THRIFT-2083 Improve the go lib: buffered Transport, save memory allocation, handle concurrent request

Patch: Feng Shen
diff --git a/lib/go/thrift/binary_protocol.go b/lib/go/thrift/binary_protocol.go
index 5880f65..6fb8624 100644
--- a/lib/go/thrift/binary_protocol.go
+++ b/lib/go/thrift/binary_protocol.go
@@ -24,15 +24,15 @@
 	"fmt"
 	"io"
 	"math"
-	"strings"
 )
 
 type TBinaryProtocol struct {
-	trans            TTransport
+	trans           TTransport
 	strictRead      bool
 	strictWrite     bool
 	readLength      int
 	checkReadLength bool
+	buffer          [8]byte
 }
 
 type TBinaryProtocolFactory struct {
@@ -180,33 +180,22 @@
 }
 
 func (p *TBinaryProtocol) WriteI16(value int16) error {
-	h := byte(0xff & (value >> 8))
-	l := byte(0xff & value)
-	v := []byte{h, l}
+	v := p.buffer[0:2]
+	binary.BigEndian.PutUint16(v, uint16(value))
 	_, e := p.trans.Write(v)
 	return NewTProtocolException(e)
 }
 
 func (p *TBinaryProtocol) WriteI32(value int32) error {
-	a := byte(0xff & (value >> 24))
-	b := byte(0xff & (value >> 16))
-	c := byte(0xff & (value >> 8))
-	d := byte(0xff & value)
-	v := []byte{a, b, c, d}
+	v := p.buffer[0:4]
+	binary.BigEndian.PutUint32(v, uint32(value))
 	_, e := p.trans.Write(v)
 	return NewTProtocolException(e)
 }
 
 func (p *TBinaryProtocol) WriteI64(value int64) error {
-	a := byte(0xff & (value >> 56))
-	b := byte(0xff & (value >> 48))
-	c := byte(0xff & (value >> 40))
-	d := byte(0xff & (value >> 32))
-	e := byte(0xff & (value >> 24))
-	f := byte(0xff & (value >> 16))
-	g := byte(0xff & (value >> 8))
-	h := byte(0xff & value)
-	v := []byte{a, b, c, d, e, f, g, h}
+	v := p.buffer[:]
+	binary.BigEndian.PutUint64(v, uint64(value))
 	_, err := p.trans.Write(v)
 	return NewTProtocolException(err)
 }
@@ -216,7 +205,7 @@
 }
 
 func (p *TBinaryProtocol) WriteString(value string) error {
-	return p.WriteBinaryFromReader(strings.NewReader(value), len(value))
+	return p.WriteBinary([]byte(value))
 }
 
 func (p *TBinaryProtocol) WriteBinary(value []byte) error {
@@ -228,15 +217,6 @@
 	return NewTProtocolException(err)
 }
 
-func (p *TBinaryProtocol) WriteBinaryFromReader(reader io.Reader, size int) error {
-	e := p.WriteI32(int32(size))
-	if e != nil {
-		return e
-	}
-	_, err := io.CopyN(p.trans, reader, int64(size))
-	return NewTProtocolException(err)
-}
-
 /**
  * Reading methods
  */
@@ -385,34 +365,34 @@
 }
 
 func (p *TBinaryProtocol) ReadByte() (value byte, err error) {
-	buf := []byte{0}
+	buf := p.buffer[0:1]
 	err = p.readAll(buf)
 	return buf[0], err
 }
 
 func (p *TBinaryProtocol) ReadI16() (value int16, err error) {
-	buf := []byte{0, 0}
+	buf := p.buffer[0:2]
 	err = p.readAll(buf)
 	value = int16(binary.BigEndian.Uint16(buf))
 	return value, err
 }
 
 func (p *TBinaryProtocol) ReadI32() (value int32, err error) {
-	buf := []byte{0, 0, 0, 0}
+	buf := p.buffer[0:4]
 	err = p.readAll(buf)
 	value = int32(binary.BigEndian.Uint32(buf))
 	return value, err
 }
 
 func (p *TBinaryProtocol) ReadI64() (value int64, err error) {
-	buf := []byte{0, 0, 0, 0, 0, 0, 0, 0}
+	buf := p.buffer[0:8]
 	err = p.readAll(buf)
 	value = int64(binary.BigEndian.Uint64(buf))
 	return value, err
 }
 
