| // 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" |
| "io" |
| "io/ioutil" |
| |
| "github.com/klauspost/compress/gzip" |
| "golang.org/x/xerrors" |
| ) |
| |
| type gzipCodec struct{} |
| |
| func (gzipCodec) NewReader(r io.Reader) io.ReadCloser { |
| ret, err := gzip.NewReader(r) |
| if err != nil { |
| panic(xerrors.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 = ioutil.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{} |
| } |