migrate some commands

blob.go

@@ -0,0 +1,23 @@
+// Copyright 2015 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package git
+
+import (
+	"bytes"
+	"io"
+)
+
+type Blob struct {
+	repo *Repository
+	*TreeEntry
+}
+
+func (b *Blob) Data() (io.Reader, error) {
+	stdout, err := NewCommand("show", b.ID.String()).RunInDirBytes(b.repo.Path)
+	if err != nil {
+		return nil, err
+	}
+	return bytes.NewBuffer(stdout), nil
+}

command.go

@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"os/exec"
 	"strings"
+	"time"
 )
 
 // Command represents a command with its subcommands or arguments.
@@ -38,39 +39,79 @@ func (c *Command) AddArguments(args ...string) *Command {
 	return c
 }
 
-func (c *Command) run(dir string) (string, error) {
+const DEFAULT_TIMEOUT = 60 * time.Second
+
+// RunInDirTimeout executes the command in given directory with given timeout,
+// and returns stdout in []byte and error (combined with stderr).
+func (c *Command) RunInDirTimeout(timeout time.Duration, dir string) ([]byte, error) {
+	if timeout == -1 {
+		timeout = DEFAULT_TIMEOUT
+	}
+
 	stdout := new(bytes.Buffer)
 	stderr := new(bytes.Buffer)
 
-	cmd := exec.Command(c.name, c.args...)
-	cmd.Dir = dir
-	cmd.Stdout = stdout
-	cmd.Stderr = stderr
-
 	if len(dir) == 0 {
 		log(c.String())
 	} else {
 		log("%s: %v", dir, c)
 	}
 
-	if err := cmd.Run(); err != nil {
-		return stdout.String(), concatenateError(err, stderr.String())
+	cmd := exec.Command(c.name, c.args...)
+	cmd.Dir = dir
+	cmd.Stdout = stdout
+	cmd.Stderr = stderr
+	if err := cmd.Start(); err != nil {
+		return nil, concatenateError(err, stderr.String())
 	}
+
+	done := make(chan error)
+	go func() {
+		done <- cmd.Wait()
+	}()
+
+	var err error
+	select {
+	case <-time.After(timeout):
+		if cmd.Process != nil && cmd.ProcessState != nil && !cmd.ProcessState.Exited() {
+			if err := cmd.Process.Kill(); err != nil {
+				return nil, fmt.Errorf("fail to kill process: %v", err)
+			}
+		}
+
+		<-done
+		return nil, ErrExecTimeout{timeout}
+	case err = <-done:
+	}
+
+	if err != nil {
+		return nil, concatenateError(err, stderr.String())
+	}
+
 	if stdout.Len() > 0 {
 		log("stdout:\n%s", stdout)
 	}
-
-	return stdout.String(), nil
-}
-
-// Run executes the command in defualt working directory
-// and returns stdout and error (combined with stderr).
-func (c *Command) Run() (string, error) {
-	return c.run("")
+	return stdout.Bytes(), nil
 }
 
 // RunInDir executes the command in given directory
-// and returns stdout and error (combined with stderr).
-func (c *Command) RunInDir(dir string) (string, error) {
-	return c.run(dir)
+// and returns stdout in []byte and error (combined with stderr).
+func (c *Command) RunInDirBytes(dir string) ([]byte, error) {
+	return c.RunInDirTimeout(-1, dir)
+}
+
+// RunInDir executes the command in given directory
+// and returns stdout in string and error (combined with stderr).
+func (c *Command) RunInDir(dir string) (string, error) {
+	stdout, err := c.RunInDirTimeout(-1, dir)
+	if err != nil {
+		return "", err
+	}
+	return string(stdout), nil
+}
+
+// Run executes the command in defualt working directory
+// and returns stdout in string and error (combined with stderr).
+func (c *Command) Run() (string, error) {
+	return c.RunInDir("")
 }

