def task_prerun_handler(*args, **kwargs):
"""
Before each Task is ran, we have to instantiate Johnny's query cache
monkey patch. This will make sure that any table writes invalidate table
caches, and reads pull from any existing caches.
"""
get_backend().patch()
def cache_on_models(*models):
"""
Returns a decorator that allows a function to be cached on the given set of
models. If any of the models is invalidated (i.e. its generation key
changes), the decorated function will be re-run and re-cached.
"""
backend = johnny_cache.get_backend()
table_names = map(lambda model: model._meta.db_table, models)
def _cache_on_tables_decorator(fn):
multi_generation_key = backend.keyhandler.get_generation(*table_names)
fn_key = '%s.%s' % (fn.__module__, fn.__name__)
def _fn_with_caching(*args, **kwargs):
""" Wraps the given function, fn, with caching. """
key_parts = [multi_generation_key, fn_key, args, kwargs]
key = json.dumps(key_parts)
key = base64.b64encode(key)
value = django_cache.get(key)
if value == None:
value = fn(*args, **kwargs)
# pass timeout of 0 to cache forever
django_cache.set(key, value, 0)
return value
return _fn_with_caching
return _cache_on_tables_decorator
def test_savepoint_localstore_flush(self):
"""
This is a very simple test to see if savepoints will actually
be committed, i.e. flushed out from localstore into cache.
"""
transaction.enter_transaction_management()
managed()
TABLE_NAME = 'test_table'
cache_backend = cache.get_backend()
cache_backend.patch()
keyhandler = cache_backend.keyhandler
keygen = keyhandler.keygen
tm = cache_backend.cache_backend
# First, we set one key-val pair generated for our non-existing table.
table_key = keygen.gen_table_key(TABLE_NAME)
tm.set(table_key, 'val1')
# Then we create a savepoint.
# The key-value pair is moved into 'trans_sids' item of localstore.
tm._create_savepoint('savepoint1')
# We then commit all the savepoints (i.e. only one in this case)
# The items stored in 'trans_sids' should be moved back to the
# top-level dictionary of our localstore
tm._commit_all_savepoints()
# And this checks if it actually happened.
self.assertTrue(table_key in tm.local)
def test_savepoint_localstore_flush(self):
"""
This is a very simple test to see if savepoints will actually
be committed, i.e. flushed out from localstore into cache.
"""
transaction.enter_transaction_management()
managed()
TABLE_NAME = 'test_table'
cache_backend = cache.get_backend()
cache_backend.patch()
keyhandler = cache_backend.keyhandler
keygen = keyhandler.keygen
tm = cache_backend.cache_backend
# First, we set one key-val pair generated for our non-existing table.
table_key = keygen.gen_table_key(TABLE_NAME)
tm.set(table_key, 'val1')
# Then we create a savepoint.
# The key-value pair is moved into 'trans_sids' item of localstore.
tm._create_savepoint('savepoint1')
# We then commit all the savepoints (i.e. only one in this case)
# The items stored in 'trans_sids' should be moved back to the
# top-level dictionary of our localstore
tm._commit_all_savepoints()
# And this checks if it actually happened.
self.assertTrue(table_key in tm.local)
def cache_on_models(*models):
"""
Returns a decorator that allows a function to be cached on the given set of
models. If any of the models is invalidated (i.e. its generation key
changes), the decorated function will be re-run and re-cached.
"""
backend = johnny_cache.get_backend()
table_names = map(lambda model: model._meta.db_table, models)
def _cache_on_tables_decorator(fn):
multi_generation_key = backend.keyhandler.get_generation(*table_names)
fn_key = '%s.%s' % (fn.__module__, fn.__name__)
def _fn_with_caching(*args, **kwargs):
""" Wraps the given function, fn, with caching. """
key_parts = [multi_generation_key, fn_key, args, kwargs]
key = json.dumps(key_parts)
key = base64.b64encode(key)
value = django_cache.get(key)
if value == None:
value = fn(*args, **kwargs)
# pass timeout of 0 to cache forever
django_cache.set(key, value, 0)
return value
return _fn_with_caching
return _cache_on_tables_decorator
def newf(*args, **kwargs):
backend = get_backend()
was_patched = backend._patched
get_backend().patch()
#since this function takes all keyword arguments,
#we will pass only the ones the function below accepts, just as celery does
supported_keys = fun_takes_kwargs(f, kwargs)
new_kwargs = dict((key, val) for key, val in kwargs.items()
if key in supported_keys)
try:
ret = f(*args, **new_kwargs)
finally:
local.clear()
if not was_patched:
get_backend().unpatch()
return ret
def handle(self, **options):
print 'Registering plugins...'
