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-rw-r--r--tree_diff.go205
-rw-r--r--tree_diff_test.go398
2 files changed, 603 insertions, 0 deletions
diff --git a/tree_diff.go b/tree_diff.go
new file mode 100644
index 0000000..9c550dd
--- /dev/null
+++ b/tree_diff.go
@@ -0,0 +1,205 @@
+package git
+
+import (
+ "bytes"
+ "fmt"
+ "io"
+ "sort"
+ "strings"
+
+ "gopkg.in/src-d/go-git.v3/core"
+)
+
+type Action int
+
+func (a Action) String() string {
+ switch a {
+ case Insert:
+ return "Insert"
+ case Delete:
+ return "Delete"
+ case Modify:
+ return "Modify"
+ default:
+ panic(fmt.Sprintf("unsupported action: %d", a))
+ }
+}
+
+const (
+ Insert Action = iota
+ Delete
+ Modify
+)
+
+type Change struct {
+ Action
+ Name string
+ Files [2]*File
+}
+
+func (c *Change) String() string {
+ return fmt.Sprintf("<Action: %s, Path: %s>", c.Action, c.Name)
+}
+
+type Changes []*Change
+
+func newEmpty() Changes {
+ return make([]*Change, 0, 0)
+}
+
+func DiffTree(a, b *Tree) ([]*Change, error) {
+ if a == b {
+ return newEmpty(), nil
+ }
+
+ if a == nil || b == nil {
+ return newWithEmpty(a, b)
+ }
+
+ return newDiffTree(a, b)
+}
+
+func (c Changes) Len() int {
+ return len(c)
+}
+
+func (c Changes) Swap(i, j int) {
+ c[i], c[j] = c[j], c[i]
+}
+
+func (c Changes) Less(i, j int) bool {
+ return strings.Compare(c[i].Name, c[j].Name) < 0
+}
+
+func (c Changes) String() string {
+ var buffer bytes.Buffer
+ buffer.WriteString("[")
+ comma := ""
+ for _, v := range c {
+ buffer.WriteString(comma)
+ buffer.WriteString(v.String())
+ comma = ", "
+ }
+ buffer.WriteString("]")
+
+ return buffer.String()
+}
+
+func newWithEmpty(a, b *Tree) (Changes, error) {
+ changes := newEmpty()
+
+ var action Action
+ var tree *Tree
+ if a == nil {
+ action = Insert
+ tree = b
+ } else {
+ action = Delete
+ tree = a
+ }
+
+ iter := tree.Files()
+ defer iter.Close()
+
+ for {
+ file, err := iter.Next()
+ if err == io.EOF {
+ break
+ } else if err != nil {
+ return nil, fmt.Errorf("cannot get next file: %s", err)
+ }
+
+ var files [2]*File
+ if action == Insert {
+ files[1] = file
+ } else {
+ files[0] = file
+ }
+
+ changes = append(changes, &Change{
+ Action: action,
+ Name: file.Name,
+ Files: files,
+ })
+ }
+
+ return changes, nil
+}
+
+// FIXME: this is very inefficient, but correct.
+// The proper way to do this is to implement a diff-tree algorithm,
+// while taking advantage of the tree hashes to avoid traversing
+// subtrees when the hash is equal in both inputs.
+func newDiffTree(a, b *Tree) ([]*Change, error) {
+ result := make([]*Change, 0)
+
+ aChanges, err := newWithEmpty(a, nil)
+ if err != nil {
+ return nil, fmt.Errorf("cannot create nil-diff of source tree: %s", err)
+ }
+ sort.Sort(aChanges)
+
+ bChanges, err := newWithEmpty(nil, b)
+ if err != nil {
+ return nil, fmt.Errorf("cannot create nil-diff of destination tree: %s", err)
+ }
+ sort.Sort(bChanges)
+
+ for len(aChanges) > 0 && len(bChanges) > 0 {
+ switch comp := strings.Compare(aChanges[0].Name, bChanges[0].Name); {
+ case comp == 0: // append as "Modify" or ignore if not changed
+ modified, err := hasChange(a, b, aChanges[0].Name)
+ if err != nil {
+ return nil, err
+ }
+
+ if modified {
+ result = append(result, &Change{
+ Action: Modify,
+ Name: aChanges[0].Name,
+ Files: [2]*File{aChanges[0].Files[0], bChanges[0].Files[1]},
+ })
+ }
+
+ aChanges = aChanges[1:]
+ bChanges = bChanges[1:]
+ case comp < 0: // delete first a change
+ result = append(result, aChanges[0])
+ aChanges = aChanges[1:]
+ case comp > 0: // insert first b change
+ result = append(result, bChanges[0])
+ bChanges = bChanges[1:]
+ }
+ }
+
+ // append all remaining changes in aChanges, if any, as deletes
+ // append all remaining changes in bChanges, if any, as inserts
+ result = append(result, aChanges...)
