set 30sec query cache on pyro source, important speedup for pages generating multiple time the same external query
"""Source to query another RQL repository using pyro
:organization: Logilab
:copyright: 2007-2009 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr
"""
__docformat__ = "restructuredtext en"
import threading
from os.path import join
from mx.DateTime import DateTimeFromTicks
from Pyro.errors import PyroError, ConnectionClosedError
from logilab.common.configuration import REQUIRED
from rql.nodes import Constant
from rql.utils import rqlvar_maker
from cubicweb import dbapi, server
from cubicweb import BadConnectionId, UnknownEid, ConnectionError
from cubicweb.cwconfig import register_persistent_options
from cubicweb.server.sources import AbstractSource, ConnectionWrapper, TimedCache
class ReplaceByInOperator:
def __init__(self, eids):
self.eids = eids
class PyroRQLSource(AbstractSource):
"""External repository source, using Pyro connection"""
# boolean telling if modification hooks should be called when something is
# modified in this source
should_call_hooks = False
# boolean telling if the repository should connect to this source during
# migration
connect_for_migration = False
support_entities = None
options = (
# XXX pyro-ns host/port
('pyro-ns-id',
{'type' : 'string',
'default': REQUIRED,
'help': 'identifier of the repository in the pyro name server',
'group': 'pyro-source', 'inputlevel': 0,
}),
('mapping-file',
{'type' : 'string',
'default': REQUIRED,
'help': 'path to a python file with the schema mapping definition',
'group': 'pyro-source', 'inputlevel': 1,
}),
('cubicweb-user',
{'type' : 'string',
'default': REQUIRED,
'help': 'user to use for connection on the distant repository',
'group': 'pyro-source', 'inputlevel': 0,
}),
('cubicweb-password',
{'type' : 'password',
'default': '',
'help': 'user to use for connection on the distant repository',
'group': 'pyro-source', 'inputlevel': 0,
}),
('base-url',
{'type' : 'string',
'default': '',
'help': 'url of the web site for the distant repository, if you want '
'to generate external link to entities from this repository',
'group': 'pyro-source', 'inputlevel': 1,
}),
('pyro-ns-host',
{'type' : 'string',
'default': None,
'help': 'Pyro name server\'s host. If not set, default to the value \
from all_in_one.conf.',
'group': 'pyro-source', 'inputlevel': 1,
}),
('pyro-ns-port',
{'type' : 'int',
'default': None,
'help': 'Pyro name server\'s listening port. If not set, default to \
the value from all_in_one.conf.',
'group': 'pyro-source', 'inputlevel': 1,
}),
('pyro-ns-group',
{'type' : 'string',
'default': None,
'help': 'Pyro name server\'s group where the repository will be \
registered. If not set, default to the value from all_in_one.conf.',
'group': 'pyro-source', 'inputlevel': 1,
}),
('synchronization-interval',
{'type' : 'int',
'default': 5*60,
'help': 'interval between synchronization with the external \
repository (default to 5 minutes).',
'group': 'pyro-source', 'inputlevel': 2,
}),
)
PUBLIC_KEYS = AbstractSource.PUBLIC_KEYS + ('base-url',)
_conn = None
def __init__(self, repo, appschema, source_config, *args, **kwargs):
AbstractSource.__init__(self, repo, appschema, source_config,
*args, **kwargs)
mappingfile = source_config['mapping-file']
if not mappingfile[0] == '/':
mappingfile = join(repo.config.apphome, mappingfile)
mapping = {}
execfile(mappingfile, mapping)
self.support_entities = mapping['support_entities']
self.support_relations = mapping.get('support_relations', {})
self.dont_cross_relations = mapping.get('dont_cross_relations', ())
self.cross_relations = mapping.get('cross_relations', ())
baseurl = source_config.get('base-url')
if baseurl and not baseurl.endswith('/'):
source_config['base-url'] += '/'
self.config = source_config
myoptions = (('%s.latest-update-time' % self.uri,
{'type' : 'int', 'sitewide': True,
'default': 0,
'help': _('timestamp of the latest source synchronization.'),
'group': 'sources',
}),)
register_persistent_options(myoptions)
self._query_cache = TimedCache(30)