register_all_plugins(verbose=True)
# cache invalidation
print 'Invalidating plugins cache...'
query_cache_backend = cache.get_backend()
query_cache_backend.patch()
cache.invalidate(RegisteredPlugin._meta.db_table)
print 'Done.'
def search(self, term, replacement='', case_sensitive=False):
if cache:
backend = cache.get_backend()
backend.unpatch()
for model, options in self.models.items():
info = build_info(model, options, term, replacement, case_sensitive)
yield info, list(options.search(term, replacement, case_sensitive))
if cache:
backend.patch()
def newf(*args, **kwargs):
backend = get_backend()
was_patched = backend._patched
get_backend().patch()
# since this function takes all keyword arguments,
# we will pass only the ones the function below accepts,
# just as celery does
supported_keys = fun_takes_kwargs(f, kwargs)
new_kwargs = dict((key, val) for key, val in kwargs.items()
if key in supported_keys)
try:
ret = f(*args, **new_kwargs)
finally:
local.clear()
if not was_patched:
get_backend().unpatch()
return ret
def replace(self, queryset, term, replacement, case_sensitive):
if cache:
backend = cache.get_backend()
backend.unpatch()
self.models[queryset.model].replace(queryset, term, replacement,
case_sensitive)
if cache:
backend.patch()
cache.invalidate(queryset.model)
def search(self, term, replacement='', case_sensitive=False):
if cache:
backend = cache.get_backend()
backend.unpatch()
for model, options in self.models.items():
info = build_info(model, options, term, replacement,
case_sensitive)
yield info, list(options.search(term, replacement, case_sensitive))
if cache:
backend.patch()
def replace(self, queryset, term, replacement, case_sensitive):
if cache:
backend = cache.get_backend()
backend.unpatch()
self.models[queryset.model].replace(queryset, term, replacement,
case_sensitive)
if cache:
backend.patch()
cache.invalidate(queryset.model)
def __init__(self):
self.__dict__ = self.__state
self.disabled = settings.DISABLE_QUERYSET_CACHE
self.installed = getattr(self, 'installed', False)
if not self.installed and not self.disabled:
# when we install, lets refresh the blacklist, just in case johnny
# was loaded before the setting exists somehow...
cache.blacklist = settings.BLACKLIST
self.query_cache_backend = cache.get_backend()
self.query_cache_backend.patch()
self.installed = True
def __init__(self):
self.__dict__ = self.__state
self.disabled = settings.DISABLE_QUERYSET_CACHE
self.installed = getattr(self, 'installed', False)
if not self.installed and not self.disabled:
# when we install, lets refresh the blacklist, just in case johnny
# was loaded before the setting exists somehow...
cache.blacklist = settings.BLACKLIST
self.query_cache_backend = cache.get_backend()
self.query_cache_backend.patch()
self.installed = True
def run_tests(test_labels, verbosity=1, interactive=True, extra_tests=[]):
# Disable Johnny cache backend because it does weird things. See #852
query_cache_backend = cache.get_backend()
query_cache_backend.unpatch()
query_cache_backend.flush_query_cache()
settings.CACHES = {
'default': {
'BACKEND': 'django.core.cache.backends.dummy.DummyCache',
}
}
return django_run_tests(test_labels, verbosity, interactive, extra_tests)
def forwards(self, orm):
"Write your forwards methods here."
from django.conf import settings
from johnny import cache
from merengue.pluggable import register_plugin
from merengue.pluggable.utils import install_plugin
# Unpatch cache backend to disable johnny cache. Johny does weird things
query_cache_backend = cache.get_backend()
query_cache_backend.unpatch()
from django.db import transaction
for plug_dir in settings.DEMO_PLUGINS:
plugin = register_plugin(plug_dir)
plugin.installed = True
plugin.active = True
plugin.save()
install_plugin(plugin)
transaction.commit()
from django.conf import settings
if 'johnny.middleware.QueryCacheMiddleware' in settings.MIDDLEWARE_CLASSES:
from johnny.cache import get_backend
from johnny.settings import MIDDLEWARE_SECONDS
jc_backend = get_backend()
else:
jc_backend = None
MIDDLEWARE_SECONDS = None
def process_exception(self, *args, **kwargs):
cache.local.clear()
cache.get_backend().cache_backend.rollback()
def process_response(self, req, resp):
cache.local.clear()
cache.get_backend().cache_backend.rollback()
return resp
