fast read on first packet

common/buf/io.go

@@ -57,18 +57,6 @@ func NewReader(reader io.Reader) Reader {
 
 	return &BytesToBufferReader{
 		reader: reader,
-		buffer: make([]byte, 32*1024),
-	}
-}
-
-func NewMergingReader(reader io.Reader) Reader {
-	return NewMergingReaderSize(reader, 32*1024)
-}
-
-func NewMergingReaderSize(reader io.Reader, size uint32) Reader {
-	return &BytesToBufferReader{
-		reader: reader,
-		buffer: make([]byte, size),
 	}
 }
 

common/buf/reader.go

@@ -12,8 +12,30 @@ type BytesToBufferReader struct {
 	buffer []byte
 }
 
+func NewBytesToBufferReader(reader io.Reader) Reader {
+	return &BytesToBufferReader{
+		reader: reader,
+	}
+}
+
+func (r *BytesToBufferReader) readSmall() (MultiBuffer, error) {
+	b := New()
+	if err := b.Reset(ReadFrom(r.reader)); err != nil {
+		b.Release()
+		return nil, err
+	}
+	if b.IsFull() {
+		r.buffer = make([]byte, 32*1024)
+	}
+	return NewMultiBufferValue(b), nil
+}
+
 // Read implements Reader.Read().
 func (r *BytesToBufferReader) Read() (MultiBuffer, error) {
+	if r.buffer == nil {
+		return r.readSmall()
+	}
+
 	nBytes, err := r.reader.Read(r.buffer)
 	if err != nil {
 		return nil, err

common/buf/reader_test.go

@@ -14,12 +14,13 @@ import (
 func TestAdaptiveReader(t *testing.T) {
 	assert := With(t)
 
-	rawContent := make([]byte, 1024*1024)
-	buffer := bytes.NewBuffer(rawContent)
-
-	reader := NewReader(buffer)
+	reader := NewReader(bytes.NewReader(make([]byte, 1024*1024)))
 	b, err := reader.Read()
 	assert(err, IsNil)
+	assert(b.Len(), Equals, 2*1024)
+
+	b, err = reader.Read()
+	assert(err, IsNil)
 	assert(b.Len(), Equals, 32*1024)
 }