diff --git a/app/dispatcher/impl/default.go b/app/dispatcher/impl/default.go
index 4f6c93136..5ae2f6475 100644
--- a/app/dispatcher/impl/default.go
+++ b/app/dispatcher/impl/default.go
@@ -62,7 +62,7 @@ func (v *DefaultDispatcher) DispatchToOutbound(session *proxy.SessionInfo) ray.I
 	}
 
 	if session.Inbound != nil && session.Inbound.AllowPassiveConnection {
-		go dispatcher.Dispatch(destination, buf.NewLocalBuffer(32), direct)
+		go dispatcher.Dispatch(destination, buf.NewLocal(32), direct)
 	} else {
 		go v.FilterPacketAndDispatch(destination, direct, dispatcher)
 	}
diff --git a/app/dispatcher/testing/dispatcher.go b/app/dispatcher/testing/dispatcher.go
index 9ff73e6aa..dfea35799 100644
--- a/app/dispatcher/testing/dispatcher.go
+++ b/app/dispatcher/testing/dispatcher.go
@@ -20,7 +20,7 @@ func NewTestPacketDispatcher(handler func(destination v2net.Destination, traffic
 				if err != nil {
 					break
 				}
-				output := buf.NewBuffer()
+				output := buf.New()
 				output.Append([]byte("Processed: "))
 				output.Append(payload.Bytes())
 				payload.Release()
diff --git a/app/dns/nameserver.go b/app/dns/nameserver.go
index 27be872b0..94adff650 100644
--- a/app/dns/nameserver.go
+++ b/app/dns/nameserver.go
@@ -145,7 +145,7 @@ func (v *UDPNameServer) HandleResponse(dest v2net.Destination, payload *buf.Buff
 }
 
 func (v *UDPNameServer) BuildQueryA(domain string, id uint16) *buf.Buffer {
-	buffer := buf.NewBuffer()
+	buffer := buf.New()
 	msg := new(dns.Msg)
 	msg.Id = id
 	msg.RecursionDesired = true
diff --git a/common/buf/buffer.go b/common/buf/buffer.go
index dc53d25e8..35957f308 100644
--- a/common/buf/buffer.go
+++ b/common/buf/buffer.go
@@ -1,12 +1,12 @@
-// Package alloc provides a light-weight memory allocation mechanism.
+// Package buf provides a light-weight memory allocation mechanism.
 package buf
 
 import (
 	"io"
 )
 
-// BytesWriter is a writer that writes contents into the given buffer.
-type BytesWriter func([]byte) int
+// Supplier is a writer that writes contents into the given buffer.
+type Supplier func([]byte) (int, error)
 
 // Buffer is a recyclable allocation of a byte array. Buffer.Release() recycles
 // the buffer into an internal buffer pool, in order to recreate a buffer more
@@ -59,10 +59,11 @@ func (b *Buffer) Append(data []byte) {
 	b.end += nBytes
 }
 
-// AppendFunc appends the content of a BytesWriter to the buffer.
-func (b *Buffer) AppendFunc(writer BytesWriter) {
-	nBytes := writer(b.v[b.end:])
+// AppendSupplier appends the content of a BytesWriter to the buffer.
+func (b *Buffer) AppendSupplier(writer Supplier) error {
+	nBytes, err := writer(b.v[b.end:])
 	b.end += nBytes
+	return err
 }
 
 // Byte returns the bytes at index.
@@ -80,9 +81,11 @@ func (b *Buffer) Bytes() []byte {
 	return b.v[b.start:b.end]
 }
 
-func (b *Buffer) SetBytesFunc(writer BytesWriter) {
+func (b *Buffer) Reset(writer Supplier) error {
 	b.start = 0
-	b.end = b.start + writer(b.v[b.start:])
+	nBytes, err := writer(b.v[b.start:])
+	b.end = b.start + nBytes
+	return err
 }
 
 // BytesRange returns a slice of this buffer with given from and to bounary.
@@ -172,33 +175,21 @@ func (b *Buffer) Read(data []byte) (int, error) {
 	return nBytes, nil
 }
 
-func (b *Buffer) FillFrom(reader io.Reader) (int, error) {
-	nBytes, err := reader.Read(b.v[b.end:])
-	b.end += nBytes
-	return nBytes, err
-}
-
-func (b *Buffer) FillFullFrom(reader io.Reader, amount int) (int, error) {
-	nBytes, err := io.ReadFull(reader, b.v[b.end:b.end+amount])
-	b.end += nBytes
-	return nBytes, err
-}
-
 func (b *Buffer) String() string {
 	return string(b.Bytes())
 }
 
-// NewBuffer creates a Buffer with 8K bytes of arbitrary content.
-func NewBuffer() *Buffer {
+// New creates a Buffer with 8K bytes of arbitrary content.
+func New() *Buffer {
 	return mediumPool.Allocate()
 }
 
-// NewSmallBuffer returns a buffer with 2K bytes capacity.
-func NewSmallBuffer() *Buffer {
+// NewSmall returns a buffer with 2K bytes capacity.
+func NewSmall() *Buffer {
 	return smallPool.Allocate()
 }
 
-// NewLocalBuffer creates and returns a buffer on current thread.
-func NewLocalBuffer(size int) *Buffer {
+// NewLocal creates and returns a buffer on current thread.
+func NewLocal(size int) *Buffer {
 	return CreateBuffer(make([]byte, size), nil)
 }
diff --git a/common/buf/buffer_pool.go b/common/buf/buffer_pool.go
index ec13cf8e9..2d369f0c1 100644
--- a/common/buf/buffer_pool.go
+++ b/common/buf/buffer_pool.go
@@ -84,15 +84,15 @@ func (p *BufferPool) Free(buffer *Buffer) {
 }
 
 const (
-	BufferSize      = 8 * 1024
-	SmallBufferSize = 2 * 1024
+	Size      = 8 * 1024
+	SizeSmall = 2 * 1024
 
 	PoolSizeEnvKey = "v2ray.buffer.size"
 )
 
 var (
 	mediumPool Pool
-	smallPool  = NewSyncPool(2048)
+	smallPool  = NewSyncPool(SizeSmall)
 )
 
 func init() {
@@ -106,8 +106,8 @@ func init() {
 	}
 	if size > 0 {
 		totalByteSize := size * 1024 * 1024
-		mediumPool = NewBufferPool(BufferSize, totalByteSize/BufferSize)
+		mediumPool = NewBufferPool(Size, totalByteSize/Size)
 	} else {
-		mediumPool = NewSyncPool(BufferSize)
+		mediumPool = NewSyncPool(Size)
 	}
 }
diff --git a/common/buf/buffer_test.go b/common/buf/buffer_test.go
index 61bd01803..fac397b4b 100644
--- a/common/buf/buffer_test.go
+++ b/common/buf/buffer_test.go
@@ -11,7 +11,7 @@ import (
 func TestBufferClear(t *testing.T) {
 	assert := assert.On(t)
 
-	buffer := NewBuffer()
+	buffer := New()
 	defer buffer.Release()
 
 	payload := "Bytes"
@@ -25,7 +25,7 @@ func TestBufferClear(t *testing.T) {
 func TestBufferIsEmpty(t *testing.T) {
 	assert := assert.On(t)
 
-	buffer := NewBuffer()
+	buffer := New()
 	defer buffer.Release()
 
 	assert.Bool(buffer.IsEmpty()).IsTrue()
@@ -34,17 +34,17 @@ func TestBufferIsEmpty(t *testing.T) {
 func TestBufferString(t *testing.T) {
 	assert := assert.On(t)
 
-	buffer := NewBuffer()
+	buffer := New()
 	defer buffer.Release()
 
-	buffer.AppendFunc(serial.WriteString("Test String"))
+	buffer.AppendSupplier(serial.WriteString("Test String"))
 	assert.String(buffer.String()).Equals("Test String")
 }
 
 func TestBufferWrite(t *testing.T) {
 	assert := assert.On(t)
 
