feat(compress): add lz4hc support

client.go

@@ -307,19 +307,27 @@ const (
 	CompressionZSTD
 	// CompressionNone uses no compression but data has checksums.
 	CompressionNone
+	// CompressionLZ4HC enables LZ4 HC compression for data. High CPU overhead.
+	CompressionLZ4HC
 )
 
+// CompressionLevel setting. A level == 0 is invalid and resolves to the default.
+//
+// Supported by: LZ4HC.
+type CompressionLevel uint32
+
 // Options for Client. Zero value is valid.
 type Options struct {
-	Logger      *zap.Logger // defaults to Nop.
-	Address     string      // 127.0.0.1:9000
-	Database    string      // "default"
-	User        string      // "default"
-	Password    string      // blank string by default
-	QuotaKey    string      // blank string by default
-	Compression Compression // disabled by default
-	ClientName  string      // blank string by default
-	Settings    []Setting   // none by default
+	Logger           *zap.Logger      // defaults to Nop.
+	Address          string           // 127.0.0.1:9000
+	Database         string           // "default"
+	User             string           // "default"
+	Password         string           // blank string by default
+	QuotaKey         string           // blank string by default
+	Compression      Compression      // disabled by default
+	CompressionLevel CompressionLevel // compression algorithm specific default
+	ClientName       string           // blank string by default
+	Settings         []Setting        // none by default
 
 	// ReadTimeout is a timeout for reading a single packet from the server.
 	//
@@ -459,7 +467,7 @@ func Connect(ctx context.Context, conn net.Conn, opt Options) (*Client, error) {
 
 		readTimeout: opt.ReadTimeout,
 
-		compressor: compress.NewWriter(),
+		compressor: compress.NewWriterWithLevel(compress.Level(opt.CompressionLevel)),
 
 		version:         ver,
 		protocolVersion: opt.ProtocolVersion,
@@ -479,6 +487,9 @@ func Connect(ctx context.Context, conn net.Conn, opt Options) (*Client, error) {
 	case CompressionLZ4:
 		c.compression = proto.CompressionEnabled
 		c.compressionMethod = compress.LZ4
+	case CompressionLZ4HC:
+		c.compression = proto.CompressionEnabled
+		c.compressionMethod = compress.LZ4HC
 	case CompressionZSTD:
 		c.compression = proto.CompressionEnabled
 		c.compressionMethod = compress.ZSTD

compress/_golden/data_compressed_lz4_hc.hex

@@ -0,0 +1,3 @@
+00000000  34 39 ad b3 8d 96 d2 87  bb 3b aa 1e 3f 4b 64 f5  |49.......;..?Kd.|
+00000010  82 1d 00 00 00 af 00 00  00 8f 48 65 6c 6c 6f 21  |..........Hello!|
+00000020  0a 48 07 00 8d 70 48 65  6c 6c 6f 21 0a           |.H...pHello!.|

compress/compress.go

@@ -7,18 +7,38 @@ import (
 	"github.com/go-faster/city"
 )
 
-//go:generate go run github.com/dmarkham/enumer -transform snake_upper -type Method -output method_enum.go
+//go:generate go run github.com/dmarkham/enumer -transform upper -type Method -output method_enum.go
 
 // Method is compression codec.
 type Method byte
 
 // Possible compression methods.
 const (
-	None Method = 0x02
-	LZ4  Method = 0x82
-	ZSTD Method = 0x90
+	None Method = iota
+	LZ4
+	LZ4HC
+	ZSTD
 )
 
+type methodEncoding byte
+
+const (
+	encodedNone  methodEncoding = 0x02
+	encodedLZ4   methodEncoding = 0x82
+	encodedLZ4HC methodEncoding = encodedLZ4
+	encodedZSTD  methodEncoding = 0x90
+)
+
+var methodTable = map[Method]methodEncoding{
+	None:  encodedNone,
+	LZ4:   encodedLZ4,
+	LZ4HC: encodedLZ4HC,
+	ZSTD:  encodedZSTD,
+}
+
+// Level for supporting compression codecs.
+type Level uint32
+
 // Constants for compression encoding.
 //
 // See https://go-faster.org/docs/clickhouse/compression for reference.

