[dataimport] add a .schema shortcut attribute on the massive store
also rephrase a bit a method along the way
# coding: utf-8
# copyright 2015-2016 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# This file is part of CubicWeb.
#
# CubicWeb is free software: you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 2.1 of the License, or (at your option)
# any later version.
#
# CubicWeb is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with CubicWeb. If not, see <http://www.gnu.org/licenses/>.
import logging
from datetime import datetime
from collections import defaultdict
from io import StringIO
from itertools import chain
from six.moves import range
import pytz
from yams.constraints import SizeConstraint
from cubicweb.schema import PURE_VIRTUAL_RTYPES
from cubicweb.server.schema2sql import rschema_has_table
from cubicweb.server.sqlutils import SQL_PREFIX
from cubicweb.dataimport import stores, pgstore
from cubicweb.utils import make_uid
class MassiveObjectStore(stores.RQLObjectStore):
"""
Store for massive import of data, with delayed insertion of meta data.
WARNINGS:
- This store may only be used with PostgreSQL for now, as it relies
on the COPY FROM method, and on specific PostgreSQL tables to get all
the indexes.
- This store can only insert relations that are not inlined (i.e.,
which do *not* have inlined=True in their definition in the schema), unless they are
specified as entity attributes.
It should be used as follows:
store = MassiveObjectStore(cnx)
store.init_rtype_table('Person', 'lives_in', 'Location')
...
store.prepare_insert_entity('Person', subj_iid_attribute=person_iid, ...)
store.prepare_insert_entity('Location', obj_iid_attribute=location_iid, ...)
...
# subj_iid_attribute and obj_iid_attribute are argument names
# chosen by the user (e.g. "cwuri"). These names can be identical.
# person_iid and location_iid are unique IDs and depend on the data
# (e.g URI).
store.flush()
store.relate_by_iid(person_iid, 'lives_in', location_iid)
# For example:
store.prepare_insert_entity('Person',
cwuri='http://dbpedia.org/toto',
name='Toto')
store.prepare_insert_entity('Location',
uri='http://geonames.org/11111',
name='Somewhere')
store.flush()
store.relate_by_iid('http://dbpedia.org/toto',
'lives_in',
'http://geonames.org/11111')
# Finally
store.convert_relations('Person', 'lives_in', 'Location',
'subj_iid_attribute', 'obj_iid_attribute')
# For the previous example:
store.convert_relations('Person', 'lives_in', 'Location', 'cwuri', 'uri')
...
store.commit()
store.finish()
"""
# max size of the iid, used to create the iid_eid conversion table
iid_maxsize = 1024
def __init__(self, cnx,
on_commit_callback=None, on_rollback_callback=None,
slave_mode=False,
source=None,
eids_seq_range=10000):
""" Create a MassiveObject store, with the following attributes:
- cnx: CubicWeb cnx
- eids_seq_range: size of eid range reserved by the store for each batch
"""
super(MassiveObjectStore, self).__init__(cnx)
self.on_commit_callback = on_commit_callback
self.on_rollback_callback = on_rollback_callback
self.slave_mode = slave_mode
self.eids_seq_range = eids_seq_range
self.logger = logging.getLogger('dataimport.massive_store')
self.sql = cnx.system_sql
self.schema = self._cnx.vreg.schema
self.default_values = get_default_values(self.schema)
self.get_next_eid = lambda g=self._get_eid_gen(): next(g)
self._dbh = PGHelper(cnx)
cnx.read_security = False
cnx.write_security = False
self._data_uri_relations = defaultdict(list)
self._data_entities = defaultdict(list)
self._data_relations = defaultdict(list)
# etypes for which we have a uri_eid_%(etype)s table
self._init_uri_eid = set()
# etypes for which we have a uri_eid_%(e)s_idx index
self._uri_eid_inserted = set()
# set of rtypes for which we have a %(rtype)s_relation_iid_tmp table
self._uri_rtypes = set()