-	buffer := NewLocalBuffer(8)
+	buffer := NewLocal(8)
 	nBytes, err := buffer.Write([]byte("abcd"))
 	assert.Error(err).IsNil()
 	assert.Int(nBytes).Equals(4)
@@ -56,28 +56,28 @@ func TestBufferWrite(t *testing.T) {
 
 func BenchmarkNewBuffer8192(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		buffer := NewBuffer()
+		buffer := New()
 		buffer.Release()
 	}
 }
 
 func BenchmarkNewLocalBuffer8192(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		buffer := NewLocalBuffer(8192)
+		buffer := NewLocal(8192)
 		buffer.Release()
 	}
 }
 
 func BenchmarkNewBuffer2048(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		buffer := NewSmallBuffer()
+		buffer := NewSmall()
 		buffer.Release()
 	}
 }
 
 func BenchmarkNewLocalBuffer2048(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		buffer := NewLocalBuffer(2048)
+		buffer := NewLocal(2048)
 		buffer.Release()
 	}
 }
@@ -94,7 +94,7 @@ func BenchmarkBufferValue(b *testing.B) {
 }
 
 func BenchmarkBufferPointer(b *testing.B) {
-	x := NewSmallBuffer()
+	x := NewSmall()
 	doSomething := func(a *Buffer) {
 		_ = a.Len()
 	}
diff --git a/common/buf/io.go b/common/buf/io.go
new file mode 100644
index 000000000..29e760a79
--- /dev/null
+++ b/common/buf/io.go
@@ -0,0 +1,15 @@
+package buf
+
+import "io"
+
+func ReadFrom(reader io.Reader) Supplier {
+	return func(b []byte) (int, error) {
+		return reader.Read(b)
+	}
+}
+
+func ReadFullFrom(reader io.Reader, size int) Supplier {
+	return func(b []byte) (int, error) {
+		return io.ReadFull(reader, b[:size])
+	}
+}
diff --git a/common/crypto/auth.go b/common/crypto/auth.go
index f142a298c..dd443a680 100644
--- a/common/crypto/auth.go
+++ b/common/crypto/auth.go
@@ -81,7 +81,7 @@ type AuthenticationReader struct {
 func NewAuthenticationReader(auth Authenticator, reader io.Reader, aggressive bool) *AuthenticationReader {
 	return &AuthenticationReader{
 		auth:       auth,
-		buffer:     buf.NewLocalBuffer(32 * 1024),
+		buffer:     buf.NewLocal(32 * 1024),
 		reader:     reader,
 		aggressive: aggressive,
 	}
@@ -135,11 +135,11 @@ func (v *AuthenticationReader) EnsureChunk() error {
 				v.buffer.Clear()
 			} else {
 				leftover := v.buffer.Bytes()
-				v.buffer.SetBytesFunc(func(b []byte) int {
-					return copy(b, leftover)
+				v.buffer.Reset(func(b []byte) (int, error) {
+					return copy(b, leftover), nil
 				})
 			}
-			_, err = v.buffer.FillFrom(v.reader)
+			err = v.buffer.AppendSupplier(buf.ReadFrom(v.reader))
 		}
 		return err
 	}
diff --git a/common/io/buffered_reader.go b/common/io/buffered_reader.go
index bf9c93f92..5cebe90a9 100644
--- a/common/io/buffered_reader.go
+++ b/common/io/buffered_reader.go
@@ -17,7 +17,7 @@ type BufferedReader struct {
 func NewBufferedReader(rawReader io.Reader) *BufferedReader {
 	return &BufferedReader{
 		reader: rawReader,
-		buffer: buf.NewBuffer(),
+		buffer: buf.New(),
 		cached: true,
 	}
 }
@@ -54,7 +54,7 @@ func (v *BufferedReader) Read(b []byte) (int, error) {
 		return v.reader.Read(b)
 	}
 	if v.buffer.IsEmpty() {
-		_, err := v.buffer.FillFrom(v.reader)
+		err := v.buffer.AppendSupplier(buf.ReadFrom(v.reader))
 		if err != nil {
 			return 0, err
 		}
diff --git a/common/io/buffered_reader_test.go b/common/io/buffered_reader_test.go
index 49d9edb39..24bf6f11d 100644
--- a/common/io/buffered_reader_test.go
+++ b/common/io/buffered_reader_test.go
@@ -1,9 +1,9 @@
 package io_test
 
 import (
+	"crypto/rand"
 	"testing"
 
-	"crypto/rand"
 	"v2ray.com/core/common/buf"
 	. "v2ray.com/core/common/io"
 	"v2ray.com/core/testing/assert"
@@ -12,8 +12,8 @@ import (
 func TestBufferedReader(t *testing.T) {
 	assert := assert.On(t)
 
-	content := buf.NewBuffer()
-	content.FillFrom(rand.Reader)
+	content := buf.New()
+	content.AppendSupplier(buf.ReadFrom(rand.Reader))
 
 	len := content.Len()
 
diff --git a/common/io/buffered_writer.go b/common/io/buffered_writer.go
index 67df6be80..4a868930d 100644
--- a/common/io/buffered_writer.go
+++ b/common/io/buffered_writer.go
@@ -3,6 +3,7 @@ package io
 import (
 	"io"
 	"sync"
+
 	"v2ray.com/core/common/buf"
 	"v2ray.com/core/common/errors"
 )
@@ -17,7 +18,7 @@ type BufferedWriter struct {
 func NewBufferedWriter(rawWriter io.Writer) *BufferedWriter {
 	return &BufferedWriter{
 		writer: rawWriter,
-		buffer: buf.NewSmallBuffer(),
+		buffer: buf.NewSmall(),
 		cached: true,
 	}
 }
@@ -32,8 +33,9 @@ func (v *BufferedWriter) ReadFrom(reader io.Reader) (int64, error) {
 
 	totalBytes := int64(0)
 	for {
-		nBytes, err := v.buffer.FillFrom(reader)
-		totalBytes += int64(nBytes)
+		oriSize := v.buffer.Len()
+		err := v.buffer.AppendSupplier(buf.ReadFrom(reader))
+		totalBytes += int64(v.buffer.Len() - oriSize)
 		if err != nil {
 			if errors.Cause(err) == io.EOF {
 				return totalBytes, nil
diff --git a/common/io/buffered_writer_test.go b/common/io/buffered_writer_test.go
index 215b918c0..56e0997af 100644
--- a/common/io/buffered_writer_test.go
+++ b/common/io/buffered_writer_test.go
@@ -12,7 +12,7 @@ import (
 func TestBufferedWriter(t *testing.T) {
 	assert := assert.On(t)
 
-	content := buf.NewBuffer()
+	content := buf.New()
 
 	writer := NewBufferedWriter(content)
 	assert.Bool(writer.Cached()).IsTrue()
@@ -32,7 +32,7 @@ func TestBufferedWriter(t *testing.T) {
 func TestBufferedWriterLargePayload(t *testing.T) {
 	assert := assert.On(t)
 
-	content := buf.NewLocalBuffer(128 * 1024)
+	content := buf.NewLocal(128 * 1024)
 
 	writer := NewBufferedWriter(content)
 	assert.Bool(writer.Cached()).IsTrue()
diff --git a/common/io/chain_writer.go b/common/io/chain_writer.go
index 6cf0d4705..446191fc8 100644
--- a/common/io/chain_writer.go
+++ b/common/io/chain_writer.go
@@ -28,7 +28,7 @@ func (v *ChainWriter) Write(payload []byte) (int, error) {
 	bytesWritten := 0
 	size := len(payload)
 	for size > 0 {
-		buffer := buf.NewBuffer()
+		buffer := buf.New()
 		nBytes, _ := buffer.Write(payload)
 		size -= nBytes
 		payload = payload[nBytes:]
diff --git a/common/io/reader.go b/common/io/reader.go
index 5614a4a18..3e6c21996 100644
--- a/common/io/reader.go
+++ b/common/io/reader.go
@@ -33,24 +33,24 @@ func NewAdaptiveReader(reader io.Reader) *AdaptiveReader {
 func (v *AdaptiveReader) Read() (*buf.Buffer, error) {
 	if v.highVolumn && v.largeBuffer.IsEmpty() {
 		if v.largeBuffer == nil {
-			v.largeBuffer = buf.NewLocalBuffer(32 * 1024)
+			v.largeBuffer = buf.NewLocal(32 * 1024)
 		}
-		nBytes, err := v.largeBuffer.FillFrom(v.reader)
+		err := v.largeBuffer.AppendSupplier(buf.ReadFrom(v.reader))
 		if err != nil {
 			return nil, err
 		}
-		if nBytes < buf.BufferSize {
+		if v.largeBuffer.Len() < buf.Size {
 			v.highVolumn = false
 		}
 	}
 
-	buffer := buf.NewBuffer()
+	buffer := buf.New()
 	if !v.largeBuffer.IsEmpty() {
-		buffer.FillFrom(v.largeBuffer)
+		buffer.AppendSupplier(buf.ReadFrom(v.largeBuffer))
 		return buffer, nil
 	}
 
