diff options
Diffstat (limited to 'vendor/github.com/peterbourgon/diskv/compression.go')
-rw-r--r-- | vendor/github.com/peterbourgon/diskv/compression.go | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/vendor/github.com/peterbourgon/diskv/compression.go b/vendor/github.com/peterbourgon/diskv/compression.go new file mode 100644 index 000000000..5192b0273 --- /dev/null +++ b/vendor/github.com/peterbourgon/diskv/compression.go @@ -0,0 +1,64 @@ +package diskv + +import ( + "compress/flate" + "compress/gzip" + "compress/zlib" + "io" +) + +// Compression is an interface that Diskv uses to implement compression of +// data. Writer takes a destination io.Writer and returns a WriteCloser that +// compresses all data written through it. Reader takes a source io.Reader and +// returns a ReadCloser that decompresses all data read through it. You may +// define these methods on your own type, or use one of the NewCompression +// helpers. +type Compression interface { + Writer(dst io.Writer) (io.WriteCloser, error) + Reader(src io.Reader) (io.ReadCloser, error) +} + +// NewGzipCompression returns a Gzip-based Compression. +func NewGzipCompression() Compression { + return NewGzipCompressionLevel(flate.DefaultCompression) +} + +// NewGzipCompressionLevel returns a Gzip-based Compression with the given level. +func NewGzipCompressionLevel(level int) Compression { + return &genericCompression{ + wf: func(w io.Writer) (io.WriteCloser, error) { return gzip.NewWriterLevel(w, level) }, + rf: func(r io.Reader) (io.ReadCloser, error) { return gzip.NewReader(r) }, + } +} + +// NewZlibCompression returns a Zlib-based Compression. +func NewZlibCompression() Compression { + return NewZlibCompressionLevel(flate.DefaultCompression) +} + +// NewZlibCompressionLevel returns a Zlib-based Compression with the given level. +func NewZlibCompressionLevel(level int) Compression { + return NewZlibCompressionLevelDict(level, nil) +} + +// NewZlibCompressionLevelDict returns a Zlib-based Compression with the given +// level, based on the given dictionary. +func NewZlibCompressionLevelDict(level int, dict []byte) Compression { + return &genericCompression{ + func(w io.Writer) (io.WriteCloser, error) { return zlib.NewWriterLevelDict(w, level, dict) }, + func(r io.Reader) (io.ReadCloser, error) { return zlib.NewReaderDict(r, dict) }, + } +} + +type genericCompression struct { + wf func(w io.Writer) (io.WriteCloser, error) + rf func(r io.Reader) (io.ReadCloser, error) +} + +func (g *genericCompression) Writer(dst io.Writer) (io.WriteCloser, error) { + return g.wf(dst) +} + +func (g *genericCompression) Reader(src io.Reader) (io.ReadCloser, error) { + return g.rf(src) +} |