plumbing: blame, Complete rewrite. Fixes #603

Signed-off-by: Arieh Schneier <15041913+AriehSchneier@users.noreply.github.com>

1 files changed, 0 insertions, 264 deletions

diff --git a/references.go b/references.go
deleted file mode 100644
index 6d96035..0000000
--- a/references.go
+++ /dev/null
@@ -1,264 +0,0 @@
-package git
-
-import (
-	"io"
-	"sort"
-
-	"github.com/go-git/go-git/v5/plumbing"
-	"github.com/go-git/go-git/v5/plumbing/object"
-	"github.com/go-git/go-git/v5/utils/diff"
-
-	"github.com/sergi/go-diff/diffmatchpatch"
-)
-
-// References returns a slice of Commits for the file at "path", starting from
-// the commit provided that contains the file from the provided path. The last
-// commit into the returned slice is the commit where the file was created.
-// If the provided commit does not contains the specified path, a nil slice is
-// returned. The commits are sorted in commit order, newer to older.
-//
-// Caveats:
-//
-// - Moves and copies are not currently supported.
-//
-// - Cherry-picks are not detected unless there are no commits between them and
-// therefore can appear repeated in the list. (see git path-id for hints on how
-// to fix this).
-func references(c *object.Commit, path string) ([]*object.Commit, error) {
-	var result []*object.Commit
-	seen := make(map[plumbing.Hash]struct{})
-	if err := walkGraph(&result, &seen, c, path); err != nil {
-		return nil, err
-	}
-
-	// TODO result should be returned without ordering
-	sortCommits(result)
-
-	// for merges of identical cherry-picks
-	return removeComp(path, result, equivalent)
-}
-
-type commitSorterer struct {
-	l []*object.Commit
-}
-
-func (s commitSorterer) Len() int {
-	return len(s.l)
-}
-
-func (s commitSorterer) Less(i, j int) bool {
-	return s.l[i].Committer.When.Before(s.l[j].Committer.When) ||
-		s.l[i].Committer.When.Equal(s.l[j].Committer.When) &&
-			s.l[i].Author.When.Before(s.l[j].Author.When)
-}
-
-func (s commitSorterer) Swap(i, j int) {
-	s.l[i], s.l[j] = s.l[j], s.l[i]
-}
-
-// SortCommits sorts a commit list by commit date, from older to newer.
-func sortCommits(l []*object.Commit) {
-	s := &commitSorterer{l}
-	sort.Sort(s)
-}
-
-// Recursive traversal of the commit graph, generating a linear history of the
-// path.
-func walkGraph(result *[]*object.Commit, seen *map[plumbing.Hash]struct{}, current *object.Commit, path string) error {
-	// check and update seen
-	if _, ok := (*seen)[current.Hash]; ok {
-		return nil
-	}
-	(*seen)[current.Hash] = struct{}{}
-
-	// if the path is not in the current commit, stop searching.
-	if _, err := current.File(path); err != nil {
-		return nil
-	}
-
-	// optimization: don't traverse branches that does not
-	// contain the path.
-	parents, err := parentsContainingPath(path, current)
-	if err != nil {
-		return err
-	}
-	switch len(parents) {
-	// if the path is not found in any of its parents, the path was
-	// created by this commit; we must add it to the revisions list and
-	// stop searching. This includes the case when current is the
-	// initial commit.
-	case 0:
-		*result = append(*result, current)
-		return nil
-	case 1: // only one parent contains the path
-		// if the file contents has change, add the current commit
-		different, err := differentContents(path, current, parents)
-		if err != nil {
-			return err
-		}
-		if len(different) == 1 {
-			*result = append(*result, current)
-		}
-		// in any case, walk the parent
-		return walkGraph(result, seen, parents[0], path)
-	default: // more than one parent contains the path
-		// TODO: detect merges that had a conflict, because they must be
-		// included in the result here.
-		for _, p := range parents {
-			err := walkGraph(result, seen, p, path)
-			if err != nil {
-				return err
-			}
-		}