-	_, err := buffer.FillFrom(v.reader)
+	err := buffer.AppendSupplier(buf.ReadFrom(v.reader))
 	if err != nil {
 		buffer.Release()
 		return nil, err
diff --git a/common/io/reader_test.go b/common/io/reader_test.go
index 67ab1600d..f991a2af1 100644
--- a/common/io/reader_test.go
+++ b/common/io/reader_test.go
@@ -19,8 +19,8 @@ func TestAdaptiveReader(t *testing.T) {
 	b1, err := reader.Read()
 	assert.Error(err).IsNil()
 	assert.Bool(b1.IsFull()).IsTrue()
-	assert.Int(b1.Len()).Equals(buf.BufferSize)
-	assert.Int(buffer.Len()).Equals(cap(rawContent) - buf.BufferSize)
+	assert.Int(b1.Len()).Equals(buf.Size)
+	assert.Int(buffer.Len()).Equals(cap(rawContent) - buf.Size)
 
 	b2, err := reader.Read()
 	assert.Error(err).IsNil()
diff --git a/common/io/writer_test.go b/common/io/writer_test.go
index 90ce69cb2..1ac93ad15 100644
--- a/common/io/writer_test.go
+++ b/common/io/writer_test.go
@@ -13,8 +13,8 @@ import (
 func TestAdaptiveWriter(t *testing.T) {
 	assert := assert.On(t)
 
-	lb := buf.NewBuffer()
-	lb.FillFrom(rand.Reader)
+	lb := buf.New()
+	lb.AppendSupplier(buf.ReadFrom(rand.Reader))
 
 	expectedBytes := append([]byte(nil), lb.Bytes()...)
 
diff --git a/common/serial/hash.go b/common/serial/hash.go
index 84683d84b..ffb576377 100644
--- a/common/serial/hash.go
+++ b/common/serial/hash.go
@@ -6,9 +6,9 @@ import (
 	"v2ray.com/core/common/buf"
 )
 
-func WriteHash(h hash.Hash) buf.BytesWriter {
-	return func(b []byte) int {
+func WriteHash(h hash.Hash) buf.Supplier {
+	return func(b []byte) (int, error) {
 		h.Sum(b[:0])
-		return h.Size()
+		return h.Size(), nil
 	}
 }
diff --git a/common/serial/numbers.go b/common/serial/numbers.go
index bd670b606..692942e09 100644
--- a/common/serial/numbers.go
+++ b/common/serial/numbers.go
@@ -14,10 +14,10 @@ func Uint16ToString(value uint16) string {
 	return strconv.Itoa(int(value))
 }
 
-func WriteUint16(value uint16) buf.BytesWriter {
-	return func(b []byte) int {
+func WriteUint16(value uint16) buf.Supplier {
+	return func(b []byte) (int, error) {
 		b = Uint16ToBytes(value, b[:0])
-		return 2
+		return 2, nil
 	}
 }
 
@@ -29,10 +29,10 @@ func Uint32ToString(value uint32) string {
 	return strconv.FormatUint(uint64(value), 10)
 }
 
-func WriteUint32(value uint32) buf.BytesWriter {
-	return func(b []byte) int {
+func WriteUint32(value uint32) buf.Supplier {
+	return func(b []byte) (int, error) {
 		b = Uint32ToBytes(value, b[:0])
-		return 4
+		return 4, nil
 	}
 }
 
diff --git a/common/serial/string.go b/common/serial/string.go
index e21eb126b..823d96656 100644
--- a/common/serial/string.go
+++ b/common/serial/string.go
@@ -36,9 +36,8 @@ func Concat(v ...interface{}) string {
 	return strings.Join(values, "")
 }
 
-func WriteString(s string) buf.BytesWriter {
-	return func(b []byte) int {
-		copy(b, []byte(s))
-		return len(s)
+func WriteString(s string) buf.Supplier {
+	return func(b []byte) (int, error) {
+		return copy(b, []byte(s)), nil
 	}
 }
diff --git a/proxy/blackhole/config.go b/proxy/blackhole/config.go
index 05e5ab432..c73be808c 100644
--- a/proxy/blackhole/config.go
+++ b/proxy/blackhole/config.go
@@ -32,8 +32,8 @@ func (v *NoneResponse) AsAny() *any.Any {
 }
 
 func (v *HTTPResponse) WriteTo(writer v2io.Writer) {
-	b := buf.NewLocalBuffer(512)
-	b.AppendFunc(serial.WriteString(http403response))
+	b := buf.NewLocal(512)
+	b.AppendSupplier(serial.WriteString(http403response))
 	writer.Write(b)
 }
 
diff --git a/proxy/blackhole/config_test.go b/proxy/blackhole/config_test.go
index 3d34ab92e..e0bc06cf6 100644
--- a/proxy/blackhole/config_test.go
+++ b/proxy/blackhole/config_test.go
@@ -14,7 +14,7 @@ import (
 func TestHTTPResponse(t *testing.T) {
 	assert := assert.On(t)
 
-	buffer := buf.NewBuffer()
+	buffer := buf.New()
 
 	httpResponse := new(HTTPResponse)
 	httpResponse.WriteTo(v2io.NewAdaptiveWriter(buffer))
diff --git a/proxy/freedom/freedom_test.go b/proxy/freedom/freedom_test.go
index f0584e5f1..30c715cc7 100644
--- a/proxy/freedom/freedom_test.go
+++ b/proxy/freedom/freedom_test.go
@@ -47,7 +47,7 @@ func TestSinglePacket(t *testing.T) {
 
 	traffic := ray.NewRay()
 	data2Send := "Data to be sent to remote"
-	payload := buf.NewLocalBuffer(2048)
+	payload := buf.NewLocal(2048)
 	payload.Append([]byte(data2Send))
 
 	go freedom.Dispatch(v2net.TCPDestination(v2net.LocalHostIP, tcpServer.Port), payload, traffic)
diff --git a/proxy/shadowsocks/ota.go b/proxy/shadowsocks/ota.go
index 174d2ae62..fbacac299 100644
--- a/proxy/shadowsocks/ota.go
+++ b/proxy/shadowsocks/ota.go
@@ -27,13 +27,12 @@ func NewAuthenticator(keygen KeyGenerator) *Authenticator {
 	}
 }
 
-func (v *Authenticator) Authenticate(data []byte) buf.BytesWriter {
+func (v *Authenticator) Authenticate(data []byte) buf.Supplier {
 	hasher := hmac.New(sha1.New, v.key())
 	hasher.Write(data)
 	res := hasher.Sum(nil)
-	return func(b []byte) int {
-		copy(b, res[:AuthSize])
-		return AuthSize
+	return func(b []byte) (int, error) {
+		return copy(b, res[:AuthSize]), nil
 	}
 }
 
@@ -75,22 +74,22 @@ func (v *ChunkReader) Release() {
 }
 
 func (v *ChunkReader) Read() (*buf.Buffer, error) {
-	buffer := buf.NewBuffer()
-	if _, err := buffer.FillFullFrom(v.reader, 2); err != nil {
+	buffer := buf.New()
+	if err := buffer.AppendSupplier(buf.ReadFullFrom(v.reader, 2)); err != nil {
 		buffer.Release()
 		return nil, err
 	}
 	// There is a potential buffer overflow here. Large buffer is 64K bytes,
 	// while uin16 + 10 will be more than that
 	length := serial.BytesToUint16(buffer.BytesTo(2)) + AuthSize
-	if length > buf.BufferSize {
+	if length > buf.Size {
 		// Theoretically the size of a chunk is 64K, but most Shadowsocks implementations used <4K buffer.
 		buffer.Release()
-		buffer = buf.NewLocalBuffer(int(length) + 128)
+		buffer = buf.NewLocal(int(length) + 128)
 	}
 
 	buffer.Clear()
-	if _, err := buffer.FillFullFrom(v.reader, int(length)); err != nil {
+	if err := buffer.AppendSupplier(buf.ReadFullFrom(v.reader, int(length))); err != nil {
 		buffer.Release()
 		return nil, err
 	}
diff --git a/proxy/shadowsocks/ota_test.go b/proxy/shadowsocks/ota_test.go
index 2bad69762..8a93eb341 100644
--- a/proxy/shadowsocks/ota_test.go
+++ b/proxy/shadowsocks/ota_test.go
@@ -11,7 +11,7 @@ import (
 func TestNormalChunkReading(t *testing.T) {
 	assert := assert.On(t)
 
-	buffer := buf.NewBuffer()
+	buffer := buf.New()
 	buffer.AppendBytes(
 		0, 8, 39, 228, 69, 96, 133, 39, 254, 26, 201, 70, 11, 12, 13, 14, 15, 16, 17, 18)
 	reader := NewChunkReader(buffer, NewAuthenticator(ChunkKeyGenerator(
@@ -24,11 +24,11 @@ func TestNormalChunkReading(t *testing.T) {
 func TestNormalChunkWriting(t *testing.T) {
 	assert := assert.On(t)
 
-	buffer := buf.NewLocalBuffer(512)
+	buffer := buf.NewLocal(512)
 	writer := NewChunkWriter(buffer, NewAuthenticator(ChunkKeyGenerator(
 		[]byte{21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36})))
 