# set of etypes whose tables are created
self._entities = set()
# set of rtypes for which we have a %(rtype)s_relation_tmp table
self._rtypes = set()
self._now = datetime.now(pytz.utc)
self._default_cwuri = make_uid('_auto_generated')
if not self.slave_mode:
# drop constraint and metadata table, they will be recreated when self.finish() is
# called
self._drop_all_constraints()
self._drop_metatables_constraints()
if source is None:
source = cnx.repo.system_source
self.source = source
self._etype_eid_idx = dict(cnx.execute('Any XN,X WHERE X is CWEType, X name XN'))
# INIT FUNCTIONS ########################################################
def _drop_all_constraints(self):
etypes_tables = ('cw_%s' % eschema.type.lower() for eschema in self.schema.entities()
if not eschema.final)
rtypes_tables = ('%s_relation' % rschema.type.lower() for rschema in self.schema.relations()
if rschema_has_table(rschema, skip_relations=PURE_VIRTUAL_RTYPES))
for tablename in chain(etypes_tables, rtypes_tables, ('entities',)):
self._store_and_drop_constraints(tablename)
def _store_and_drop_constraints(self, tablename):
# Create a table to save the constraints, it allows reloading even after crash
self.sql('CREATE TABLE IF NOT EXISTS cwmassive_constraints'
'(origtable text, query text, type varchar(256))')
constraints = self._dbh.table_constraints(tablename)
for name, query in constraints.items():
self.sql('INSERT INTO cwmassive_constraints VALUES (%(e)s, %(c)s, %(t)s)',
{'e': tablename, 'c': query, 't': 'constraint'})
self.sql('ALTER TABLE %s DROP CONSTRAINT %s' % (tablename, name))
def reapply_all_constraints(self):
if not self._dbh.table_exists('cwmassive_constraints'):
self.logger.info('The table cwmassive_constraints does not exist')
return
cu = self.sql("SELECT query FROM cwmassive_constraints WHERE type='constraint'")
for query, in cu.fetchall():
self.sql(query)
self.sql("DELETE FROM cwmassive_constraints WHERE type='constraint' AND query=%(q)s",
{'q': query})
def init_rtype_table(self, etype_from, rtype, etype_to):
""" Build temporary table for standard rtype """
# Create an uri_eid table for each etype for a better
# control of which etype is concerned by a particular
# possibly multivalued relation.
for etype in (etype_from, etype_to):
if etype and etype not in self._init_uri_eid:
self._init_uri_eid_table(etype)
if rtype not in self._uri_rtypes:
# Create the temporary table
if not self.schema.rschema(rtype).inlined:
self.sql('CREATE TABLE IF NOT EXISTS %(r)s_relation_iid_tmp'
'(uri_from character varying(%(s)s), uri_to character varying(%(s)s))'
% {'r': rtype, 's': self.iid_maxsize})
else:
self.logger.warning("inlined relation %s: cannot insert it", rtype)
# Add it to the initialized set
self._uri_rtypes.add(rtype)
def _init_uri_eid_table(self, etype):
""" Build a temporary table for id/eid convertion
"""
self.sql('CREATE TABLE IF NOT EXISTS uri_eid_%(e)s'
'(uri character varying(%(size)s), eid integer)'
% {'e': etype.lower(), 'size': self.iid_maxsize})
# Add it to the initialized set
self._init_uri_eid.add(etype)
# RELATE FUNCTION #######################################################
def relate_by_iid(self, iid_from, rtype, iid_to):
"""Add new relation based on the internal id (iid)
of the entities (not the eid)"""
# Push data
if isinstance(iid_from, unicode):
iid_from = iid_from.encode('utf-8')
if isinstance(iid_to, unicode):
iid_to = iid_to.encode('utf-8')
self._data_uri_relations[rtype].append({'uri_from': iid_from, 'uri_to': iid_to})
# FLUSH FUNCTIONS #######################################################
def flush_relations(self):
""" Flush the relations data
"""
for rtype, data in self._data_uri_relations.items():
if not data:
self.logger.info('No data for rtype %s', rtype)
buf = StringIO('\n'.join(['%(uri_from)s\t%(uri_to)s' % d for d in data]))
if not buf:
