github.com/apache/arrow/go/v7@v7.0.1/parquet/compress/snappy.go (about)

     1  // Licensed to the Apache Software Foundation (ASF) under one
     2  // or more contributor license agreements.  See the NOTICE file
     3  // distributed with this work for additional information
     4  // regarding copyright ownership.  The ASF licenses this file
     5  // to you under the Apache License, Version 2.0 (the
     6  // "License"); you may not use this file except in compliance
     7  // with the License.  You may obtain a copy of the License at
     8  //
     9  // http://www.apache.org/licenses/LICENSE-2.0
    10  //
    11  // Unless required by applicable law or agreed to in writing, software
    12  // distributed under the License is distributed on an "AS IS" BASIS,
    13  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14  // See the License for the specific language governing permissions and
    15  // limitations under the License.
    16  
    17  package compress
    18  
    19  import (
    20  	"io"
    21  	"io/ioutil"
    22  
    23  	"github.com/golang/snappy"
    24  )
    25  
    26  type snappyCodec struct{}
    27  
    28  func (snappyCodec) Encode(dst, src []byte) []byte {
    29  	return snappy.Encode(dst, src)
    30  }
    31  
    32  func (snappyCodec) EncodeLevel(dst, src []byte, _ int) []byte {
    33  	return snappy.Encode(dst, src)
    34  }
    35  
    36  func (snappyCodec) Decode(dst, src []byte) []byte {
    37  	dst, err := snappy.Decode(dst, src)
    38  	if err != nil {
    39  		panic(err)
    40  	}
    41  	return dst
    42  }
    43  
    44  func (snappyCodec) NewReader(r io.Reader) io.ReadCloser {
    45  	return ioutil.NopCloser(snappy.NewReader(r))
    46  }
    47  
    48  func (snappyCodec) CompressBound(len int64) int64 {
    49  	return int64(snappy.MaxEncodedLen(int(len)))
    50  }
    51  
    52  func (snappyCodec) NewWriter(w io.Writer) io.WriteCloser {
    53  	return snappy.NewBufferedWriter(w)
    54  }
    55  
    56  func (s snappyCodec) NewWriterLevel(w io.Writer, _ int) (io.WriteCloser, error) {
    57  	return s.NewWriter(w), nil
    58  }
    59  
    60  func init() {
    61  	codecs[Codecs.Snappy] = snappyCodec{}
    62  }