+ result = append(result, bChanges...)
+
+ return result, nil
+}
+
+func hasChange(a, b *Tree, path string) (bool, error) {
+ ha, err := hash(a, path)
+ if err != nil {
+ return false, err
+ }
+
+ hb, err := hash(b, path)
+ if err != nil {
+ return false, err
+ }
+
+ return ha != hb, nil
+}
+
+func hash(tree *Tree, path string) (core.Hash, error) {
+ file, err := tree.File(path)
+ if err != nil {
+ var empty core.Hash
+ return empty, fmt.Errorf("cannot find file %s in tree: %s", path, err)
+ }
+
+ return file.Hash, nil
+}
diff --git a/tree_diff_test.go b/tree_diff_test.go
new file mode 100644
index 0000000..93b9b74
--- /dev/null
+++ b/tree_diff_test.go
@@ -0,0 +1,398 @@
+package git
+
+import (
+ "os"
+ "sort"
+
+ "gopkg.in/src-d/go-git.v3/core"
+ "gopkg.in/src-d/go-git.v3/formats/packfile"
+
+ . "gopkg.in/check.v1"
+)
+
+type DiffTreeSuite struct {
+ repos map[string]*Repository
+}
+
+var _ = Suite(&DiffTreeSuite{})
+
+func (s *DiffTreeSuite) SetUpSuite(c *C) {
+ fixtureRepos := [...]struct {
+ url string
+ packfile string
+ }{
+ {"git://github.com/github/gem-builder.git",
+ "fixtures/pack-1ea0b3971fd64fdcdf3282bfb58e8cf10095e4e6.pack"},
+ {"git://github.com/githubtraining/example-branches.git",
+ "fixtures/pack-bb8ee94710d3fa39379a630f76812c187217b312.pack"},
+ {"git://github.com/rumpkernel/rumprun-xen.git",
+ "fixtures/pack-7861f2632868833a35fe5e4ab94f99638ec5129b.pack"},
+ {"git://github.com/mcuadros/skeetr.git",
+ "fixtures/pack-36ef7a2296bfd526020340d27c5e1faa805d8d38.pack"},
+ {"git://github.com/dezfowler/LiteMock.git",
+ "fixtures/pack-0d9b6cfc261785837939aaede5986d7a7c212518.pack"},
+ {"git://github.com/tyba/storable.git",
+ "fixtures/pack-0d3d824fb5c930e7e7e1f0f399f2976847d31fd3.pack"},
+ {"git://github.com/toqueteos/ts3.git",
+ "fixtures/pack-21b33a26eb7ffbd35261149fe5d886b9debab7cb.pack"},
+ }
+
+ s.repos = make(map[string]*Repository, 0)
+ for _, fixRepo := range fixtureRepos {
+ s.repos[fixRepo.url] = NewPlainRepository()
+
+ f, err := os.Open(fixRepo.packfile)
+ c.Assert(err, IsNil)
+
+ r := packfile.NewSeekable(f)
+ d := packfile.NewDecoder(r)
+ err = d.Decode(s.repos[fixRepo.url].Storage)
+ c.Assert(err, IsNil)
+
+ c.Assert(f.Close(), IsNil)
+ }
+}
+
+func (s *DiffTreeSuite) TestActionString(c *C) {
+ expected := "Insert"
+ action := Insert
+ obtained := action.String()
+ c.Assert(obtained, Equals, expected)
+
+ expected = "Delete"
+ action = Delete
+ obtained = action.String()
+ c.Assert(obtained, Equals, expected)
+
+ expected = "Modify"
+ action = Modify
+ obtained = action.String()
+ c.Assert(obtained, Equals, expected)
+
+ action = 37
+ c.Assert(func() { action.String() },
+ PanicMatches, "unsupported action: 37")
+}
+
+func (s *DiffTreeSuite) TestChangeString(c *C) {
+ expected := "<Action: Insert, Path: foo>"
+ change := &Change{