commit.go

@@ -0,0 +1,67 @@
+// Copyright 2015 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package git
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/mcuadros/go-version"
+)
+
+// Commit represents a git commit.
+type Commit struct {
+	Tree
+	ID            sha1 // The ID of this commit object
+	Author        *Signature
+	Committer     *Signature
+	CommitMessage string
+
+	parents []sha1 // SHA1 strings
+	// submodules map[string]*SubModule
+}
+
+// AddAllChanges marks local changes to be ready for commit.
+func AddChanges(repoPath string, all bool, files ...string) error {
+	cmd := NewCommand("add")
+	if all {
+		cmd.AddArguments("--all")
+	}
+	_, err := cmd.AddArguments(files...).RunInDir(repoPath)
+	return err
+}
+
+// CommitChanges commits local changes with given message and author.
+func CommitChanges(repoPath, message string, author *Signature) error {
+	cmd := NewCommand("commit", "-m", message)
+	if author != nil {
+		cmd.AddArguments(fmt.Sprintf("--author='%s <%s>'", author.Name, author.Email))
+	}
+	_, err := cmd.RunInDir(repoPath)
+
+	// No stderr but exit status 1 means nothing to commit.
+	if err != nil && err.Error() == "exit status 1" {
+		return nil
+	}
+	return err
+}
+
+// CommitsCount returns number of total commits of until given revision.
+func CommitsCount(repoPath, revision string) (int64, error) {
+	if version.Compare(gitVersion, "1.8.0", "<") {
+		stdout, err := NewCommand("log", "--pretty=format:''", revision).RunInDir(repoPath)
+		if err != nil {
+			return 0, err
+		}
+		return int64(len(strings.Split(stdout, "\n"))), nil
+	}
+
+	stdout, err := NewCommand("rev-list", "--count", revision).RunInDir(repoPath)
+	if err != nil {
+		return 0, err
+	}
+	return strconv.ParseInt(strings.TrimSpace(stdout), 10, 64)
+}

error.go

@@ -6,11 +6,32 @@ package git
 
 import (
 	"fmt"
+	"time"
 )
 
-func concatenateError(err error, stderr string) error {
-	if len(stderr) == 0 {
-		return err
-	}
-	return fmt.Errorf("%v - %s", err, stderr)
+type ErrExecTimeout struct {
+	Duration time.Duration
+}
+
+func IsErrExecTimeout(err error) bool {
+	_, ok := err.(ErrExecTimeout)
+	return ok
+}
+
+func (err ErrExecTimeout) Error() string {
+	return fmt.Sprintf("execution is timeout [duration: %v]", err.Duration)
+}
+
+type ErrNotExist struct {
+	ID      string
+	RelPath string
+}
+
+func IsErrNotExist(err error) bool {
+	_, ok := err.(ErrNotExist)
+	return ok
+}
+
+func (err ErrNotExist) Error() string {
+	return fmt.Sprintf("object does not exist [id: %s, rel_path: %s]", err.ID, err.RelPath)
 }

git.go

@@ -49,3 +49,7 @@ func Version() (string, error) {
 	gitVersion = fields[2]
 	return gitVersion, nil
 }
+
+func init() {
+	Version()
+}

repo.go

@@ -5,10 +5,43 @@
 package git
 
 import (
+	"bytes"
+	"container/list"
+	"errors"
 	"os"
+	"path"
+	"path/filepath"
 )
 
-// InitRepository initializes a new Git repository in choice of bare or not.
+// Repository represents a Git repository.
+type Repository struct {
+	Path string
+
+	commitCache map[sha1]*Commit
+}
+
+const _PRETTY_LOG_FORMAT = `--pretty=format:%H`
+
+func (repo *Repository) parsePrettyFormatLogToList(logs []byte) (*list.List, error) {
+	l := list.New()
+	if len(logs) == 0 {
+		return l, nil
+	}
+
+	parts := bytes.Split(logs, []byte{'\n'})
+
+	for _, commitId := range parts {
+		commit, err := repo.GetCommit(string(commitId))
+		if err != nil {
+			return nil, err
+		}
+		l.PushBack(commit)
+	}
+
+	return l, nil
+}
+
+// InitRepository initializes a new Git repository.
 func InitRepository(repoPath string, bare bool) error {
 	os.MkdirAll(repoPath, os.ModePerm)
 