self.logger.info('Empty Buffer for rtype %s', rtype)
continue
cursor = self._cnx.cnxset.cu
if not self.schema.rschema(rtype).inlined:
cursor.copy_from(buf, '%s_relation_iid_tmp' % rtype.lower(),
null='NULL', columns=('uri_from', 'uri_to'))
else:
self.logger.warning("inlined relation %s: cannot insert it", rtype)
buf.close()
# Clear data cache
self._data_uri_relations[rtype] = []
def fill_uri_eid_table(self, etype, uri_label):
""" Fill the uri_eid table
"""
self.logger.info('Fill uri_eid for etype %s', etype)
self.sql('INSERT INTO uri_eid_%(e)s SELECT cw_%(l)s, cw_eid FROM cw_%(e)s'
% {'l': uri_label, 'e': etype.lower()})
# Add indexes
self.sql('CREATE INDEX uri_eid_%(e)s_idx ON uri_eid_%(e)s' '(uri)' % {'e': etype.lower()})
# Set the etype as converted
self._uri_eid_inserted.add(etype)
def convert_relations(self, etype_from, rtype, etype_to,
uri_label_from='cwuri', uri_label_to='cwuri'):
""" Flush the converted relations
"""
# Always flush relations to be sure
self.logger.info('Convert relations %s %s %s', etype_from, rtype, etype_to)
self.flush_relations()
if uri_label_from and etype_from not in self._uri_eid_inserted:
self.fill_uri_eid_table(etype_from, uri_label_from)
if uri_label_to and etype_to not in self._uri_eid_inserted:
self.fill_uri_eid_table(etype_to, uri_label_to)
if self.schema.rschema(rtype).inlined:
self.logger.warning("Can't insert inlined relation %s", rtype)
return
if uri_label_from and uri_label_to:
sql = '''INSERT INTO %(r)s_relation (eid_from, eid_to) SELECT DISTINCT O1.eid, O2.eid
FROM %(r)s_relation_iid_tmp AS T, uri_eid_%(ef)s as O1, uri_eid_%(et)s as O2
WHERE O1.uri=T.uri_from AND O2.uri=T.uri_to AND NOT EXISTS (
SELECT 1 FROM %(r)s_relation AS TT WHERE TT.eid_from=O1.eid AND TT.eid_to=O2.eid);
'''
elif uri_label_to:
sql = '''INSERT INTO %(r)s_relation (eid_from, eid_to) SELECT DISTINCT
CAST(T.uri_from AS INTEGER), O1.eid
FROM %(r)s_relation_iid_tmp AS T, uri_eid_%(et)s as O1
WHERE O1.uri=T.uri_to AND NOT EXISTS (
SELECT 1 FROM %(r)s_relation AS TT WHERE
TT.eid_from=CAST(T.uri_from AS INTEGER) AND TT.eid_to=O1.eid);
'''
elif uri_label_from:
sql = '''INSERT INTO %(r)s_relation (eid_from, eid_to) SELECT DISTINCT O1.eid, T.uri_to
O1.eid, CAST(T.uri_to AS INTEGER)
FROM %(r)s_relation_iid_tmp AS T, uri_eid_%(ef)s as O1
WHERE O1.uri=T.uri_from AND NOT EXISTS (
SELECT 1 FROM %(r)s_relation AS TT WHERE
TT.eid_from=O1.eid AND TT.eid_to=CAST(T.uri_to AS INTEGER));
'''
try:
self.sql(sql % {'r': rtype.lower(),
'et': etype_to.lower() if etype_to else u'',
'ef': etype_from.lower() if etype_from else u''})
except Exception as ex:
self.logger.error("Can't insert relation %s: %s", rtype, ex)
# SQL UTILITIES #########################################################
def drop_and_store_indexes(self, tablename):
"""Drop indexes and constraints"""
# Create a table to save the constraints, it allows reloading even after crash
self.sql('CREATE TABLE IF NOT EXISTS cwmassive_constraints'
'(origtable text, query text, type varchar(256))')
self._drop_table_indexes(tablename)
def _drop_table_indexes(self, tablename):
""" Drop and store table constraints and indexes """
indexes = self._dbh.table_indexes(tablename)
for name, query in indexes.items():
self.sql('INSERT INTO cwmassive_constraints VALUES (%(e)s, %(c)s, %(t)s)',
{'e': tablename, 'c': query, 't': 'index'})
self.sql('DROP INDEX %s' % name)
def reapply_constraint_index(self, tablename):
if not self._dbh.table_exists('cwmassive_constraints'):
self.logger.info('The table cwmassive_constraints does not exist')
return
cu = self.sql('SELECT query FROM cwmassive_constraints WHERE origtable = %(e)s',
{'e': tablename})
for query, in cu.fetchall():
self.sql(query)
self.sql('DELETE FROM cwmassive_constraints WHERE origtable = %(e)s '
'AND query = %(q)s', {'e': tablename, 'q': query})
