lazymixin system now supports per-attribute baking, it is up to the class whether it bakes more. This also leads to more efficient use of memory as values are only cached and set when required - the baking system does not require an own tracking variable anymore, and values are only to be cached once - then python will natively find the cache without involving any additional overhead. This works by using __getattr__ instead of __get_attribute__ which would always be called

5 files changed, 113 insertions, 143 deletions

diff --git a/lib/git/base.py b/lib/git/base.py
index 22c73491..f3510558 100644
--- a/lib/git/base.py
+++ b/lib/git/base.py
@@ -7,43 +7,38 @@ import os
 
 class LazyMixin(object):
 	lazy_properties = []
+	__slots__ = tuple()
 	
-	__slots__ = "__baked__"
-	
-	def __init__(self):
-		self.__baked__ = False
-
-	def __getattribute__(self, attr):
-		val = object.__getattribute__(self, attr)
-		if val is not None:
-			return val
-		else:
-			self.__prebake__()
-			return object.__getattribute__(self, attr)
-
-	def __bake__(self):
-		""" This method should be overridden in the derived class. """
-		raise NotImplementedError(" '__bake__' method has not been implemented.")
-
-	def __prebake__(self):
-		if self.__baked__:
-			return
-		self.__bake__()
-		self.__baked__ = True
+	def __getattr__(self, attr):
+		"""
+		Whenever an attribute is requested that we do not know, we allow it 
+		to be created and set. Next time the same attribute is reqeusted, it is simply
+		returned from our dict/slots.
+		"""
+		self._set_cache_(attr)
+		# will raise in case the cache was not created
+		return object.__getattribute__(self, attr)
 
-	def __bake_it__(self):
-		self.__baked__ = True
+	def _set_cache_(self, attr):
+		""" This method should be overridden in the derived class. 
+		It should check whether the attribute named by attr can be created
+		and cached. Do nothing if you do not know the attribute or call your subclass
 		
+		The derived class may create as many additional attributes as it deems 
+		necessary in case a git command returns more information than represented 
+		in the single attribute."""
+		pass
+	
 		
 class Object(LazyMixin):
 	"""
 	Implements an Object which may be Blobs, Trees, Commits and Tags
 	"""
 	TYPES = ("blob", "tree", "commit", "tag")
-	__slots__ = ("repo", "id", "size", "_data_cached" )
+	__slots__ = ("repo", "id", "size", "data" )
 	type = None			# to be set by subclass
 	
-	def __init__(self, repo, id, size=None):
+	def __init__(self, repo, id):
 		"""
 		Initialize an object by identifying it by its id. All keyword arguments
 		will be set on demand if None.
@@ -53,21 +48,32 @@ class Object(LazyMixin):
 			
 		``id``
 			SHA1 or ref suitable for git-rev-parse
-			
-		``size``
-			Size of the object's data in bytes
 		"""
 		super(Object,self).__init__()
 		self.repo = repo
 		self.id = id
-		self.size = size
-		self._data_cached = type(None)
 		
-	def __bake__(self):
+	def _set_self_from_args_(self, args_dict):
+		"""
+		Initialize attributes on self from the given dict that was retrieved
+		from locals() in the calling method.
+		
+		Will only set an attribute on self if the corresponding value in args_dict
+		is not None
+		"""
+		for attr, val in args_dict.items():
+			if attr != "self" and val is not None:
+				setattr( self, attr, val )
+		# END set all non-None attributes
+	
+	def _set_cache_(self, attr):
 		"""
 		Retrieve object information
 		"""
-		self.size = int(self.repo.git.cat_file(self.id, s=True).rstrip())
+		if attr  == "size":
+			self.size = int(self.repo.git.cat_file(self.id, s=True).rstrip())
+		elif attr == "data":
+			self.data = self.repo.git.cat_file(self.id, p=True, with_raw_output=True)
 		
 	def __eq__(self, other):
 		"""
@@ -105,18 +111,12 @@ class Object(LazyMixin):
 		return '<git.%s "%s">' % (self.__class__.__name__, self.id)
 	
 	@property
-	def data(self):
+	def id_abbrev(self):
 		"""
-		The binary contents of this object.
-
 		Returns
-			str
-			
-		NOTE
-			The data will be cached after the first access.
+			First 7 bytes of the commit's sha id as an abbreviation of the full string.
 		"""
-		self._data_cached = ( self._data_cached is not type(None) and self._data_cached ) or self.repo.git.cat_file(self.id, p=True, with_raw_output=True)
-		return self._data_cached
+		return self.id[0:7]
 	
 	@classmethod
 	def get_type_by_name(cls, object_type_name):
@@ -154,7 +154,7 @@ class IndexObject(Object):
 	"""
 	__slots__ = ("path", "mode") 
 	
