Adjusted previous object creators to use the rev_parse method directly. rev_parse could be adjusted not to return Objects anymore, providing better performance for those who just want a sha only. On the other hand, the method is high-level and should be convenient to use as well, its a starting point for more usually, hence its unlikely to call it in tight loops

Author: Byron

lib/git/index/base.py

@@ -1122,7 +1122,7 @@ def diff(self, other=diff.Diffable.Index, paths=None, create_patch=False, **kwar
 		# item. Handle existing -R flags properly. Transform strings to the object
 		# so that we can call diff on it
 		if isinstance(other, basestring):
-			other = Object.new(self.repo, other)
+			other = self.repo.rev_parse(other)
 		# END object conversion
 
 		if isinstance(other, Object):

lib/git/objects/base.py

@@ -49,10 +49,7 @@ def new(cls, repo, id):
 			
 		:note: This cannot be a __new__ method as it would always call __init__
 			with the input id which is not necessarily a binsha."""
-		hexsha, typename, size = repo.git.get_object_header(id)
-		inst = get_object_type_by_name(typename)(repo, hex_to_bin(hexsha))
-		inst.size = size
-		return inst
+		return repo.rev_parse(str(id))
 
 	@classmethod
 	def new_from_sha(cls, repo, sha1):

lib/git/refs.py

@@ -345,7 +345,7 @@ def _create(cls, repo, path, resolve, reference, force):
 		# figure out target data
 		target = reference
 		if resolve:
-			target = Object.new(repo, reference)
+			target = repo.rev_parse(str(reference))
 
 		if not force and isfile(abs_ref_path):
 			target_data = str(target)

lib/git/remote.py

@@ -391,7 +391,7 @@ def _from_line(cls, repo, line, fetch_line):
 				split_token = '...'
 				if control_character == ' ':
 					split_token = split_token[:-1]
-				old_commit = Commit.new(repo, operation.split(split_token)[0])
+				old_commit = repo.rev_parse(operation.split(split_token)[0])
 			# END handle refspec
 		# END reference flag handling
 

lib/git/repo/base.py

@@ -323,11 +323,9 @@ def commit(self, rev=None):
 		:param rev: revision specifier, see git-rev-parse for viable options.
 		:return: ``git.Commit``"""
 		if rev is None:
-			rev = self.active_branch
-		
-		c = Object.new(self, rev)
-		assert c.type == "commit", "Revision %s did not point to a commit, but to %s" % (rev, c)
-		return c
+			return self.active_branch.commit
+		else:
+			return self.rev_parse(str(rev)+"^0")
 
 	def iter_trees(self, *args, **kwargs):
 		""":return: Iterator yielding Tree objects
@@ -348,14 +346,9 @@ def tree(self, rev=None):
 			it cannot know about its path relative to the repository root and subsequent 
 			operations might have unexpected results."""
 		if rev is None:
-			rev = self.active_branch
-		
-		c = Object.new(self, rev)
-		if c.type == "commit":
-			return c.tree
-		elif c.type == "tree":
-			return c
-		raise ValueError( "Revision %s did not point to a treeish, but to %s" % (rev, c))
+			return self.active_branch.commit.tree
+		else:
+			return self.rev_parse(str(rev)+"^{tree}")
 
 	def iter_commits(self, rev=None, paths='', **kwargs):
 		"""A list of Commit objects representing the history of a given ref/commit

test/git/test_repo.py

@@ -7,7 +7,7 @@
 from git import *
 from git.util import join_path_native
 from git.exc import BadObject
-from gitdb.util import hex_to_bin
+from gitdb.util import hex_to_bin, bin_to_hex
 
 import os, sys
 import tempfile
@@ -57,7 +57,12 @@ def test_tree_from_revision(self):
 		assert self.rorepo.tree(tree) == tree
 
 		# try from invalid revision that does not exist
-		self.failUnlessRaises(ValueError, self.rorepo.tree, 'hello world')
+		self.failUnlessRaises(BadObject, self.rorepo.tree, 'hello world')
+		
+	def test_commit_from_revision(self):
+		commit = self.rorepo.commit('0.1.4')
+		assert commit.type == 'commit'
+		assert self.rorepo.commit(commit) == commit
 
 	def test_commits(self):
 		mc = 10
@@ -445,7 +450,7 @@ def test_rev_parse(self):
 		rev_parse = self.rorepo.rev_parse
 
 		# try special case: This one failed beforehand
-		assert self.rorepo.odb.partial_to_complete_sha_hex("33ebe") == hex_to_bin("33ebe7acec14b25c5f84f35a664803fcab2f7781")
+		assert rev_parse("33ebe").hexsha == "33ebe7acec14b25c5f84f35a664803fcab2f7781"
 
 		# start from reference
 		num_resolved = 0
@@ -507,6 +512,16 @@ def test_rev_parse(self):
 			assert tag.object == rev_parse('0.1.4%s' % token)
 		# END handle multiple tokens
 
+		# try partial parsing
+		max_items = 40
+		for i, binsha in enumerate(self.rorepo.odb.sha_iter()):
+			assert rev_parse(bin_to_hex(binsha)[:8-(i%2)]).binsha == binsha
+			if i > max_items:
+				# this is rather slow currently, as rev_parse returns an object
+				# which requires accessing packs, it has some additional overhead
+				break
+		# END for each binsha in repo
+		
 		# missing closing brace commit^{tree
 		self.failUnlessRaises(ValueError, rev_parse, '0.1.4^{tree')