+ Action: Insert,
+ Name: "foo",
+ }
+
+ obtained := change.String()
+ c.Assert(obtained, Equals, expected)
+}
+
+func (s *DiffTreeSuite) TestChangesString(c *C) {
+ expected := "[]"
+ changes := newEmpty()
+ obtained := changes.String()
+ c.Assert(obtained, Equals, expected)
+
+ expected = "[<Action: Modify, Path: bla>]"
+ changes = make([]*Change, 1)
+ changes[0] = &Change{Action: Modify, Name: "bla"}
+ obtained = changes.String()
+ c.Assert(obtained, Equals, expected)
+
+ expected = "[<Action: Modify, Path: bla>, <Action: Insert, Path: foo/bar>]"
+ changes = make([]*Change, 2)
+ changes[0] = &Change{Action: Modify, Name: "bla"}
+ changes[1] = &Change{Action: Insert, Name: "foo/bar"}
+ obtained = changes.String()
+ c.Assert(obtained, Equals, expected)
+}
+
+func (s *DiffTreeSuite) TestDiffTree(c *C) {
+ for i, t := range []struct {
+ repo string // the repo name as in localRepos
+ commit1 string // the commit of the first tree
+ commit2 string // the commit of the second tree
+ expected Changes // the expected list of changes
+ }{
+ {
+ "git://github.com/dezfowler/LiteMock.git",
+ "",
+ "",
+ Changes{},
+ },
+ {
+ "git://github.com/dezfowler/LiteMock.git",
+ "b7965eaa2c4f245d07191fe0bcfe86da032d672a",
+ "b7965eaa2c4f245d07191fe0bcfe86da032d672a",
+ Changes{},
+ },
+ {
+ "git://github.com/dezfowler/LiteMock.git",
+ "",
+ "b7965eaa2c4f245d07191fe0bcfe86da032d672a",
+ Changes{
+ {Action: Insert, Name: "README"},
+ },
+ },
+ {
+ "git://github.com/dezfowler/LiteMock.git",
+ "b7965eaa2c4f245d07191fe0bcfe86da032d672a",
+ "",
+ Changes{
+ {Action: Delete, Name: "README"},
+ },
+ },
+ {
+ "git://github.com/githubtraining/example-branches.git",
+ "",
+ "f0eb272cc8f77803478c6748103a1450aa1abd37",
+ Changes{
+ {Action: Insert, Name: "README.md"},
+ },
+ },
+ {
+ "git://github.com/githubtraining/example-branches.git",
+ "f0eb272cc8f77803478c6748103a1450aa1abd37",
+ "",
+ Changes{
+ {Action: Delete, Name: "README.md"},
+ },
+ },
+ {
+ "git://github.com/githubtraining/example-branches.git",
+ "f0eb272cc8f77803478c6748103a1450aa1abd37",
+ "f0eb272cc8f77803478c6748103a1450aa1abd37",
+ Changes{},
+ },
+ {
+ "git://github.com/github/gem-builder.git",
+ "",
+ "9608eed92b3839b06ebf72d5043da547de10ce85",
+ Changes{
+ {Action: Insert, Name: "README"},
+ {Action: Insert, Name: "gem_builder.rb"},
+ {Action: Insert, Name: "gem_eval.rb"},
+ },
+ },
+ {
+ "git://github.com/github/gem-builder.git",
+ "9608eed92b3839b06ebf72d5043da547de10ce85",
+ "",
+ Changes{
+ {Action: Delete, Name: "README"},
+ {Action: Delete, Name: "gem_builder.rb"},
+ {Action: Delete, Name: "gem_eval.rb"},
+ },
+ },
+ {
+ "git://github.com/github/gem-builder.git",
+ "9608eed92b3839b06ebf72d5043da547de10ce85",
+ "9608eed92b3839b06ebf72d5043da547de10ce85",
+ Changes{},
+ },
+ {
