def get_fragment_graph(fid):
if not r.sismember('{}:fragments'.format(AGENT_ID), fid):
raise NotFound('The fragment {} does not exist'.format(fid))
lock = fragment_lock(fid)
lock.acquire()
try:
response = make_response(fragment_graph(fid).serialize(format='turtle'))
response.headers['Content-Type'] = 'text/turtle'
finally:
lock.release()
return response
def get_fragment(**kwargs):
fid = kwargs['id']
lock = fragment_lock(fid)
lock.acquire()
try:
updated = r.get('{}:fragments:{}:updated'.format(AGENT_ID, fid))
if updated:
kwargs['last_updated'] = updated
kwargs['triples'] = len(fragment_graph(fid))
pulling = r.get('{}:fragments:{}:pulling'.format(AGENT_ID, fid))
kwargs['pulling'] = False if pulling is None else eval(pulling)
return kwargs
finally:
lock.release()
def _query(fid, gp):
"""
Query the fragment using the original request graph pattern
:param gp:
:param fid:
:return: The query result
"""
def __build_query_from(x, depth=0):
def build_pattern_query((u, v, data)):
return '\nOPTIONAL { %s %s %s %s }' % (u, data['predicate'], v, __build_query_from(v, depth + 1))
out_edges = list(gp_graph.out_edges_iter(x, data=True))
out_edges = reversed(sorted(out_edges, key=lambda x: gp_graph.out_degree))
if out_edges:
return ' '.join([build_pattern_query(x) for x in out_edges])
return ''
gp_parts = [tp_parts(tp) for tp in gp]
blocks = []
gp_graph = nx.DiGraph()
for gp_part in gp_parts:
gp_graph.add_edge(gp_part[0], gp_part[2], predicate=gp_part[1])
roots = filter(lambda x: gp_graph.in_degree(x) == 0, gp_graph.nodes())
blocks += ['%s a stoa:Root\nOPTIONAL { %s }' % (root, __build_query_from(root)) for root in roots]
where_gp = ' .\n'.join(blocks)
q = """SELECT DISTINCT * WHERE { %s }""" % where_gp
result = []
try:
log.info('Querying fragment {}:\n{}'.format(fid, q))
result = fragment_graph(fid).query(q)
except Exception as e: # ParseException from query
traceback.print_exc()
log.warning(e.message)
return result