-	b := buf.NewLocalBuffer(256)
+	b := buf.NewLocal(256)
 	b.Append([]byte{11, 12, 13, 14, 15, 16, 17, 18})
 	err := writer.Write(b)
 	assert.Error(err).IsNil()
diff --git a/proxy/shadowsocks/protocol.go b/proxy/shadowsocks/protocol.go
index 75c8ebd37..e57cb5f7e 100644
--- a/proxy/shadowsocks/protocol.go
+++ b/proxy/shadowsocks/protocol.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"crypto/rand"
 	"io"
+
 	"v2ray.com/core/common/buf"
 	"v2ray.com/core/common/crypto"
 	"v2ray.com/core/common/errors"
@@ -29,11 +30,11 @@ func ReadTCPSession(user *protocol.User, reader io.Reader) (*protocol.RequestHea
 	}
 	account := rawAccount.(*ShadowsocksAccount)
 
-	buffer := buf.NewLocalBuffer(512)
+	buffer := buf.NewLocal(512)
 	defer buffer.Release()
 
 	ivLen := account.Cipher.IVSize()
-	_, err = buffer.FillFullFrom(reader, ivLen)
+	err = buffer.AppendSupplier(buf.ReadFullFrom(reader, ivLen))
 	if err != nil {
 		return nil, nil, errors.Base(err).Message("Shadowsocks|TCP: Failed to read IV.")
 	}
@@ -54,7 +55,7 @@ func ReadTCPSession(user *protocol.User, reader io.Reader) (*protocol.RequestHea
 	}
 
 	buffer.Clear()
-	_, err = buffer.FillFullFrom(reader, 1)
+	err = buffer.AppendSupplier(buf.ReadFullFrom(reader, 1))
 	if err != nil {
 		return nil, nil, errors.Base(err).Message("Shadowsocks|TCP: Failed to read address type.")
 	}
@@ -74,24 +75,24 @@ func ReadTCPSession(user *protocol.User, reader io.Reader) (*protocol.RequestHea
 
 	switch addrType {
 	case AddrTypeIPv4:
-		_, err := buffer.FillFullFrom(reader, 4)
+		err := buffer.AppendSupplier(buf.ReadFullFrom(reader, 4))
 		if err != nil {
 			return nil, nil, errors.Base(err).Message("Shadowsocks|TCP: Failed to read IPv4 address.")
 		}
 		request.Address = v2net.IPAddress(buffer.BytesFrom(-4))
 	case AddrTypeIPv6:
-		_, err := buffer.FillFullFrom(reader, 16)
+		err := buffer.AppendSupplier(buf.ReadFullFrom(reader, 16))
 		if err != nil {
 			return nil, nil, errors.Base(err).Message("Shadowsocks|TCP: Failed to read IPv6 address.")
 		}
 		request.Address = v2net.IPAddress(buffer.BytesFrom(-16))
 	case AddrTypeDomain:
-		_, err := buffer.FillFullFrom(reader, 1)
+		err := buffer.AppendSupplier(buf.ReadFullFrom(reader, 1))
 		if err != nil {
 			return nil, nil, errors.Base(err).Message("Shadowsocks|TCP: Failed to read domain lenth.")
 		}
 		domainLength := int(buffer.BytesFrom(-1)[0])
-		_, err = buffer.FillFullFrom(reader, domainLength)
+		err = buffer.AppendSupplier(buf.ReadFullFrom(reader, domainLength))
 		if err != nil {
 			return nil, nil, errors.Base(err).Message("Shadowsocks|TCP: Failed to read domain.")
 		}
@@ -100,7 +101,7 @@ func ReadTCPSession(user *protocol.User, reader io.Reader) (*protocol.RequestHea
 		return nil, nil, errors.New("Shadowsocks|TCP: Unknown address type: ", addrType)
 	}
 
-	_, err = buffer.FillFullFrom(reader, 2)
+	err = buffer.AppendSupplier(buf.ReadFullFrom(reader, 2))
 	if err != nil {
 		return nil, nil, errors.Base(err).Message("Shadowsocks|TCP: Failed to read port.")
 	}
@@ -110,7 +111,7 @@ func ReadTCPSession(user *protocol.User, reader io.Reader) (*protocol.RequestHea
 		actualAuth := make([]byte, AuthSize)
 		authenticator.Authenticate(buffer.Bytes())(actualAuth)
 
-		_, err := buffer.FillFullFrom(reader, AuthSize)
+		err := buffer.AppendSupplier(buf.ReadFullFrom(reader, AuthSize))
 		if err != nil {
 			return nil, nil, errors.Base(err).Message("Shadowsocks|TCP: Failed to read OTA.")
 		}
@@ -152,7 +153,7 @@ func WriteTCPRequest(request *protocol.RequestHeader, writer io.Writer) (v2io.Wr
 
 	writer = crypto.NewCryptionWriter(stream, writer)
 
-	header := buf.NewLocalBuffer(512)
+	header := buf.NewLocal(512)
 
 	switch request.Address.Family() {
 	case v2net.AddressFamilyIPv4:
@@ -168,13 +169,13 @@ func WriteTCPRequest(request *protocol.RequestHeader, writer io.Writer) (v2io.Wr
 		return nil, errors.New("Shadowsocks|TCP: Unsupported address type: ", request.Address.Family())
 	}
 
-	header.AppendFunc(serial.WriteUint16(uint16(request.Port)))
+	header.AppendSupplier(serial.WriteUint16(uint16(request.Port)))
 
 	if request.Option.Has(RequestOptionOneTimeAuth) {
 		header.SetByte(0, header.Byte(0)|0x10)
 
 		authenticator := NewAuthenticator(HeaderKeyGenerator(account.Key, iv))
-		header.AppendFunc(authenticator.Authenticate(header.Bytes()))
+		header.AppendSupplier(authenticator.Authenticate(header.Bytes()))
 	}
 
 	_, err = writer.Write(header.Bytes())
@@ -243,9 +244,9 @@ func EncodeUDPPacket(request *protocol.RequestHeader, payload *buf.Buffer) (*buf
 	}
 	account := rawAccount.(*ShadowsocksAccount)
 
-	buffer := buf.NewSmallBuffer()
+	buffer := buf.NewSmall()
 	ivLen := account.Cipher.IVSize()
-	buffer.FillFullFrom(rand.Reader, ivLen)
+	buffer.AppendSupplier(buf.ReadFullFrom(rand.Reader, ivLen))
 	iv := buffer.Bytes()
 
 	switch request.Address.Family() {
@@ -262,14 +263,14 @@ func EncodeUDPPacket(request *protocol.RequestHeader, payload *buf.Buffer) (*buf
 		return nil, errors.New("Shadowsocks|UDP: Unsupported address type: ", request.Address.Family())
 	}
 
-	buffer.AppendFunc(serial.WriteUint16(uint16(request.Port)))
+	buffer.AppendSupplier(serial.WriteUint16(uint16(request.Port)))
 	buffer.Append(payload.Bytes())
 
 	if request.Option.Has(RequestOptionOneTimeAuth) {
 		authenticator := NewAuthenticator(HeaderKeyGenerator(account.Key, iv))
 		buffer.SetByte(ivLen, buffer.Byte(ivLen)|0x10)
 
-		buffer.AppendFunc(authenticator.Authenticate(buffer.BytesFrom(ivLen)))
+		buffer.AppendSupplier(authenticator.Authenticate(buffer.BytesFrom(ivLen)))
 	}
 
 	stream, err := account.Cipher.NewEncodingStream(account.Key, iv)
@@ -360,8 +361,8 @@ type UDPReader struct {
 }
 
 func (v *UDPReader) Read() (*buf.Buffer, error) {
-	buffer := buf.NewSmallBuffer()
-	_, err := buffer.FillFrom(v.Reader)
+	buffer := buf.NewSmall()
+	err := buffer.AppendSupplier(buf.ReadFrom(v.Reader))
 	if err != nil {
 		buffer.Release()
 		return nil, err
diff --git a/proxy/shadowsocks/protocol_test.go b/proxy/shadowsocks/protocol_test.go
index d27d78b9d..f730ed016 100644
--- a/proxy/shadowsocks/protocol_test.go
+++ b/proxy/shadowsocks/protocol_test.go
@@ -30,8 +30,8 @@ func TestUDPEncoding(t *testing.T) {
 		},
 	}
 
-	data := buf.NewLocalBuffer(256)
-	data.AppendFunc(serial.WriteString("test string"))
+	data := buf.NewLocal(256)
+	data.AppendSupplier(serial.WriteString("test string"))
 	encodedData, err := EncodeUDPPacket(request, data)
 	assert.Error(err).IsNil()
 
