxlen {
dst = make([]byte, 0, maxlen)
}
buf := bytes.NewBuffer(dst[:0])
w, err := gzip.NewWriterLevel(buf, level)
if err != nil {
panic(err)
}
_, err = w.Write(src)
if err != nil {
panic(err)
}
if err := w.Close(); err != nil {
panic(err)
}
return buf.Bytes()
}
func (g gzipCodec) Encode(dst, src []byte) []byte {
return g.EncodeLevel(dst, src, DefaultCompressionLevel)
}
func (gzipCodec) CompressBound(len int64) int64 {
return len + ((len + 7) >> 3) + ((len + 63) >> 6) + 5
}
func (gzipCodec) NewWriter(w io.Writer) io.WriteCloser {
return gzip.NewWriter(w)
}
func (gzipCodec) NewWriterLevel(w io.Writer, level int) (io.WriteCloser, error) {
return gzip.NewWriterLevel(w, level)
}
func init() {
codecs[Codecs.Gzip] = gzipCodec{}
}
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