"""Repository users' and internal' sessions.
:organization: Logilab
:copyright: 2001-2009 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.
:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses
"""
__docformat__ = "restructuredtext en"
import sys
import threading
from time import time
from logilab.common.deprecation import obsolete
from rql.nodes import VariableRef, Function, ETYPE_PYOBJ_MAP, etype_from_pyobj
from yams import BASE_TYPES
from cubicweb import RequestSessionMixIn, Binary, UnknownEid
from cubicweb.dbapi import ConnectionProperties
from cubicweb.utils import make_uid
from cubicweb.server.rqlrewrite import RQLRewriter
ETYPE_PYOBJ_MAP[Binary] = 'Bytes'
def is_final(rqlst, variable, args):
# try to find if this is a final var or not
for select in rqlst.children:
for sol in select.solutions:
etype = variable.get_type(sol, args)
if etype is None:
continue
if etype in BASE_TYPES:
return True
return False
def _make_description(selected, args, solution):
"""return a description for a result set"""
description = []
for term in selected:
description.append(term.get_type(solution, args))
return description
from rql import stmts
assert hasattr(stmts.Union, 'get_variable_variables'), "You need RQL > 0.18.3"
class Session(RequestSessionMixIn):
"""tie session id, user, connections pool and other session data all
together
"""
def __init__(self, user, repo, cnxprops=None, _id=None):
super(Session, self).__init__(repo.vreg)
self.id = _id or make_uid(user.login.encode('UTF8'))
cnxprops = cnxprops or ConnectionProperties('inmemory')
self.user = user
self.repo = repo
self.cnxtype = cnxprops.cnxtype
self.creation = time()
self.timestamp = self.creation
self.is_internal_session = False
self.is_super_session = False
# short cut to querier .execute method
self._execute = repo.querier.execute
# shared data, used to communicate extra information between the client
# and the rql server
self.data = {}
# i18n initialization
self.set_language(cnxprops.lang)
# internals
self._threaddata = threading.local()
self._threads_in_transaction = set()
self._closed = False
def __str__(self):
return '<%ssession %s (%s 0x%x)>' % (self.cnxtype, self.user.login,
self.id, id(self))
# resource accessors ######################################################
def actual_session(self):
"""return the original parent session if any, else self"""
return self
def etype_class(self, etype):
"""return an entity class for the given entity type"""
return self.vreg.etype_class(etype)
def system_sql(self, sql, args=None):
"""return a sql cursor on the system database"""
if not sql.split(None, 1)[0].upper() == 'SELECT':
self.mode = 'write'
return self.pool.source('system').doexec(self, sql, args)
def set_language(self, language):
"""i18n configuration for translation"""
vreg = self.vreg
language = language or self.user.property_value('ui.language')
try:
self._ = self.__ = vreg.config.translations[language]
except KeyError:
language = vreg.property_value('ui.language')
try:
self._ = self.__ = vreg.config.translations[language]
except KeyError:
self._ = self.__ = unicode
self.lang = language
def change_property(self, prop, value):
assert prop == 'lang' # this is the only one changeable property for now
self.set_language(value)
# connection management ###################################################
def get_mode(self):
return getattr(self._threaddata, 'mode', 'read')
def set_mode(self, value):
self._threaddata.mode = value
mode = property(get_mode, set_mode,
doc='transaction mode (read/write), resetted to read on '
'commit / rollback')
def get_commit_state(self):
return getattr(self._threaddata, 'commit_state', None)
def set_commit_state(self, value):
self._threaddata.commit_state = value
commit_state = property(get_commit_state, set_commit_state)
@property
def pool(self):
"""connections pool, set according to transaction mode for each query"""
return getattr(self._threaddata, 'pool', None)
def set_pool(self):
"""the session need a pool to execute some queries"""
if self._closed:
raise Exception('try to set pool on a closed session')
if self.pool is None:
# get pool first to avoid race-condition
self._threaddata.pool = pool = self.repo._get_pool()
try:
pool.pool_set()
except:
