codec: H264 and MJPEG lexers now using codecutil package for byte scanner functionality

codec/codecutil/bytescanner.go

@@ -23,7 +23,7 @@ LICENSE
 */
 
 // Package bytescan implements a byte-level scanner.
-package bytescan
+package codecutil
 
 import "io"
 

codec/codecutil/bytescanner_test.go

@@ -25,7 +25,7 @@ LICENSE
   in gpl.txt. If not, see http://www.gnu.org/licenses.
 */
 
-package bytescan
+package codecutil
 
 import (
 	"bytes"

codec/h264/lex.go

@@ -32,6 +32,8 @@ package h264
 import (
 	"io"
 	"time"
+
+	"bitbucket.org/ausocean/av/codec/codecutil"
 )
 
 var noDelay = make(chan time.Time)
@@ -58,7 +60,7 @@ func Lex(dst io.Writer, src io.Reader, delay time.Duration) error {
 
 	const bufSize = 8 << 10
 
-	c := newScanner(src, make([]byte, 4<<10)) // Standard file buffer size.
+	c := codecutil.NewByteScanner(src, make([]byte, 4<<10)) // Standard file buffer size.
 
 	buf := make([]byte, len(h264Prefix), bufSize)
 	copy(buf, h264Prefix[:])
@@ -67,7 +69,7 @@ outer:
 	for {
 		var b byte
 		var err error
-		buf, b, err = c.scanUntilZeroInto(buf)
+		buf, b, err = c.ScanUntil(buf, 0x00)
 		if err != nil {
 			if err != io.EOF {
 				return err
@@ -76,7 +78,7 @@ outer:
 		}
 
 		for n := 1; b == 0x0 && n < 4; n++ {
-			b, err = c.readByte()
+			b, err = c.ReadByte()
 			if err != nil {
 				if err != io.EOF {
 					return err
@@ -101,7 +103,7 @@ outer:
 				writeOut = false
 			}
 
-			b, err = c.readByte()
+			b, err = c.ReadByte()
 			if err != nil {
 				if err != io.EOF {
 					return err
@@ -131,70 +133,3 @@ outer:
 	_, err := dst.Write(buf)
 	return err
 }
-
-// scanner is a byte scanner.
-type scanner struct {
-	buf []byte
-	off int
-
-	// r is the source of data for the scanner.
-	r io.Reader
-}
-
-// newScanner returns a scanner initialised with an io.Reader and a read buffer.
-func newScanner(r io.Reader, buf []byte) *scanner {
-	return &scanner{r: r, buf: buf[:0]}
-}
-
-// scanUntilZeroInto scans the scanner's underlying io.Reader until a zero byte
-// has been read, appending all read bytes to dst. The resulting appended data,
-// the last read byte and whether the last read byte was zero are returned.
-func (c *scanner) scanUntilZeroInto(dst []byte) (res []byte, b byte, err error) {
-outer:
-	for {
-		var i int
-		for i, b = range c.buf[c.off:] {
-			if b != 0x0 {
-				continue
-			}
-			dst = append(dst, c.buf[c.off:c.off+i+1]...)
-			c.off += i + 1
-			break outer
-		}
-		dst = append(dst, c.buf[c.off:]...)
-		err = c.reload()
-		if err != nil {
-			break
-		}
-	}
-	return dst, b, err
-}
-
-// readByte is an unexported ReadByte.
-func (c *scanner) readByte() (byte, error) {
-	if c.off >= len(c.buf) {
-		err := c.reload()
-		if err != nil {
-			return 0, err
-		}
-	}
-	b := c.buf[c.off]
-	c.off++
-	return b, nil
-}
-
-// reload re-fills the scanner's buffer.
-func (c *scanner) reload() error {
-	n, err := c.r.Read(c.buf[:cap(c.buf)])
-	c.buf = c.buf[:n]
-	if err != nil {
-		if err != io.EOF {
-			return err
-		}
-		if n == 0 {
-			return io.EOF
-		}
-	}
-	c.off = 0
-	return nil
-}

codec/h264/lex_test.go

@@ -30,9 +30,6 @@ LICENSE
 package h264
 
 import (
-	"bytes"
-	"reflect"
-	"testing"
 	"time"
 )
 