def last_update_time(self):
pkey = u'sources.%s.latest-update-time' % self.uri
rql = 'Any V WHERE X is EProperty, X value V, X pkey %(k)s'
session = self.repo.internal_session()
try:
rset = session.execute(rql, {'k': pkey})
if not rset:
# insert it
session.execute('INSERT EProperty X: X pkey %(k)s, X value %(v)s',
{'k': pkey, 'v': u'0'})
session.commit()
timestamp = 0
else:
assert len(rset) == 1
timestamp = int(rset[0][0])
return DateTimeFromTicks(timestamp)
finally:
session.close()
def init(self):
"""method called by the repository once ready to handle request"""
interval = int(self.config.get('synchronization-interval', 5*60))
self.repo.looping_task(interval, self.synchronize)
self.repo.looping_task(self._query_cache.ttl.seconds/10, self._query_cache.clear_expired)
def synchronize(self, mtime=None):
"""synchronize content known by this repository with content in the
external repository
"""
self.info('synchronizing pyro source %s', self.uri)
cnx = self.get_connection()
extrepo = cnx._repo
etypes = self.support_entities.keys()
if mtime is None:
mtime = self.last_update_time()
updatetime, modified, deleted = extrepo.entities_modified_since(etypes,
mtime)
repo = self.repo
session = repo.internal_session()
try:
for etype, extid in modified:
try:
exturi = cnx.describe(extid)[1]
if exturi == 'system' or not exturi in repo.sources_by_uri:
eid = self.extid2eid(extid, etype, session)
rset = session.eid_rset(eid, etype)
entity = rset.get_entity(0, 0)
entity.complete(entity.e_schema.indexable_attributes())
repo.index_entity(session, entity)
except:
self.exception('while updating %s with external id %s of source %s',
etype, extid, self.uri)
continue
for etype, extid in deleted:
try:
eid = self.extid2eid(extid, etype, session, insert=False)
# entity has been deleted from external repository but is not known here
if eid is not None:
repo.delete_info(session, eid)
except:
self.exception('while updating %s with external id %s of source %s',
etype, extid, self.uri)
continue
session.execute('SET X value %(v)s WHERE X pkey %(k)s',
{'k': u'sources.%s.latest-update-time' % self.uri,
'v': unicode(int(updatetime.ticks()))})
session.commit()
finally:
session.close()
def _get_connection(self):
"""open and return a connection to the source"""
nshost = self.config.get('pyro-ns-host') or self.repo.config['pyro-ns-host']
nsport = self.config.get('pyro-ns-port') or self.repo.config['pyro-ns-port']
nsgroup = self.config.get('pyro-ns-group') or self.repo.config['pyro-ns-group']
#cnxprops = ConnectionProperties(cnxtype=self.config['cnx-type'])
return dbapi.connect(database=self.config['pyro-ns-id'],
user=self.config['cubicweb-user'],
password=self.config['cubicweb-password'],
host=nshost, port=nsport, group=nsgroup,
setvreg=False) #cnxprops=cnxprops)
def get_connection(self):
try:
return self._get_connection()
except (ConnectionError, PyroError):
self.critical("can't get connection to source %s", self.uri,
exc_info=1)
return ConnectionWrapper()
def check_connection(self, cnx):
"""check connection validity, return None if the connection is still valid
else a new connection
"""
# we have to transfer manually thread ownership. This can be done safely
# since the pool to which belong the connection is affected to one
# session/thread and can't be called simultaneously
try:
cnx._repo._transferThread(threading.currentThread())
except AttributeError:
# inmemory connection
pass
if not isinstance(cnx, ConnectionWrapper):
try:
cnx.check()
return # ok
except (BadConnectionId, ConnectionClosedError):
pass
# try to reconnect
return self.get_connection()
def syntax_tree_search(self, session, union, args=None, cachekey=None,
varmap=None):
assert not varmap, (varmap, union)
rqlkey = union.as_string(kwargs=args)
try:
results = self._query_cache[rqlkey]
print 'cache hit', rqlkey
except KeyError:
results = self._syntax_tree_search(session, union, args)
print 'cache miss', rqlkey
self._query_cache[rqlkey] = results
return results
def _syntax_tree_search(self, session, union, args):
"""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.