-	}
-	return nil
-}
-
-func parentsContainingPath(path string, c *object.Commit) ([]*object.Commit, error) {
-	// TODO: benchmark this method making git.object.Commit.parent public instead of using
-	// an iterator
-	var result []*object.Commit
-	iter := c.Parents()
-	for {
-		parent, err := iter.Next()
-		if err == io.EOF {
-			return result, nil
-		}
-		if err != nil {
-			return nil, err
-		}
-		if _, err := parent.File(path); err == nil {
-			result = append(result, parent)
-		}
-	}
-}
-
-// Returns an slice of the commits in "cs" that has the file "path", but with different
-// contents than what can be found in "c".
-func differentContents(path string, c *object.Commit, cs []*object.Commit) ([]*object.Commit, error) {
-	result := make([]*object.Commit, 0, len(cs))
-	h, found := blobHash(path, c)
-	if !found {
-		return nil, object.ErrFileNotFound
-	}
-	for _, cx := range cs {
-		if hx, found := blobHash(path, cx); found && h != hx {
-			result = append(result, cx)
-		}
-	}
-	return result, nil
-}
-
-// blobHash returns the hash of a path in a commit
-func blobHash(path string, commit *object.Commit) (hash plumbing.Hash, found bool) {
-	file, err := commit.File(path)
-	if err != nil {
-		var empty plumbing.Hash
-		return empty, found
-	}
-	return file.Hash, true
-}
-
-type contentsComparatorFn func(path string, a, b *object.Commit) (bool, error)
-
-// Returns a new slice of commits, with duplicates removed.  Expects a
-// sorted commit list.  Duplication is defined according to "comp".  It
-// will always keep the first commit of a series of duplicated commits.
-func removeComp(path string, cs []*object.Commit, comp contentsComparatorFn) ([]*object.Commit, error) {
-	result := make([]*object.Commit, 0, len(cs))
-	if len(cs) == 0 {
-		return result, nil
-	}
-	result = append(result, cs[0])
-	for i := 1; i < len(cs); i++ {
-		equals, err := comp(path, cs[i], cs[i-1])
-		if err != nil {
-			return nil, err
-		}
-		if !equals {
-			result = append(result, cs[i])
-		}
-	}
-	return result, nil
-}
-
-// Equivalent commits are commits whose patch is the same.
-func equivalent(path string, a, b *object.Commit) (bool, error) {
-	numParentsA := a.NumParents()
-	numParentsB := b.NumParents()
-
-	// the first commit is not equivalent to anyone
-	// and "I think" merges can not be equivalent to anything
-	if numParentsA != 1 || numParentsB != 1 {
-		return false, nil
-	}
-
-	diffsA, err := patch(a, path)
-	if err != nil {
-		return false, err
-	}
-	diffsB, err := patch(b, path)
-	if err != nil {
-		return false, err
-	}
-
-	return sameDiffs(diffsA, diffsB), nil
-}
-
-func patch(c *object.Commit, path string) ([]diffmatchpatch.Diff, error) {
-	// get contents of the file in the commit
-	file, err := c.File(path)
-	if err != nil {
-		return nil, err
-	}
-	content, err := file.Contents()
-	if err != nil {
-		return nil, err
-	}
-
-	// get contents of the file in the first parent of the commit
-	var contentParent string
-	iter := c.Parents()
-	parent, err := iter.Next()
-	if err != nil {
-		return nil, err
-	}
-	file, err = parent.File(path)
-	if err != nil {
-		contentParent = ""
-	} else {
-		contentParent, err = file.Contents()
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	// compare the contents of parent and child
-	return diff.Do(content, contentParent), nil
-}
-
-func sameDiffs(a, b []diffmatchpatch.Diff) bool {
-	if len(a) != len(b) {
-		return false
-	}
-	for i := range a {
-		if !sameDiff(a[i], b[i]) {
-			return false
-		}
-	}
-	return true
-}
-
-func sameDiff(a, b diffmatchpatch.Diff) bool {
-	if a.Type != b.Type {
-		return false
-	}
-	switch a.Type {
-	case 0:
-		return countLines(a.Text) == countLines(b.Text)
-	case 1, -1:
-		return a.Text == b.Text
-	default:
-		panic("unreachable")
-	}
-}