github.com/rbisecke/kafka-go@v0.4.27/compress/lz4/lz4.go (about)

     1  package lz4
     2  
     3  import (
     4  	"io"
     5  	"sync"
     6  
     7  	"github.com/pierrec/lz4"
     8  )
     9  
    10  var (
    11  	readerPool sync.Pool
    12  	writerPool sync.Pool
    13  )
    14  
    15  // Codec is the implementation of a compress.Codec which supports creating
    16  // readers and writers for kafka messages compressed with lz4.
    17  type Codec struct{}
    18  
    19  // Code implements the compress.Codec interface.
    20  func (c *Codec) Code() int8 { return 3 }
    21  
    22  // Name implements the compress.Codec interface.
    23  func (c *Codec) Name() string { return "lz4" }
    24  
    25  // NewReader implements the compress.Codec interface.
    26  func (c *Codec) NewReader(r io.Reader) io.ReadCloser {
    27  	z, _ := readerPool.Get().(*lz4.Reader)
    28  	if z != nil {
    29  		z.Reset(r)
    30  	} else {
    31  		z = lz4.NewReader(r)
    32  	}
    33  	return &reader{Reader: z}
    34  }
    35  
    36  // NewWriter implements the compress.Codec interface.
    37  func (c *Codec) NewWriter(w io.Writer) io.WriteCloser {
    38  	z, _ := writerPool.Get().(*lz4.Writer)
    39  	if z != nil {
    40  		z.Reset(w)
    41  	} else {
    42  		z = lz4.NewWriter(w)
    43  	}
    44  	return &writer{Writer: z}
    45  }
    46  
    47  type reader struct{ *lz4.Reader }
    48  
    49  func (r *reader) Close() (err error) {
    50  	if z := r.Reader; z != nil {
    51  		r.Reader = nil
    52  		z.Reset(nil)
    53  		readerPool.Put(z)
    54  	}
    55  	return
    56  }
    57  
    58  type writer struct{ *lz4.Writer }
    59  
    60  func (w *writer) Close() (err error) {
    61  	if z := w.Writer; z != nil {
    62  		w.Writer = nil
    63  		err = z.Close()
    64  		z.Reset(nil)
    65  		writerPool.Put(z)
    66  	}
    67  	return
    68  }