def _drop_metatables_constraints(self):
""" Drop all the constraints for the meta data"""
for tablename in ('created_by_relation', 'owned_by_relation',
'is_instance_of_relation', 'is_relation',
'entities'):
self.drop_and_store_indexes(tablename)
def _create_metatables_constraints(self):
""" Create all the constraints for the meta data"""
for tablename in ('entities',
'created_by_relation', 'owned_by_relation',
'is_instance_of_relation', 'is_relation'):
# Indexes and constraints
self.reapply_constraint_index(tablename)
def init_relation_table(self, rtype):
""" Get and remove all indexes for performance sake """
# Create temporary table
if not self.slave_mode and rtype not in self._rtypes:
self.sql('CREATE TABLE %s_relation_tmp (eid_from integer, eid_to integer)'
% rtype.lower())
# Drop indexes and constraints
tablename = '%s_relation' % rtype.lower()
self.drop_and_store_indexes(tablename)
# Push the etype in the initialized table for easier restart
self.init_create_initialized_table()
self.sql('INSERT INTO cwmassive_initialized VALUES (%(e)s, %(t)s)',
{'e': rtype, 't': 'rtype'})
# Mark rtype as "initialized" for faster check
self._rtypes.add(rtype)
def init_create_initialized_table(self):
""" Create the cwmassive initialized table
"""
self.sql('CREATE TABLE IF NOT EXISTS cwmassive_initialized'
'(retype text, type varchar(128))')
def init_etype_table(self, etype):
""" Add eid sequence to a particular etype table and
remove all indexes for performance sake """
if etype not in self._entities:
# Only for non-initialized etype and not slave mode store
if not self.slave_mode:
# Drop indexes and constraints
tablename = 'cw_%s' % etype.lower()
self.drop_and_store_indexes(tablename)
# Push the etype in the initialized table for easier restart
self.init_create_initialized_table()
self.sql("INSERT INTO cwmassive_initialized VALUES (%(e)s, 'etype')", {'e': etype})
# Mark etype as "initialized" for faster check
self._entities.add(etype)
def restart_eid_sequence(self, start_eid):
self._cnx.system_sql(self._cnx.repo.system_source.dbhelper.sql_restart_numrange(
'entities_id_seq', initial_value=start_eid))
self._cnx.commit()
# ENTITIES CREATION #####################################################
def _get_eid_gen(self):
""" Function getting the next eid. This is done by preselecting
a given number of eids from the 'entities_id_seq', and then
storing them"""
while True:
last_eid = self._cnx.repo.system_source.create_eid(self._cnx, self.eids_seq_range)
for eid in range(last_eid - self.eids_seq_range + 1, last_eid + 1):
yield eid
def _apply_default_values(self, etype, kwargs):
"""Apply the default values for a given etype, attribute and value."""
default_values = self.default_values[etype]
missing_keys = set(default_values) - set(kwargs)
kwargs.update((key, default_values[key]) for key in missing_keys)
# store api ################################################################
def prepare_insert_entity(self, etype, **kwargs):
"""Given an entity type, attributes and inlined relations, returns the inserted entity's
eid.
"""
# Init the table if necessary
self.init_etype_table(etype)
# Add meta data if not given
if 'modification_date' not in kwargs:
kwargs['modification_date'] = self._now
if 'creation_date' not in kwargs:
kwargs['creation_date'] = self._now
if 'cwuri' not in kwargs:
kwargs['cwuri'] = self._default_cwuri + str(self._count_cwuri)
self._count_cwuri += 1
if 'eid' not in kwargs:
# If eid is not given and the eids sequence is set,
# use the value from the sequence
kwargs['eid'] = self.get_next_eid()
self._apply_default_values(etype, kwargs)
self._data_entities[etype].append(kwargs)
return kwargs.get('eid')
def prepare_insert_relation(self, eid_from, rtype, eid_to, **kwargs):
"""Insert into the database a relation ``rtype`` between entities with eids ``eid_from``
and ``eid_to``.