@@ -60,9 +60,9 @@ func TestTCPRequest(t *testing.T) {
 		},
 	}
 
-	data := buf.NewLocalBuffer(256)
-	data.AppendFunc(serial.WriteString("test string"))
-	cache := buf.NewBuffer()
+	data := buf.NewLocal(256)
+	data.AppendSupplier(serial.WriteString("test string"))
+	cache := buf.New()
 
 	writer, err := WriteTCPRequest(request, cache)
 	assert.Error(err).IsNil()
@@ -88,7 +88,7 @@ func TestUDPReaderWriter(t *testing.T) {
 			CipherType: CipherType_CHACHA20_IEFT,
 		}),
 	}
-	cache := buf.NewBuffer()
+	cache := buf.New()
 	writer := &UDPWriter{
 		Writer: cache,
 		Request: &protocol.RequestHeader{
@@ -105,8 +105,8 @@ func TestUDPReaderWriter(t *testing.T) {
 		User:   user,
 	}
 
-	b := buf.NewBuffer()
-	b.AppendFunc(serial.WriteString("test payload"))
+	b := buf.New()
+	b.AppendSupplier(serial.WriteString("test payload"))
 	err := writer.Write(b)
 	assert.Error(err).IsNil()
 
@@ -114,8 +114,8 @@ func TestUDPReaderWriter(t *testing.T) {
 	assert.Error(err).IsNil()
 	assert.String(payload.String()).Equals("test payload")
 
-	b = buf.NewBuffer()
-	b.AppendFunc(serial.WriteString("test payload 2"))
+	b = buf.New()
+	b.AppendSupplier(serial.WriteString("test payload 2"))
 	err = writer.Write(b)
 	assert.Error(err).IsNil()
 
diff --git a/proxy/socks/protocol/socks.go b/proxy/socks/protocol/socks.go
index 9408bb22c..4f59c3dcf 100644
--- a/proxy/socks/protocol/socks.go
+++ b/proxy/socks/protocol/socks.go
@@ -3,12 +3,13 @@ package protocol
 import (
 	"fmt"
 	"io"
+
 	"v2ray.com/core/common/buf"
+	"v2ray.com/core/common/crypto"
 	"v2ray.com/core/common/errors"
 	"v2ray.com/core/common/log"
 	v2net "v2ray.com/core/common/net"
 	"v2ray.com/core/proxy"
-	"v2ray.com/core/common/crypto"
 )
 
 const (
@@ -120,10 +121,10 @@ func (request Socks5UserPassRequest) AuthDetail() string {
 }
 
 func ReadUserPassRequest(reader io.Reader) (request Socks5UserPassRequest, err error) {
-	buffer := buf.NewLocalBuffer(512)
+	buffer := buf.NewLocal(512)
 	defer buffer.Release()
 
-	_, err = buffer.FillFullFrom(reader, 2)
+	err = buffer.AppendSupplier(buf.ReadFullFrom(reader, 2))
 	if err != nil {
 		return
 	}
@@ -131,18 +132,18 @@ func ReadUserPassRequest(reader io.Reader) (request Socks5UserPassRequest, err e
 	nUsername := int(buffer.Byte(1))
 
 	buffer.Clear()
-	_, err = buffer.FillFullFrom(reader, nUsername)
+	err = buffer.AppendSupplier(buf.ReadFullFrom(reader, nUsername))
 	if err != nil {
 		return
 	}
 	request.username = string(buffer.Bytes())
 
-	_, err = buffer.FillFullFrom(reader, 1)
+	err = buffer.AppendSupplier(buf.ReadFullFrom(reader, 1))
 	if err != nil {
 		return
 	}
 	nPassword := int(buffer.Byte(0))
-	_, err = buffer.FillFullFrom(reader, nPassword)
+	err = buffer.AppendSupplier(buf.ReadFullFrom(reader, nPassword))
 	if err != nil {
 		return
 	}
@@ -188,10 +189,10 @@ type Socks5Request struct {
 }
 
 func ReadRequest(reader io.Reader) (request *Socks5Request, err error) {
-	buffer := buf.NewLocalBuffer(512)
+	buffer := buf.NewLocal(512)
 	defer buffer.Release()
 
-	_, err = buffer.FillFullFrom(reader, 4)
+	err = buffer.AppendSupplier(buf.ReadFullFrom(reader, 4))
 	if err != nil {
 		return
 	}
@@ -210,12 +211,12 @@ func ReadRequest(reader io.Reader) (request *Socks5Request, err error) {
 		}
 	case AddrTypeDomain:
 		buffer.Clear()
-		_, err = buffer.FillFullFrom(reader, 1)
+		err = buffer.AppendSupplier(buf.ReadFullFrom(reader, 1))
 		if err != nil {
 			return
 		}
 		domainLength := int(buffer.Byte(0))
-		_, err = buffer.FillFullFrom(reader, domainLength)
+		err = buffer.AppendSupplier(buf.ReadFullFrom(reader, domainLength))
 		if err != nil {
 			return
 		}
@@ -231,7 +232,7 @@ func ReadRequest(reader io.Reader) (request *Socks5Request, err error) {
 		return
 	}
 
-	_, err = buffer.FillFullFrom(reader, 2)
+	err = buffer.AppendSupplier(buf.ReadFullFrom(reader, 2))
 	if err != nil {
 		return
 	}
diff --git a/proxy/socks/protocol/socks4_test.go b/proxy/socks/protocol/socks4_test.go
index 6050aa3ac..75b9b8986 100644
--- a/proxy/socks/protocol/socks4_test.go
+++ b/proxy/socks/protocol/socks4_test.go
@@ -31,7 +31,7 @@ func TestSocks4AuthenticationResponseToBytes(t *testing.T) {
 
 	response := NewSocks4AuthenticationResponse(byte(0x10), 443, []byte{1, 2, 3, 4})
 
-	buffer := buf.NewLocalBuffer(2048)
+	buffer := buf.NewLocal(2048)
 	defer buffer.Release()
 
 	response.Write(buffer)
diff --git a/proxy/socks/protocol/socks_test.go b/proxy/socks/protocol/socks_test.go
index f25164c2b..45f11930f 100644
--- a/proxy/socks/protocol/socks_test.go
+++ b/proxy/socks/protocol/socks_test.go
@@ -6,10 +6,10 @@ import (
 	"testing"
 
 	"v2ray.com/core/common/buf"
+	"v2ray.com/core/common/crypto"
 	v2net "v2ray.com/core/common/net"
 	"v2ray.com/core/proxy"
 	"v2ray.com/core/testing/assert"
-	"v2ray.com/core/common/crypto"
 )
 
 func TestHasAuthenticationMethod(t *testing.T) {
@@ -30,7 +30,7 @@ func TestHasAuthenticationMethod(t *testing.T) {
 func TestAuthenticationRequestRead(t *testing.T) {
 	assert := assert.On(t)
 
-	buffer := buf.NewBuffer()
+	buffer := buf.New()
 	buffer.AppendBytes(
 		0x05, // version
 		0x01, // nMethods
@@ -85,7 +85,7 @@ func TestResponseWrite(t *testing.T) {
 		[16]byte{},
 		v2net.Port(53),
 	}
-	buffer := buf.NewLocalBuffer(2048)
+	buffer := buf.NewLocal(2048)
 	defer buffer.Release()
 
 	response.Write(buffer)
@@ -106,7 +106,7 @@ func TestSetIPv6(t *testing.T) {
 	response := NewSocks5Response()
 	response.SetIPv6([]byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15})
 
-	buffer := buf.NewLocalBuffer(2048)
+	buffer := buf.NewLocal(2048)
 	defer buffer.Release()
 	response.Write(buffer)
 	assert.Bytes(buffer.Bytes()).Equals([]byte{
@@ -119,7 +119,7 @@ func TestSetDomain(t *testing.T) {
 	response := NewSocks5Response()
 	response.SetDomain("v2ray.com")
 
-	buffer := buf.NewLocalBuffer(2048)
+	buffer := buf.NewLocal(2048)
 	defer buffer.Release()
 	response.Write(buffer)
 	assert.Bytes(buffer.Bytes()).Equals([]byte{
@@ -129,7 +129,7 @@ func TestSetDomain(t *testing.T) {
 func TestEmptyAuthRequest(t *testing.T) {
 	assert := assert.On(t)
 
-	_, _, err := ReadAuthentication(buf.NewBuffer())
+	_, _, err := ReadAuthentication(buf.New())
 	assert.Error(err).Equals(io.EOF)
 }
 
@@ -143,7 +143,7 @@ func TestSingleByteAuthRequest(t *testing.T) {
 func TestZeroAuthenticationMethod(t *testing.T) {
 	assert := assert.On(t)
 