@@ -19,3 +52,50 @@ func InitRepository(repoPath string, bare bool) error {
 	_, err := cmd.RunInDir(repoPath)
 	return err
 }
+
+// OpenRepository opens the repository at the given path.
+func OpenRepository(repoPath string) (*Repository, error) {
+	repoPath, err := filepath.Abs(repoPath)
+	if err != nil {
+		return nil, err
+	} else if !isDir(repoPath) {
+		return nil, errors.New("no such file or directory")
+	}
+
+	return &Repository{Path: repoPath}, nil
+}
+
+// Clone clones original repository to target path.
+func Clone(from, to string) error {
+	toDir := path.Dir(to)
+	os.MkdirAll(toDir, os.ModePerm)
+
+	_, err := NewCommand("clone", from, to).Run()
+	return err
+}
+
+// Pull pulls changes from remotes.
+func Pull(repoPath string, all bool) error {
+	cmd := NewCommand("pull")
+	if all {
+		cmd.AddArguments("--all")
+	}
+	_, err := cmd.RunInDir(repoPath)
+	return err
+}
+
+// Push pushs local commits to given remote branch.
+func Push(repoPath, remote, branch string) error {
+	_, err := NewCommand("push", remote, branch).RunInDir(repoPath)
+	return err
+}
+
+// Reset resets HEAD to given revision or head of branch.
+func Reset(repoPath string, hard bool, revision string) error {
+	cmd := NewCommand("reset")
+	if hard {
+		cmd.AddArguments("--hard")
+	}
+	_, err := cmd.AddArguments(revision).RunInDir(repoPath)
+	return err
+}

repo_branch.go

@@ -0,0 +1,42 @@
+// Copyright 2015 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package git
+
+import (
+	"fmt"
+	"strings"
+)
+
+const BRANCH_PREFIX = "refs/heads/"
+
+// Branch represents a Git branch.
+type Branch struct {
+	Name string
+	Path string
+}
+
+// GetHEADBranch returns corresponding branch of HEAD.
+func (repo *Repository) GetHEADBranch() (*Branch, error) {
+	stdout, err := NewCommand("symbolic-ref", "HEAD").RunInDir(repo.Path)
+	if err != nil {
+		return nil, err
+	}
+	stdout = strings.TrimSpace(stdout)
+
+	if !strings.HasPrefix(stdout, BRANCH_PREFIX) {
+		return nil, fmt.Errorf("invalid HEAD branch: %v", stdout)
+	}
+
+	return &Branch{
+		Name: stdout[len(BRANCH_PREFIX):],
+		Path: stdout,
+	}, nil
+}
+
+// IsBranchExist returns true if given branch exists in repository.
+func IsBranchExist(repoPath, branch string) bool {
+	_, err := NewCommand("show-ref", "--verify", BRANCH_PREFIX+branch).RunInDir(repoPath)
+	return err == nil
+}

