Use a dictionnary for tree contents

It seems more natural to use a dictionnary for directories, since we
usually want to access them by name, and entry order is not relevant.

Also, finding a particular blob given its name is O(1) instead of O(N).

3 files changed, 8 insertions, 9 deletions

diff --git a/lib/git/tree.py b/lib/git/tree.py
index f1aa0b3b..86e893ef 100644
--- a/lib/git/tree.py
+++ b/lib/git/tree.py
@@ -32,13 +32,13 @@ class Tree(LazyMixin):
     def construct_initialize(self, repo, id, text):
         self.repo = repo
         self.id = id
-        self.contents = []
+        self.contents = {}
         self.__baked__ = False
 
         for line in text.splitlines():
-            self.contents.append(self.content_from_string(self.repo, line))
-
-        self.contents = [c for c in self.contents if c is not None]
+            obj = self.content_from_string(self.repo, line)
+            if obj:
+                self.contents[obj.name] = obj
 
         self.__bake_it__()
         return self
@@ -84,8 +84,7 @@ class Tree(LazyMixin):
         Returns
             ``GitPython.Blob`` or ``GitPython.Tree`` or ``None`` if not found
         """
-        contents = [c for c in self.contents if c.name == file]
-        return contents and contents[0] or None
+        return self.contents.get(file)
 
     @property
     def basename(self):
diff --git a/test/git/test_repo.py b/test/git/test_repo.py
index 7550e1d6..c7a4c01b 100644
--- a/test/git/test_repo.py
+++ b/test/git/test_repo.py
@@ -96,8 +96,8 @@ class TestRepo(object):
 
         tree = self.repo.tree('master')
 
-        assert_equal(4, len([c for c in tree.contents if isinstance(c, Blob)]))
-        assert_equal(3, len([c for c in tree.contents if isinstance(c, Tree)]))
+        assert_equal(4, len([c for c in tree.contents.values() if isinstance(c, Blob)]))
+        assert_equal(3, len([c for c in tree.contents.values() if isinstance(c, Tree)]))
 
         assert_true(git.called)
         assert_equal(git.call_args, (('ls_tree', 'master'), {}))
diff --git a/test/git/test_tree.py b/test/git/test_tree.py
index 957b8962..d66764b3 100644
--- a/test/git/test_tree.py
+++ b/test/git/test_tree.py
@@ -18,7 +18,7 @@ class TestTree(object):
     
         tree = self.repo.tree('master')
 
-        child = tree.contents[-1]
+        child = tree.contents['grit']
         child.contents
         child.contents