def _get_item_(self, key):
'''
Returns cache item by specifed key.
@param key: item key
'''
with transaction.begin_root(pool_name = self._pool_name):
try:
store = transaction.get_current_transaction(self._pool_name).get_connection()
cursor = create_raw_cursor(store)
cursor.execute('''select item_value,
item_creation_time,
item_last_reset_time,
item_expired from DELTA_CACHE_CONTENT
where cache_id = :cache_id
and item_key = :item_key''',
[self._id, key])
result = cursor.fetchone()
if result is not None:
(item_value,
item_creation_time,
item_last_reset_time,
item_expired,) = result
item = CacheItem(key, cPickle.loads(item_value))
item.creation_time = item_creation_time
item.last_reset_time = item_last_reset_time
item.expired = item_expired
return item
return None
except:
raise
def get_items(self):
'''
Returns all items in cache.
@return: [object]
'''
with transaction.begin_root(pool_name = self._pool_name):
store = transaction.get_current_transaction(self._pool_name).get_connection()
cursor = create_raw_cursor(store)
cursor.execute('''select item_key,
item_value,
item_creation_time,
item_last_reset_time,
item_expired
from DELTA_CACHE_CONTENT
where cache_id = :cache_id''',
[self._id])
items = []
for (item_key,
item_value,
item_creation_time,
item_last_reset_time,
item_expired,) in cursor.fetchall():
item = CacheItem(item_key, cPickle.loads(item_value))
self.creation_time = item_creation_time
self.last_reset_time = item_last_reset_time
self.expired = item_expired
items.append(item)
return items
def _attach_to_transaction(self, request):
'''
Attaches to current transaction to rollback request in case of error occurred.
'''
# Appending reverse callable for current transaction
if self._should_be_reversed:
current_transaction = transaction_services.get_current_transaction(
)
current_transaction.add_before_rollback_trigger(
self._reverse_request, request)
def _remove_expired_items_(self):
'''
Removes oldest item from cache.
'''
with transaction.begin_root(pool_name = self._pool_name):
store = transaction.get_current_transaction(self._pool_name).get_connection()
cursor = create_raw_cursor(store)
cursor.execute('''delete from DELTA_CACHE_CONTENT
where cache_id = :cache_id
and item_expired = 1 ''',
[self._id])
def _remove_oldest_item_(self):
'''
Removes oldest item from cache.
'''
with transaction.begin_root(pool_name = self._pool_name):
last_reset_time = self.get_last_reset_time()
if last_reset_time is not None:
store = transaction.get_current_transaction(self._pool_name).get_connection()
cursor = create_raw_cursor(store)
cursor.execute('''delete from DELTA_CACHE_CONTENT
where cache_id = :cache_id
and item_last_reset_time <= :item_last_reset_time''',
[self._id,
last_reset_time])
def remove(self, key):
'''
Removes specified item from cache.
@param key: item key
'''
with transaction.begin_root(pool_name = self._pool_name):
store = transaction.get_current_transaction(self._pool_name).get_connection()
cursor = create_raw_cursor(store)
cursor.execute('''delete from DELTA_CACHE_CONTENT
where cache_id = :cache_id
and item_key = :item_key''',
[self._id, key])
def clear(self):
'''
Removes all cache items.
'''
with transaction.begin_root(pool_name = self._pool_name):
store = transaction.get_current_transaction(self._pool_name).get_connection()
cursor = create_raw_cursor(store)
cursor.execute('''delete from DELTA_CACHE_CONTENT
where cache_id = :cache_id''',
[self._id])
size, = cursor.fetchone()
return size
def set(self, key, value):
'''
Sets given item using specified key.
@param key: item key
@param value: item value
'''
with transaction.begin_root(pool_name = self._pool_name):
try:
store = transaction.get_current_transaction(self._pool_name).get_connection()
cursor = create_raw_cursor(store)
if self.has_key(key):
cursor.execute('''update DELTA_CACHE_CONTENT
set item_value = :item_value,
item_last_reset_time = :item_last_reset_time,
item_expired = :item_expired
where cache_id = :cache_id
and item_key = :item_key''',
[buffer(cPickle.dumps(value, protocol = 0)),
time.time(),
False,
self._id,
key])
else:
size = self.get_size()
if size != 0 and self.get_len() >= size:
self._remove_oldest_item_()
cursor.execute('''insert into
DELTA_CACHE_CONTENT(cache_id,
item_key,
item_value,
item_creation_time,
item_last_reset_time,
item_expired)
values(:cache_id,
:item_key,
:item_value,
:item_creation_time,
:item_last_reset_time,
:item_expired)''',
[self._id,
key,
buffer(cPickle.dumps(value, protocol = 0)),
time.time(),
time.time(),
False])
except:
raise
def reset(self):
'''
Resets the cache.
