"""cubicweb server sources support
:organization: Logilab
:copyright: 2001-2008 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
"""
__docformat__ = "restructuredtext en"
from logging import getLogger
from cubicweb import set_log_methods
class AbstractSource(object):
"""an abstract class for sources"""
# boolean telling if modification hooks should be called when something is
# modified in this source
should_call_hooks = True
# boolean telling if the repository should connect to this source during
# migration
connect_for_migration = True
# mappings telling which entities and relations are available in the source
# keys are supported entity/relation types and values are boolean indicating
# wether the support is read-only (False) or read-write (True)
support_entities = {}
support_relations = {}
# a global identifier for this source, which has to be set by the source
# instance
uri = None
# a reference to the system information helper
repo = None
# a reference to the application'schema (may differs from the source'schema)
schema = None
def __init__(self, repo, appschema, source_config, *args, **kwargs):
self.repo = repo
self.uri = source_config['uri']
set_log_methods(self, getLogger('cubicweb.sources.'+self.uri))
self.set_schema(appschema)
self.support_relations['identity'] = False
def init_creating(self):
"""method called by the repository once ready to create a new instance"""
pass
def init(self):
"""method called by the repository once ready to handle request"""
pass
def reset_caches(self):
"""method called during test to reset potential source caches"""
pass
def clear_eid_cache(self, eid, etype):
"""clear potential caches for the given eid"""
pass
def __repr__(self):
return '<%s source>' % self.uri
def __cmp__(self, other):
"""simple comparison function to get predictable source order, with the
system source at last
"""
if self.uri == other.uri:
return 0
if self.uri == 'system':
return 1
if other.uri == 'system':
return -1
return cmp(self.uri, other.uri)
def set_schema(self, schema):
"""set the application'schema"""
self.schema = schema
def support_entity(self, etype, write=False):
"""return true if the given entity's type is handled by this adapter
if write is true, return true only if it's a RW support
"""
try:
wsupport = self.support_entities[etype]
except KeyError:
return False
if write:
return wsupport
return True
def support_relation(self, rtype, write=False):
"""return true if the given relation's type is handled by this adapter
if write is true, return true only if it's a RW support
current implementation return true if the relation is defined into
`support_relations` or if it is a final relation of a supported entity
type
"""
try:
wsupport = self.support_relations[rtype]
except KeyError:
rschema = self.schema.rschema(rtype)
if not rschema.is_final() or rschema == 'has_text':
return False
for etype in rschema.subjects():
try:
wsupport = self.support_entities[etype]
break
except KeyError:
continue
else:
return False
if write:
return wsupport
return True
def eid2extid(self, eid, session=None):
return self.repo.eid2extid(self, eid, session)
def extid2eid(self, value, etype, session=None, insert=True):
return self.repo.extid2eid(self, value, etype, session, insert)
PUBLIC_KEYS = ('adapter', 'uri')
def remove_sensitive_information(self, sourcedef):
"""remove sensitive information such as login / password from source
definition
"""
for key in sourcedef.keys():
if not key in self.PUBLIC_KEYS:
sourcedef.pop(key)
def _cleanup_system_relations(self, session):
"""remove relation in the system source referencing entities coming from
this source
"""
cu = session.system_sql('SELECT eid FROM entities WHERE source=%(uri)s',
{'uri': self.uri})
myeids = ','.join(str(r[0]) for r in cu.fetchall())
if not myeids:
return
# delete relations referencing one of those eids
for rschema in self.schema.relations():
if rschema.is_final() or rschema.type == 'identity':
continue
if rschema.inlined:
for subjtype in rschema.subjects():
for objtype in rschema.objects(subjtype):
if self.support_entity(objtype):
sql = 'UPDATE %s SET %s = NULL WHERE eid IN (%s);' % (
subjtype, rschema.type, myeids)
session.system_sql(sql)
break
continue
for etype in rschema.subjects():
if self.support_entity(etype):
sql = 'DELETE FROM %s_relation WHERE eid_from IN (%s);' % (
rschema.type, myeids)
session.system_sql(sql)
break
for etype in rschema.objects():
if self.support_entity(etype):
sql = 'DELETE FROM %s_relation WHERE eid_to IN (%s);' % (
rschema.type, myeids)
session.system_sql(sql)
break
def cleanup_entities_info(self, session):
"""cleanup system tables from information for entities coming from
this source. This should be called when a source is removed to
properly cleanup the database
"""
self._cleanup_system_relations(session)
# fti / entities tables cleanup
# sqlite doesn't support DELETE FROM xxx USING yyy
dbhelper = session.pool.source('system').dbhelper
session.system_sql('DELETE FROM %s WHERE %s.%s IN (SELECT eid FROM '
'entities WHERE entities.source=%%(uri)s)'
% (dbhelper.fti_table, dbhelper.fti_table,
dbhelper.fti_uid_attr),
{'uri': self.uri})
session.system_sql('DELETE FROM entities WHERE source=%(uri)s',
{'uri': self.uri})
# abstract methods to override (at least) in concrete source classes #######
def get_connection(self):
"""open and return a connection to the source"""
raise NotImplementedError()
def check_connection(self, cnx):
"""check connection validity, return None if the connection is still valid
else a new connection (called when the pool using the given connection is
being attached to a session)
do nothing by default
"""
pass
def pool_reset(self, cnx):
"""the pool using the given connection is being reseted from its current
attached session
do nothing by default
"""
pass
def authenticate(self, session, login, password):
"""if the source support EUser entity type, it should implements
this method which should return EUser eid for the given login/password
if this account is defined in this source and valid login / password is
given. Else raise `AuthenticationError`
"""
raise NotImplementedError()
def syntax_tree_search(self, session, union,
args=None, cachekey=None, varmap=None, debug=0):
"""return result from this source for a rql query (actually from a rql
syntax tree and a solution dictionary mapping each used variable to a
possible type). If cachekey is given, the query necessary to fetch the
results (but not the results themselves) may be cached using this key.
