[repository] #1460066: backport datafeed cube as cubicweb source
* add some attributes to CWSource to handle this kind of source
(not natural to put everything in 'config' string). Adding a CWSource
subclass has been attempted then rollbacked because it adds pain
to handle multi-sources planning and it introduce an ambiguity on
a generic relation (cw_source), which may be a penalty in multiple
case
* data feed sources are a new kind of source, namely 'copy based',
which have no effect on the query planner
* a data feed source is associated to a list of url and a parser (appobjects
in the 'parsers' registry
* entities imported by a data feed have cwuri set to their url on the distant
site, their cw_source relation point to the data feed source, though their
source stored in the entities table (returned by cw_metainformation) is their
physical source, hence 'system'
for rtype in ('cw_support', 'cw_dont_cross', 'cw_may_cross'):
drop_relation_type(rtype)
add_entity_type('CWSourceSchemaConfig')
if not 'url' in schema['CWSource'].subjrels:
add_attribute('CWSource', 'url')
add_attribute('CWSource', 'parser')
add_attribute('CWSource', 'latest_retrieval')
try:
from cubicweb.server.sources.pyrorql import PyroRQLSource
except ImportError:
pass
else:
from os.path import join
# function to read old python mapping file
def load_mapping_file(source):
mappingfile = source.config['mapping-file']
mappingfile = join(source.repo.config.apphome, mappingfile)
mapping = {}
execfile(mappingfile, mapping)
for junk in ('__builtins__', '__doc__'):
mapping.pop(junk, None)
mapping.setdefault('support_relations', {})
mapping.setdefault('dont_cross_relations', set())
mapping.setdefault('cross_relations', set())
# do some basic checks of the mapping content
assert 'support_entities' in mapping, \
'mapping file should at least define support_entities'
assert isinstance(mapping['support_entities'], dict)
assert isinstance(mapping['support_relations'], dict)
assert isinstance(mapping['dont_cross_relations'], set)
assert isinstance(mapping['cross_relations'], set)
unknown = set(mapping) - set( ('support_entities', 'support_relations',
'dont_cross_relations', 'cross_relations') )
assert not unknown, 'unknown mapping attribute(s): %s' % unknown
# relations that are necessarily not crossed
for rtype in ('is', 'is_instance_of', 'cw_source'):
assert rtype not in mapping['dont_cross_relations'], \
'%s relation should not be in dont_cross_relations' % rtype
assert rtype not in mapping['support_relations'], \
'%s relation should not be in support_relations' % rtype
return mapping
# for now, only pyrorql sources have a mapping
for source in repo.sources_by_uri.values():
if not isinstance(source, PyroRQLSource):
continue
sourceentity = session.entity_from_eid(source.eid)
mapping = load_mapping_file(source)
# write mapping as entities
print 'migrating map for', source
for etype, write in mapping['support_entities'].items():
create_entity('CWSourceSchemaConfig',
cw_for_source=sourceentity,
cw_schema=session.entity_from_eid(schema[etype].eid),
options=write and u'write' or None,
ask_confirm=False)
for rtype, write in mapping['support_relations'].items():
options = []
if write:
options.append(u'write')
if rtype in mapping['cross_relations']:
options.append(u'maycross')
create_entity('CWSourceSchemaConfig',
cw_for_source=sourceentity,
cw_schema=session.entity_from_eid(schema[rtype].eid),
options=u':'.join(options) or None,
ask_confirm=False)
for rtype in mapping['dont_cross_relations']:
create_entity('CWSourceSchemaConfig',
cw_for_source=source,
cw_schema=session.entity_from_eid(schema[etype].eid),
options=u'dontcross')