summaryrefslogtreecommitdiffstats
path: root/pyload/lib/beaker/ext/database.py
diff options
context:
space:
mode:
Diffstat (limited to 'pyload/lib/beaker/ext/database.py')
-rw-r--r--pyload/lib/beaker/ext/database.py165
1 files changed, 165 insertions, 0 deletions
diff --git a/pyload/lib/beaker/ext/database.py b/pyload/lib/beaker/ext/database.py
new file mode 100644
index 000000000..701e6f7d2
--- /dev/null
+++ b/pyload/lib/beaker/ext/database.py
@@ -0,0 +1,165 @@
+import cPickle
+import logging
+import pickle
+from datetime import datetime
+
+from beaker.container import OpenResourceNamespaceManager, Container
+from beaker.exceptions import InvalidCacheBackendError, MissingCacheParameter
+from beaker.synchronization import file_synchronizer, null_synchronizer
+from beaker.util import verify_directory, SyncDict
+
+log = logging.getLogger(__name__)
+
+sa = None
+pool = None
+types = None
+
+class DatabaseNamespaceManager(OpenResourceNamespaceManager):
+ metadatas = SyncDict()
+ tables = SyncDict()
+
+ @classmethod
+ def _init_dependencies(cls):
+ global sa, pool, types
+ if sa is not None:
+ return
+ try:
+ import sqlalchemy as sa
+ import sqlalchemy.pool as pool
+ from sqlalchemy import types
+ except ImportError:
+ raise InvalidCacheBackendError("Database cache backend requires "
+ "the 'sqlalchemy' library")
+
+ def __init__(self, namespace, url=None, sa_opts=None, optimistic=False,
+ table_name='beaker_cache', data_dir=None, lock_dir=None,
+ **params):
+ """Creates a database namespace manager
+
+ ``url``
+ SQLAlchemy compliant db url
+ ``sa_opts``
+ A dictionary of SQLAlchemy keyword options to initialize the engine
+ with.
+ ``optimistic``
+ Use optimistic session locking, note that this will result in an
+ additional select when updating a cache value to compare version
+ numbers.
+ ``table_name``
+ The table name to use in the database for the cache.
+ """
+ OpenResourceNamespaceManager.__init__(self, namespace)
+
+ if sa_opts is None:
+ sa_opts = params
+
+ if lock_dir:
+ self.lock_dir = lock_dir
+ elif data_dir:
+ self.lock_dir = data_dir + "/container_db_lock"
+ if self.lock_dir:
+ verify_directory(self.lock_dir)
+
+ # Check to see if the table's been created before
+ url = url or sa_opts['sa.url']
+ table_key = url + table_name
+ def make_cache():
+ # Check to see if we have a connection pool open already
+ meta_key = url + table_name
+ def make_meta():
+ # SQLAlchemy pops the url, this ensures it sticks around
+ # later
+ sa_opts['sa.url'] = url
+ engine = sa.engine_from_config(sa_opts, 'sa.')
+ meta = sa.MetaData()
+ meta.bind = engine
+ return meta
+ meta = DatabaseNamespaceManager.metadatas.get(meta_key, make_meta)
+ # Create the table object and cache it now
+ cache = sa.Table(table_name, meta,
+ sa.Column('id', types.Integer, primary_key=True),
+ sa.Column('namespace', types.String(255), nullable=False),
+ sa.Column('accessed', types.DateTime, nullable=False),
+ sa.Column('created', types.DateTime, nullable=False),
+ sa.Column('data', types.PickleType, nullable=False),
+ sa.UniqueConstraint('namespace')
+ )
+ cache.create(checkfirst=True)
+ return cache
+ self.hash = {}
+ self._is_new = False
+ self.loaded = False
+ self.cache = DatabaseNamespaceManager.tables.get(table_key, make_cache)
+
+ def get_access_lock(self):
+ return null_synchronizer()
+
+ def get_creation_lock(self, key):
+ return file_synchronizer(
+ identifier ="databasecontainer/funclock/%s" % self.namespace,
+ lock_dir = self.lock_dir)
+
+ def do_open(self, flags):
+ # If we already loaded the data, don't bother loading it again
+ if self.loaded:
+ self.flags = flags
+ return
+
+ cache = self.cache
+ result = sa.select([cache.c.data],
+ cache.c.namespace==self.namespace
+ ).execute().fetchone()
+ if not result:
+ self._is_new = True
+ self.hash = {}
+ else:
+ self._is_new = False
+ try:
+ self.hash = result['data']
+ except (IOError, OSError, EOFError, cPickle.PickleError,
+ pickle.PickleError):
+ log.debug("Couln't load pickle data, creating new storage")
+ self.hash = {}
+ self._is_new = True
+ self.flags = flags
+ self.loaded = True
+
+ def do_close(self):
+ if self.flags is not None and (self.flags == 'c' or self.flags == 'w'):
+ cache = self.cache
+ if self._is_new:
+ cache.insert().execute(namespace=self.namespace, data=self.hash,
+ accessed=datetime.now(),
+ created=datetime.now())
+ self._is_new = False
+ else:
+ cache.update(cache.c.namespace==self.namespace).execute(
+ data=self.hash, accessed=datetime.now())
+ self.flags = None
+
+ def do_remove(self):
+ cache = self.cache
+ cache.delete(cache.c.namespace==self.namespace).execute()
+ self.hash = {}
+
+ # We can retain the fact that we did a load attempt, but since the
+ # file is gone this will be a new namespace should it be saved.
+ self._is_new = True
+
+ def __getitem__(self, key):
+ return self.hash[key]
+
+ def __contains__(self, key):
+ return self.hash.has_key(key)
+
+ def __setitem__(self, key, value):
+ self.hash[key] = value
+
+ def __delitem__(self, key):
+ del self.hash[key]
+
+ def keys(self):
+ return self.hash.keys()
+
+class DatabaseContainer(Container):
+ namespace_manager = DatabaseNamespaceManager