self._threaddata.pool = None
self.repo._free_pool(pool)
raise
self._threads_in_transaction.add(threading.currentThread())
return self._threaddata.pool
def reset_pool(self):
"""the session is no longer using its pool, at least for some time"""
# pool may be none if no operation has been done since last commit
# or rollback
if self.pool is not None and self.mode == 'read':
# even in read mode, we must release the current transaction
pool = self.pool
try:
self._threads_in_transaction.remove(threading.currentThread())
except KeyError:
pass
pool.pool_reset()
self._threaddata.pool = None
# free pool once everything is done to avoid race-condition
self.repo._free_pool(pool)
def _touch(self):
"""update latest session usage timestamp and reset mode to read"""
self.timestamp = time()
self.local_perm_cache.clear()
self._threaddata.mode = 'read'
# shared data handling ###################################################
def get_shared_data(self, key, default=None, pop=False):
"""return value associated to `key` in session data"""
if pop:
return self.data.pop(key, default)
else:
return self.data.get(key, default)
def set_shared_data(self, key, value, querydata=False):
"""set value associated to `key` in session data"""
if querydata:
self.transaction_data[key] = value
else:
self.data[key] = value
# request interface #######################################################
def set_entity_cache(self, entity):
# no entity cache in the server, too high risk of inconsistency
# between pre/post hooks
pass
def entity_cache(self, eid):
raise KeyError(eid)
def base_url(self):
return self.repo.config['base-url'] or u''
def from_controller(self):
"""return the id (string) of the controller issuing the request (no
sense here, always return 'view')
"""
return 'view'
def source_defs(self):
return self.repo.source_defs()
def describe(self, eid):
"""return a tuple (type, sourceuri, extid) for the entity with id <eid>"""
return self.repo.type_and_source_from_eid(eid, self)
# db-api like interface ###################################################
def source_from_eid(self, eid):
"""return the source where the entity with id <eid> is located"""
return self.repo.source_from_eid(eid, self)
def decorate_rset(self, rset, propagate=False):
rset.vreg = self.vreg
rset.req = propagate and self or self.actual_session()
return rset
@property
def super_session(self):
try:
csession = self._threaddata.childsession
except AttributeError:
if self.is_super_session:
csession = self
else:
csession = ChildSession(self)
self._threaddata.childsession = csession
# need shared pool set
self.set_pool()
return csession
def unsafe_execute(self, rql, kwargs=None, eid_key=None, build_descr=False,
propagate=False):
"""like .execute but with security checking disabled (this method is
internal to the server, it's not part of the db-api)
if `propagate` is true, the super_session will be attached to the result
set instead of the parent session, hence further query done through
entities fetched from this result set will bypass security as well
"""
return self.super_session.execute(rql, kwargs, eid_key, build_descr,
propagate)
@property
def cursor(self):
"""return a rql cursor"""
return self
def execute(self, rql, kwargs=None, eid_key=None, build_descr=True,
propagate=False):
"""db-api like method directly linked to the querier execute method
Becare that unlike actual cursor.execute, `build_descr` default to
false
"""
rset = self._execute(self, rql, kwargs, eid_key, build_descr)
return self.decorate_rset(rset, propagate)
def commit(self, reset_pool=True):
"""commit the current session's transaction"""
if self.pool is None:
assert not self.pending_operations
self.transaction_data.clear()
self._touch()
self.debug('commit session %s done (no db activity)', self.id)
return
if self.commit_state:
return
# on rollback, an operation should have the following state
# information:
# - processed by the precommit/commit event or not
# - if processed, is it the failed operation
try:
for trstate in ('precommit', 'commit'):
processed = []
self.commit_state = trstate
try:
while self.pending_operations:
operation = self.pending_operations.pop(0)
operation.processed = trstate
processed.append(operation)
operation.handle_event('%s_event' % trstate)
