move plumbing from top level package to plumbing (#183)

* plumbing: rename Object -> EncodedObject.

* plumbing/storer: rename ObjectStorer -> EncodedObjectStorer.

* move difftree to plumbing/difftree.

* move diff -> utils/diff

* make Object/Tag/Blob/Tree/Commit/File depend on storer.

* Object and its implementations now depend only on
  storer.EncodedObjectStorer, not git.Repository.
* Tests are decoupled accordingly.

* move Object/Commit/File/Tag/Tree to plumbing/object.

* move Object/Commit/File/Tag/Tree to plumbing/object.
* move checkClose to utils/ioutil.

* move RevListObjects to plumbing/revlist.Objects.

* move DiffTree to plumbing/difftree package.

* rename files with plural nouns to singular

* plumbing/object: add GetBlob/GetCommit/GetTag/GetTree.

1 files changed, 0 insertions, 123 deletions

diff --git a/revlist.go b/revlist.go
deleted file mode 100644
index 70dcb95..0000000
--- a/revlist.go
+++ /dev/null
@@ -1,123 +0,0 @@
-package git
-
-import (
-	"io"
-
-	"gopkg.in/src-d/go-git.v4/plumbing"
-)
-
-// RevListObjects applies a complementary set. It gets all the hashes from all
-// the reachable objects from the given commits. Ignore param are object hashes
-// that we want to ignore on the result. It is a list because is
-// easier to interact with other porcelain elements, but internally it is
-// converted to a map. All that objects must be accessible from the Repository.
-func RevListObjects(
-	r *Repository,
-	commits []*Commit,
-	ignore []plumbing.Hash) ([]plumbing.Hash, error) {
-
-	seen := hashListToSet(ignore)
-	result := make(map[plumbing.Hash]bool)
-	for _, c := range commits {
-		err := reachableObjects(r, c, seen, func(h plumbing.Hash) error {
-			if !seen[h] {
-				result[h] = true
-				seen[h] = true
-			}
-
-			return nil
-		})
-
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	return hashSetToList(result), nil
-}
-
-// reachableObjects returns, using the callback function, all the reachable
-// objects from the specified commit. To avoid to iterate over seen commits,
-// if a commit hash is into the 'seen' set, we will not iterate all his trees
-// and blobs objects.
-func reachableObjects(
-	r *Repository,
-	commit *Commit,
-	seen map[plumbing.Hash]bool,
-	cb func(h plumbing.Hash) error) error {
-
-	return iterateCommits(commit, func(commit *Commit) error {
-		if seen[commit.Hash] {
-			return nil
-		}
-
-		if err := cb(commit.Hash); err != nil {
-			return err
-		}
-
-		return iterateCommitTrees(r, commit, func(h plumbing.Hash) error {
-			return cb(h)
-		})
-	})
-}
-
-// iterateCommits iterate all reachable commits from the given one
-func iterateCommits(commit *Commit, cb func(c *Commit) error) error {
-	if err := cb(commit); err != nil {
-		return err
-	}
-
-	return WalkCommitHistory(commit, func(c *Commit) error {
-		return cb(c)
-	})
-}
-
-// iterateCommitTrees iterate all reachable trees from the given commit
-func iterateCommitTrees(
-	repository *Repository,
-	commit *Commit,
-	cb func(h plumbing.Hash) error) error {
-
-	tree, err := commit.Tree()
-	if err != nil {
-		return err
-	}
-	if err := cb(tree.Hash); err != nil {
-		return err
-	}
-
-	treeWalker := NewTreeWalker(repository, tree, true)
-
-	for {
-		_, e, err := treeWalker.Next()
-		if err == io.EOF {
-			break
-		}
-		if err != nil {
-			return err
-		}
-		if err := cb(e.Hash); err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
-
-func hashSetToList(hashes map[plumbing.Hash]bool) []plumbing.Hash {
-	var result []plumbing.Hash
-	for key := range hashes {
-		result = append(result, key)
-	}
-
-	return result
-}
-
-func hashListToSet(hashes []plumbing.Hash) map[plumbing.Hash]bool {
-	result := make(map[plumbing.Hash]bool)
-	for _, h := range hashes {
-		result[h] = true
-	}
-
-	return result
-}