"""
if not args is None:
args = args.copy()
if server.DEBUG:
print 'RQL FOR PYRO SOURCE', self.uri
print union.as_string()
if args: print 'ARGS', args
print 'SOLUTIONS', ','.join(str(s.solutions) for s in union.children)
# get cached cursor anyway
cu = session.pool[self.uri]
if cu is None:
# this is a ConnectionWrapper instance
msg = session._("can't connect to source %s, some data may be missing")
session.set_shared_data('sources_error', msg % self.uri)
return []
try:
rql, cachekey = RQL2RQL(self).generate(session, union, args)
except UnknownEid, ex:
if server.DEBUG:
print 'unknown eid', ex, 'no results'
return []
if server.DEBUG:
print 'TRANSLATED RQL', rql
try:
rset = cu.execute(rql, args, cachekey)
except Exception, ex:
self.exception(str(ex))
msg = session._("error while querying source %s, some data may be missing")
session.set_shared_data('sources_error', msg % self.uri)
return []
descr = rset.description
if rset:
needtranslation = []
rows = rset.rows
for i, etype in enumerate(descr[0]):
if (etype is None or not self.schema.eschema(etype).is_final() or
getattr(union.locate_subquery(i, etype, args).selection[i], 'uidtype', None)):
needtranslation.append(i)
if needtranslation:
cnx = session.pool.connection(self.uri)
for rowindex in xrange(rset.rowcount - 1, -1, -1):
row = rows[rowindex]
for colindex in needtranslation:
if row[colindex] is not None: # optional variable
etype = descr[rowindex][colindex]
exttype, exturi, extid = cnx.describe(row[colindex])
if exturi == 'system' or not exturi in self.repo.sources_by_uri:
eid = self.extid2eid(row[colindex], etype, session)
row[colindex] = eid
else:
# skip this row
del rows[rowindex]
del descr[rowindex]
break
results = rows
else:
results = []
if server.DEBUG:
if len(results)>10:
print '--------------->', results[:10], '...', len(results)
else:
print '--------------->', results
return results
def _entity_relations_and_kwargs(self, session, entity):
relations = []
kwargs = {'x': self.eid2extid(entity.eid, session)}
for key, val in entity.iteritems():
relations.append('X %s %%(%s)s' % (key, key))
kwargs[key] = val
return relations, kwargs
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"""
relations, kwargs = self._entity_relations_and_kwargs(session, entity)
cu = session.pool[self.uri]
cu.execute('SET %s WHERE X eid %%(x)s' % ','.join(relations),
kwargs, 'x')
def delete_entity(self, session, etype, eid):
"""delete an entity from the source"""
cu = session.pool[self.uri]
cu.execute('DELETE %s X WHERE X eid %%(x)s' % etype,
{'x': self.eid2extid(eid, session)}, 'x')
def add_relation(self, session, subject, rtype, object):
"""add a relation to the source"""
cu = session.pool[self.uri]
cu.execute('SET X %s Y WHERE X eid %%(x)s, Y eid %%(y)s' % rtype,
{'x': self.eid2extid(subject, session),
'y': self.eid2extid(object, session)}, ('x', 'y'))
def delete_relation(self, session, subject, rtype, object):
"""delete a relation from the source"""
cu = session.pool[self.uri]
cu.execute('DELETE X %s Y WHERE X eid %%(x)s, Y eid %%(y)s' % rtype,
{'x': self.eid2extid(subject, session),
'y': self.eid2extid(object, session)}, ('x', 'y'))
class RQL2RQL(object):
"""translate a local rql query to be executed on a distant repository"""
def __init__(self, source):
self.source = source
self.current_operator = None
def _accept_children(self, node):
res = []
for child in node.children:
rql = child.accept(self)
if rql is not None:
res.append(rql)
return res
def generate(self, session, rqlst, args):
self._session = session
self.kwargs = args
self.cachekey = []
self.need_translation = False
return self.visit_union(rqlst), self.cachekey
def visit_union(self, node):
s = self._accept_children(node)
if len(s) > 1:
return ' UNION '.join('(%s)' % q for q in s)
return s[0]
def visit_select(self, node):
"""return the tree as an encoded rql string"""
self._varmaker = rqlvar_maker(defined=node.defined_vars.copy())
self._const_var = {}
if node.distinct:
base = 'DISTINCT Any'
else:
base = 'Any'
s = ['%s %s' % (base, ','.join(v.accept(self) for v in node.selection))]
if node.groupby:
s.append('GROUPBY %s' % ', '.join(group.accept(self)
for group in node.groupby))
if node.orderby:
s.append('ORDERBY %s' % ', '.join(self.visit_sortterm(term)
for term in node.orderby))
if node.limit is not None:
s.append('LIMIT %s' % node.limit)
if node.offset:
s.append('OFFSET %s' % node.offset)
restrictions = []
if node.where is not None:
nr = node.where.accept(self)
if nr is not None:
restrictions.append(nr)
if restrictions:
s.append('WHERE %s' % ','.join(restrictions))
if node.having:
s.append('HAVING %s' % ', '.join(term.accept(self)
for term in node.having))
subqueries = []
for subquery in node.with_:
subqueries.append('%s BEING (%s)' % (','.join(ca.name for ca in subquery.aliases),
self.visit_union(subquery.query)))
if subqueries:
s.append('WITH %s' % (','.join(subqueries)))
return ' '.join(s)
def visit_and(self, node):
res = self._accept_children(node)
if res:
return ', '.join(res)
return
def visit_or(self, node):
res = self._accept_children(node)
if len(res) > 1:
return ' OR '.join('(%s)' % rql for rql in res)
elif res:
return res[0]
return
def visit_not(self, node):
rql = node.children[0].accept(self)
if rql:
return 'NOT (%s)' % rql
return
def visit_exists(self, node):
return 'EXISTS(%s)' % node.children[0].accept(self)
def visit_relation(self, node):
try:
if isinstance(node.children[0], Constant):
# simplified rqlst, reintroduce eid relation
try:
restr, lhs = self.process_eid_const(node.children[0])
except UnknownEid:
# can safely skip not relation with an unsupported eid
if node.neged(strict=True):
return
raise
else:
lhs = node.children[0].accept(self)
restr = None
except UnknownEid:
# can safely skip not relation with an unsupported eid
if node.neged(strict=True):
return
# XXX what about optional relation or outer NOT EXISTS()
raise
if node.optional in ('left', 'both'):
lhs += '?'