repo_commit.go

@@ -0,0 +1,137 @@
+// Copyright 2015 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package git
+
+import (
+	"bytes"
+	"strings"
+)
+
+// getCommitIDOfRef returns the last commit ID string of given reference (branch or tag).
+func (repo *Repository) getCommitIDOfRef(refName string) (string, error) {
+	stdout, err := NewCommand("show-ref", "--verify", refName).RunInDir(repo.Path)
+	if err != nil {
+		return "", err
+	}
+	return strings.Split(stdout, " ")[0], nil
+}
+
+// GetCommitIDOfBranch returns last commit ID string of given branch.
+func (repo *Repository) GetCommitIDOfBranch(branch string) (string, error) {
+	return repo.getCommitIDOfRef(BRANCH_PREFIX + branch)
+}
+
+// parseCommitData parses commit information from the (uncompressed) raw
+// data from the commit object.
+// \n\n separate headers from message
+func parseCommitData(data []byte) (*Commit, error) {
+	commit := new(Commit)
+	commit.parents = make([]sha1, 0, 1)
+	// we now have the contents of the commit object. Let's investigate...
+	nextline := 0
+l:
+	for {
+		eol := bytes.IndexByte(data[nextline:], '\n')
+		switch {
+		case eol > 0:
+			line := data[nextline : nextline+eol]
+			spacepos := bytes.IndexByte(line, ' ')
+			reftype := line[:spacepos]
+			switch string(reftype) {
+			case "tree":
+				id, err := NewIDFromString(string(line[spacepos+1:]))
+				if err != nil {
+					return nil, err
+				}
+				commit.Tree.ID = id
+			case "parent":
+				// A commit can have one or more parents
+				oid, err := NewIDFromString(string(line[spacepos+1:]))
+				if err != nil {
+					return nil, err
+				}
+				commit.parents = append(commit.parents, oid)
+			case "author":
+				sig, err := newSignatureFromCommitline(line[spacepos+1:])
+				if err != nil {
+					return nil, err
+				}
+				commit.Author = sig
+			case "committer":
+				sig, err := newSignatureFromCommitline(line[spacepos+1:])
+				if err != nil {
+					return nil, err
+				}
+				commit.Committer = sig
+			}
+			nextline += eol + 1
+		case eol == 0:
+			commit.CommitMessage = string(data[nextline+1:])
+			break l
+		default:
+			break l
+		}
+	}
+	return commit, nil
+}
+
+func (repo *Repository) getCommit(id sha1) (*Commit, error) {
+	if repo.commitCache != nil {
+		log("Hit cache: %s", id)
+		if c, ok := repo.commitCache[id]; ok {
+			return c, nil
+		}
+	} else {
+		repo.commitCache = make(map[sha1]*Commit, 10)
+	}
+
+	data, err := NewCommand("cat-file", "-p", id.String()).RunInDirBytes(repo.Path)
+	if err != nil {
+		return nil, err
+	}
+
+	commit, err := parseCommitData(data)
+	if err != nil {
+		return nil, err
+	}
+	commit.repo = repo
+	commit.ID = id
+
+	repo.commitCache[id] = commit
+	return commit, nil
+}
+
+// GetCommit returns commit object of by ID string.
+func (repo *Repository) GetCommit(commitID string) (*Commit, error) {
+	id, err := NewIDFromString(commitID)
+	if err != nil {
+		return nil, err
+	}
+
+	return repo.getCommit(id)
+}
+
+// GetCommitOfBranch returns the last commit of given branch.
+func (repo *Repository) GetCommitOfBranch(branch string) (*Commit, error) {
+	commitID, err := repo.GetCommitIDOfBranch(branch)
+	if err != nil {
+		return nil, err
+	}
+	return repo.GetCommit(commitID)
+}
+
+// GetCommitByPath returns the last commit of relative path.
+func (repo *Repository) GetCommitByPath(relpath string) (*Commit, error) {
+	stdout, err := NewCommand("log", "-1", _PRETTY_LOG_FORMAT, "--", relpath).RunInDirBytes(repo.Path)
+	if err != nil {
+		return nil, err
+	}
+
+	commits, err := repo.parsePrettyFormatLogToList(stdout)
+	if err != nil {
+		return nil, err
+	}
+	return commits.Front().Value.(*Commit), nil
+}

repo_hook.go

@@ -0,0 +1,23 @@
+// Copyright 2015 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package git
+
+import (
+	"io/ioutil"
+	"os"
+	"path"
+)
+
+const (
+	HOOK_PATH_UPDATE = "hooks/update"
+)
+
+// SetUpdateHook writes given content to update hook of the reposiotry.
+func SetUpdateHook(repoPath, content string) error {
+	log("Setting update hook: %s", repoPath)
+	hookPath := path.Join(repoPath, HOOK_PATH_UPDATE)
+	os.MkdirAll(path.Dir(hookPath), os.ModePerm)
+	return ioutil.WriteFile(hookPath, []byte(content), 0777)
+}