self.pending_operations[:] = processed
self.debug('%s session %s done', trstate, self.id)
except:
self.exception('error while %sing', trstate)
operation.failed = True
for operation in processed:
operation.handle_event('revert%s_event' % trstate)
self.rollback(reset_pool)
raise
self.pool.commit()
finally:
self._touch()
self.commit_state = None
self.pending_operations[:] = []
self.transaction_data.clear()
if reset_pool:
self.reset_pool()
def rollback(self, reset_pool=True):
"""rollback the current session's transaction"""
if self.pool is None:
assert not self.pending_operations
self.transaction_data.clear()
self._touch()
self.debug('rollback session %s done (no db activity)', self.id)
return
try:
while self.pending_operations:
try:
operation = self.pending_operations.pop(0)
operation.handle_event('rollback_event')
except:
self.critical('rollback error', exc_info=sys.exc_info())
continue
self.pool.rollback()
self.debug('rollback for session %s done', self.id)
finally:
self._touch()
self.pending_operations[:] = []
self.transaction_data.clear()
if reset_pool:
self.reset_pool()
def close(self):
"""do not close pool on session close, since they are shared now"""
self._closed = True
# copy since _threads_in_transaction maybe modified while waiting
for thread in self._threads_in_transaction.copy():
if thread is threading.currentThread():
continue
self.info('waiting for thread %s', thread)
# do this loop/break instead of a simple join(10) in case thread is
# the main thread (in which case it will be removed from
# self._threads_in_transaction but still be alive...)
for i in xrange(10):
thread.join(1)
if not (thread.isAlive() and
thread in self._threads_in_transaction):
break
else:
self.error('thread %s still alive after 10 seconds, will close '
'session anyway', thread)
self.rollback()
# transaction data/operations management ##################################
@property
def transaction_data(self):
try:
return self._threaddata.transaction_data
except AttributeError:
self._threaddata.transaction_data = {}
return self._threaddata.transaction_data
@property
def pending_operations(self):
try:
return self._threaddata.pending_operations
except AttributeError:
self._threaddata.pending_operations = []
return self._threaddata.pending_operations
def add_operation(self, operation, index=None):
"""add an observer"""
assert self.commit_state != 'commit'
if index is not None:
self.pending_operations.insert(index, operation)
else:
self.pending_operations.append(operation)
# querier helpers #########################################################
@property
def rql_rewriter(self):
try:
return self._threaddata._rewriter
except AttributeError:
self._threaddata._rewriter = RQLRewriter(self.repo.querier, self)
return self._threaddata._rewriter
def build_description(self, rqlst, args, result):
"""build a description for a given result"""
if len(rqlst.children) == 1 and len(rqlst.children[0].solutions) == 1:
# easy, all lines are identical
selected = rqlst.children[0].selection
solution = rqlst.children[0].solutions[0]
description = _make_description(selected, args, solution)
return [tuple(description)] * len(result)
# hard, delegate the work :o)
return self.manual_build_descr(rqlst, args, result)
def manual_build_descr(self, rqlst, args, result):
"""build a description for a given result by analysing each row
XXX could probably be done more efficiently during execution of query
"""
# not so easy, looks for variable which changes from one solution
# to another
unstables = rqlst.get_variable_variables()
basedescription = []
todetermine = []
selected = rqlst.children[0].selection # sample selection
for i, term in enumerate(selected):
if isinstance(term, Function) and term.descr().rtype is not None:
basedescription.append(term.get_type(term.descr().rtype, args))
continue
for vref in term.get_nodes(VariableRef):
if vref.name in unstables:
basedescription.append(None)
todetermine.append( (i, is_final(rqlst, vref.variable, args)) )
break
else:
# sample etype
etype = rqlst.children[0].solutions[0]
basedescription.append(term.get_type(etype, args))
if not todetermine:
return [tuple(basedescription)] * len(result)
return self._build_descr(result, basedescription, todetermine)
