github.com/qiniu/x/bufiox

bufiox/bufio.go

@@ -0,0 +1,69 @@
+package bufiox
+
+import (
+	"bufio"
+	"bytes"
+	"io"
+	"unsafe"
+)
+
+// -----------------------------------------------------------------------------
+
+type nilReaderImpl int
+
+func (p nilReaderImpl) Read(b []byte) (n int, err error) {
+	return 0, io.EOF
+}
+
+var nilReader io.Reader = nilReaderImpl(0)
+
+// -----------------------------------------------------------------------------
+
+type reader struct {
+	buf          []byte
+	rd           io.Reader // reader provided by the client
+	r, w         int       // buf read and write positions
+	err          error
+	lastByte     int
+	lastRuneSize int
+}
+
+// NewReaderBuffer returns a new Reader who uses a extern buffer.
+func NewReaderBuffer(buf []byte) *bufio.Reader {
+	r := &reader{
+		buf:          buf,
+		rd:           nilReader,
+		w:            len(buf),
+		lastByte:     -1,
+		lastRuneSize: -1,
+	}
+	b := new(bufio.Reader)
+	*b = *(*bufio.Reader)(unsafe.Pointer(r))
+	return b
+}
+
+// Buffer is reserved for internal use.
+func Buffer(b *bufio.Reader) []byte {
+	r := (*reader)(unsafe.Pointer(b))
+	return r.buf
+}
+
+// IsReaderBuffer returns if this Reader instance is returned by NewReaderBuffer
+func IsReaderBuffer(b *bufio.Reader) bool {
+	r := (*reader)(unsafe.Pointer(b))
+	return r.rd == nilReader
+}
+
+// ReadAll reads all data
+func ReadAll(b *bufio.Reader) (ret []byte, err error) {
+	r := (*reader)(unsafe.Pointer(b))
+	if r.rd == nilReader {
+		ret, r.buf = r.buf, nil
+		return
+	}
+	var w bytes.Buffer
+	_, err1 := b.WriteTo(&w)
+	return w.Bytes(), err1
+}
+
+// -----------------------------------------------------------------------------