repo_object.go

@@ -0,0 +1,14 @@
+// Copyright 2014 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package git
+
+type ObjectType string
+
+const (
+	OBJECT_COMMIT ObjectType = "commit"
+	OBJECT_TREE   ObjectType = "tree"
+	OBJECT_BLOB   ObjectType = "blob"
+	OBJECT_TAG    ObjectType = "tag"
+)

repo_tree.go

@@ -0,0 +1,17 @@
+// Copyright 2015 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package git
+
+func (repo *Repository) getTree(id sha1) (*Tree, error) {
+	treePath := filepathFromSHA1(repo.Path, id.String())
+	if isFile(treePath) {
+		_, err := NewCommand("ls-tree", id.String()).RunInDir(repo.Path)
+		if err != nil {
+			return nil, ErrNotExist{id.String(), ""}
+		}
+	}
+
+	return NewTree(repo, id), nil
+}

sha1.go

@@ -0,0 +1,51 @@
+// Copyright 2015 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package git
+
+import (
+	"encoding/hex"
+	"fmt"
+	"strings"
+)
+
+type sha1 [20]byte
+
+// String returns string (hex) representation of the Oid.
+func (s sha1) String() string {
+	result := make([]byte, 0, 40)
+	hexvalues := []byte("0123456789abcdef")
+	for i := 0; i < 20; i++ {
+		result = append(result, hexvalues[s[i]>>4])
+		result = append(result, hexvalues[s[i]&0xf])
+	}
+	return string(result)
+}
+
+// NewID creates a new sha1 from a [20]byte array.
+func NewID(b []byte) (sha1, error) {
+	var id sha1
+	if len(b) != 20 {
+		return id, fmt.Errorf("Length must be 20: %v", b)
+	}
+
+	for i := 0; i < 20; i++ {
+		id[i] = b[i]
+	}
+	return id, nil
+}
+
+// NewIDFromString creates a new sha1 from a ID string of length 40.
+func NewIDFromString(s string) (sha1, error) {
+	var id sha1
+	s = strings.TrimSpace(s)
+	if len(s) != 40 {
+		return id, fmt.Errorf("Length must be 40: %s", s)
+	}
+	b, err := hex.DecodeString(s)
+	if err != nil {
+		return id, err
+	}
+	return NewID(b)
+}

signature.go

@@ -5,6 +5,8 @@
 package git
 
 import (
+	"bytes"
+	"strconv"
 	"time"
 )
 
@@ -14,3 +16,33 @@ type Signature struct {
 	Name  string
 	When  time.Time
 }
+
+// Helper to get a signature from the commit line, which looks like these:
+//     author Patrick Gundlach <gundlach@speedata.de> 1378823654 +0200
+//     author Patrick Gundlach <gundlach@speedata.de> Thu, 07 Apr 2005 22:13:13 +0200
+// but without the "author " at the beginning (this method should)
+// be used for author and committer.
+//
+// FIXME: include timezone for timestamp!
+func newSignatureFromCommitline(line []byte) (_ *Signature, err error) {
+	sig := new(Signature)
+	emailStart := bytes.IndexByte(line, '<')
+	sig.Name = string(line[:emailStart-1])
+	emailEnd := bytes.IndexByte(line, '>')
+	sig.Email = string(line[emailStart+1 : emailEnd])
+
+	// Check date format.
+	firstChar := line[emailEnd+2]
+	if firstChar >= 48 && firstChar <= 57 {
+		timestop := bytes.IndexByte(line[emailEnd+2:], ' ')
+		timestring := string(line[emailEnd+2 : emailEnd+2+timestop])
+		seconds, _ := strconv.ParseInt(timestring, 10, 64)
+		sig.When = time.Unix(seconds, 0)
+	} else {
+		sig.When, err = time.Parse("Mon Jan _2 15:04:05 2006 -0700", string(line[emailEnd+2:]))
+		if err != nil {
+			return nil, err
+		}
+	}
+	return sig, nil
+}

