use net.Buffers to reduce memory inuse bytes..

client.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"crypto/tls"
 	"fmt"
-	"io"
 	"net"
 	"strconv"
 	"strings"
@@ -94,6 +93,7 @@ func (c *Client) Close() error {
 		return errors.Wrap(err, "conn")
 	}
 
+	c.buf.Reset() // avoid memory leak.
 	return nil
 }
 
@@ -269,15 +269,13 @@ func (c *Client) flushBuf(ctx context.Context, b *proto.Buffer) error {
 		// Reset deadline.
 		defer func() { _ = c.conn.SetWriteDeadline(time.Time{}) }()
 	}
-	n, err := c.conn.Write(b.Buf)
+	b.Buffers = append(b.Buffers, b.Buf)
+	n, err := b.Buffers.WriteTo(c.conn)
 	if err != nil {
 		return errors.Wrap(err, "write")
 	}
-	if n != len(b.Buf) {
-		return errors.Wrap(io.ErrShortWrite, "wrote less than expected")
-	}
 	if ce := c.lg.Check(zap.DebugLevel, "Flush"); ce != nil {
-		ce.Write(zap.Int("bytes", n))
+		ce.Write(zap.Int("bytes", int(n)))
 	}
 	b.Reset()
 	return nil

proto/buffer.go

@@ -5,11 +5,13 @@
 	"encoding/binary"
 	"io"
 	"math"
+	"net"
 )
 
 // Buffer implements ClickHouse binary protocol encoding.
 type Buffer struct {
 	Buf []byte
+	net.Buffers
 }
 
 // Reader returns new *Reader from *Buffer.
@@ -45,6 +47,7 @@
 // Reset buffer to zero length.
 func (b *Buffer) Reset() {
 	b.Buf = b.Buf[:0]
+	b.Buffers = nil
 }
 
 // Read implements io.Reader.
@@ -122,7 +125,7 @@
 }
 
 func (b *Buffer) PutInt8(v int8) {
 	b.PutUInt8(uint8(v))
 }
 
 func (b *Buffer) PutInt16(v int16) {

proto/col_str.go

@@ -21,6 +21,7 @@ type ColStr struct {
 
 // Append string to column.
 func (c *ColStr) Append(v string) {
+	c.Buf = binary.AppendUvarint(c.Buf, uint64(len(v)))
 	start := len(c.Buf)
 	c.Buf = append(c.Buf, v...)
 	end := len(c.Buf)
@@ -29,6 +30,7 @@ func (c *ColStr) Append(v string) {
 
 // AppendBytes append byte slice as string to column.
 func (c *ColStr) AppendBytes(v []byte) {
+	c.Buf = binary.AppendUvarint(c.Buf, uint64(len(v)))
 	start := len(c.Buf)
 	c.Buf = append(c.Buf, v...)
 	end := len(c.Buf)
@@ -68,12 +70,11 @@ func (c *ColStr) Reset() {
 
 // EncodeColumn encodes String rows to *Buffer.
 func (c ColStr) EncodeColumn(b *Buffer) {
-	buf := make([]byte, binary.MaxVarintLen64)
-	for _, p := range c.Pos {
-		n := binary.PutUvarint(buf, uint64(p.End-p.Start))
-		b.Buf = append(b.Buf, buf[:n]...)
-		b.Buf = append(b.Buf, c.Buf[p.Start:p.End]...)
+	if b.Buf != nil {
+		b.Buffers = append(b.Buffers, b.Buf)
+		b.Buf = nil
 	}
+	b.Buffers = append(b.Buffers, c.Buf)
 }
 
 // ForEach calls f on each string from column.

query.go

@@ -301,6 +301,7 @@
 	// Note: only blocks are compressed.
 	// See "Compressible" method of server or client code for reference.
 	if c.compression == proto.CompressionEnabled {
+		// TODO SUPPORT COMPRESS
 		data := c.buf.Buf[start:]
 		if err := c.compressor.Compress(c.compressionMethod, data); err != nil {
 			return errors.Wrap(err, "compress")
@@ -448,7 +449,7 @@
 		if err != nil {
 			return errors.Wrap(err, "progress")
 		}
 		c.metricsInc(ctx, queryMetrics{Rows: int(p.Rows), Bytes: int(p.Bytes)})
 		if ce := c.lg.Check(zap.DebugLevel, "Progress"); ce != nil {
 			ce.Write(
 				zap.Uint64("rows", p.Rows),