"""
raise NotImplementedError()
def flying_insert(self, table, session, union, args=None, varmap=None):
"""similar as .syntax_tree_search, but inserts data in the temporary
table (on-the-fly if possible, eg for the system source whose the given
cursor come from). If not possible, inserts all data by calling
.executemany().
"""
res = self.syntax_tree_search(session, union, args, varmap=varmap)
session.pool.source('system')._manual_insert(res, table, session)
# system source don't have to implement the two methods below
def before_entity_insertion(self, session, lid, etype, eid):
"""called by the repository when an eid has been attributed for an
entity stored here but the entity has not been inserted in the system
table yet.
This method must return the an Entity instance representation of this
entity.
"""
entity = self.repo.vreg.etype_class(etype)(session, None)
entity.set_eid(eid)
return entity
def after_entity_insertion(self, session, lid, entity):
"""called by the repository after an entity stored here has been
inserted in the system table.
"""
pass
# read-only sources don't have to implement methods below
def get_extid(self, entity):
"""return the external id for the given newly inserted entity"""
raise NotImplementedError()
def add_entity(self, session, entity):
"""add a new entity to the source"""
raise NotImplementedError()
def update_entity(self, session, entity):
"""update an entity in the source"""
raise NotImplementedError()
def delete_entity(self, session, etype, eid):
"""delete an entity from the source"""
raise NotImplementedError()
def add_relation(self, session, subject, rtype, object):
"""add a relation to the source"""
raise NotImplementedError()
def delete_relation(self, session, subject, rtype, object):
"""delete a relation from the source"""
raise NotImplementedError()
# system source interface #################################################
def eid_type_source(self, session, eid):
"""return a tuple (type, source, extid) for the entity with id <eid>"""
raise NotImplementedError()
def create_eid(self, session):
raise NotImplementedError()
def add_info(self, session, entity, source, extid=None):
"""add type and source info for an eid into the system table"""
raise NotImplementedError()
def delete_info(self, session, eid, etype, uri, extid):
"""delete system information on deletion of an entity by transfering
record from the entities table to the deleted_entities table
"""
raise NotImplementedError()
def fti_unindex_entity(self, session, eid):
"""remove text content for entity with the given eid from the full text
index
"""
raise NotImplementedError()
def fti_index_entity(self, session, entity):
"""add text content of a created/modified entity to the full text index
"""
raise NotImplementedError()
def modified_entities(self, session, etypes, mtime):
"""return a 2-uple:
* list of (etype, eid) of entities of the given types which have been
modified since the given timestamp (actually entities whose full text
index content has changed)
* list of (etype, eid) of entities of the given types which have been
deleted since the given timestamp
"""
raise NotImplementedError()
# sql system source interface #############################################
def sqlexec(self, session, sql, args=None):
"""execute the query and return its result"""
raise NotImplementedError()
def temp_table_def(self, selection, solution, table, basemap):
raise NotImplementedError()
def create_index(self, session, table, column, unique=False):
raise NotImplementedError()
def drop_index(self, session, table, column, unique=False):
raise NotImplementedError()
def create_temp_table(self, session, table, schema):
raise NotImplementedError()
def clean_temp_data(self, session, temptables):
"""remove temporary data, usually associated to temporary tables"""
pass
class TrFunc(object):
"""lower, upper"""
def __init__(self, trname, index, attrname=None):
self._tr = trname.lower()
self.index = index
self.attrname = attrname
def apply(self, resdict):
value = resdict.get(self.attrname)
if value is not None:
return getattr(value, self._tr)()
return None
class GlobTrFunc(TrFunc):
"""count, sum, max, min, avg"""
funcs = {
'count': len,
'sum': sum,
'max': max,
'min': min,
# XXX avg
}
def apply(self, result):
"""have to 'groupby' manually. For instance, if we 'count' for index 1:
>>> self.apply([(1, 2), (3, 4), (1, 5)])
[(1, 7), (3, 4)]
"""
keys, values = [], {}
for row in result:
key = tuple(v for i, v in enumerate(row) if i != self.index)
value = row[self.index]
try:
values[key].append(value)
except KeyError:
keys.append(key)
values[key] = [value]
result = []
trfunc = self.funcs[self._tr]
for key in keys:
row = list(key)
row.insert(self.index, trfunc(values[key]))
result.append(row)
return result
class ConnectionWrapper(object):
def __init__(self, cnx=None):
self.cnx = cnx
def commit(self):
pass
def rollback(self):
pass
def cursor(self):
return None # no actual cursor support
from cubicweb.server import SOURCE_TYPES
def source_adapter(source_config):
adapter_type = source_config['adapter'].lower()
try:
return SOURCE_TYPES[adapter_type]
except KeyError:
raise RuntimeError('Unknown adapter %r' % adapter_type)
def get_source(source_config, global_schema, repo):
"""return a source adapter according to the adapter field in the
source's configuration
"""
return source_adapter(source_config)(repo, global_schema, source_config)