def _build_descr(self, result, basedescription, todetermine):
description = []
etype_from_eid = self.describe
for row in result:
row_descr = basedescription
for index, isfinal in todetermine:
value = row[index]
if value is None:
# None value inserted by an outer join, no type
row_descr[index] = None
continue
if isfinal:
row_descr[index] = etype_from_pyobj(value)
else:
try:
row_descr[index] = etype_from_eid(value)[0]
except UnknownEid:
self.critical('wrong eid %s in repository, should check database' % value)
row_descr[index] = row[index] = None
description.append(tuple(row_descr))
return description
@obsolete('use direct access to session.transaction_data')
def query_data(self, key, default=None, setdefault=False, pop=False):
if setdefault:
assert not pop
return self.transaction_data.setdefault(key, default)
if pop:
return self.transaction_data.pop(key, default)
else:
return self.transaction_data.get(key, default)
@obsolete('use entity_from_eid(eid, etype=None)')
def entity(self, eid):
"""return a result set for the given eid"""
return self.eid_rset(eid).get_entity(0, 0)
class ChildSession(Session):
"""child (or internal) session are used to hijack the security system
"""
cnxtype = 'inmemory'
def __init__(self, parent_session):
self.id = None
self.is_internal_session = False
self.is_super_session = True
# session which has created this one
self.parent_session = parent_session
self.user = InternalManager()
self.repo = parent_session.repo
self.vreg = parent_session.vreg
self.data = parent_session.data
self.encoding = parent_session.encoding
self.lang = parent_session.lang
self._ = self.__ = parent_session._
# short cut to querier .execute method
self._execute = self.repo.querier.execute
@property
def super_session(self):
return self
def get_mode(self):
return self.parent_session.mode
def set_mode(self, value):
self.parent_session.set_mode(value)
mode = property(get_mode, set_mode)
def get_commit_state(self):
return self.parent_session.commit_state
def set_commit_state(self, value):
self.parent_session.set_commit_state(value)
commit_state = property(get_commit_state, set_commit_state)
@property
def pool(self):
return self.parent_session.pool
@property
def pending_operations(self):
return self.parent_session.pending_operations
@property
def transaction_data(self):
return self.parent_session.transaction_data
def set_pool(self):
"""the session need a pool to execute some queries"""
self.parent_session.set_pool()
def reset_pool(self):
"""the session has no longer using its pool, at least for some time
"""
self.parent_session.reset_pool()
def actual_session(self):
"""return the original parent session if any, else self"""
return self.parent_session
def commit(self, reset_pool=True):
"""commit the current session's transaction"""
self.parent_session.commit(reset_pool)
def rollback(self, reset_pool=True):
"""rollback the current session's transaction"""
self.parent_session.rollback(reset_pool)
def close(self):
"""do not close pool on session close, since they are shared now"""
self.rollback()
def user_data(self):
"""returns a dictionnary with this user's information"""
return self.parent_session.user_data()
class InternalSession(Session):
"""special session created internaly by the repository"""
def __init__(self, repo, cnxprops=None):
super(InternalSession, self).__init__(_IMANAGER, repo, cnxprops,
_id='internal')
self.cnxtype = 'inmemory'
self.is_internal_session = True
self.is_super_session = True
@property
def super_session(self):
return self
class InternalManager(object):
"""a manager user with all access rights used internally for task such as
bootstrapping the repository or creating regular users according to
repository content
"""
def __init__(self):
self.eid = -1
self.login = u'__internal_manager__'
self.properties = {}
def matching_groups(self, groups):
return 1
def is_in_group(self, group):
return True
def owns(self, eid):
return True
def has_permission(self, pname, contexteid=None):
return True
def property_value(self, key):
if key == 'ui.language':
return 'en'
return None
_IMANAGER = InternalManager()
from logging import getLogger
from cubicweb import set_log_methods
set_log_methods(Session, getLogger('cubicweb.session'))