First commit

1 files changed, 124 insertions, 0 deletions

diff --git a/pkg/gitdiff/testdata/apply/bin.go b/pkg/gitdiff/testdata/apply/bin.go
new file mode 100644
index 0000000..e34f06b
--- /dev/null
+++ b/pkg/gitdiff/testdata/apply/bin.go
@@ -0,0 +1,124 @@
+//go:build ignore
+
+// bin.go is a helper CLI to manipulate binary diff data for testing purposes.
+// It can decode patches generated by git using the standard parsing functions
+// or it can encode binary data back into the format expected by Git. It
+// operates on stdin writes results (possibly binary) to stdout.
+
+package main
+
+import (
+	"bytes"
+	"compress/zlib"
+	"encoding/binary"
+	"flag"
+	"io/ioutil"
+	"log"
+	"os"
+	"strings"
+
+	"github.com/bluekeyes/go-gitdiff/gitdiff"
+)
+
+var (
+	b85Powers = []uint32{52200625, 614125, 7225, 85, 1}
+	b85Alpha  = []byte(
+		"0123456789" + "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + "abcdefghijklmnopqrstuvwxyz" + "!#$%&()*+-;<=>?@^_`{|}~",
+	)
+)
+
+var mode string
+
+func base85Encode(data []byte) []byte {
+	chunks, remaining := len(data)/4, len(data)%4
+	if remaining > 0 {
+		data = append(data, make([]byte, 4-remaining)...)
+		chunks++
+	}
+
+	var n int
+	out := make([]byte, 5*chunks)
+
+	for i := 0; i < len(data); i += 4 {
+		v := binary.BigEndian.Uint32(data[i : i+4])
+		for j := 0; j < 5; j++ {
+			p := v / b85Powers[j]
+			out[n+j] = b85Alpha[p]
+			v -= b85Powers[j] * p
+		}
+		n += 5
+	}
+
+	return out
+}
+
+func compress(data []byte) ([]byte, error) {
+	var b bytes.Buffer
+	w := zlib.NewWriter(&b)
+
+	if _, err := w.Write(data); err != nil {
+		return nil, err
+	}
+	if err := w.Close(); err != nil {
+		return nil, err
+	}
+
+	return b.Bytes(), nil
+}
+
+func wrap(data []byte) string {
+	var s strings.Builder
+	for i := 0; i < len(data); i += 52 {
+		c := 52
+		if c > len(data)-i {
+			c = len(data) - i
+		}
+		b := (c / 5) * 4
+
+		if b <= 26 {
+			s.WriteByte(byte('A' + b - 1))
+		} else {
+			s.WriteByte(byte('a' + b - 27))
+		}
+		s.Write(data[i : i+c])
+		s.WriteByte('\n')
+	}
+	return s.String()
+}
+
+func init() {
+	flag.StringVar(&mode, "mode", "parse", "operation mode, one of 'parse' or 'encode'")
+}
+
+func main() {
+	flag.Parse()
+
+	switch mode {
+	case "parse":
+		files, _, err := gitdiff.Parse(os.Stdin)
+		if err != nil {
+			log.Fatalf("failed to parse file: %v", err)
+		}
+		if len(files) != 1 {
+			log.Fatalf("patch contains more than one file: %d", len(files))
+		}
+		if files[0].BinaryFragment == nil {
+			log.Fatalf("patch file does not contain a binary fragment")
+		}
+		os.Stdout.Write(files[0].BinaryFragment.Data)
+
+	case "encode":
+		data, err := ioutil.ReadAll(os.Stdin)
+		if err != nil {
+			log.Fatalf("failed to read input: %v", err)
+		}
+		data, err = compress(data)
+		if err != nil {
+			log.Fatalf("failed to compress data: %v", err)
+		}
+		os.Stdout.WriteString(wrap(base85Encode(data)))
+
+	default:
+		log.Fatalf("unknown mode: %s", mode)
+	}
+}