-	buffer := buf.NewBuffer()
+	buffer := buf.New()
 	buffer.AppendBytes(5, 0)
 	_, _, err := ReadAuthentication(buffer)
 	assert.Error(err).Equals(crypto.ErrAuthenticationFailed)
@@ -151,7 +151,7 @@ func TestZeroAuthenticationMethod(t *testing.T) {
 func TestWrongProtocolVersion(t *testing.T) {
 	assert := assert.On(t)
 
-	buffer := buf.NewBuffer()
+	buffer := buf.New()
 	buffer.AppendBytes(6, 1, 0)
 	_, _, err := ReadAuthentication(buffer)
 	assert.Error(err).Equals(proxy.ErrInvalidProtocolVersion)
@@ -160,14 +160,14 @@ func TestWrongProtocolVersion(t *testing.T) {
 func TestEmptyRequest(t *testing.T) {
 	assert := assert.On(t)
 
-	_, err := ReadRequest(buf.NewBuffer())
+	_, err := ReadRequest(buf.New())
 	assert.Error(err).Equals(io.EOF)
 }
 
 func TestIPv6Request(t *testing.T) {
 	assert := assert.On(t)
 
-	b := buf.NewBuffer()
+	b := buf.New()
 	b.AppendBytes(5, 1, 0, 4, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 0, 8)
 	request, err := ReadRequest(b)
 	assert.Error(err).IsNil()
diff --git a/proxy/socks/protocol/udp.go b/proxy/socks/protocol/udp.go
index f85d7001e..89974b6dc 100644
--- a/proxy/socks/protocol/udp.go
+++ b/proxy/socks/protocol/udp.go
@@ -36,7 +36,7 @@ func (request *Socks5UDPRequest) Write(buffer *buf.Buffer) {
 		buffer.AppendBytes(AddrTypeDomain, byte(len(request.Address.Domain())))
 		buffer.Append([]byte(request.Address.Domain()))
 	}
-	buffer.AppendFunc(serial.WriteUint16(request.Port.Value()))
+	buffer.AppendSupplier(serial.WriteUint16(request.Port.Value()))
 	buffer.Append(request.Data.Bytes())
 }
 
@@ -83,7 +83,7 @@ func ReadUDPRequest(packet []byte) (*Socks5UDPRequest, error) {
 	}
 
 	if len(packet) > dataBegin {
-		b := buf.NewSmallBuffer()
+		b := buf.NewSmall()
 		b.Append(packet[dataBegin:])
 		request.Data = b
 	}
diff --git a/proxy/socks/server_udp.go b/proxy/socks/server_udp.go
index 05c31063d..2a8a6b191 100644
--- a/proxy/socks/server_udp.go
+++ b/proxy/socks/server_udp.go
@@ -55,7 +55,7 @@ func (v *Server) handleUDPPayload(payload *buf.Buffer, session *proxy.SessionInf
 		}
 		log.Info("Socks: Writing back UDP response with ", payload.Len(), " bytes to ", destination)
 
-		udpMessage := buf.NewLocalBuffer(2048)
+		udpMessage := buf.NewLocal(2048)
 		response.Write(udpMessage)
 
 		v.udpMutex.RLock()
diff --git a/proxy/vmess/encoding/commands.go b/proxy/vmess/encoding/commands.go
index 654bb3cc7..5f6c6af47 100644
--- a/proxy/vmess/encoding/commands.go
+++ b/proxy/vmess/encoding/commands.go
@@ -32,7 +32,7 @@ func MarshalCommand(command interface{}, writer io.Writer) error {
 		return ErrUnknownCommand
 	}
 
-	buffer := buf.NewLocalBuffer(512)
+	buffer := buf.NewLocal(512)
 	defer buffer.Release()
 
 	err := factory.Marshal(command, buffer)
diff --git a/proxy/vmess/encoding/commands_test.go b/proxy/vmess/encoding/commands_test.go
index f5cbe3310..142c73cb7 100644
--- a/proxy/vmess/encoding/commands_test.go
+++ b/proxy/vmess/encoding/commands_test.go
@@ -21,7 +21,7 @@ func TestSwitchAccount(t *testing.T) {
 		ValidMin: 16,
 	}
 
-	buffer := buf.NewBuffer()
+	buffer := buf.New()
 	err := MarshalCommand(sa, buffer)
 	assert.Error(err).IsNil()
 
diff --git a/proxy/vmess/encoding/encoding_test.go b/proxy/vmess/encoding/encoding_test.go
index 7948e920a..e5452834d 100644
--- a/proxy/vmess/encoding/encoding_test.go
+++ b/proxy/vmess/encoding/encoding_test.go
@@ -36,7 +36,7 @@ func TestRequestSerialization(t *testing.T) {
 		Security: protocol.Security(protocol.SecurityType_AES128_GCM),
 	}
 
-	buffer := buf.NewBuffer()
+	buffer := buf.New()
 	client := NewClientSession(protocol.DefaultIDHash)
 	client.EncodeRequestHeader(expectedRequest, buffer)
 
diff --git a/proxy/vmess/inbound/inbound.go b/proxy/vmess/inbound/inbound.go
index 2f43796e8..8b0f562b4 100644
--- a/proxy/vmess/inbound/inbound.go
+++ b/proxy/vmess/inbound/inbound.go
@@ -225,7 +225,7 @@ func (v *VMessInboundHandler) HandleConnection(connection internet.Connection) {
 	}
 	output.Release()
 	if request.Option.Has(protocol.RequestOptionChunkStream) {
-		if err := bodyWriter.Write(buf.NewLocalBuffer(8)); err != nil {
+		if err := bodyWriter.Write(buf.NewLocal(8)); err != nil {
 			connection.SetReusable(false)
 		}
 	}
diff --git a/proxy/vmess/outbound/outbound.go b/proxy/vmess/outbound/outbound.go
index 44255e38d..f7a02f80c 100644
--- a/proxy/vmess/outbound/outbound.go
+++ b/proxy/vmess/outbound/outbound.go
@@ -116,7 +116,7 @@ func (v *VMessOutboundHandler) handleRequest(session *encoding.ClientSession, co
 	}
 
 	if request.Option.Has(protocol.RequestOptionChunkStream) {
-		err := bodyWriter.Write(buf.NewLocalBuffer(8))
+		err := bodyWriter.Write(buf.NewLocal(8))
 		if err != nil {
 			conn.SetReusable(false)
 		}
diff --git a/testing/scenarios/shadowsocks_test.go b/testing/scenarios/shadowsocks_test.go
index df7a3fa9a..e32c71956 100644
--- a/testing/scenarios/shadowsocks_test.go
+++ b/testing/scenarios/shadowsocks_test.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"net"
 	"testing"
+
 	"v2ray.com/core/common/buf"
 	v2net "v2ray.com/core/common/net"
 	"v2ray.com/core/testing/assert"
@@ -42,11 +43,11 @@ func TestShadowsocksTCP(t *testing.T) {
 
 		//conn.CloseWrite()
 
-		response := buf.NewBuffer()
+		response := buf.New()
 		finished := false
 		expectedResponse := "Processed: " + payload
 		for {
-			_, err := response.FillFrom(conn)
+			err := response.AppendSupplier(buf.ReadFrom(conn))
 			assert.Error(err).IsNil()
 			if err != nil {
 				break
diff --git a/transport/internet/authenticator.go b/transport/internet/authenticator.go
deleted file mode 100644
index 45391542b..000000000
--- a/transport/internet/authenticator.go
+++ /dev/null
@@ -1,70 +0,0 @@
-package internet
-
-import (
-	"v2ray.com/core/common"
-	"v2ray.com/core/common/buf"
-)
-
-type Authenticator interface {
-	Seal(*buf.Buffer)
-	Open(*buf.Buffer) bool
-	Overhead() int
-}
-
-type AuthenticatorFactory interface {
-	Create(interface{}) Authenticator
-}
-
-var (
-	authenticatorCache = make(map[string]AuthenticatorFactory)
-)
-
-func RegisterAuthenticator(name string, factory AuthenticatorFactory) error {
-	if _, found := authenticatorCache[name]; found {
-		return common.ErrDuplicatedName
-	}
-	authenticatorCache[name] = factory
-	return nil
-}
-
-func CreateAuthenticator(name string, config interface{}) (Authenticator, error) {
-	factory, found := authenticatorCache[name]
-	if !found {
-		return nil, common.ErrObjectNotFound
-	}
-	return factory.Create(config), nil
-}
-
-type AuthenticatorChain struct {
-	authenticators []Authenticator
-}
-
-func NewAuthenticatorChain(auths ...Authenticator) Authenticator {
-	return &AuthenticatorChain{
-		authenticators: auths,
-	}
-}
-
-func (v *AuthenticatorChain) Overhead() int {
-	total := 0
-	for _, auth := range v.authenticators {
-		total += auth.Overhead()
-	}
-	return total
-}
-
-func (v *AuthenticatorChain) Open(payload *buf.Buffer) bool {
-	for _, auth := range v.authenticators {
-		if !auth.Open(payload) {
-			return false
-		}
-	}
-	return true
-}
-
-func (v *AuthenticatorChain) Seal(payload *buf.Buffer) {
-	for i := len(v.authenticators) - 1; i >= 0; i-- {
-		auth := v.authenticators[i]
-		auth.Seal(payload)
-	}
-}
diff --git a/transport/internet/header.go b/transport/internet/header.go
index d49906422..30d4e7136 100644
--- a/transport/internet/header.go
+++ b/transport/internet/header.go
@@ -4,7 +4,7 @@ import "v2ray.com/core/common"
 