tree.go

@@ -0,0 +1,151 @@
+// Copyright 2015 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package git
+
+import (
+	"bytes"
+	"fmt"
+	"strings"
+)
+
+// Tree represents a flat directory listing.
+type Tree struct {
+	ID   sha1
+	repo *Repository
+
+	// parent tree
+	ptree *Tree
+
+	entries       Entries
+	entriesParsed bool
+}
+
+func NewTree(repo *Repository, id sha1) *Tree {
+	return &Tree{
+		ID:   id,
+		repo: repo,
+	}
+}
+
+var escapeChar = []byte("\\")
+
+// UnescapeChars reverses escaped characters.
+func UnescapeChars(in []byte) []byte {
+	if bytes.Index(in, escapeChar) == -1 {
+		return in
+	}
+
+	endIdx := len(in) - 1
+	isEscape := false
+	out := make([]byte, 0, endIdx+1)
+	for i := range in {
+		if in[i] == '\\' && !isEscape {
+			isEscape = true
+			continue
+		}
+		isEscape = false
+		out = append(out, in[i])
+	}
+	return out
+}
+
+// parseTreeData parses tree information from the (uncompressed) raw
+// data from the tree object.
+func parseTreeData(tree *Tree, data []byte) ([]*TreeEntry, error) {
+	entries := make([]*TreeEntry, 0, 10)
+	l := len(data)
+	pos := 0
+	for pos < l {
+		entry := new(TreeEntry)
+		entry.ptree = tree
+		step := 6
+		switch string(data[pos : pos+step]) {
+		case "100644":
+			entry.mode = ENTRY_MODE_BLOB
+			entry.Type = OBJECT_BLOB
+		case "100755":
+			entry.mode = ENTRY_MODE_EXEC
+			entry.Type = OBJECT_BLOB
+		case "120000":
+			entry.mode = ENTRY_MODE_SYMLINK
+			entry.Type = OBJECT_BLOB
+		case "160000":
+			entry.mode = ENTRY_MODE_COMMIT
+			entry.Type = OBJECT_COMMIT
+
+			step = 8
+		case "040000":
+			entry.mode = ENTRY_MODE_TREE
+			entry.Type = OBJECT_TREE
+		default:
+			return nil, fmt.Errorf("unknown type: %v", string(data[pos:pos+step]))
+		}
+		pos += step + 6 // Skip string type of entry type.
+
+		step = 40
+		id, err := NewIDFromString(string(data[pos : pos+step]))
+		if err != nil {
+			return nil, err
+		}
+		entry.ID = id
+		pos += step + 1 // Skip half of sha1.
+
+		step = bytes.IndexByte(data[pos:], '\n')
+
+		// In case entry name is surrounded by double quotes(it happens only in git-shell).
+		if data[pos] == '"' {
+			entry.name = string(UnescapeChars(data[pos+1 : pos+step-1]))
+		} else {
+			entry.name = string(data[pos : pos+step])
+		}
+
+		pos += step + 1
+		entries = append(entries, entry)
+	}
+	return entries, nil
+}
+
+func (t *Tree) SubTree(rpath string) (*Tree, error) {
+	if len(rpath) == 0 {
+		return t, nil
+	}
+
+	paths := strings.Split(rpath, "/")
+	var (
+		err error
+		g   = t
+		p   = t
+		te  *TreeEntry
+	)
+	for _, name := range paths {
+		te, err = p.GetTreeEntryByPath(name)
+		if err != nil {
+			return nil, err
+		}
+
+		g, err = t.repo.getTree(te.ID)
+		if err != nil {
+			return nil, err
+		}
+		g.ptree = p
+		p = g
+	}
+	return g, nil
+}
+
+// ListEntries returns all entries of current tree.
+func (t *Tree) ListEntries(relpath string) (Entries, error) {
+	if t.entriesParsed {
+		return t.entries, nil
+	}
+	t.entriesParsed = true
+
+	stdout, err := NewCommand("ls-tree", t.ID.String()).RunInDirBytes(t.repo.Path)
+	if err != nil {
+		return nil, err
+	}
+	t.entries, err = parseTreeData(t, stdout)
+	return t.entries, err
+}

