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authorMáximo Cuadros <mcuadros@gmail.com>2017-04-12 15:18:41 +0200
committerGitHub <noreply@github.com>2017-04-12 15:18:41 +0200
commit932ced9f55f556de02610425cfa161c35c6a758b (patch)
tree9b5dd9ad1665fad8424dfbdc5bd93b531f714b09 /utils/merkletrie/filesystem/node.go
parent9b45f468c61a0756dd19d09b64c2b1a88cc99ec5 (diff)
parent5bcf802213e801c4d52102612f007defa5d0397f (diff)
downloadgo-git-932ced9f55f556de02610425cfa161c35c6a758b.tar.gz
Merge pull request #339 from mcuadros/status
worktree, status and reset implementation based on merkletrie
Diffstat (limited to 'utils/merkletrie/filesystem/node.go')
-rw-r--r--utils/merkletrie/filesystem/node.go144
1 files changed, 144 insertions, 0 deletions
diff --git a/utils/merkletrie/filesystem/node.go b/utils/merkletrie/filesystem/node.go
new file mode 100644
index 0000000..6c09d29
--- /dev/null
+++ b/utils/merkletrie/filesystem/node.go
@@ -0,0 +1,144 @@
+package filesystem
+
+import (
+ "io"
+ "os"
+ "path/filepath"
+
+ "gopkg.in/src-d/go-billy.v2"
+ "gopkg.in/src-d/go-git.v4/plumbing"
+ "gopkg.in/src-d/go-git.v4/plumbing/filemode"
+ "gopkg.in/src-d/go-git.v4/utils/merkletrie/noder"
+)
+
+var ignore = map[string]bool{
+ ".git": true,
+}
+
+// The node represents a file or a directory in a billy.Filesystem. It
+// implements the interface noder.Noder of merkletrie package.
+//
+// This implementation implements a "standard" hash method being able to be
+// compared with any other noder.Noder implementation inside of go-git.
+type node struct {
+ fs billy.Filesystem
+
+ path string
+ hash []byte
+ children []noder.Noder
+ isDir bool
+}
+
+// NewRootNode returns the root node based on a given billy.Filesystem
+func NewRootNode(fs billy.Filesystem) noder.Noder {
+ return &node{fs: fs, isDir: true}
+}
+
+// Hash the hash of a filesystem is the result of concatenating the computed
+// plumbing.Hash of the file as a Blob and its plumbing.FileMode; that way the
+// difftree algorithm will detect changes in the contents of files and also in
+// their mode.
+//
+// The hash of a directory is always a 24-bytes slice of zero values
+func (n *node) Hash() []byte {
+ return n.hash
+}
+
+func (n *node) Name() string {
+ return filepath.Base(n.path)
+}
+
+func (n *node) IsDir() bool {
+ return n.isDir
+}
+
+func (n *node) Children() ([]noder.Noder, error) {
+ if err := n.calculateChildren(); err != nil {
+ return nil, err
+ }
+
+ return n.children, nil
+}
+
+func (n *node) NumChildren() (int, error) {
+ if err := n.calculateChildren(); err != nil {
+ return -1, err
+ }
+
+ return len(n.children), nil
+}
+
+func (n *node) calculateChildren() error {
+ if len(n.children) != 0 {
+ return nil
+ }
+
+ files, err := n.fs.ReadDir(n.path)
+ if err != nil {
+ if os.IsNotExist(err) {
+ return nil
+ }
+
+ return nil
+ }
+
+ for _, file := range files {
+ if _, ok := ignore[file.Name()]; ok {
+ continue
+ }
+
+ c, err := n.newChildNode(file)
+ if err != nil {
+ return err
+ }
+
+ n.children = append(n.children, c)
+ }
+
+ return nil
+}
+
+func (n *node) newChildNode(file billy.FileInfo) (*node, error) {
+ path := filepath.Join(n.path, file.Name())
+ hash, err := n.calculateHash(path, file)
+ if err != nil {
+ return nil, err
+ }
+
+ return &node{
+ fs: n.fs,
+ path: path,
+ hash: hash,
+ isDir: file.IsDir(),
+ }, nil
+}
+
+func (n *node) calculateHash(path string, file billy.FileInfo) ([]byte, error) {
+ if file.IsDir() {
+ return make([]byte, 24), nil
+ }
+
+ f, err := n.fs.Open(path)
+ if err != nil {
+ return nil, err
+ }
+
+ defer f.Close()
+
+ h := plumbing.NewHasher(plumbing.BlobObject, file.Size())
+ if _, err := io.Copy(h, f); err != nil {
+ return nil, err
+ }
+
+ mode, err := filemode.NewFromOSFileMode(file.Mode())
+ if err != nil {
+ return nil, err
+ }
+
+ hash := h.Sum()
+ return append(hash[:], mode.Bytes()...), nil
+}
+
+func (n *node) String() string {
+ return n.path
+}