package object import ( "bufio" "errors" "fmt" "io" "os" "path" "strconv" "strings" "gopkg.in/src-d/go-git.v4/plumbing" "gopkg.in/src-d/go-git.v4/plumbing/storer" "gopkg.in/src-d/go-git.v4/utils/ioutil" ) const ( maxTreeDepth = 1024 startingStackSize = 8 submoduleMode = 0160000 directoryMode = 0040000 ) // New errors defined by this package. var ( ErrMaxTreeDepth = errors.New("maximum tree depth exceeded") ErrFileNotFound = errors.New("file not found") ErrDirectoryNotFound = errors.New("directory not found") ) // Tree is basically like a directory - it references a bunch of other trees // and/or blobs (i.e. files and sub-directories) type Tree struct { Entries []TreeEntry Hash plumbing.Hash s storer.EncodedObjectStorer m map[string]*TreeEntry } // GetTree gets a tree from an object storer and decodes it. func GetTree(s storer.EncodedObjectStorer, h plumbing.Hash) (*Tree, error) { o, err := s.EncodedObject(plumbing.TreeObject, h) if err != nil { return nil, err } return DecodeTree(s, o) } // DecodeTree decodes an encoded object into a *Tree and associates it to the // given object storer. func DecodeTree(s storer.EncodedObjectStorer, o plumbing.EncodedObject) (*Tree, error) { t := &Tree{s: s} if err := t.Decode(o); err != nil { return nil, err } return t, nil } // TreeEntry represents a file type TreeEntry struct { Name string Mode os.FileMode Hash plumbing.Hash } // File returns the hash of the file identified by the `path` argument. // The path is interpreted as relative to the tree receiver. func (t *Tree) File(path string) (*File, error) { e, err := t.findEntry(path) if err != nil { return nil, ErrFileNotFound } blob, err := GetBlob(t.s, e.Hash) if err != nil { if err == plumbing.ErrObjectNotFound { return nil, ErrFileNotFound } return nil, err } return NewFile(path, e.Mode, blob), nil } // Tree returns the tree identified by the `path` argument. // The path is interpreted as relative to the tree receiver. func (t *Tree) Tree(path string) (*Tree, error) { e, err := t.findEntry(path) if err != nil { return nil, ErrDirectoryNotFound } tree, err := GetTree(t.s, e.Hash) if err == plumbing.ErrObjectNotFound { return nil, ErrDirectoryNotFound } return tree, err } // TreeEntryFile returns the *File for a given *TreeEntry. func (t *Tree) TreeEntryFile(e *TreeEntry) (*File, error) { blob, err := GetBlob(t.s, e.Hash) if err != nil { return nil, err } return NewFile(e.Name, e.Mode, blob), nil } func (t *Tree) findEntry(path string) (*TreeEntry, error) { pathParts := strings.Split(path, "/") var tree *Tree var err error for tree = t; len(pathParts) > 1; pathParts = pathParts[1:] { if tree, err = tree.dir(pathParts[0]); err != nil { return nil, err } } return tree.entry(pathParts[0]) } func (t *Tree) dir(baseName string) (*Tree, error) { entry, err := t.entry(baseName) if err != nil { return nil, ErrDirectoryNotFound } obj, err := t.s.EncodedObject(plumbing.TreeObject, entry.Hash) if err != nil { return nil, err } tree := &Tree{s: t.s} tree.Decode(obj) return tree, nil } var errEntryNotFound = errors.New("entry not found") func (t *Tree) entry(baseName string) (*TreeEntry, error) { if t.m == nil { t.buildMap() } entry, ok := t.m[baseName] if !ok { return nil, errEntryNotFound } return entry, nil } // Files returns a FileIter allowing to iterate over the Tree func (t *Tree) Files() *FileIter { return NewFileIter(t.s, t) } // ID returns the object ID of the tree. The returned value will always match // the current value of Tree.Hash. // // ID is present to fulfill the Object interface. func (t *Tree) ID() plumbing.Hash { return t.Hash } // Type returns the type of object. It always returns plumbing.TreeObject. func (t *Tree) Type() plumbing.ObjectType { return plumbing.TreeObject } // Decode transform an plumbing.EncodedObject into a Tree struct func (t *Tree) Decode(o plumbing.EncodedObject) (err error) { if o.Type() != plumbing.TreeObject { return ErrUnsupportedObject } t.Hash = o.Hash() if o.Size() == 0 { return nil } t.Entries = nil t.m = nil reader, err := o.Reader() if err != nil { return err } defer ioutil.CheckClose(reader, &err) r := bufio.NewReader(reader) for { mode, err := r.ReadString(' ') if err != nil { if err == io.EOF { break } return err } fm, err := t.decodeFileMode(mode[:len(mode)-1]) if err != nil && err != io.EOF { return err } name, err := r.ReadString(0) if err != nil && err != io.EOF { return err } var hash plumbing.Hash if _, err = io.ReadFull(r, hash[:]); err != nil { return err } baseName := name[:len(name)-1] t.Entries = append(t.Entries, TreeEntry{ Hash: hash, Mode: fm, Name: baseName, }) } return nil } func (t *Tree) decodeFileMode(mode string) (os.FileMode, error) { fm, err := strconv.ParseInt(mode, 8, 