"""
# Init the table if necessary
self.init_relation_table(rtype)
self._data_relations[rtype].append({'eid_from': eid_from, 'eid_to': eid_to})
def flush(self):
"""Flush the data"""
self.flush_entities()
self.flush_internal_relations()
self.flush_relations()
def commit(self):
"""Commit the database transaction."""
self.on_commit()
super(MassiveObjectStore, self).commit()
def finish(self):
"""Remove temporary tables and columns."""
self.logger.info("Start cleaning")
if self.slave_mode:
raise RuntimeError('Store cleanup is not allowed in slave mode')
self.logger.info("Start cleaning")
# Cleanup relations tables
for etype in self._init_uri_eid:
self.sql('DROP TABLE uri_eid_%s' % etype.lower())
# Remove relations tables
for rtype in self._uri_rtypes:
if not self.schema.rschema(rtype).inlined:
self.sql('DROP TABLE %(r)s_relation_iid_tmp' % {'r': rtype})
else:
self.logger.warning("inlined relation %s: no cleanup to be done for it" % rtype)
# Create meta constraints (entities, is_instance_of, ...)
self._create_metatables_constraints()
# Get all the initialized etypes/rtypes
if self._dbh.table_exists('cwmassive_initialized'):
cu = self.sql('SELECT retype, type FROM cwmassive_initialized')
for retype, _type in cu.fetchall():
self.logger.info('Cleanup for %s' % retype)
if _type == 'etype':
# Cleanup entities tables - Recreate indexes
self._cleanup_entities(retype)
elif _type == 'rtype':
# Cleanup relations tables
self._cleanup_relations(retype)
self.sql('DELETE FROM cwmassive_initialized WHERE retype = %(e)s',
{'e': retype})
self.reapply_all_constraints()
# Delete the meta data table
for table_name in ('cwmassive_initialized', 'cwmassive_constraints', 'cwmassive_metadata'):
self.sql('DROP TABLE IF EXISTS %s' % table_name)
self.commit()
# FLUSH #################################################################
def on_commit(self):
if self.on_commit_callback:
self.on_commit_callback()
def on_rollback(self, exc, etype, data):
if self.on_rollback_callback:
self.on_rollback_callback(exc, etype, data)
self._cnx.rollback()
else:
raise exc
def flush_internal_relations(self):
""" Flush the relations data
"""
for rtype, data in self._data_relations.items():
if not data:
# There is no data for these etype for this flush round.
continue
buf = pgstore._create_copyfrom_buffer(data, ('eid_from', 'eid_to'))
if not buf:
# The buffer is empty. This is probably due to error in _create_copyfrom_buffer
raise ValueError
cursor = self._cnx.cnxset.cu
# Push into the tmp table
cursor.copy_from(buf, '%s_relation_tmp' % rtype.lower(),
null='NULL', columns=('eid_from', 'eid_to'))
# Clear data cache
self._data_relations[rtype] = []
def flush_entities(self):
""" Flush the entities data
"""
for etype, data in self._data_entities.items():
if not data:
# There is no data for these etype for this flush round.
continue
# XXX It may be interresting to directly infer the columns' names from the schema
# XXX For now, the _create_copyfrom_buffer does a "row[column]"
# which can lead to a key error.
# Thus we should create dictionary with all the keys.
columns = set()
for d in data:
columns.update(d.keys())
_data = []
_base_data = dict.fromkeys(columns)
for d in data:
_d = _base_data.copy()
_d.update(d)
_data.append(_d)
buf = pgstore._create_copyfrom_buffer(_data, columns)
if not buf:
# The buffer is empty. This is probably due to error in _create_copyfrom_buffer
raise ValueError('Error in buffer creation for etype %s' % etype)
columns = ['cw_%s' % attr for attr in columns]
cursor = self._cnx.cnxset.cu
try:
cursor.copy_from(buf, 'cw_%s' % etype.lower(), null='NULL', columns=columns)
except Exception as exc:
self.on_rollback(exc, etype, data)
# Clear data cache
self._data_entities[etype] = []
if not self.slave_mode:
self.flush_meta_data()
def flush_meta_data(self):
""" Flush the meta data (entities table, is_instance table, ...)
