utils: binary reader, add ReadUntilFromBufioReader()

Signed-off-by: Arran Walker <[email protected]>

Author: saracen

utils/binary/read.go

@@ -26,12 +26,7 @@ func Read(r io.Reader, data ...interface{}) error {
 // ReadUntil reads from r untin delim is found
 func ReadUntil(r io.Reader, delim byte) ([]byte, error) {
 	if bufr, ok := r.(*bufio.Reader); ok {
-		value, err := bufr.ReadBytes(delim)
-		if err != nil || len(value) == 0 {
-			return nil, err
-		}
-
-		return value[:len(value)-1], nil
+		return ReadUntilFromBufioReader(bufr, delim)
 	}
 
 	var buf [1]byte
@@ -53,6 +48,17 @@ func ReadUntil(r io.Reader, delim byte) ([]byte, error) {
 	}
 }
 
+// ReadUntilFromBufioReader is like bufio.ReadBytes but drops the delimiter
+// from the result.
+func ReadUntilFromBufioReader(r *bufio.Reader, delim byte) ([]byte, error) {
+	value, err := r.ReadBytes(delim)
+	if err != nil || len(value) == 0 {
+		return nil, err
+	}
+
+	return value[:len(value)-1], nil
+}
+
 // ReadVariableWidthInt reads and returns an int in Git VLQ special format:
 //
 // Ordinary VLQ has some redundancies, example:  the number 358 can be

utils/binary/read_test.go

@@ -1,6 +1,7 @@
 package binary
 
 import (
+	"bufio"
 	"bytes"
 	"encoding/binary"
 	"testing"
@@ -39,6 +40,15 @@ func (s *BinarySuite) TestReadUntil(c *C) {
 	c.Assert(string(b), Equals, "foo")
 }
 
+func (s *BinarySuite) TestReadUntilFromBufioReader(c *C) {
+	buf := bufio.NewReader(bytes.NewBuffer([]byte("foo bar")))
+
+	b, err := ReadUntilFromBufioReader(buf, ' ')
+	c.Assert(err, IsNil)
+	c.Assert(b, HasLen, 3)
+	c.Assert(string(b), Equals, "foo")
+}
+
 func (s *BinarySuite) TestReadVariableWidthInt(c *C) {
 	buf := bytes.NewBuffer([]byte{129, 110})