-	def __init__(self, repo, id, mode=None, path=None, size = None):
+	def __init__(self, repo, id, mode=None, path=None):
 		"""
 		Initialize a newly instanced IndexObject
 		``repo``
@@ -169,14 +169,11 @@ class IndexObject(Object):
 		``path`` : str
 			is the path to the file in the file system, relative to the git repository root, i.e.
 			file.ext or folder/other.ext
-			
-		 ``size`` : int
-		 	size of the object data in bytes
 		"""
-		super(IndexObject, self).__init__(repo, id, size)
+		super(IndexObject, self).__init__(repo, id)
 		self.mode = mode
 		self.path = path
-		
+	
 	@property
 	def basename(self):
 	  """
@@ -304,5 +301,6 @@ class Ref(object):
 			git.Head
 		"""
 		full_path, hexsha, type_name, object_size = line.split("\x00")
-		obj = Object.get_type_by_name(type_name)(repo, hexsha, object_size)
+		obj = Object.get_type_by_name(type_name)(repo, hexsha)
+		obj.size = object_size
 		return cls(full_path, obj)
diff --git a/lib/git/commit.py b/lib/git/commit.py
index 1ae84799..5d494621 100644
--- a/lib/git/commit.py
+++ b/lib/git/commit.py
@@ -25,6 +25,8 @@ class Commit(base.Object):
 	
 	# object configuration 
 	type = "commit"
+	__slots__ = ("tree", "author", "authored_date", "committer", "committed_date",
+					"message", "parents")
 	
 	def __init__(self, repo, id, tree=None, author=None, authored_date=None,
 				 committer=None, committed_date=None, message=None, parents=None):
@@ -38,7 +40,7 @@ class Commit(base.Object):
 			is the sha id of the commit
 
 		``parents`` : list( Commit, ... )
-			is a list of commit ids
+			is a list of commit ids or actual Commits
 
 		``tree`` : Tree
 			is the corresponding tree id
@@ -61,49 +63,34 @@ class Commit(base.Object):
 		Returns
 			git.Commit
 		"""
-		super(Commit,self).__init__(repo, id, "commit")
-		self.parents = None
-		self.tree = None
-		self.author = author
-		self.authored_date = authored_date
-		self.committer = committer
-		self.committed_date = committed_date
-		self.message = message
-
-		if self.id:
-			if parents is not None:
-				self.parents = [Commit(repo, p) for p in parents]
-			if tree is not None:
-				self.tree = Tree(repo, id=tree)
-
-	def __eq__(self, other):
-		return self.id == other.id
-	
-	def __ne__(self, other):
-		return self.id != other.id
-	
-	def __bake__(self):
-		"""
-		Called by LazyMixin superclass when the first uninitialized member needs 
-		to be set as it is queried.
-		"""
-		super(Commit, self).__bake__()
-		temp = Commit.find_all(self.repo, self.id, max_count=1)[0]
-		self.parents = temp.parents
-		self.tree = temp.tree
-		self.author = temp.author
-		self.authored_date = temp.authored_date
-		self.committer = temp.committer
-		self.committed_date = temp.committed_date
-		self.message = temp.message
+		super(Commit,self).__init__(repo, id)
+		self._set_self_from_args_(locals())
 
-	@property
-	def id_abbrev(self):
+		if parents is not None:
+			self.parents = tuple( self.__class__(repo, p) for p in parents )
+		# END for each parent to convert
+			
+		if self.id and tree is not None:
+			self.tree = Tree(repo, id=tree)
+		# END id to tree conversion
+
+	def _set_cache_(self, attr):
 		"""
-		Returns
-			First 7 bytes of the commit's sha id as an abbreviation of the full string.
+		Called by LazyMixin superclass when the given uninitialized member needs 
+		to be set.
+		We set all values at once.
 		"""
-		return self.id[0:7]
+		if attr in self.__slots__:
+			temp = Commit.find_all(self.repo, self.id, max_count=1)[0]
+			self.parents = temp.parents
+			self.tree = temp.tree
+			self.author = temp.author
+			self.authored_date = temp.authored_date
+			self.committer = temp.committer
+			self.committed_date = temp.committed_date
+			self.message = temp.message
+		else:
+			super(Commit, self)._set_cache_(attr)
 
 	@property
 	def summary(self):
diff --git a/lib/git/head.py b/lib/git/head.py
index f4e94637..42dfd735 100644
--- a/lib/git/head.py
+++ b/lib/git/head.py
@@ -27,20 +27,6 @@ class Head(base.Ref):
 		'1c09f116cbc2cb4100fb6935bb162daa4723f455'
 	"""
 
