1 files changed, 77 insertions, 0 deletions
diff --git a/textproto/catblob.go b/textproto/catblob.go
new file mode 100644
index 0000000..9b0f8d7
--- /dev/null
+++ b/textproto/catblob.go
@@ -0,0 +1,77 @@
+package textproto
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"strconv"
+)
+
+type CatBlobReader struct {
+	r *bufio.Reader
+}
+
+func NewCatBlobReader(r io.Reader) *CatBlobReader {
+	return &CatBlobReader{
+		r: bufio.NewReader(r),
+	}
+}
+
+func (cbr *CatBlobReader) ReadLine() (line string, err error) {
+	for len(line) <= 1 {
+		line, err = cbr.r.ReadString('\n')
+		if err != nil {
+			return
+		}
+	}
+
+	// get-mark : <sha1> LF
+	// cat-blob : <sha1> SP 'blob' SP <size> LF
+	//            <data> LF
+	// ls       : <mode> SP ('blob' | 'tree' | 'commit') SP <dataref> HT <path> LF
+	// ls       : 'missing' SP <path> LF
+
+	// decide if we have a cat-blob result (return early if we don't)
+	if len(line) <= 46 || line[40:46] != " blob " {
+		return
+	}
+	for _, b := range line[:40] {
+		if !(('0' <= b && b <= '9') || ('a' <= b && b <= 'f')) {
+			return
+		}
+	}
+	// we have a cat-blob result
+	var size int
+	size, err = strconv.Atoi(line[46 : len(line)-1])
+	if err != nil {
+		return
+	}
+	data := make([]byte, size+1)
+	_, err = io.ReadFull(cbr.r, data)
+	line += string(data[:size])
+	return
+}
+
+type CatBlobWriter struct {
+	w io.Writer
+}
+
+func NewCatBlobWriter(w io.Writer) *CatBlobWriter {
+	return &CatBlobWriter{
+		w: w,
+	}
+}
+
+func (cbw *CatBlobWriter) WriteLine(a ...interface{}) error {
+	_, err := fmt.Fprintln(cbw.w, a...)
+	return err
+}
+
+func (cbw *CatBlobWriter) WriteBlob(sha1 string, data string) error {
+	err := cbw.WriteLine(sha1, "blob", len(data))
+	if err != nil {
+		return err
+	}
+	_, err = io.WriteString(cbw.w, data)
+	return err
+}