'''
with transaction.begin_root(pool_name = self._pool_name):
store = transaction.get_current_transaction(self._pool_name).get_connection()
cursor = create_raw_cursor(store)
cursor.execute('''update DELTA_CACHE_CONTENT
set item_last_reset_time = :item_last_reset_time,
item_expired = :item_expired
where cache_id = :cache_id''',
[time.time(),
True,
self._id])
def get_len(self):
'''
Returns cache items count.
@return: int
'''
with transaction.begin_root(pool_name = self._pool_name):
store = transaction.get_current_transaction(self._pool_name).get_connection()
cursor = create_raw_cursor(store)
cursor.execute('''select count(*) from DELTA_CACHE_CONTENT
where cache_id = :cache_id ''',
[self._id])
length, = cursor.fetchone()
return length
def values(self):
'''
Returns all values.
@return: [object]
'''
with transaction.begin_root(pool_name = self._pool_name):
store = transaction.get_current_transaction(self._pool_name).get_connection()
cursor = create_raw_cursor(store)
cursor.execute('''select item_value from DELTA_CACHE_CONTENT
where cache_id = :cache_id''',
[self._id])
values = []
for item_value, in cursor.fetchall():
values.append(cPickle.loads(item_value))
return values
def keys(self):
'''
Returns all keys.
@return: [object]
'''
with transaction.begin_root(pool_name = self._pool_name):
store = transaction.get_current_transaction(self._pool_name).get_connection()
cursor = create_raw_cursor(store)
cursor.execute('''select item_key from DELTA_CACHE_CONTENT
where cache_id = :cache_id''',
[self._id])
keys = []
for item_key in cursor.fetchall():
keys.append(item_key)
return keys
def get_size(self):
'''
Returns cache size.
@return: int
'''
with transaction.begin_root(pool_name = self._pool_name):
store = transaction.get_current_transaction(self._pool_name).get_connection()
cursor = create_raw_cursor(store)
cursor.execute('''select cache_size from DELTA_CACHE_HEADER
where app_name = :app_name
and app_instance = :app_instance
and cache_name = :cache_name''',
[self._app_name, self._instance_name, self.get_name()])
size, = cursor.fetchone()
return size
def get_last_reset_time(self):
'''
Returns last reset time of the cache.
@return: float
'''
with transaction.begin_root(pool_name = self._pool_name):
store = transaction.get_current_transaction(self._pool_name).get_connection()
cursor = create_raw_cursor(store)
cursor.execute('''select item_last_reset_time from DELTA_CACHE_CONTENT
where cache_id = :cache_id
order by item_last_reset_time desc''',
[self._id])
result = cursor.fetchone()
item_last_reset_time = None
if result is not None:
item_last_reset_time, = cursor.fetchone()
return item_last_reset_time
def get_id(self):
'''
Returns cache id.
@return: object
'''
if self._cache_id is None:
with transaction.begin_root(pool_name = self._pool_name):
store = transaction.get_current_transaction(self._pool_name).get_connection()
cursor = create_raw_cursor(store)
cursor.execute('''select cache_id from DELTA_CACHE_HEADER
where app_name = :app_name
and app_instance = :app_instance
and cache_name = :cache_name''',
[self._app_name, self._instance_name, self.get_name()])
result = cursor.fetchone()
if result is not None:
cache_id, = result
else:
cache_id = hash(self._app_name + self._instance_name + self.get_name())
cursor.execute('''insert into
DELTA_CACHE_HEADER(app_name,
app_instance,
cache_name,
cache_id,
cache_size)
values(:app_name,
:app_instance,
:cache_name,
:cache_id,
:cache_size)''',
[self._app_name,
self._instance_name,
self.get_name(),
cache_id,
CacheBase.get_size(self)])
self._cache_id = cache_id
return self._cache_id
def _get_root_transaction_id_(self):
trx = get_current_transaction()
parent_trx = trx.get_parent()
if parent_trx is not None:
return parent_trx.get_id()
return trx.get_id()
