go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/auth_service/impl/util/zlib/codec.go (about)

     1  // Copyright 2024 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  // Package zlib contains functions for zlib encoding and decoding.
    16  package zlib
    17  
    18  import (
    19  	"bytes"
    20  	"compress/zlib"
    21  	"io"
    22  )
    23  
    24  func Compress(input []byte) ([]byte, error) {
    25  	var b bytes.Buffer
    26  	w := zlib.NewWriter(&b)
    27  	if _, err := w.Write(input); err != nil {
    28  		// Error writing; close the writer before returning.
    29  		_ = w.Close()
    30  		return nil, err
    31  	}
    32  
    33  	if err := w.Close(); err != nil {
    34  		// Error closing writer.
    35  		return nil, err
    36  	}
    37  
    38  	return b.Bytes(), nil
    39  }
    40  
    41  func Decompress(input []byte) ([]byte, error) {
    42  	r, err := zlib.NewReader(bytes.NewBuffer(input))
    43  	if err != nil {
    44  		// Error creating reader.
    45  		return nil, err
    46  	}
    47  
    48  	w := bytes.NewBuffer([]byte{})
    49  	if _, err := io.Copy(w, r); err != nil {
    50  		// Error copying from reader; close the reader before returning.
    51  		_ = r.Close()
    52  		return nil, err
    53  	}
    54  
    55  	if err := r.Close(); err != nil {
    56  		// Error closing the reader.
    57  		return nil, err
    58  	}
    59  
    60  	return w.Bytes(), nil
    61  }