Markus Korn has proposed merging
lp:~thekorn/zeitgeist/fix-598666-remove_cache_entry into lp:zeitgeist.
Requested reviews:
Zeitgeist Framework Team (zeitgeist)
Related bugs:
Bug #598666 in Zeitgeist Framework: "Invalid cache access (was: Error when
trying to fetch items)"
https://bugs.launchpad.net/zeitgeist/+bug/598666
For more details, see:
https://code.launchpad.net/~thekorn/zeitgeist/fix-598666-remove_cache_entry/+merge/56710
This branch adds a fix/workaround for bug 598666, where the caches are not
updated properly if one cached item gets deleted in the database.
https://bugs.launchpad.net/zeitgeist/+bug/598666/comments/16 describes how this
works.
This branch also factors in all review comments by Mikkel and Siegfried made in
the bug.
--
https://code.launchpad.net/~thekorn/zeitgeist/fix-598666-remove_cache_entry/+merge/56710
Your team Zeitgeist Framework Team is requested to review the proposed merge of
lp:~thekorn/zeitgeist/fix-598666-remove_cache_entry into lp:zeitgeist.
=== modified file '_zeitgeist/engine/main.py'
--- _zeitgeist/engine/main.py 2011-04-07 07:23:41 +0000
+++ _zeitgeist/engine/main.py 2011-04-07 07:56:30 +0000
@@ -5,7 +5,7 @@
# Copyright © 2009 Mikkel Kamstrup Erlandsen <mikkel.kamst...@gmail.com>
# Copyright © 2009-2010 Siegfried-Angel Gevatter Pujals <rai...@ubuntu.com>
# Copyright © 2009-2011 Seif Lotfy <s...@lotfy.com>
-# Copyright © 2009 Markus Korn <thek...@gmx.net>
+# Copyright © 2009-2011 Markus Korn <thek...@gmx.net>
# Copyright © 2011 Collabora Ltd.
# By Seif Lotfy <s...@lotfy.com>
#
@@ -133,6 +133,11 @@
def close(self):
log.debug("Closing down the zeitgeist engine...")
self.extensions.unload()
+ # make sure all symbol table are in good shape
+ # this Exception should never be raised, it would indicate a bug
+ # in the workaround for (LP: #598666)
+ if self._cursor.execute("SELECT * FROM _fix_cache").fetchone():
+ raise RuntimeError("Symbol cache is in bad state")
self._cursor.connection.close()
self._cursor = None
unset_cursor()
@@ -732,7 +737,16 @@
% ",".join(["?"] * len(ids)), ids)
self._cursor.connection.commit()
log.debug("Deleted %s" % map(int, ids))
-
+ clean_fix_cache = False
+ for cached_table, cached_id in self._cursor.execute("SELECT * FROM _fix_cache"):
+ if cached_table not in ("interpretation", "manifestation", "mimetype", "actor"):
+ raise ValueError("Unable to fix cache for '%s'" %cached_table)
+ clean_fix_cache = True
+ getattr(self, "_%s" %cached_table).remove_id(cached_id)
+ if clean_fix_cache:
+ # delete all rows from _fix_cache, as all caches are fixed by now
+ self._cursor.execute("DELETE FROM _fix_cache")
+ self._cursor.connection.commit()
self.extensions.apply_post_delete(ids, sender)
return timestamps
else:
=== modified file '_zeitgeist/engine/sql.py'
--- _zeitgeist/engine/sql.py 2011-03-25 18:30:46 +0000
+++ _zeitgeist/engine/sql.py 2011-04-07 07:56:30 +0000
@@ -4,7 +4,7 @@
#
# Copyright © 2009-2010 Siegfried-Angel Gevatter Pujals <rai...@ubuntu.com>
# Copyright © 2009 Mikkel Kamstrup Erlandsen <mikkel.kamst...@gmail.com>
-# Copyright © 2009 Markus Korn <thek...@gmx.net>
+# Copyright © 2009-2011 Markus Korn <thek...@gmx.net>
# Copyright © 2009 Seif Lotfy <s...@lotfy.com>
#
# This program is free software: you can redistribute it and/or modify
@@ -166,6 +166,11 @@
# one connection to the database is allowed to revert this setting set locking_mode to NORMAL.
cursor.execute("PRAGMA locking_mode = EXCLUSIVE")
+ # as part of the workaround for (LP: #598666) we need to
+ # create the '_fix_cache' TEMP table on every start,
+ # this table gets purged once the engine gets closed.
+ cursor.execute("CREATE TEMP TABLE _fix_cache (t VARCHAR, id INTEGER)")
+
# Always assume that temporary memory backed DBs have good schemas
if constants.DATABASE_FILE != ":memory:":
if not new_database and _check_core_schema_upgrade(cursor):
@@ -453,6 +458,14 @@
self[row["value"]] = row["id"]
self._inv_dict = dict((value, key) for key, value in self.iteritems())
+
+ cursor.execute("""
+ CREATE TEMP TRIGGER update_cache_%(table)s
+ BEFORE DELETE ON %(table)s
+ BEGIN
+ INSERT INTO _fix_cache VALUES ("%(table)s", OLD.id);
+ END;
+ """ % {"table": table})
def __getitem__(self, name):
# Use this for inserting new properties into the database
@@ -483,6 +496,11 @@
# database already. Eg., in find_eventids.
return super(TableLookup, self).__getitem__(name)
+ def remove_id(self, id):
+ value = self.value(id)
+ del self._inv_dict[id]
+ del self[value]
+
def get_right_boundary(text):
""" returns the smallest string which is greater than `text` """
if not text:
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