github.com/grailbio/base@v0.0.11/compress/zstd/zstd_cgo.go (about)

     1  // Package zstd wraps github.com/DataDog/zstd and
     2  // github.com/klauspost/compress/zstd.  It uses DataDog/zstd in cgo mode, and
     3  // klauspost/compress/zstd in noncgo mode.
     4  
     5  // +build cgo
     6  
     7  package zstd
     8  
     9  import (
    10  	"io"
    11  
    12  	cgozstd "github.com/DataDog/zstd"
    13  )
    14  
    15  // Compress compresses the given source data.  Scratch can be passed to prevent
    16  // prevent allocation.  If it is too small, or if nil is passed, a new buffer
    17  // will be allocated and returned.  Arg level specifies the compression
    18  // level. level < 0 means the default compression level.
    19  func CompressLevel(scratch []byte, in []byte, level int) ([]byte, error) {
    20  	if level < 0 {
    21  		level = cgozstd.DefaultCompression
    22  	}
    23  	if cap(scratch) == 0 {
    24  		scratch = nil
    25  	} else {
    26  		scratch = scratch[:cap(scratch)]
    27  	}
    28  	return cgozstd.CompressLevel(scratch, in, level)
    29  }
    30  
    31  // Decompress uncompresses the given source data.  Scratch can be passed to
    32  // prevent allocation.  If it is too small, or if nil is passed, a new buffer
    33  // will be allocated and returned.
    34  func Decompress(scratch []byte, in []byte) ([]byte, error) {
    35  	if cap(scratch) == 0 {
    36  		scratch = nil
    37  	} else {
    38  		scratch = scratch[:cap(scratch)]
    39  	}
    40  	return cgozstd.Decompress(scratch, in)
    41  }
    42  
    43  // NewReader creates a ReadCloser that uncompresses data.  The returned object
    44  // must be Closed after use.
    45  func NewReader(r io.Reader) (io.ReadCloser, error) {
    46  	return cgozstd.NewReader(r), nil
    47  }
    48  
    49  // NewWriter creates a WriterCloser that compresses data.  The returned object
    50  // must be Closed after use.
    51  func NewWriter(w io.Writer) (io.WriteCloser, error) {
    52  	return cgozstd.NewWriter(w), nil
    53  }