+ "git://github.com/toqueteos/ts3.git",
+ "",
+ "764e914b75d6d6df1fc5d832aa9840f590abf1bb",
+ Changes{
+ {Action: Insert, Name: "examples/bot.go"},
+ {Action: Insert, Name: "examples/raw_shell.go"},
+ {Action: Insert, Name: "helpers.go"},
+ {Action: Insert, Name: "README.markdown"},
+ {Action: Insert, Name: "ts3.go"},
+ },
+ },
+ {
+ "git://github.com/toqueteos/ts3.git",
+ "764e914b75d6d6df1fc5d832aa9840f590abf1bb",
+ "",
+ Changes{
+ {Action: Delete, Name: "examples/bot.go"},
+ {Action: Delete, Name: "examples/raw_shell.go"},
+ {Action: Delete, Name: "helpers.go"},
+ {Action: Delete, Name: "README.markdown"},
+ {Action: Delete, Name: "ts3.go"},
+ },
+ },
+ {
+ "git://github.com/toqueteos/ts3.git",
+ "764e914b75d6d6df1fc5d832aa9840f590abf1bb",
+ "764e914b75d6d6df1fc5d832aa9840f590abf1bb",
+ Changes{},
+ },
+ {
+ "git://github.com/github/gem-builder.git",
+ "9608eed92b3839b06ebf72d5043da547de10ce85",
+ "6c41e05a17e19805879689414026eb4e279f7de0",
+ Changes{
+ {Action: Modify, Name: "gem_eval.rb"},
+ },
+ },
+ {
+ "git://github.com/github/gem-builder.git",
+ "6c41e05a17e19805879689414026eb4e279f7de0",
+ "89be3aac2f178719c12953cc9eaa23441f8d9371",
+ Changes{
+ {Action: Modify, Name: "gem_eval.rb"},
+ {Action: Insert, Name: "gem_eval_test.rb"},
+ {Action: Insert, Name: "security.rb"},
+ {Action: Insert, Name: "security_test.rb"},
+ },
+ },
+ {
+ "git://github.com/github/gem-builder.git",
+ "89be3aac2f178719c12953cc9eaa23441f8d9371",
+ "597240b7da22d03ad555328f15abc480b820acc0",
+ Changes{
+ {Action: Modify, Name: "gem_eval.rb"},
+ },
+ },
+ {
+ "git://github.com/github/gem-builder.git",
+ "597240b7da22d03ad555328f15abc480b820acc0",
+ "0260380e375d2dd0e1a8fcab15f91ce56dbe778e",
+ Changes{
+ {Action: Modify, Name: "gem_eval.rb"},
+ {Action: Modify, Name: "gem_eval_test.rb"},
+ {Action: Insert, Name: "lazy_dir.rb"},
+ {Action: Insert, Name: "lazy_dir_test.rb"},
+ {Action: Modify, Name: "security.rb"},
+ {Action: Modify, Name: "security_test.rb"},
+ },
+ },
+ {
+ "git://github.com/github/gem-builder.git",
+ "0260380e375d2dd0e1a8fcab15f91ce56dbe778e",
+ "597240b7da22d03ad555328f15abc480b820acc0",
+ Changes{
+ {Action: Modify, Name: "gem_eval.rb"},
+ {Action: Modify, Name: "gem_eval_test.rb"},
+ {Action: Delete, Name: "lazy_dir.rb"},
+ {Action: Delete, Name: "lazy_dir_test.rb"},
+ {Action: Modify, Name: "security.rb"},
+ {Action: Modify, Name: "security_test.rb"},
+ },
+ },
+ {
+ "git://github.com/github/gem-builder.git",
+ "0260380e375d2dd0e1a8fcab15f91ce56dbe778e",
+ "ca9fd470bacb6262eb4ca23ee48bb2f43711c1ff",
+ Changes{
+ {Action: Modify, Name: "gem_eval.rb"},
+ {Action: Modify, Name: "security.rb"},
+ {Action: Modify, Name: "security_test.rb"},
+ },
+ },
+ {
+ "git://github.com/github/gem-builder.git",
+ "fe3c86745f887c23a0d38c85cfd87ca957312f86",
