def build_inner_query(request, tags):
"""Build an "inner query" -- a query which yields a list of stream
ids (indexes in the stream table). These match the identifiers
used in the reading db, or can be used as part of a join. The
query performs auth checks and will check for the tags specified.
"""
# the inner query builds a list of streams matching all the
# clauses which we can then select from
clauses = []
uuid_clause = "true"
for (k, v) in tags:
if k == 'uuid':
if v != None:
uuid_clause = "s.uuid = %s" % escape_string(v)
continue
if v != None:
clauses.append("hstore(%s, %s)" % (escape_string(k),
escape_string(v)))
else: break
if len(clauses) == 0: clauses = ["hstore(array[]::varchar[])"]
inner_query = """
(SELECT s.id FROM stream s, subscription sub
WHERE s.subscription_id = sub.id AND (%s) AND (%s) AND s.metadata @> (%s))
""" % (build_authcheck(request), uuid_clause, ' || '.join(clauses))
return inner_query, clauses
def render_GET(self, request):
if len(request.prepath) == 2 or \
(len(request.prepath) == 3 and request.prepath[-1] == ''):
d = self.db.runQuery("""
SELECT id, url, resource
FROM subscription sub WHERE """ + build_authcheck(request))
d.addCallback(lambda x: self._done_subs(request, x))
d.addErrback(makeErrback(request))
else:
when = int(time.time()) * 1000
d = self.db.runQuery("""
SELECT m.tagval, s.uuid
FROM subscription sub, stream s, metadata2 m
WHERE """ + build_authcheck(request) + """ AND
tagname = 'Path' AND
m.stream_id = s.id AND
s.subscription_id = sub.id AND
sub.id = %s
""", (int(request.prepath[-1]), ))
d.addCallback(lambda x: self._done_streams(request, x))
d.addErrback(makeErrback(request))
return server.NOT_DONE_YET