compress/reader.go

@@ -70,8 +70,8 @@ func (r *Reader) readBlock() error {
 			DataSize:  dataSize,
 		}, "mismatch")
 	}
-	switch m := Method(r.header[hMethod]); m {
-	case LZ4:
+	switch m := methodEncoding(r.header[hMethod]); m {
+	case encodedLZ4: // == encodedLZ4HC, as decompression is similar for both
 		n, err := lz4.UncompressBlock(r.raw[headerSize:], r.data)
 		if err != nil {
 			return errors.Wrap(err, "uncompress")
@@ -81,7 +81,7 @@ func (r *Reader) readBlock() error {
 				n, dataSize,
 			)
 		}
-	case ZSTD:
+	case encodedZSTD:
 		if r.zstd == nil {
 			// Lazily initializing to prevent spawning goroutines in NewReader.
 			// See https://github.com/golang/go/issues/47056#issuecomment-997436820
@@ -104,7 +104,7 @@ func (r *Reader) readBlock() error {
 			)
 		}
 		r.data = data
-	case None:
+	case encodedNone:
 		copy(r.data, r.raw[headerSize:])
 	default:
 		return errors.Errorf("compression 0x%02x not implemented", m)

compress/writer.go

@@ -2,27 +2,34 @@ package compress
 
 import (
 	"encoding/binary"
+	"math"
 
 	"github.com/go-faster/city"
 	"github.com/go-faster/errors"
 	"github.com/klauspost/compress/zstd"
 	"github.com/pierrec/lz4/v4"
 )
 
+const (
+	CompressionLevelLZ4HCDefault Level = 9
+	CompressionLevelLZ4HCMax     Level = 12
+)
+
 // Writer encodes compressed blocks.
 type Writer struct {
 	Data []byte
 
-	lz4  *lz4.Compressor
-	zstd *zstd.Encoder
+	lz4   *lz4.Compressor
+	lz4hc *lz4.CompressorHC
+	zstd  *zstd.Encoder
 }
 
 // Compress buf into Data.
 func (w *Writer) Compress(m Method, buf []byte) error {
 	maxSize := lz4.CompressBlockBound(len(buf))
 	w.Data = append(w.Data[:0], make([]byte, maxSize+headerSize)...)
 	_ = w.Data[:headerSize]
-	w.Data[hMethod] = byte(m)
+	w.Data[hMethod] = byte(methodTable[m])
 
 	var n int
 
@@ -33,6 +40,12 @@ func (w *Writer) Compress(m Method, buf []byte) error {
 			return errors.Wrap(err, "block")
 		}
 		n = compressedSize
+	case LZ4HC:
+		compressedSize, err := w.lz4hc.CompressBlock(buf, w.Data[headerSize:])
+		if err != nil {
+			return errors.Wrap(err, "block")
+		}
+		n = compressedSize
 	case ZSTD:
 		w.Data = w.zstd.EncodeAll(buf, w.Data[:headerSize])
 		n = len(w.Data) - headerSize
@@ -51,7 +64,7 @@ func (w *Writer) Compress(m Method, buf []byte) error {
 	return nil
 }
 
-func NewWriter() *Writer {
+func NewWriterWithLevel(l Level) *Writer {
 	w, err := zstd.NewWriter(nil,
 		zstd.WithEncoderLevel(zstd.SpeedDefault),
 		zstd.WithEncoderConcurrency(1),
@@ -60,8 +73,22 @@ func NewWriter() *Writer {
 	if err != nil {
 		panic(err)
 	}
+
+	// handle level for LZ4HC
+	levelLZ4HC := l
+	if levelLZ4HC == 0 {
+		levelLZ4HC = CompressionLevelLZ4HCDefault
+	} else {
+		levelLZ4HC = Level(math.Min(float64(levelLZ4HC), float64(CompressionLevelLZ4HCMax)))
+	}
+
 	return &Writer{
-		lz4:  &lz4.Compressor{},
-		zstd: w,
+		lz4:   &lz4.Compressor{},
+		lz4hc: &lz4.CompressorHC{Level: lz4.CompressionLevel(1 << (8 + levelLZ4HC))},
+		zstd:  w,
 	}
 }
+
+func NewWriter() *Writer {
+	return NewWriterWithLevel(0)
+}

query_test.go

@@ -1061,6 +1061,7 @@ func TestClientCompression(t *testing.T) {
 		}
 	}
 	t.Run("LZ4", testCompression(CompressionLZ4))
+	t.Run("LZ4HC", testCompression(CompressionLZ4HC))
 	t.Run("ZSTD", testCompression(CompressionZSTD))
 	t.Run("None", testCompression(CompressionNone))
 	t.Run("Disabled", testCompression(CompressionDisabled))