if node.r_type == 'eid' or not self.source.schema.rschema(node.r_type).is_final():
self.need_translation = True
self.current_operator = node.operator()
if isinstance(node.children[0], Constant):
self.current_etypes = (node.children[0].uidtype,)
else:
self.current_etypes = node.children[0].variable.stinfo['possibletypes']
try:
rhs = node.children[1].accept(self)
except UnknownEid:
# can safely skip not relation with an unsupported eid
if node.neged(strict=True):
return
# XXX what about optional relation or outer NOT EXISTS()
raise
except ReplaceByInOperator, ex:
rhs = 'IN (%s)' % ','.join(str(eid) for eid in ex.eids)
self.need_translation = False
self.current_operator = None
if node.optional in ('right', 'both'):
rhs += '?'
if restr is not None:
return '%s %s %s, %s' % (lhs, node.r_type, rhs, restr)
return '%s %s %s' % (lhs, node.r_type, rhs)
def visit_comparison(self, node):
if node.operator in ('=', 'IS'):
return node.children[0].accept(self)
return '%s %s' % (node.operator.encode(),
node.children[0].accept(self))
def visit_mathexpression(self, node):
return '(%s %s %s)' % (node.children[0].accept(self),
node.operator.encode(),
node.children[1].accept(self))
def visit_function(self, node):
#if node.name == 'IN':
res = []
for child in node.children:
try:
rql = child.accept(self)
except UnknownEid, ex:
continue
res.append(rql)
if not res:
raise ex
return '%s(%s)' % (node.name, ', '.join(res))
def visit_constant(self, node):
if self.need_translation or node.uidtype:
if node.type == 'Int':
return str(self.eid2extid(node.value))
if node.type == 'Substitute':
key = node.value
# ensure we have not yet translated the value...
if not key in self._const_var:
self.kwargs[key] = self.eid2extid(self.kwargs[key])
self.cachekey.append(key)
self._const_var[key] = None
return node.as_string()
def visit_variableref(self, node):
"""get the sql name for a variable reference"""
return node.name
def visit_sortterm(self, node):
if node.asc:
return node.term.accept(self)
return '%s DESC' % node.term.accept(self)
def process_eid_const(self, const):
value = const.eval(self.kwargs)
try:
return None, self._const_var[value]
except:
var = self._varmaker.next()
self.need_translation = True
restr = '%s eid %s' % (var, self.visit_constant(const))
self.need_translation = False
self._const_var[value] = var
return restr, var
def eid2extid(self, eid):
try:
return self.source.eid2extid(eid, self._session)
except UnknownEid:
operator = self.current_operator
if operator is not None and operator != '=':
# deal with query like X eid > 12
#
# The problem is
# that eid order in the external source may differ from the
# local source
#
# So search for all eids from this
# source matching the condition locally and then to replace the
# > 12 branch by IN (eids) (XXX we may have to insert a huge
# number of eids...)
# planner so that
sql = "SELECT extid FROM entities WHERE source='%s' AND type IN (%s) AND eid%s%s"
etypes = ','.join("'%s'" % etype for etype in self.current_etypes)
cu = self._session.system_sql(sql % (self.source.uri, etypes,
operator, eid))
# XXX buggy cu.rowcount which may be zero while there are some
# results
rows = cu.fetchall()
if rows:
raise ReplaceByInOperator((r[0] for r in rows))
raise