def build_indexes(self, index_nodes=True, iterate=False):
next_node_id = 1
coords_node = {}
if self._src is not None:
request = QgsFeatureRequest()
request.FetchAttributes = False
self._edge_map = dict([(f.id(), f)
for f in self._src.getFeatures(request)])
total = len(self._edge_map)
for (i, (fid, feature)) in enumerate(self._edge_map.items(), start=1):
fid = feature.id()
ls = feature.geometry().constGet()
endpoints = []
for point in [ls.startPoint(), ls.endPoint()]:
coords = (point.x(), point.y())
node_id = coords_node.get(coords, None)
if node_id is None:
node_id = next_node_id
next_node_id += 1
coords_node[coords] = node_id
node_feature = self._make_node_feature(node_id, point)
self._node_map[node_id] = node_feature
if index_nodes:
self._node_index.insertFeature(node_feature)
endpoints.append(node_id)
self._node_edges[node_id].add(fid)
self._edge_index.insertFeature(feature)
self._edge_nodes[fid] = endpoints
if iterate:
yield float(i) / total
