diff options
Diffstat (limited to 'src/compress/flate/deflate.go')
| -rw-r--r-- | src/compress/flate/deflate.go | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/src/compress/flate/deflate.go b/src/compress/flate/deflate.go index 8a085ba347..3e4dc7b57e 100644 --- a/src/compress/flate/deflate.go +++ b/src/compress/flate/deflate.go @@ -15,7 +15,17 @@ const ( BestSpeed = 1 BestCompression = 9 DefaultCompression = -1 - HuffmanOnly = -2 // Disables match search and only does Huffman entropy reduction. + + // HuffmanOnly disables Lempel-Ziv match searching and only performs Huffman + // entropy encoding. This mode is useful in compressing data that has + // already been compressed with an LZ style algorithm (e.g. Snappy or LZ4) + // that lacks an entropy encoder. Compression gains are achieved when + // certain bytes in the input stream occur more frequently than others. + // + // Note that HuffmanOnly produces a compressed output that is + // RFC 1951 compliant. That is, any valid DEFLATE decompressor will + // continue to be able to decompress this output. + HuffmanOnly = -2 ) const ( @@ -644,7 +654,6 @@ func (d *compressor) close() error { // a very fast compression for all types of input, but sacrificing considerable // compression efficiency. // -// // If level is in the range [-2, 9] then the error returned will be nil. // Otherwise the error returned will be non-nil. func NewWriter(w io.Writer, level int) (*Writer, error) { |