32) if err != nil && err != io.EOF { return 0, err } m := os.FileMode(fm) switch fm { case 0040000: //tree m = m | os.ModeDir case 0120000: //symlink m = m | os.ModeSymlink } return m, nil } // Encode transforms a Tree into a plumbing.EncodedObject. func (t *Tree) Encode(o plumbing.EncodedObject) error { o.SetType(plumbing.TreeObject) w, err := o.Writer() if err != nil { return err } var size int defer ioutil.CheckClose(w, &err) for _, entry := range t.Entries { n, err := fmt.Fprintf(w, "%o %s", entry.Mode, entry.Name) if err != nil { return err } size += n n, err = w.Write([]byte{0x00}) if err != nil { return err } size += n n, err = w.Write([]byte(entry.Hash[:])) if err != nil { return err } size += n } o.SetSize(int64(size)) return err } func (t *Tree) buildMap() { t.m = make(map[string]*TreeEntry) for i := 0; i < len(t.Entries); i++ { t.m[t.Entries[i].Name] = &t.Entries[i] } } // treeEntryIter facilitates iterating through the TreeEntry objects in a Tree. type treeEntryIter struct { t *Tree pos int } func (iter *treeEntryIter) Next() (TreeEntry, error) { if iter.pos >= len(iter.t.Entries) { return TreeEntry{}, io.EOF } iter.pos++ return iter.t.Entries[iter.pos-1], nil } // TreeWalker provides a means of walking through all of the entries in a Tree. type TreeWalker struct { stack []treeEntryIter base string recursive bool s storer.EncodedObjectStorer t *Tree } // NewTreeWalker returns a new TreeWalker for the given tree. // // It is the caller's responsibility to call Close() when finished with the // tree walker. func NewTreeWalker(t *Tree, recursive bool) *TreeWalker { stack := make([]treeEntryIter, 0, startingStackSize) stack = append(stack, treeEntryIter{t, 0}) return &TreeWalker{ stack: stack, recursive: recursive, s: t.s, t: t, } } // Next returns the next object from the tree. Objects are returned in order // and subtrees are included. After the last object has been returned further // calls to Next() will return io.EOF. // // In the current implementation any objects which cannot be found in the // underlying repository will be skipped automatically. It is possible that this // may change in future versions. func (w *TreeWalker) Next() (name string, entry TreeEntry, err error) { var obj Object for { current := len(w.stack) - 1 if current < 0 { // Nothing left on the stack so we're finished err = io.EOF return } if current > maxTreeDepth { // We're probably following bad data or some self-referencing tree err = ErrMaxTreeDepth return } entry, err = w.stack[current].Next() if err == io.EOF { // Finished with the current tree, move back up to the parent w.stack = w.stack[:current] w.base, _ = path.Split(w.base) w.base = path.Clean(w.base) // Remove trailing slash continue } if err != nil { return } if entry.Mode == submoduleMode { err = nil continue } if entry.Mode.IsDir() { obj, err = GetTree(w.s, entry.Hash) } name = path.Join(w.base, entry.Name) if err != nil { err = io.EOF return } break } if !w.recursive { return } if t, ok := obj.(*Tree); ok { w.stack = append(w.stack, treeEntryIter{t, 0}) w.base = path.Join(w.base, entry.Name) } return } // Tree returns the tree that the tree walker most recently operated on. func (w *TreeWalker) Tree() *Tree { current := len(w.stack) - 1 if w.stack[current].pos == 0 { current-- } if current < 0 { return nil } return w.stack[current].t } // Close releases any resources used by the TreeWalker. func (w *TreeWalker) Close() { w.stack = nil } // TreeIter provides an iterator for a set of trees. type TreeIter struct { storer.EncodedObjectIter s storer.EncodedObjectStorer } // NewTreeIter returns a TreeIter for the given repository and underlying // object iterator. // // The returned TreeIter will automatically skip over non-tree objects. func NewTreeIter(s storer.EncodedObjectStorer, iter storer.EncodedObjectIter) *TreeIter { return &TreeIter{iter, s} } // Next moves the iterator to the next tree and returns a pointer to it. If it // has reached the end of the set it will return io.EOF. func (iter *TreeIter) Next() (*Tree, error) { for { obj, err := iter.EncodedObjectIter.Next() if err != nil { return nil, err } if obj.Type() != plumbing.TreeObject { continue } return DecodeTree(iter.s, obj) } } // ForEach call the cb function for each tree contained on this iter until // an error happens or the end of the iter is reached. If ErrStop is sent // the iteration is stop but no error is returned. The iterator is closed. func (iter *TreeIter) ForEach(cb func(*Tree) error) error { return iter.EncodedObjectIter.ForEach(func(obj plumbing.EncodedObject) error { if obj.Type() != plumbing.TreeObject { return nil } t, err := DecodeTree(iter.s, obj) if err != nil { return err } return cb(t) }) }