Source code for yarom.dataUser

from rdflib import URIRef, Literal, Graph, Namespace, ConjunctiveGraph
from rdflib.namespace import RDFS, RDF, NamespaceManager
from .configure import Configureable,BadConf
import transaction
from .data import Data
from .rdfUtils import triples_to_bgp

__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): Configureable.__init__(self) 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': # 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 (URIRef, URIRef, 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 (URIRef, URIRef, 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