 type PacketHeader interface {
 	Size() int
-	Write([]byte) int
+	Write([]byte) (int, error)
 }
 
 type PacketHeaderFactory interface {
diff --git a/transport/internet/headers/http/http.go b/transport/internet/headers/http/http.go
index 7ef1b0610..cd66d456f 100644
--- a/transport/internet/headers/http/http.go
+++ b/transport/internet/headers/http/http.go
@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"strings"
 	"time"
+
 	"v2ray.com/core/common/buf"
 	"v2ray.com/core/common/loader"
 	"v2ray.com/core/common/serial"
@@ -46,9 +47,9 @@ type HeaderReader struct {
 }
 
 func (*HeaderReader) Read(reader io.Reader) (*buf.Buffer, error) {
-	buffer := buf.NewSmallBuffer()
+	buffer := buf.NewSmall()
 	for {
-		_, err := buffer.FillFrom(reader)
+		err := buffer.AppendSupplier(buf.ReadFrom(reader))
 		if err != nil {
 			return nil, err
 		}
@@ -143,39 +144,39 @@ type HttpAuthenticator struct {
 }
 
 func (v HttpAuthenticator) GetClientWriter() *HeaderWriter {
-	header := buf.NewSmallBuffer()
+	header := buf.NewSmall()
 	config := v.config.Request
-	header.AppendFunc(serial.WriteString(strings.Join([]string{config.Method.GetValue(), config.PickUri(), config.GetFullVersion()}, " ")))
-	header.AppendFunc(writeCRLF)
+	header.AppendSupplier(serial.WriteString(strings.Join([]string{config.Method.GetValue(), config.PickUri(), config.GetFullVersion()}, " ")))
+	header.AppendSupplier(writeCRLF)
 
 	headers := config.PickHeaders()
 	for _, h := range headers {
-		header.AppendFunc(serial.WriteString(h))
-		header.AppendFunc(writeCRLF)
+		header.AppendSupplier(serial.WriteString(h))
+		header.AppendSupplier(writeCRLF)
 	}
-	header.AppendFunc(writeCRLF)
+	header.AppendSupplier(writeCRLF)
 	return &HeaderWriter{
 		header: header,
 	}
 }
 
 func (v HttpAuthenticator) GetServerWriter() *HeaderWriter {
-	header := buf.NewSmallBuffer()
+	header := buf.NewSmall()
 	config := v.config.Response
-	header.AppendFunc(serial.WriteString(strings.Join([]string{config.GetFullVersion(), config.Status.GetCode(), config.Status.GetReason()}, " ")))
-	header.AppendFunc(writeCRLF)
+	header.AppendSupplier(serial.WriteString(strings.Join([]string{config.GetFullVersion(), config.Status.GetCode(), config.Status.GetReason()}, " ")))
+	header.AppendSupplier(writeCRLF)
 
 	headers := config.PickHeaders()
 	for _, h := range headers {
-		header.AppendFunc(serial.WriteString(h))
-		header.AppendFunc(writeCRLF)
+		header.AppendSupplier(serial.WriteString(h))
+		header.AppendSupplier(writeCRLF)
 	}
 	if !config.HasHeader("Date") {
-		header.AppendFunc(serial.WriteString("Date: "))
-		header.AppendFunc(serial.WriteString(time.Now().Format(http.TimeFormat)))
-		header.AppendFunc(writeCRLF)
+		header.AppendSupplier(serial.WriteString("Date: "))
+		header.AppendSupplier(serial.WriteString(time.Now().Format(http.TimeFormat)))
+		header.AppendSupplier(writeCRLF)
 	}
-	header.AppendFunc(writeCRLF)
+	header.AppendSupplier(writeCRLF)
 	return &HeaderWriter{
 		header: header,
 	}
diff --git a/transport/internet/headers/http/http_test.go b/transport/internet/headers/http/http_test.go
index 612f08e72..8fb5a4e2e 100644
--- a/transport/internet/headers/http/http_test.go
+++ b/transport/internet/headers/http/http_test.go
@@ -12,9 +12,9 @@ import (
 func TestReaderWriter(t *testing.T) {
 	assert := assert.On(t)
 
-	cache := buf.NewBuffer()
-	b := buf.NewLocalBuffer(256)
-	b.AppendFunc(serial.WriteString("abcd" + ENDING))
+	cache := buf.New()
+	b := buf.NewLocal(256)
+	b.AppendSupplier(serial.WriteString("abcd" + ENDING))
 	writer := NewHeaderWriter(b)
 	writer.Write(cache)
 	cache.Write([]byte{'e', 'f', 'g'})
@@ -41,7 +41,7 @@ func TestRequestHeader(t *testing.T) {
 		},
 	}).(HttpAuthenticator)
 
-	cache := buf.NewBuffer()
+	cache := buf.New()
 	err := auth.GetClientWriter().Write(cache)
 	assert.Error(err).IsNil()
 
diff --git a/transport/internet/headers/noop/noop.go b/transport/internet/headers/noop/noop.go
index b976628e4..4f0ed5946 100644
--- a/transport/internet/headers/noop/noop.go
+++ b/transport/internet/headers/noop/noop.go
@@ -12,8 +12,8 @@ type NoOpHeader struct{}
 func (v NoOpHeader) Size() int {
 	return 0
 }
-func (v NoOpHeader) Write([]byte) int {
-	return 0
+func (v NoOpHeader) Write([]byte) (int, error) {
+	return 0, nil
 }
 
 type NoOpHeaderFactory struct{}
diff --git a/transport/internet/headers/srtp/srtp.go b/transport/internet/headers/srtp/srtp.go
index ce0b1a616..5290a87bc 100644
--- a/transport/internet/headers/srtp/srtp.go
+++ b/transport/internet/headers/srtp/srtp.go
@@ -17,11 +17,11 @@ func (v *SRTP) Size() int {
 	return 4
 }
 
-func (v *SRTP) Write(b []byte) int {
+func (v *SRTP) Write(b []byte) (int, error) {
 	v.number++
 	b = serial.Uint16ToBytes(v.number, b[:0])
 	b = serial.Uint16ToBytes(v.number, b)
-	return 4
+	return 4, nil
 }
 
 type SRTPFactory struct {
diff --git a/transport/internet/headers/srtp/srtp_test.go b/transport/internet/headers/srtp/srtp_test.go
index 5e2c0de9c..f0e0be2ba 100644
--- a/transport/internet/headers/srtp/srtp_test.go
+++ b/transport/internet/headers/srtp/srtp_test.go
@@ -14,8 +14,8 @@ func TestSRTPWrite(t *testing.T) {
 	content := []byte{'a', 'b', 'c', 'd', 'e', 'f', 'g'}
 	srtp := SRTP{}
 
-	payload := buf.NewLocalBuffer(2048)
-	payload.AppendFunc(srtp.Write)
+	payload := buf.NewLocal(2048)
+	payload.AppendSupplier(srtp.Write)
 	payload.Append(content)
 
 	assert.Int(payload.Len()).Equals(len(content) + srtp.Size())
diff --git a/transport/internet/headers/utp/utp.go b/transport/internet/headers/utp/utp.go
index 9334483f8..7dab46c33 100644
--- a/transport/internet/headers/utp/utp.go
+++ b/transport/internet/headers/utp/utp.go
@@ -18,10 +18,10 @@ func (v *UTP) Size() int {
 	return 4
 }
 
