2009-09-23  Wakaba  <wakaba@suika.fam.cx>

	* Document.pm (lock): Typo; it did not lock in fact, orz.

	* Graph.pm (schelling_update): Reuse the |repo| object's child
	objects where possible to avoid locking timing problem and so on.

2009-09-23  Wakaba  <wakaba@suika.fam.cx>

	* Document.pm (prop_untainted): Typo.
	(untainted_prop): The |prop_untainted| property was not set.

2009-09-21  Wakaba  <wakaba@suika.fam.cx>

	* Repository.pm (weight_lock, weight_unlock): New methods.
	(term_weight_vector, save_term_weight_vector): Changed to use
	global props to save the term weight vector.

2009-09-21  Wakaba  <wakaba@suika.fam.cx>

	* Document.pm (repo, prop_untainted, untainted_prop, save_prop,
	locked): New method.  Introduced the concept of "tainted" such
	that we can access to the property in the locked code fragment
	without being afraid to update the property using old values.
	(get_or_create_graph_node): Updated to utilize |prop| family of
	method with locks.

	* Graph.pm (repo, lock, unlock): New methods.
	(add_nodes, create_node, schelling_update): Locks the database
	before the modifications.

	* Repository.pm (graph, get_document_by_id): New methods.

	* Node.pm (repo): New method.

2009-09-21  Wakaba  <wakaba@suika.fam.cx>

	* Document.pm (lock): Changed to use the $db->id_lock method to
	obtain the lock object.

	* Node.pm (neighbor_documents): New method.

2009-09-21  Wakaba  <wakaba@suika.fam.cx>

	* Document.pm (title, get_or_create_graph_node): New methods (made
	from codes moved from main.pl).

2009-09-20  Wakaba  <wakaba@suika.fam.cx>

	* Graph.pm (schelling_update): Implemented.

2009-09-20  Wakaba  <wakaba@suika.fam.cx>

	* Graph.pm (add_nodes): Improved the way to determine the number
	of added nodes.

2009-09-14  Wakaba  <wakaba@suika.fam.cx>

	* Document.pm (prop): New method.
	(content_media_type): Changed to return the real media type.
	(to_xml_media_type, to_text_media_type, to_xml, to_html_fragment):
	Changed to return appropriate default value.

2009-09-14  Wakaba  <wakaba@suika.fam.cx>

	* Document.pm: Added |rebless| method family.  Moved
	SWML-to-HTML/XML/text convertion methods to another module.

	* Document/: New directory.

2009-09-14  Wakaba  <wakaba@suika.fam.cx>

	* Document.pm (to_html_fragment): New method.

2009-09-14  Wakaba  <wakaba@suika.fam.cx>

	* Document.pm (to_xml, to_text): New methods.

2009-07-12  Wakaba  <wakaba@suika.fam.cx>

	* Document.pm (new_id): New method.

2009-07-12  Wakaba  <wakaba@suika.fam.cx>

	* Document.pm (update_tfidf): New method copied from main.pl.

2009-07-12  Wakaba  <wakaba@suika.fam.cx>

	* Document.pm: New module.

2009-03-16  Wakaba  <wakaba@suika.fam.cx>

	* Repository.pm (are_related_ids): Repeat the relearning process
	until the right answer is deduced.

2009-03-16  Wakaba  <wakaba@suika.fam.cx>

	* Repository.pm: New module.

2009-03-15  Wakaba  <wakaba@suika.fam.cx>

	* Node.pm (document_id): New method.

2009-03-15  Wakaba  <wakaba@suika.fam.cx>

	* Graph.pm (get_node_by_id): New method.
	(create_node): Changed to instantiate SWE::Object::Node.

	* Node.pm: New module.

2009-03-15  Wakaba  <wakaba@suika.fam.cx>

	* Graph.pm: New module.

2009-03-15  Wakaba  <wakaba@suika.fam.cx>

	* ChangeLog: New file.