def __init__(self, db_connection, build_graphs=True):
self.io = StupidIO()
self.id_attributes = {'id':(STATIC_ATTRIBUTE, int), 'addr':(STATIC_ATTRIBUTE, str)}
self.node_env = {}
self.db_connection = db_connection
self.build_graphs = build_graphs
self.id_only_view_spec = StatementParser.parse('''
CREATE VIEW id_only
AS SELECT node.id
FROM parent
FOREACH BUCKET
;
''')
def run_circle_with_nodes(self, nodes):
max_id = len(nodes) - 1
n_count=6
view_def = Template('''
CREATE VIEW circle_neighbours
AS SELECT node.id, node.addr
RANKED lowest(n_count, min(abs(local.id - node.id),
$max_id - abs(local.id - node.id)))
FROM db
WITH local, n_count
;
''').substitute(max_id=max_id)
# FIXME: twisted ...
view_spec = StatementParser.parse(view_def)
for node in nodes:
node_env = self.node_env[node.addr]
spec = ViewSpecification(view_spec,
new_name='circle_neighbours_%010x' % node.id,
new_parents=(node_env['db'].name,))
view = NodeView(spec, node_env['vr'],
local=node, n_count=n_count)
node_env['spec'] = spec
node_env['view'] = view
for node in nodes:
node_env = self.node_env[node.addr]
harvester = BidirectionalGossipHarvester(
node_env['io'], node,
node_env['db'], node_env['vr'], SQLNodeView,
(node_env['spec'], node_env['view'])
)
node_env['harvester'] = harvester
def is_correct(node):
distances = sum( min(abs(nid - view_node.id), max_id - abs(nid - view_node.id))
for view_node in node._view )
return distances <= (n_count ** 2) / 2 # FIXME ...
def is_complete(node):
return len(self.node_env[node.addr]['view']) < n_count
self.run_harvesting(nodes)
def run_chord_with_nodes(self, nodes):
log_nodes = int(math.log(len(nodes), 2))
max_id = len(nodes) - 1
n_count=6
def chord_dist(n1, n2):
dist = n2 - n1
if dist < 0:
dist += max_id + 1
return dist
sql_chord_dist = """
CREATE FUNCTION %%s(integer, integer) RETURNS integer AS '
SELECT CASE WHEN ($2-$1) < 0 THEN %s + ($2-$1) ELSE ($2-$1) END
' LANGUAGE SQL STRICT;
""" % (max_id+1)
for node_env in self.node_env.itervalues():
node_db = node_env['db']
node_db.create_function('dist', sql_chord_dist)
func_def = {'dist' : chord_dist}
view_def = Template('''
CREATE VIEW circle_neighbours
AS SELECT node.id, node.addr
RANKED highest(i+1, dist(local.id, node.id))
FROM db
WITH local
HAVING dist(local.id, node.id) in (2^i : 2^(i+1))
FOREACH i IN (0:$log_nodes)
;
''').substitute(log_nodes=log_nodes)
view_spec = StatementParser.parse(view_def)
deferreds = []
for node in nodes:
node_env = self.node_env[node.addr]
node_db = node_env['db']
view_reg = node_env['vr']
spec = ViewSpecification(view_spec, func_def,
new_name='circle_neighbours_%010x' % node.id,
new_parents=(node_db.name,))
node_env['spec'] = spec
deferred = node_db.create_view(spec, view_reg)
deferreds.append(deferred)
def is_correct(node):
node_env = self.node_env[node.addr]
view = node_env['view']
deferred = view.iterBuckets()
nid = node.id
def bucket_test(buckets):
for (i,), bucket in buckets:
if len(bucket) == 0:
return False
id_range = xrange(2**i, 2**(i+1))
for neighbour in bucket:
if chord_dist(nid, neighbour.id) not in id_range:
return False
return True
deferred.addCallback(bucket_test)
return deferred
def is_complete(node):
node_env = self.node_env[node.addr]
view = node_env['view']
deferred = view.iterBuckets()
def bucket_test(buckets):
bucket_count = 0
for (i,), bucket in buckets:
bucket_count += 1
if len(bucket) < i:
return False
return bucket_count > 0
deferred.addCallback(bucket_test)
return deferred
deferred_list = defer.DeferredList(deferreds)
deferred_list.addCallback(self._unpack_list)
deferred_list.addCallback(self.build_harvesters, nodes, is_correct, is_complete)
return deferred_list