1 files changed, 146 insertions, 0 deletions
diff --git a/src/edit/git.go b/src/edit/git.go
new file mode 100644
index 0000000..010c928
--- /dev/null
+++ b/src/edit/git.go
@@ -0,0 +1,146 @@
+package main
+
+import (
+	"strconv"
+	"io"
+	"bytes"
+	"fmt"
+	"os/exec"
+	"time"
+	"errors"
+)
+
+func GitPull() error {
+	return exec.Command("git", "pull").Run()
+}
+
+func GitPush() error {
+	return exec.Command("git", "push").Run()
+}
+
+type Edit struct {
+	UserName string
+	UserEmail string
+	Time time.Time
+	Message string
+	Files map[string][]byte
+}
+
+func gitTime(t time.Time) string {
+	return fmt.Sprintf("%d %s", t.Unix(), t.Format("-0700"))
+}
+
+func (edit Edit) WriteTo(w io.Writer) error {
+	var err error
+	commit := make([]string, len(edit.Files))
+	i := 0
+	for name, content := range edit.Files {
+		commit[i] = name
+		if content != nil {
+			if _, err = fmt.Fprintf(w, "blob\nmark :%d\ndata %d\n%s", i+1, len(content), content); err != nil {
+				return err
+			}
+		}
+	}
+	_, err = fmt.Fprintf(w, `commit HEAD
+author %s <%s> %s
+committer %s <%s> %s
+data %d
+%sfrom HEAD
+`,
+		edit.UserName, edit.UserEmail, gitTime(edit.Time),
+		edit.UserName, edit.UserEmail, gitTime(edit.Time),
+		len(edit.Message), edit.Message)
+	if err != nil {
+		return err
+	}
+	for i, filename := range commit {
+		if edit.Files[filename] != nil {
+			if _, err = fmt.Fprintf(w, "M 100644 :%d %s\n", i+1, filename); err != nil {
+				return err
+			}
+		} else {
+			if _, err = fmt.Fprintf(w, "D %s\n", filename); err != nil {
+				return err
+			}
+		}	
+	}
+	return nil
+}
+
+
+func GitCommit(edit Edit) error {
+	cmd := exec.Command("git", "fast-import")
+	pip, err := cmd.StdinPipe()
+	if err != nil {
+		return err
+	}
+	if err = cmd.Start(); err != nil {
+		return err
+	}
+	werr := edit.WriteTo(pip)
+	if err = cmd.Wait(); err == nil {
+		err = werr
+	}
+	return err
+}
+
+type GitFile struct {
+	Mode int32 // 18 bits unsigned
+	Type string
+	Hash string
+	Size int64
+}
+
+type GitTree map[string]GitFile
+
+var ParseError = errors.New("git ls-tree parse error")
+
+func GitLsTree() (GitTree, error) {
+	data, err := exec.Command("git", "ls-tree", "-trlz", "HEAD").Output()
+	if err != nil {
+		return nil, err
+	}
+	lines := bytes.Split(data, []byte{0})
+	ret := make(GitTree, len(lines)-1)
+	for _, line := range lines[:len(ret)] {
+		// trim the trailing "\0"
+		if line[len(line)-1] != 0 {
+			return nil, ParseError
+		}
+		line = line[:len(line)-1]
+		// line = mode SP type SP hash SP size TAB name
+		a := bytes.SplitN(line, []byte{' '}, 4)
+		if len(a) != 4 {
+			return nil, ParseError
+		}
+		b := bytes.SplitN(a[3], []byte{'\t'}, 2)
+		if len(b) != 2 {
+			return nil, ParseError
+		}
+		fmode := a[0]
+		ftype := a[1]
+		fhash := a[2]
+		fsize := b[0]
+		fname := b[1]
+		fmodeN, err := strconv.ParseInt(string(fmode), 10, 19)
+		if err != nil {
+			return nil, err
+		}
+		fsizeN := int64(-1)
+		fsizeS := string(fsize)
+		if fsizeS != "-" {
+			fsizeN, err = strconv.ParseInt(fsizeS, 10, 64)
+			if err != nil {
+				return nil, err
+			}
+		}
+		ret[string(fname)] = GitFile{
+			Mode: int32(fmodeN),
+			Type: string(ftype),
+			Hash: string(fhash),
+			Size: fsizeN,
+		}
+	}
+	return ret, nil
+}