github.com/apache/arrow/go/v14@v14.0.1/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  
    22  	"github.com/golang/snappy"
    23  )
    24  
    25  type snappyCodec struct{}
    26  
    27  func (snappyCodec) Encode(dst, src []byte) []byte {
    28  	return snappy.Encode(dst, src)
    29  }
    30  
    31  func (snappyCodec) EncodeLevel(dst, src []byte, _ int) []byte {
    32  	return snappy.Encode(dst, src)
    33  }
    34  
    35  func (snappyCodec) Decode(dst, src []byte) []byte {
    36  	dst, err := snappy.Decode(dst, src)
    37  	if err != nil {
    38  		panic(err)
    39  	}
    40  	return dst
    41  }
    42  
    43  func (snappyCodec) NewReader(r io.Reader) io.ReadCloser {
    44  	return io.NopCloser(snappy.NewReader(r))
    45  }
    46  
    47  func (snappyCodec) CompressBound(len int64) int64 {
    48  	return int64(snappy.MaxEncodedLen(int(len)))
    49  }
    50  
    51  func (snappyCodec) NewWriter(w io.Writer) io.WriteCloser {
    52  	return snappy.NewBufferedWriter(w)
    53  }
    54  
    55  func (s snappyCodec) NewWriterLevel(w io.Writer, _ int) (io.WriteCloser, error) {
    56  	return s.NewWriter(w), nil
    57  }
    58  
    59  func init() {
    60  	codecs[Codecs.Snappy] = snappyCodec{}
    61  }