@@ -223,50 +220,3 @@ func TestH264(t *testing.T) {
 	}
 }
 */
-type chunkEncoder [][]byte
-
-func (e *chunkEncoder) Encode(b []byte) error {
-	*e = append(*e, b)
-	return nil
-}
-
-func (*chunkEncoder) Stream() <-chan []byte { panic("INVALID USE") }
-
-func TestScannerReadByte(t *testing.T) {
-	data := []byte("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.")
-
-	for _, size := range []int{1, 2, 8, 1 << 10} {
-		r := newScanner(bytes.NewReader(data), make([]byte, size))
-		var got []byte
-		for {
-			b, err := r.readByte()
-			if err != nil {
-				break
-			}
-			got = append(got, b)
-		}
-		if !bytes.Equal(got, data) {
-			t.Errorf("unexpected result for buffer size %d:\ngot :%q\nwant:%q", size, got, data)
-		}
-	}
-}
-
-func TestScannerScanUntilZero(t *testing.T) {
-	data := []byte("Lorem ipsum dolor sit amet, consectetur adipiscing elit,\x00 sed do eiusmod tempor incididunt ut \x00labore et dolore magna aliqua.")
-
-	for _, size := range []int{1, 2, 8, 1 << 10} {
-		r := newScanner(bytes.NewReader(data), make([]byte, size))
-		var got [][]byte
-		for {
-			buf, _, err := r.scanUntilZeroInto(nil)
-			got = append(got, buf)
-			if err != nil {
-				break
-			}
-		}
-		want := bytes.SplitAfter(data, []byte{0})
-		if !reflect.DeepEqual(got, want) {
-			t.Errorf("unexpected result for buffer zie %d:\ngot :%q\nwant:%q", size, got, want)
-		}
-	}
-}

codec/mjpeg/lex.go

@@ -87,70 +87,3 @@ func Lex(dst io.Writer, src io.Reader, delay time.Duration) error {
 		}
 	}
 }
-
-// scanner is a byte scanner.
-type scanner struct {
-	buf []byte
-	off int
-
-	// r is the source of data for the scanner.
-	r io.Reader
-}
-
-// newScanner returns a scanner initialised with an io.Reader and a read buffer.
-func newScanner(r io.Reader, buf []byte) *scanner {
-	return &scanner{r: r, buf: buf[:0]}
-}
-
-// scanUntilZeroInto scans the scanner's underlying io.Reader until a zero byte
-// has been read, appending all read bytes to dst. The resulting appended data,
-// the last read byte and whether the last read byte was zero are returned.
-func (c *scanner) scanUntilZeroInto(dst []byte) (res []byte, b byte, err error) {
-outer:
-	for {
-		var i int
-		for i, b = range c.buf[c.off:] {
-			if b != 0x0 {
-				continue
-			}
-			dst = append(dst, c.buf[c.off:c.off+i+1]...)
-			c.off += i + 1
-			break outer
-		}
-		dst = append(dst, c.buf[c.off:]...)
-		err = c.reload()
-		if err != nil {
-			break
-		}
-	}
-	return dst, b, err
-}
-
-// readByte is an unexported ReadByte.
-func (c *scanner) readByte() (byte, error) {
-	if c.off >= len(c.buf) {
-		err := c.reload()
-		if err != nil {
-			return 0, err
-		}
-	}
-	b := c.buf[c.off]
-	c.off++
-	return b, nil
-}
-
-// reload re-fills the scanner's buffer.
-func (c *scanner) reload() error {
-	n, err := c.r.Read(c.buf[:cap(c.buf)])
-	c.buf = c.buf[:n]
-	if err != nil {
-		if err != io.EOF {
-			return err
-		}
-		if n == 0 {
-			return io.EOF
-		}
-	}
-	c.off = 0
-	return nil
-}

codec/mjpeg/lex_test.go

@@ -30,9 +30,6 @@ LICENSE
 package mjpeg
 
 import (
-	"bytes"
-	"reflect"
-	"testing"
 	"time"
 )
 
@@ -115,51 +112,3 @@ func Lex(t *testing.T) {
 	}
 }
 */
-
-type chunkEncoder [][]byte
-
-func (e *chunkEncoder) Encode(b []byte) error {
-	*e = append(*e, b)
-	return nil
-}
-
-func (*chunkEncoder) Stream() <-chan []byte { panic("INVALID USE") }
-
-func TestScannerReadByte(t *testing.T) {
-	data := []byte("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.")
-
-	for _, size := range []int{1, 2, 8, 1 << 10} {
-		r := newScanner(bytes.NewReader(data), make([]byte, size))
-		var got []byte
-		for {
-			b, err := r.readByte()
-			if err != nil {
-				break
-			}
-			got = append(got, b)
-		}
-		if !bytes.Equal(got, data) {
-			t.Errorf("unexpected result for buffer size %d:\ngot :%q\nwant:%q", size, got, data)
-		}
-	}
-}
-
-func TestScannerScanUntilZero(t *testing.T) {
-	data := []byte("Lorem ipsum dolor sit amet, consectetur adipiscing elit,\x00 sed do eiusmod tempor incididunt ut \x00labore et dolore magna aliqua.")
-
-	for _, size := range []int{1, 2, 8, 1 << 10} {
-		r := newScanner(bytes.NewReader(data), make([]byte, size))
-		var got [][]byte
-		for {
-			buf, _, err := r.scanUntilZeroInto(nil)
-			got = append(got, buf)
-			if err != nil {
-				break
-			}
-		}
-		want := bytes.SplitAfter(data, []byte{0})
-		if !reflect.DeepEqual(got, want) {
-			t.Errorf("unexpected result for buffer zie %d:\ngot :%q\nwant:%q", size, got, want)
-		}
-	}
-}