Source code for yarom.dataUser

from rdflib import Graph, Namespace
from rdflib.namespace import RDF, NamespaceManager
import logging
from .configure import Configureable
from .data import Data
from .rdfUtils import triples_to_bgp

L = logging.getLogger(__name__)

__all__ = ["DataUser"]

[docs]class DataUser(Configureable): """ A convenience wrapper for users of the database Classes which use the database should inherit from DataUser. """ # TODO: Make these metadata accessible for configuration managers # TODO: Illustrate how setting variables in a config file translates into these configurations configuration_variables = { "rdf.namespace" : { "description" : "The base namespace for user objects and information.", "type" : Namespace, "directly_configureable" : True }, "" : { "description" : "Influences how statements are added to the graph.", "type" : str, "directly_configureable" : True }, "rdf.graph" : { "description" : "The rdflib graph object used for querying and storage of user objects and information.", "type" : Graph }, "rdf.namespace_manager" : { "description" : "The namespace manager associated with the rdf.graph. Stores prefixes that get used by yarom", "type" : NamespaceManager } } def __init__(self, **kwargs): super(DataUser, self).__init__(**kwargs) if not isinstance(self.conf, Data): Configureable.setConf(Data()) @property def base_namespace(self): return self.conf['rdf.namespace'] @base_namespace.setter def base_namespace(self, value): self.conf['rdf.namespace'] = value @property def rdf(self): return self.conf['rdf.graph'] @rdf.setter def rdf(self, value): self.conf['rdf.graph'] = value @property def namespace_manager(self): return self.conf['rdf.namespace_manager'] def _remove_from_store(self, g): # Note the assymetry with _add_to_store. You must add actual elements, but deletes # can be performed as a query for group in grouper(g, 1000): temp_graph = Graph() for x in group: if x is not None: temp_graph.add(x) else: break s = " DELETE DATA {" + temp_graph.serialize(format="nt") + " } " L.debug("deleting. s = " + s) self.conf['rdf.graph'].update(s) def _add_to_store(self, g, graph_name=False): if self.conf[''] == 'SPARQLUpdateStore': # XXX With Sesame, for instance, it is probably faster to do a PUT with over # the endpoint's rest interface. Just need to do it for some common endpoints try: gs = g.serialize(format="nt") except: gs = triples_to_bgp(g) if graph_name: s = " INSERT DATA { GRAPH "+graph_name.n3()+" {" + gs + " } } " else: s = " INSERT DATA { " + gs + " } " L.debug("update query = " + s) self.conf['rdf.graph'].update(s) else: gr = self.conf['rdf.graph'] for x in g: gr.add(x) if self.conf.get('rdf.inference', False): self.conf['fuxi.infer_func'](gr, g) if self.conf['rdf.source'] == 'ZODB': import transaction # Commit the current commit transaction.commit() # Fire off a new one transaction.begin()
[docs] def retract_statements(self, statements): """ Remove a set of statements from the database. Parameters ---------- triples : iter of (:class:`rdflib.term.URIRef`, :class:`rdflib.term.URIRef`, :class:`rdflib.term.URIRef`) A set of triples to remove """ for x in statements: self.rdf.remove(x)
def _remove_from_store_by_query(self, q): import logging as L s = " DELETE WHERE {" + q + " } " L.debug("deleting. s = " + s) self.conf['rdf.graph'].update(s)
[docs] def add_statements(self, graph): """ Add a set of statements to the database. Annotates the addition with uploader name, etc Parameters ---------- triples : iter of (:class:`rdflib.term.URIRef`, :class:`rdflib.term.URIRef`, :class:`rdflib.term.URIRef`) A set of triples to add to the graph """ self._add_to_store(graph)
def _reify(self,g,s): """ Add a statement object to g that binds to s """ n = self.conf['new_graph_uri'](s) g.add((n, RDF['type'], RDF['Statement'])) g.add((n, RDF['subject'], s[0])) g.add((n, RDF['predicate'], s[1])) g.add((n, RDF['object'], s[2])) return n
def grouper(iterable, n, fillvalue=None): """Collect data into fixed-length chunks or blocks""" # grouper('ABCDEFG', 3, 'x') --> ABC DEF Gxx args = [iter(iterable)] * n while True: l = [] try: for x in args: l.append(next(x)) except: pass yield l if len(l) < n: break