-func (v *UTP) Write(b []byte) int {
+func (v *UTP) Write(b []byte) (int, error) {
 	b = serial.Uint16ToBytes(v.connectionId, b[:0])
 	b = append(b, v.header, v.extension)
-	return 4
+	return 4, nil
 }
 
 type UTPFactory struct{}
diff --git a/transport/internet/headers/utp/utp_test.go b/transport/internet/headers/utp/utp_test.go
index 87808904d..3faa3bbcd 100644
--- a/transport/internet/headers/utp/utp_test.go
+++ b/transport/internet/headers/utp/utp_test.go
@@ -14,8 +14,8 @@ func TestUTPWrite(t *testing.T) {
 	content := []byte{'a', 'b', 'c', 'd', 'e', 'f', 'g'}
 	utp := UTP{}
 
-	payload := buf.NewLocalBuffer(2048)
-	payload.AppendFunc(utp.Write)
+	payload := buf.NewLocal(2048)
+	payload.AppendSupplier(utp.Write)
 	payload.Append(content)
 
 	assert.Int(payload.Len()).Equals(len(content) + utp.Size())
diff --git a/transport/internet/kcp/connection.go b/transport/internet/kcp/connection.go
index 53154f674..280b20a38 100644
--- a/transport/internet/kcp/connection.go
+++ b/transport/internet/kcp/connection.go
@@ -10,7 +10,6 @@ import (
 	"v2ray.com/core/common/errors"
 	"v2ray.com/core/common/log"
 	"v2ray.com/core/common/predicate"
-	"v2ray.com/core/transport/internet"
 	"v2ray.com/core/transport/internet/internal"
 )
 
@@ -170,7 +169,6 @@ type SystemConnection interface {
 type Connection struct {
 	conn         SystemConnection
 	connRecycler internal.ConnectionRecyler
-	block        internet.Authenticator
 	rd           time.Time
 	wd           time.Time // write deadline
 	since        int64
diff --git a/transport/internet/kcp/dialer.go b/transport/internet/kcp/dialer.go
index e85fc81c5..301dddfe9 100644
--- a/transport/internet/kcp/dialer.go
+++ b/transport/internet/kcp/dialer.go
@@ -88,12 +88,12 @@ func (o *ClientConnection) ResetSecurity(header internet.PacketHeader, security
 }
 
 func (o *ClientConnection) Run() {
-	payload := buf.NewSmallBuffer()
+	payload := buf.NewSmall()
 	defer payload.Release()
 
 	for {
 		payload.Clear()
-		_, err := payload.FillFrom(o.Conn)
+		err := payload.AppendSupplier(buf.ReadFrom(o.Conn))
 		if err != nil {
 			payload.Release()
 			return
diff --git a/transport/internet/kcp/io.go b/transport/internet/kcp/io.go
index bddfa8520..253d48a29 100644
--- a/transport/internet/kcp/io.go
+++ b/transport/internet/kcp/io.go
@@ -69,7 +69,7 @@ func (v *KCPPacketWriter) Write(b []byte) (int, error) {
 	x := v.buffer[:]
 	size := 0
 	if v.Header != nil {
-		nBytes := v.Header.Write(x)
+		nBytes, _ := v.Header.Write(x)
 		size += nBytes
 		x = x[nBytes:]
 	}
diff --git a/transport/internet/kcp/output.go b/transport/internet/kcp/output.go
index 3f5861ff1..47bd6ee7e 100644
--- a/transport/internet/kcp/output.go
+++ b/transport/internet/kcp/output.go
@@ -22,7 +22,7 @@ func NewSegmentWriter(writer io.Writer, mtu uint32) *BufferedSegmentWriter {
 	return &BufferedSegmentWriter{
 		mtu:    mtu,
 		writer: writer,
-		buffer: buf.NewSmallBuffer(),
+		buffer: buf.NewSmall(),
 	}
 }
 
@@ -35,7 +35,7 @@ func (v *BufferedSegmentWriter) Write(seg Segment) {
 		v.FlushWithoutLock()
 	}
 
-	v.buffer.AppendFunc(seg.Bytes())
+	v.buffer.AppendSupplier(seg.Bytes())
 }
 
 func (v *BufferedSegmentWriter) FlushWithoutLock() {
diff --git a/transport/internet/kcp/segment.go b/transport/internet/kcp/segment.go
index 7514888f6..9b3ed26a4 100644
--- a/transport/internet/kcp/segment.go
+++ b/transport/internet/kcp/segment.go
@@ -31,7 +31,7 @@ type Segment interface {
 	Conversation() uint16
 	Command() Command
 	ByteSize() int
-	Bytes() buf.BytesWriter
+	Bytes() buf.Supplier
 }
 
 const (
@@ -64,14 +64,14 @@ func (v *DataSegment) Command() Command {
 
 func (v *DataSegment) SetData(b []byte) {
 	if v.Data == nil {
-		v.Data = buf.NewSmallBuffer()
+		v.Data = buf.NewSmall()
 	}
 	v.Data.Clear()
 	v.Data.Append(b)
 }
 
-func (v *DataSegment) Bytes() buf.BytesWriter {
-	return func(b []byte) int {
+func (v *DataSegment) Bytes() buf.Supplier {
+	return func(b []byte) (int, error) {
 		b = serial.Uint16ToBytes(v.Conv, b[:0])
 		b = append(b, byte(CommandData), byte(v.Option))
 		b = serial.Uint32ToBytes(v.Timestamp, b)
@@ -79,7 +79,7 @@ func (v *DataSegment) Bytes() buf.BytesWriter {
 		b = serial.Uint32ToBytes(v.SendingNext, b)
 		b = serial.Uint16ToBytes(uint16(v.Data.Len()), b)
 		b = append(b, v.Data.Bytes()...)
-		return v.ByteSize()
+		return v.ByteSize(), nil
 	}
 }
 
@@ -137,8 +137,8 @@ func (v *AckSegment) ByteSize() int {
 	return 2 + 1 + 1 + 4 + 4 + 4 + 1 + int(v.Count)*4
 }
 
-func (v *AckSegment) Bytes() buf.BytesWriter {
-	return func(b []byte) int {
+func (v *AckSegment) Bytes() buf.Supplier {
+	return func(b []byte) (int, error) {
 		b = serial.Uint16ToBytes(v.Conv, b[:0])
 		b = append(b, byte(CommandACK), byte(v.Option))
 		b = serial.Uint32ToBytes(v.ReceivingWindow, b)
@@ -148,7 +148,7 @@ func (v *AckSegment) Bytes() buf.BytesWriter {
 		for i := byte(0); i < v.Count; i++ {
 			b = serial.Uint32ToBytes(v.NumberList[i], b)
 		}
-		return v.ByteSize()
+		return v.ByteSize(), nil
 	}
 }
 
@@ -181,14 +181,14 @@ func (v *CmdOnlySegment) ByteSize() int {
 	return 2 + 1 + 1 + 4 + 4 + 4
 }
 
-func (v *CmdOnlySegment) Bytes() buf.BytesWriter {
-	return func(b []byte) int {
+func (v *CmdOnlySegment) Bytes() buf.Supplier {
+	return func(b []byte) (int, error) {
 		b = serial.Uint16ToBytes(v.Conv, b[:0])
 		b = append(b, byte(v.Cmd), byte(v.Option))
 		b = serial.Uint32ToBytes(v.SendingNext, b)
 		b = serial.Uint32ToBytes(v.ReceivinNext, b)
 		b = serial.Uint32ToBytes(v.PeerRTO, b)
-		return v.ByteSize()
+		return v.ByteSize(), nil
 	}
 }
 
diff --git a/transport/internet/kcp/segment_test.go b/transport/internet/kcp/segment_test.go
index 079969308..571a6defb 100644
--- a/transport/internet/kcp/segment_test.go
+++ b/transport/internet/kcp/segment_test.go
@@ -19,7 +19,7 @@ func TestBadSegment(t *testing.T) {
 func TestDataSegment(t *testing.T) {
 	assert := assert.On(t)
 
-	b := buf.NewLocalBuffer(512)
+	b := buf.NewLocal(512)
 	b.Append([]byte{'a', 'b', 'c', 'd'})
 	seg := &DataSegment{
 		Conv:        1,
diff --git a/transport/internet/udp/hub.go b/transport/internet/udp/hub.go
index c95a6c412..4aca426a1 100644
--- a/transport/internet/udp/hub.go
+++ b/transport/internet/udp/hub.go
@@ -135,16 +135,14 @@ func (v *UDPHub) start() {
 
 	oobBytes := make([]byte, 256)
 	for v.Running() {
-		buffer := buf.NewSmallBuffer()
+		buffer := buf.NewSmall()
 		var noob int
 		var addr *net.UDPAddr
-		var err error
-		buffer.AppendFunc(func(b []byte) int {
+		err := buffer.AppendSupplier(func(b []byte) (int, error) {
 			n, nb, _, a, e := ReadUDPMsg(v.conn, b, oobBytes)
 			noob = nb
 			addr = a
-			err = e
-			return n
+			return n, e
 		})
 
 		if err != nil {