/usr/lib/python3/dist-packages/beaker/ext/database.py is in python3-beaker 1.6.4-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 | import pickle
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,
schema_name=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.
``schema_name``
The schema 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'),
schema=schema_name if schema_name else meta.schema
)
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/%s" % (
self.namespace, key
),
lock_dir=self.lock_dir)
def do_open(self, flags, replace):
# 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, pickle.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 key in self.hash
def __setitem__(self, key, value):
self.hash[key] = value
def __delitem__(self, key):
del self.hash[key]
def keys(self):
return list(self.hash.keys())
class DatabaseContainer(Container):
namespace_manager = DatabaseNamespaceManager
|