Merge pull request #350 from nishakm/316-zstd-compression

Added support for zstd compression

go.mod

@@ -9,7 +9,7 @@ require (
 	github.com/docker/go-units v0.4.0
 	github.com/golang/protobuf v1.4.2
 	github.com/google/go-cmp v0.5.0 // indirect
-	github.com/klauspost/compress v1.10.9 // indirect
+	github.com/klauspost/compress v1.11.3
 	github.com/klauspost/pgzip v1.2.4
 	github.com/kr/text v0.2.0 // indirect
 	github.com/mattn/go-colorable v0.1.6 // indirect

go.sum

@@ -56,6 +56,8 @@ github.com/jmespath/go-jmespath v0.0.0-20180206201540-c2b33e8439af/go.mod h1:Nht
 github.com/jpillora/backoff v0.0.0-20180909062703-3050d21c67d7/go.mod h1:2iMrUgbbvHEiQClaW2NsSzMyGHqN+rDFqY705q49KG0=
 github.com/klauspost/compress v1.10.9 h1:pPRt1Z78crspaHISkpSSHjDlx+Tt9suHe519dsI0vF4=
 github.com/klauspost/compress v1.10.9/go.mod h1:aoV0uJVorq1K+umq18yTdKaF57EivdYsUV+/s2qKfXs=
+github.com/klauspost/compress v1.11.3 h1:dB4Bn0tN3wdCzQxnS8r06kV74qN/TAfaIS0bVE8h3jc=
+github.com/klauspost/compress v1.11.3/go.mod h1:aoV0uJVorq1K+umq18yTdKaF57EivdYsUV+/s2qKfXs=
 github.com/klauspost/pgzip v1.2.4 h1:TQ7CNpYKovDOmqzRHKxJh0BeaBI7UdQZYc6p7pMQh1A=
 github.com/klauspost/pgzip v1.2.4/go.mod h1:Ch1tH69qFZu15pkjo5kYi6mth2Zzwzt50oCQKQE9RUs=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=

mutate/compress.go

@@ -5,6 +5,7 @@ import (
 	"io/ioutil"
 	"runtime"
 
+	zstd "github.com/klauspost/compress/zstd"
 	gzip "github.com/klauspost/pgzip"
 	"github.com/pkg/errors"
 )
@@ -67,3 +68,37 @@ func (gz gzipCompressor) Compress(reader io.Reader) (io.ReadCloser, error) {
 func (gz gzipCompressor) MediaTypeSuffix() string {
 	return "gzip"
 }
+
+// ZstdCompressor provides zstd compression.
+var ZstdCompressor Compressor = zstdCompressor{}
+
+type zstdCompressor struct{}
+
+func (zs zstdCompressor) Compress(reader io.Reader) (io.ReadCloser, error) {
+
+	pipeReader, pipeWriter := io.Pipe()
+	zenc, err := zstd.NewWriter(pipeWriter)
+	if err != nil {
+		return nil, err
+	}
+	go func() {
+		if _, err := io.Copy(zenc, reader); err != nil {
+			// #nosec G104
+			_ = pipeWriter.CloseWithError(errors.Wrap(err, "compressing layer"))
+		}
+		if err := zenc.Close(); err != nil {
+			// #nosec G104
+			_ = pipeWriter.CloseWithError(errors.Wrap(err, "close gzip writer"))
+		}
+		if err := pipeWriter.Close(); err != nil {
+			// #nosec G104
+			_ = pipeWriter.CloseWithError(errors.Wrap(err, "close pipe writer"))
+		}
+	}()
+
+	return pipeReader, nil
+}
+
+func (zs zstdCompressor) MediaTypeSuffix() string {
+	return "zstd"
+}

mutate/compress_test.go

@@ -2,9 +2,11 @@ package mutate
 
 import (
 	"bytes"
+	"io"
 	"io/ioutil"
 	"testing"
 
+	zstd "github.com/klauspost/compress/zstd"
 	gzip "github.com/klauspost/pgzip"
 	"github.com/stretchr/testify/assert"
 )
@@ -45,3 +47,22 @@ func TestGzipCompressor(t *testing.T) {
 
 	assert.Equal(string(content), fact)
 }
+
+func TestZstdCompressor(t *testing.T) {
+	assert := assert.New(t)
+
+	buf := bytes.NewBufferString(fact)
+	c := ZstdCompressor
+
+	r, err := c.Compress(buf)
+	assert.NoError(err)
+	assert.Equal(c.MediaTypeSuffix(), "zstd")
+
+	dec, err := zstd.NewReader(r)
+	assert.NoError(err)
+
+	var content bytes.Buffer
+	_, err = io.Copy(&content, dec)
+	assert.NoError(err)
+	assert.Equal(content.String(), fact)
+}