From 902bb1cc2a0a8644e160f303be1a2e0ad354bfd5 Mon Sep 17 00:00:00 2001
From: Luke Shumaker <lukeshu@lukeshu.com>
Date: Wed, 15 Nov 2017 15:38:05 -0500
Subject: initial commit

---
 io.go | 132 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 132 insertions(+)
 create mode 100644 io.go

(limited to 'io.go')

diff --git a/io.go b/io.go
new file mode 100644
index 0000000..f3f4909
--- /dev/null
+++ b/io.go
@@ -0,0 +1,132 @@
+package libfastimport
+
+import (
+	"bufio"
+	"bytes"
+	"io"
+	"strconv"
+)
+
+type FIReader struct {
+	r *bufio.Reader
+}
+
+func NewFIReader(r io.Reader) *FIReader {
+	return &FIReader{
+		r: bufio.NewReader(r),
+	}
+}
+
+func (fir *FIReader) ReadSlice() (line []byte, err error) {
+retry:
+	line, err = fir.r.ReadSlice('\n')
+	if err != nil {
+		return
+	}
+	if len(line) == 1 {
+		goto retry
+	}
+
+	if bytes.HasPrefix(line, []byte("data ")) {
+		if string(line[5:7]) == "<<" {
+			// Delimited format
+			delim := line[7 : len(line)-1]
+			suffix := []byte("\n" + string(delim) + "\n")
+
+			_line := make([]byte, len(line))
+			copy(_line, line)
+			line = _line
+
+			for !bytes.HasSuffix(line, suffix) {
+				_line, err = fir.r.ReadSlice('\n')
+				line == append(line, _line)
+				if err != nil {
+					return
+				}
+			}
+		} else {
+			// Exact byte count format
+			var size int
+			size, err = strconv.Atoi(string(line[5 : len(line)-1]))
+			if err != nil {
+				return
+			}
+			_line := make([]byte, size+len(line))
+			copy(_line, line)
+			n, err := io.ReadFull(fir.r, _line[len(line):])
+			line = _line[:n+len(line)]
+		}
+	}
+	return
+}
+
+type FIWriter struct {
+	w io.Writer
+}
+
+func NewFIWriter(w io.Writer) *FIWriter {
+	return &FIWriter{
+		w: w,
+	}
+}
+
+func (fiw *FIReader) WriteLine(a ...interface{}) error {
+	_, err := fmt.Fprintln(fiw.w, a...)
+	return err
+}
+
+func (fiw *FIReader) WriteData(data []byte) error {
+	err := fiw.WriteLine("data", len(data))
+	if err != nil {
+		return err
+	}
+	_, err = fiw.w.Write(data)
+	return err
+}
+
+type CatBlobReader struct {
+	r *bufio.Reader
+}
+
+func NewCatBlobReader(r io.Reader) *CatBlobReader {
+	return &CatBlobReader{
+		r: bufio.NewReader(r),
+	}
+}
+
+func (cbr *CatBlobReader) ReadSlice() (line []byte, err error) {
+retry:
+	line, err = fir.r.ReadSlice('\n')
+	if err != nil {
+		return
+	}
+	if len(line) == 1 {
+		goto retry
+	}
+
+	// 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
+	if len(line) <= 46 || string(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(string(line[46 : len(line)-1]))
+	if err != nil {
+		return
+	}
+	_line = make([]byte, len(line)+size+1)
+	copy(_line, line)
+	n, err := io.ReadFull(fir.r, _line[len(line):])
+	line = _line[:n+len(line)]
+	return
+}
-- 
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