Merge pull request #214 from NyaaaWhatsUpDoc/improvement/update-storage-library

add git.iim.gay/grufwub/go-store for storage backend, replacing blob.Storage

1 files changed, 104 insertions, 0 deletions

diff --git a/vendor/git.iim.gay/grufwub/go-store/storage/compressor.go b/vendor/git.iim.gay/grufwub/go-store/storage/compressor.go
new file mode 100644
index 000000000..b8cfb906c
--- /dev/null
+++ b/vendor/git.iim.gay/grufwub/go-store/storage/compressor.go
@@ -0,0 +1,104 @@
+package storage
+
+import (
+	"compress/gzip"
+	"compress/zlib"
+	"io"
+
+	"git.iim.gay/grufwub/go-store/util"
+	"github.com/golang/snappy"
+)
+
+// Compressor defines a means of compressing/decompressing values going into a key-value store
+type Compressor interface {
+	// Reader returns a new decompressing io.ReadCloser based on supplied (compressed) io.Reader
+	Reader(io.Reader) (io.ReadCloser, error)
+
+	// Writer returns a new compressing io.WriteCloser based on supplied (uncompressed) io.Writer
+	Writer(io.Writer) (io.WriteCloser, error)
+}
+
+type gzipCompressor struct {
+	level int
+}
+
+// GZipCompressor returns a new Compressor that implements GZip at default compression level
+func GZipCompressor() Compressor {
+	return GZipCompressorLevel(gzip.DefaultCompression)
+}
+
+// GZipCompressorLevel returns a new Compressor that implements GZip at supplied compression level
+func GZipCompressorLevel(level int) Compressor {
+	return &gzipCompressor{
+		level: level,
+	}
+}
+
+func (c *gzipCompressor) Reader(r io.Reader) (io.ReadCloser, error) {
+	return gzip.NewReader(r)
+}
+
+func (c *gzipCompressor) Writer(w io.Writer) (io.WriteCloser, error) {
+	return gzip.NewWriterLevel(w, c.level)
+}
+
+type zlibCompressor struct {
+	level int
+	dict  []byte
+}
+
+// ZLibCompressor returns a new Compressor that implements ZLib at default compression level
+func ZLibCompressor() Compressor {
+	return ZLibCompressorLevelDict(zlib.DefaultCompression, nil)
+}
+
+// ZLibCompressorLevel returns a new Compressor that implements ZLib at supplied compression level
+func ZLibCompressorLevel(level int) Compressor {
+	return ZLibCompressorLevelDict(level, nil)
+}
+
+// ZLibCompressorLevelDict returns a new Compressor that implements ZLib at supplied compression level with supplied dict
+func ZLibCompressorLevelDict(level int, dict []byte) Compressor {
+	return &zlibCompressor{
+		level: level,
+		dict:  dict,
+	}
+}
+
+func (c *zlibCompressor) Reader(r io.Reader) (io.ReadCloser, error) {
+	return zlib.NewReaderDict(r, c.dict)
+}
+
+func (c *zlibCompressor) Writer(w io.Writer) (io.WriteCloser, error) {
+	return zlib.NewWriterLevelDict(w, c.level, c.dict)
+}
+
+type snappyCompressor struct{}
+
+// SnappyCompressor returns a new Compressor that implements Snappy
+func SnappyCompressor() Compressor {
+	return &snappyCompressor{}
+}
+
+func (c *snappyCompressor) Reader(r io.Reader) (io.ReadCloser, error) {
+	return util.NopReadCloser(snappy.NewReader(r)), nil
+}
+
+func (c *snappyCompressor) Writer(w io.Writer) (io.WriteCloser, error) {
+	return snappy.NewBufferedWriter(w), nil
+}
+
+type nopCompressor struct{}
+
+// NoCompression is a Compressor that simply does nothing
+func NoCompression() Compressor {
+	return &nopCompressor{}
+}
+
+func (c *nopCompressor) Reader(r io.Reader) (io.ReadCloser, error) {
+	return util.NopReadCloser(r), nil
+}
+
+func (c *nopCompressor) Writer(w io.Writer) (io.WriteCloser, error) {
+	return util.NopWriteCloser(w), nil
+}