tree_blob.go

@@ -0,0 +1,57 @@
+// Copyright 2015 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package git
+
+import (
+	"path"
+	"strings"
+)
+
+func (t *Tree) GetTreeEntryByPath(relpath string) (*TreeEntry, error) {
+	if len(relpath) == 0 {
+		return &TreeEntry{
+			ID:   t.ID,
+			Type: OBJECT_TREE,
+			mode: ENTRY_MODE_TREE,
+		}, nil
+	}
+
+	relpath = path.Clean(relpath)
+	parts := strings.Split(relpath, "/")
+	var err error
+	tree := t
+	for i, name := range parts {
+		if i == len(parts)-1 {
+			entries, err := tree.ListEntries(path.Dir(relpath))
+			if err != nil {
+				return nil, err
+			}
+			for _, v := range entries {
+				if v.name == name {
+					return v, nil
+				}
+			}
+		} else {
+			tree, err = tree.SubTree(name)
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+	return nil, ErrNotExist{"", relpath}
+}
+
+func (t *Tree) GetBlobByPath(relpath string) (*Blob, error) {
+	entry, err := t.GetTreeEntryByPath(relpath)
+	if err != nil {
+		return nil, err
+	}
+
+	if !entry.IsDir() {
+		return entry.Blob(), nil
+	}
+
+	return nil, ErrNotExist{"", relpath}
+}

tree_entry.go

@@ -0,0 +1,45 @@
+// Copyright 2015 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package git
+
+type EntryMode int
+
+// There are only a few file modes in Git. They look like unix file modes, but they can only be
+// one of these.
+const (
+	ENTRY_MODE_BLOB    EntryMode = 0100644
+	ENTRY_MODE_EXEC    EntryMode = 0100755
+	ENTRY_MODE_SYMLINK EntryMode = 0120000
+	ENTRY_MODE_COMMIT  EntryMode = 0160000
+	ENTRY_MODE_TREE    EntryMode = 0040000
+)
+
+type TreeEntry struct {
+	ID   sha1
+	Type ObjectType
+
+	mode EntryMode
+	name string
+
+	ptree *Tree
+
+	commited bool
+
+	size  int64
+	sized bool
+}
+
+func (te *TreeEntry) IsDir() bool {
+	return te.mode == ENTRY_MODE_TREE
+}
+
+func (te *TreeEntry) Blob() *Blob {
+	return &Blob{
+		repo:      te.ptree.repo,
+		TreeEntry: te,
+	}
+}
+
+type Entries []*TreeEntry

utlis.go

@@ -0,0 +1,45 @@
+// Copyright 2015 The Gogs Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package git
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+// isDir returns true if given path is a directory,
+// or returns false when it's a file or does not exist.
+func isDir(dir string) bool {
+	f, e := os.Stat(dir)
+	if e != nil {
+		return false
+	}
+	return f.IsDir()
+}
+
+// isFile returns true if given path is a file,
+// or returns false when it's a directory or does not exist.
+func isFile(filePath string) bool {
+	f, e := os.Stat(filePath)
+	if e != nil {
+		return false
+	}
+	return !f.IsDir()
+}
+
+func concatenateError(err error, stderr string) error {
+	if len(stderr) == 0 {
+		return err
+	}
+	return fmt.Errorf("%v - %s", err, stderr)
+}
+
+// If the object is stored in its own file (i.e not in a pack file),
+// this function returns the full path to the object file.
+// It does not test if the file exists.
+func filepathFromSHA1(rootdir, sha1 string) string {
+	return filepath.Join(rootdir, "objects", sha1[:2], sha1[2:])
+}