"""
if self.slave_mode:
raise RuntimeError('Flushing meta data is not allow in slave mode')
if not self._dbh.table_exists('cwmassive_initialized'):
self.logger.info('No information available for initialized etypes/rtypes')
return
# Keep the correctly flush meta data in database
self.sql('CREATE TABLE IF NOT EXISTS cwmassive_metadata (etype text)')
cu = self.sql('SELECT etype FROM cwmassive_metadata')
already_flushed = set(e for e, in cu.fetchall())
cu = self.sql('SELECT retype FROM cwmassive_initialized WHERE type = %(t)s',
{'t': 'etype'})
all_etypes = set(e for e, in cu.fetchall())
for etype in all_etypes:
if etype not in already_flushed:
# Deals with meta data
self.logger.info('Flushing meta data for %s' % etype)
self.insert_massive_meta_data(etype)
self.sql('INSERT INTO cwmassive_metadata VALUES (%(e)s)', {'e': etype})
def _cleanup_entities(self, etype):
""" Cleanup etype table """
# Create indexes and constraints
tablename = SQL_PREFIX + etype.lower()
self.reapply_constraint_index(tablename)
def _cleanup_relations(self, rtype):
""" Cleanup rtype table """
# Push into relation table while removing duplicate
self.sql('INSERT INTO %(r)s_relation (eid_from, eid_to) SELECT DISTINCT '
'T.eid_from, T.eid_to FROM %(r)s_relation_tmp AS T '
'WHERE NOT EXISTS (SELECT 1 FROM %(r)s_relation AS TT WHERE '
'TT.eid_from=T.eid_from AND TT.eid_to=T.eid_to);' % {'r': rtype})
# Drop temporary relation table
self.sql('DROP TABLE %(r)s_relation_tmp' % {'r': rtype.lower()})
# Create indexes and constraints
tablename = '%s_relation' % rtype.lower()
self.reapply_constraint_index(tablename)
def insert_massive_meta_data(self, etype):
""" Massive insertion of meta data for a given etype, based on SQL statements.
"""
# Push data - Use coalesce to avoid NULL (and get 0), if there is no
# entities of this type in the entities table.
# Meta data relations
self.metagen_push_relation(etype, self._cnx.user.eid, 'created_by_relation')
self.metagen_push_relation(etype, self._cnx.user.eid, 'owned_by_relation')
self.metagen_push_relation(etype, self.source.eid, 'cw_source_relation')
self.metagen_push_relation(etype, self._etype_eid_idx[etype], 'is_relation')
self.metagen_push_relation(etype, self._etype_eid_idx[etype], 'is_instance_of_relation')
self.sql("INSERT INTO entities (eid, type, asource, extid) "
"SELECT cw_eid, '%s', 'system', NULL FROM cw_%s "
"WHERE NOT EXISTS (SELECT 1 FROM entities WHERE eid=cw_eid)"
% (etype, etype.lower()))
def metagen_push_relation(self, etype, eid_to, rtype):
self.sql("INSERT INTO %s (eid_from, eid_to) SELECT cw_eid, %s FROM cw_%s "
"WHERE NOT EXISTS (SELECT 1 FROM entities WHERE eid=cw_eid)"
% (rtype, eid_to, etype.lower()))
def get_size_constraints(schema):
"""analyzes yams ``schema`` and returns the list of size constraints.
The returned value is a dictionary mapping entity types to a
sub-dictionnaries mapping attribute names -> max size.
"""
size_constraints = {}
# iterates on all entity types
for eschema in schema.entities():
# for each entity type, iterates on attribute definitions
size_constraints[eschema.type] = eschema_constraints = {}
for rschema, aschema in eschema.attribute_definitions():
# for each attribute, if a size constraint is found,
# append it to the size constraint list
maxsize = None
rdef = rschema.rdef(eschema, aschema)
for constraint in rdef.constraints:
if isinstance(constraint, SizeConstraint):
maxsize = constraint.max
eschema_constraints[rschema.type] = maxsize
return size_constraints
def get_default_values(schema):
"""analyzes yams ``schema`` and returns the list of default values.
The returned value is a dictionary mapping entity types to a
sub-dictionnaries mapping attribute names -> default values.