+ "b7e3f636febf7a0cd3ab473b6d30081786d2c5b6",
+ Changes{
+ {Action: Modify, Name: "gem_eval.rb"},
+ {Action: Modify, Name: "gem_eval_test.rb"},
+ {Action: Insert, Name: "git_mock"},
+ {Action: Modify, Name: "lazy_dir.rb"},
+ {Action: Modify, Name: "lazy_dir_test.rb"},
+ {Action: Modify, Name: "security.rb"},
+ },
+ },
+ {
+ "git://github.com/rumpkernel/rumprun-xen.git",
+ "1831e47b0c6db750714cd0e4be97b5af17fb1eb0",
+ "51d8515578ea0c88cc8fc1a057903675cf1fc16c",
+ Changes{
+ {Action: Modify, Name: "Makefile"},
+ {Action: Modify, Name: "netbsd_init.c"},
+ {Action: Modify, Name: "rumphyper_stubs.c"},
+ {Action: Delete, Name: "sysproxy.c"},
+ },
+ },
+ {
+ "git://github.com/rumpkernel/rumprun-xen.git",
+ "1831e47b0c6db750714cd0e4be97b5af17fb1eb0",
+ "e13e678f7ee9badd01b120889e0ec5fdc8ae3802",
+ Changes{
+ {Action: Modify, Name: "app-tools/rumprun"},
+ },
+ },
+ } {
+ repo, ok := s.repos[t.repo]
+ c.Assert(ok, Equals, true,
+ Commentf("subtest %d: repo %s not found", i, t.repo))
+
+ tree1, err := tree(repo, t.commit1)
+ c.Assert(err, IsNil,
+ Commentf("subtest %d: unable to retrieve tree from commit %s and repo %s: %s", i, t.commit1, t.repo, err))
+
+ var tree2 *Tree
+ if t.commit1 == t.commit2 {
+ tree2 = tree1
+ } else {
+ tree2, err = tree(repo, t.commit2)
+ c.Assert(err, IsNil,
+ Commentf("subtest %d: unable to retrieve tree from commit %s and repo %s", i, t.commit2, t.repo, err))
+ }
+
+ obtained, err := DiffTree(tree1, tree2)
+ c.Assert(err, IsNil,
+ Commentf("subtest %d: unable to calculate difftree: %s", i, err))
+ c.Assert(equalChanges(obtained, t.expected), Equals, true,
+ Commentf("subtest:%d\nrepo=%s\ncommit1=%s\ncommit2=%s\nexpected=%s\nobtained=%s",
+ i, t.repo, t.commit1, t.commit2, t.expected, obtained))
+
+ assertChanges(obtained, c)
+ }
+}
+
+func assertChanges(a Changes, c *C) {
+ for _, changes := range a {
+ switch changes.Action {
+ case Insert:
+ c.Assert(changes.Files[0], IsNil)
+ c.Assert(changes.Files[1], NotNil)
+ case Delete:
+ c.Assert(changes.Files[0], NotNil)
+ c.Assert(changes.Files[1], IsNil)
+ case Modify:
+ c.Assert(changes.Files[0], NotNil)
+ c.Assert(changes.Files[1], NotNil)
+ }
+ }
+}
+
+func equalChanges(a, b Changes) bool {
+ if a == nil && b == nil {
+ return true
+ }
+
+ if a == nil || b == nil {
+ return false
+ }
+
+ if len(a) != len(b) {
+ return false
+ }
+
+ sort.Sort(a)
+ sort.Sort(b)
+
+ for i, va := range a {
+ vb := b[i]
+ if va.Action != vb.Action || va.Name != vb.Name {
+ return false
+ }
+ }
+
+ return true
+}
+
+func tree(repo *Repository, commitHashStr string) (*Tree, error) {
+ if commitHashStr == "" {
+ return nil, nil
+ }
+
+ commit, err := repo.Commit(core.NewHash(commitHashStr))
+ if err != nil {
+ return nil, err
+ }
+
+ return commit.Tree(), nil
+}
generated by cgit (git 2.34.1) at 2024-09-21 17:35:40 +0000