2 files changed, 33 insertions, 8 deletions
diff --git a/vendor/github.com/philhofer/fwd/reader.go b/vendor/github.com/philhofer/fwd/reader.go
index 75be62ab09..6918d3e211 100644
--- a/vendor/github.com/philhofer/fwd/reader.go
+++ b/vendor/github.com/philhofer/fwd/reader.go
@@ -50,11 +50,24 @@ func NewReader(r io.Reader) *Reader {
 }
 
 // NewReaderSize returns a new *Reader that
-// reads from 'r' and has a buffer size 'n'
+// reads from 'r' and has a buffer size 'n'.
 func NewReaderSize(r io.Reader, n int) *Reader {
+	buf := make([]byte, 0, max(n, minReaderSize))
+	return NewReaderBuf(r, buf)
+}
+
+// NewReaderBuf returns a new *Reader that
+// reads from 'r' and uses 'buf' as a buffer.
+// 'buf' is not used when has smaller capacity than 16,
+// custom buffer is allocated instead.
+func NewReaderBuf(r io.Reader, buf []byte) *Reader {
+	if cap(buf) < minReaderSize {
+		buf = make([]byte, 0, minReaderSize)
+	}
+	buf = buf[:0]
 	rd := &Reader{
 		r:    r,
-		data: make([]byte, 0, max(minReaderSize, n)),
+		data: buf,
 	}
 	if s, ok := r.(io.Seeker); ok {
 		rd.rs = s
diff --git a/vendor/github.com/philhofer/fwd/writer.go b/vendor/github.com/philhofer/fwd/writer.go
index 2dc392a91b..4d6ea15b33 100644
--- a/vendor/github.com/philhofer/fwd/writer.go
+++ b/vendor/github.com/philhofer/fwd/writer.go
@@ -29,16 +29,28 @@ func NewWriter(w io.Writer) *Writer {
 	}
 }
 
-// NewWriterSize returns a new writer
-// that writes to 'w' and has a buffer
-// that is 'size' bytes.
-func NewWriterSize(w io.Writer, size int) *Writer {
-	if wr, ok := w.(*Writer); ok && cap(wr.buf) >= size {
+// NewWriterSize returns a new writer that
+// writes to 'w' and has a buffer size 'n'.
+func NewWriterSize(w io.Writer, n int) *Writer {
+	if wr, ok := w.(*Writer); ok && cap(wr.buf) >= n {
 		return wr
 	}
+	buf := make([]byte, 0, max(n, minWriterSize))
+	return NewWriterBuf(w, buf)
+}
+
+// NewWriterBuf returns a new writer
+// that writes to 'w' and has 'buf' as a buffer.
+// 'buf' is not used when has smaller capacity than 18,
+// custom buffer is allocated instead.
+func NewWriterBuf(w io.Writer, buf []byte) *Writer {
+	if cap(buf) < minWriterSize {
+		buf = make([]byte, 0, minWriterSize)
+	}
+	buf = buf[:0]
 	return &Writer{
 		w:   w,
-		buf: make([]byte, 0, max(size, minWriterSize)),
+		buf: buf,
 	}
 }