def __delitem__(self, cpv):
"""delete a key from the cache.
This shouldn't be overriden in derived classes since it handles the readonly checks"""
if self.readonly:
raise cache_errors.ReadOnlyRestriction()
if not self.autocommits:
self.updates += 1
self._delitem(cpv)
if self.updates > self.sync_rate:
self.commit()
self.updates = 0
def _initdb_con(self, config):
"""ensure needed tables are in place.
If the derived class needs a different set of table creation commands, overload the approriate
SCHEMA_ attributes. If it needs additional execution beyond, override"""
self._dbconnect(config)
if not self._table_exists(self.SCHEMA_PACKAGE_NAME):
if self.readonly:
raise cache_errors.ReadOnlyRestriction("table %s doesn't exist" % \
self.SCHEMA_PACKAGE_NAME)
try:
self.con.execute(self.SCHEMA_PACKAGE_CREATE)
except self._BaseError, e:
raise cache_errors.InitializationError(self.__class__, e)
def __setitem__(self, cpv, values):
"""set a cpv to values
This shouldn't be overriden in derived classes since it handles the readonly checks"""
if self.readonly:
raise cache_errors.ReadOnlyRestriction()
d = copy.copy(values)
if "_eclasses_" in d:
d["_eclasses_"] = serialize_eclasses(d["_eclasses_"])
self._setitem(cpv, d)
if not self.autocommits:
self.updates += 1
if self.updates > self.sync_rate:
self.commit()
self.updates = 0
def __setitem__(self, cpv, values):
"""set a cpv to values
This shouldn't be overriden in derived classes since it handles the readonly checks"""
if self.readonly:
raise cache_errors.ReadOnlyRestriction()
if self.cleanse_keys:
d = copy.copy(values)
for k in d.keys():
if d[k] == '':
del d[k]
if "_eclasses_" in values:
d = values.copy()
d["_eclasses_"] = serialize_eclasses(d["_eclasses_"])
elif "_eclasses_" in values:
d = values.copy()
d["_eclasses_"] = serialize_eclasses(d["_eclasses_"])
else:
d = values
self._setitem(cpv, d)
if not self.autocommits:
self.updates += 1
if self.updates > self.sync_rate:
self.commit()
self.updates = 0
class SQLDatabase(template.database):
"""template class for RDBM based caches
This class is designed such that derivatives don't have to change much code, mostly constant strings.
_BaseError must be an exception class that all Exceptions thrown from the derived RDBMS are derived
from.
SCHEMA_INSERT_CPV_INTO_PACKAGE should be modified dependant on the RDBMS, as should SCHEMA_PACKAGE_CREATE-
basically you need to deal with creation of a unique pkgid. If the dbapi2 rdbms class has a method of
recovering that id, then modify _insert_cpv to remove the extra select.
Creation of a derived class involves supplying _initdb_con, and table_exists.
Additionally, the default schemas may have to be modified.
"""
SCHEMA_PACKAGE_NAME = "package_cache"
SCHEMA_PACKAGE_CREATE = "CREATE TABLE %s (\
pkgid INTEGER PRIMARY KEY, label VARCHAR(255), cpv VARCHAR(255), UNIQUE(label, cpv))" % SCHEMA_PACKAGE_NAME
SCHEMA_PACKAGE_DROP = "DROP TABLE %s" % SCHEMA_PACKAGE_NAME
SCHEMA_VALUES_NAME = "values_cache"
SCHEMA_VALUES_CREATE = "CREATE TABLE %s ( pkgid integer references %s (pkgid) on delete cascade, \
key varchar(255), value text, UNIQUE(pkgid, key))" % (SCHEMA_VALUES_NAME,
SCHEMA_PACKAGE_NAME)
SCHEMA_VALUES_DROP = "DROP TABLE %s" % SCHEMA_VALUES_NAME
SCHEMA_INSERT_CPV_INTO_PACKAGE = "INSERT INTO %s (label, cpv) VALUES(%%s, %%s)" % SCHEMA_PACKAGE_NAME
_BaseError = ()
_dbClass = None
autocommits = False
# boolean indicating if the derived RDBMS class supports replace syntax
_supports_replace = False
def __init__(self, label, auxdbkeys, **config):
"""initialize the instance.
derived classes shouldn't need to override this"""
super(SQLDatabase, self).__init__(label, auxdbkeys, **config)
config.setdefault("host", "127.0.0.1")
config.setdefault("autocommit", self.autocommits)
self._initdb_con(config)
self.label = self._sfilter(self.label)
def _dbconnect(self, config):
"""should be overridden if the derived class needs special parameters for initializing
the db connection, or cursor"""
self.db = self._dbClass(**config)
self.con = self.db.cursor()
def _initdb_con(self, config):
"""ensure needed tables are in place.
If the derived class needs a different set of table creation commands, overload the approriate
SCHEMA_ attributes. If it needs additional execution beyond, override"""
self._dbconnect(config)
if not self._table_exists(self.SCHEMA_PACKAGE_NAME):
if self.readonly:
raise cache_errors.ReadOnlyRestriction("table %s doesn't exist" % \
self.SCHEMA_PACKAGE_NAME)
try:
self.con.execute(self.SCHEMA_PACKAGE_CREATE)
except self._BaseError, e:
raise cache_errors.InitializationError(self.__class__, e)
if not self._table_exists(self.SCHEMA_VALUES_NAME):
if self.readonly:
raise cache_errors.ReadOnlyRestriction("table %s doesn't exist" % \
self.SCHEMA_VALUES_NAME)
try:
self.con.execute(self.SCHEMA_VALUES_CREATE)
except self._BaseError, e:
raise cache_errors.InitializationError(self.__class__, e)