-	def __init__(self, path, commit):
-		"""
-		Initialize a newly instanced Head
-
-		``path``
-			is the path to the head ref, relative to the .git directory, i.e.
-			refs/heads/master
-
-		`commit`
-			is the Commit object that the head points to
-		"""
-		super(Head, self).__init__(name, commit)
-
-
 	@property
 	def commit(self):
 		"""
diff --git a/lib/git/tag.py b/lib/git/tag.py
index 4266a7a9..89060ee0 100644
--- a/lib/git/tag.py
+++ b/lib/git/tag.py
@@ -74,7 +74,7 @@ class TagObject(base.Object):
 	type = "tag"
 	__slots__ = ( "object", "tag", "tagger", "tagged_date", "message" )
 		
-	def __init__(self, repo, id, size=None, object=None, tag=None, 
+	def __init__(self, repo, id, object=None, tag=None, 
 				tagger=None, tagged_date=None, message=None):
 		"""
 		Initialize a tag object with additional data
@@ -85,9 +85,6 @@ class TagObject(base.Object):
 		``id``
 			SHA1 or ref suitable for git-rev-parse
 			
-		``size``
-			Size of the object's data in bytes
-			
 		 ``object``
 			Object instance of object we are pointing to
 		 
@@ -100,29 +97,30 @@ class TagObject(base.Object):
 		  ``tagged_date`` : (tm_year, tm_mon, tm_mday, tm_hour, tm_min, tm_sec, tm_wday, tm_yday, tm_isdst)
 			is the DateTime of the tag creation
 		"""
-		super(TagObject, self).__init__(repo, id , size)
-		self.object = object
-		self.tag = tag
-		self.tagger = tagger
-		self.tagged_date = tagged_date
-		self.message = message
-		
-	def __bake__(self):
-		super(TagObject, self).__bake__()
-		
-		output = self.repo.git.cat_file(self.type,self.id)
-		lines = output.split("\n")
-		
-		obj, hexsha = lines[0].split(" ")		# object <hexsha>
-		type_token, type_name = lines[1].split(" ") # type <type_name>
-		self.object = base.Object.get_type_by_name(type_name)(self.repo, hexsha)
-		
-		self.tag = lines[2][4:]  # tag <tag name>
-		
-		tagger_info = lines[3][7:]# tagger <actor> <date>
-		self.tagger, self.tagged_date = commit.Commit._actor(tagger_info)
+		super(TagObject, self).__init__(repo, id )
+		self._set_self_from_args_(locals())
 		
-		# line 4 empty - check git source to figure out purpose
-		self.message = "\n".join(lines[5:])
+	def _set_cache_(self, attr):
+		"""
+		Cache all our attributes at once
+		"""
+		if attr in self.__slots__:
+			output = self.repo.git.cat_file(self.type,self.id)
+			lines = output.split("\n")
+			
+			obj, hexsha = lines[0].split(" ")		# object <hexsha>
+			type_token, type_name = lines[1].split(" ") # type <type_name>
+			self.object = base.Object.get_type_by_name(type_name)(self.repo, hexsha)
+			
+			self.tag = lines[2][4:]  # tag <tag name>
+			
+			tagger_info = lines[3][7:]# tagger <actor> <date>
+			self.tagger, self.tagged_date = commit.Commit._actor(tagger_info)
+			
+			# line 4 empty - check git source to figure out purpose
+			self.message = "\n".join(lines[5:])
+		# END check our attributes
+		else:
+			super(TagObject, self)._set_cache_(attr)
 		
 		
diff --git a/lib/git/tree.py b/lib/git/tree.py
index 90f1b72d..db4a3e22 100644
--- a/lib/git/tree.py
+++ b/lib/git/tree.py
@@ -13,18 +13,19 @@ class Tree(base.IndexObject):
 	type = "tree"
 	__slots__ = "_contents"
 	
-	def __init__(self, repo, id, mode=None, path=None, size=None):
-		super(Tree, self).__init__(repo, id, mode, path, size)
-		self._contents = None
-
-	def __bake__(self):
-		# Read the tree contents.
-		super(Tree, self).__bake__()
-		self._contents = {}
-		for line in self.repo.git.ls_tree(self.id).splitlines():
-			obj = self.content_from_string(self.repo, line)
-			if obj is not None:
-				self._contents[obj.path] = obj
+	def __init__(self, repo, id, mode=None, path=None):
+		super(Tree, self).__init__(repo, id, mode, path)
+
+	def _set_cache_(self, attr):
+		if attr == "_contents":
+			# Read the tree contents.
+			self._contents = {}
+			for line in self.repo.git.ls_tree(self.id).splitlines():
+				obj = self.content_from_string(self.repo, line)
+				if obj is not None:
+					self._contents[obj.path] = obj
+		else:
+			super(Tree, self)._set_cache_(attr)
 
 	@staticmethod
 	def content_from_string(repo, text):