 func (p *TBinaryProtocol) ReadDouble() (value float64, err error) {
-	buf := []byte{0, 0, 0, 0, 0, 0, 0, 0}
+	buf := p.buffer[0:8]
 	err = p.readAll(buf)
 	value = math.Float64frombits(binary.BigEndian.Uint64(buf))
 	return value, err
diff --git a/lib/go/thrift/buffed_transport.go b/lib/go/thrift/buffed_transport.go
new file mode 100644
index 0000000..1ba3053
--- /dev/null
+++ b/lib/go/thrift/buffed_transport.go
@@ -0,0 +1,87 @@
+package thrift
+
+type TBufferedTransportFactory struct {
+	size int
+}
+
+type TBuffer struct {
+	buffer     []byte
+	pos, limit int
+}
+
+type TBufferedTransport struct {
+	tp   TTransport
+	rbuf *TBuffer
+	wbuf *TBuffer
+}
+
+func (p *TBufferedTransportFactory) GetTransport(trans TTransport) TTransport {
+	return NewTBufferedTransport(trans, p.size)
+}
+
+func NewTBufferedTransportFactory(bufferSize int) *TBufferedTransportFactory {
+	return &TBufferedTransportFactory{size: bufferSize}
+}
+
+func NewTBufferedTransport(trans TTransport, bufferSize int) *TBufferedTransport {
+	rb := &TBuffer{buffer: make([]byte, bufferSize)}
+	wb := &TBuffer{buffer: make([]byte, bufferSize), limit: bufferSize}
+	return &TBufferedTransport{tp: trans, rbuf: rb, wbuf: wb}
+}
+
+func (p *TBufferedTransport) IsOpen() bool {
+	return p.tp.IsOpen()
+}
+
+func (p *TBufferedTransport) Open() (err error) {
+	return p.tp.Open()
+}
+
+func (p *TBufferedTransport) Close() (err error) {
+	return p.tp.Close()
+}
+
+func (p *TBufferedTransport) Read(buf []byte) (n int, err error) {
+	rbuf := p.rbuf
+	if rbuf.pos == rbuf.limit { // no more data to read from buffer
+		rbuf.pos = 0
+		// read data, fill buffer
+		rbuf.limit, err = p.tp.Read(rbuf.buffer)
+		if err != nil {
+			return 0, err
+		}
+	}
+	n = copy(buf, rbuf.buffer[rbuf.pos:rbuf.limit])
+	rbuf.pos += n
+	return n, nil
+}
+
+func (p *TBufferedTransport) Write(buf []byte) (n int, err error) {
+	wbuf := p.wbuf
+	size := len(buf)
+	if wbuf.pos+size > wbuf.limit { // buffer is full, flush buffer
+		p.Flush()
+	}
+	n = copy(wbuf.buffer[wbuf.pos:], buf)
+	wbuf.pos += n
+	return n, nil
+}
+
+func (p *TBufferedTransport) Flush() error {
+	start := 0
+	wbuf := p.wbuf
+	for start < wbuf.pos {
+		n, err := p.tp.Write(wbuf.buffer[start:wbuf.pos])
+		if err != nil {
+			return err
+		}
+		start += n
+	}
+
+	wbuf.pos = 0
+	return p.tp.Flush()
+}
+
+func (p *TBufferedTransport) Peek() bool {
+	return p.rbuf.pos < p.rbuf.limit || p.tp.Peek()
+}
diff --git a/lib/go/thrift/simple_server.go b/lib/go/thrift/simple_server.go
index 17be8d8..b5cb0e1 100644
--- a/lib/go/thrift/simple_server.go
+++ b/lib/go/thrift/simple_server.go
@@ -120,12 +120,14 @@
 	for !p.stopped {
 		client, err := p.serverTransport.Accept()
 		if err != nil {
-			return err
+			log.Println("Accept err: ", err)
 		}
 		if client != nil {
-			if err := p.processRequest(client); err != nil {
-				log.Println("error processing request:", err)
-			}
+			go func() {
+				if err := p.processRequest(client); err != nil {
+					log.Println("error processing request:", err)
+				}
+			}()
 		}
 	}
 	return nil