"""
default_values = {}
# iterates on all entity types
for eschema in schema.entities():
# for each entity type, iterates on attribute definitions
default_values[eschema.type] = eschema_constraints = {}
for rschema, _ in eschema.attribute_definitions():
# for each attribute, if a size constraint is found,
# append it to the size constraint list
if eschema.default(rschema.type) is not None:
eschema_constraints[rschema.type] = eschema.default(rschema.type)
return default_values
class PGHelper(object):
"""This class provides some helper methods to manipulate a postgres database metadata (index and
constraints).
"""
def __init__(self, cnx):
self.sql = cnx.system_sql
# Deals with pg schema, see #3216686
pg_schema = cnx.repo.config.system_source_config.get('db-namespace') or 'public'
self.pg_schema = pg_schema
def table_exists(self, tablename):
"""Return True if the given table already exists in the database."""
cu = self.sql('SELECT 1 from information_schema.tables '
'WHERE table_name=%(t)s AND table_schema=%(s)s',
{'t': tablename, 's': self.pg_schema})
return bool(cu.fetchone())
def table_indexes_constraints(self, tablename):
"""Return one dictionary with all indexes by name, another with all constraints by name,
for the given table.
"""
indexes = self.table_indexes(tablename)
constraints = self.table_constraints(tablename)
_indexes = {}
for name, query in indexes.items():
# Remove pkey indexes (automatically created by constraints)
# Specific cases of primary key, see #3224079
if name not in constraints:
_indexes[name] = query
return _indexes, constraints
def table_indexes(self, tablename):
"""Return a dictionary of indexes {index name: index sql}, constraints included."""
indexes = {}
for name in self._index_names(tablename):
indexes[name] = self._index_sql(name)
return indexes
def table_constraints(self, tablename):
"""Return a dictionary of constraints {constraint name: constraint sql}."""
constraints = {}
for name in self._constraint_names(tablename):
query = self._constraint_sql(name)
constraints[name] = 'ALTER TABLE %s ADD CONSTRAINT %s %s' % (tablename, name, query)
return constraints
def _index_names(self, tablename):
"""Return the names of all indexes in the given table (including constraints.)"""
cu = self.sql("SELECT c.relname FROM pg_catalog.pg_class c "
"JOIN pg_catalog.pg_index i ON i.indexrelid = c.oid "
"JOIN pg_catalog.pg_class c2 ON i.indrelid = c2.oid "
"LEFT JOIN pg_catalog.pg_user u ON u.usesysid = c.relowner "
"LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace "
"WHERE c.relkind IN ('i','') "
" AND c2.relname = %(t)s "
" AND i.indisprimary = FALSE "
" AND n.nspname NOT IN ('pg_catalog', 'pg_toast') "
" AND pg_catalog.pg_table_is_visible(c.oid);", {'t': tablename})
return [name for name, in cu.fetchall()]
def _constraint_names(self, tablename):
"""Return the names of all constraints in the given table."""
cu = self.sql("SELECT i.conname FROM pg_catalog.pg_class c "
"JOIN pg_catalog.pg_constraint i ON i.conrelid = c.oid "
"JOIN pg_catalog.pg_class c2 ON i.conrelid=c2.oid "
"LEFT JOIN pg_catalog.pg_user u ON u.usesysid = c.relowner "
"LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace "
"WHERE c2.relname = %(t)s "
"AND n.nspname NOT IN ('pg_catalog', 'pg_toast') "
"AND pg_catalog.pg_table_is_visible(c.oid)", {'t': tablename})
return [name for name, in cu.fetchall()]
def _index_sql(self, name):
"""Return the SQL to be used to recreate the index of the given name."""
return self.sql('SELECT pg_get_indexdef(c.oid) FROM pg_catalog.pg_class c '
'LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace '
'WHERE c.relname = %(r)s AND n.nspname=%(n)s',
{'r': name, 'n': self.pg_schema}).fetchone()[0]
def _constraint_sql(self, name):
"""Return the SQL to be used to recreate the constraint."""
return self.sql('SELECT pg_get_constraintdef(c.oid) FROM pg_catalog.pg_constraint c '
'LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.connamespace '
'WHERE c.conname = %(r)s AND n.nspname=%(n)s',
{'r': name, 'n': self.pg_schema}).fetchone()[0]