def _load_tiles(self):
# recreate source to assure the source belongs to the new thread, SQLite3 isn't happy about it otherwise
self._source = self._create_source(self.connection())
try:
if can_load_lib():
info("Native decoding supported!!!")
else:
bits = "32"
if sys.maxsize > 2**32:
bits = "64"
info("Native decoding not supported: {}, {}bit", sys.platform,
bits)
self._feature_count = 0
self._all_tiles = []
bounds = self._loading_options["bounds"]
clip_tiles = self._loading_options["clip_tiles"]
max_tiles = self._loading_options["max_tiles"]
layer_filter = self._loading_options["layer_filter"]
info("Tile limit enabled: {}", max_tiles is not None
and max_tiles > 0)
self.cancel_requested = False
self.feature_collections_by_layer_name_and_geotype = {}
self._update_progress(show_dialog=True)
self._clip_tiles_at_tile_bounds = clip_tiles
zoom_level = self._get_clamped_zoom_level()
all_tiles = get_all_tiles(
bounds=bounds,
is_cancel_requested_handler=lambda: self.cancel_requested,
)
tiles_to_load = set()
cached_tiles = []
tiles_to_ignore = set()
source_name = self._source.name()
scheme = self._source.scheme()
for t in all_tiles:
if self.cancel_requested or (max_tiles and
len(cached_tiles) >= max_tiles):
break
decoded_data = get_cache_entry(cache_name=source_name,
zoom_level=zoom_level,
x=t[0],
y=t[1])
if decoded_data:
tile = VectorTile(scheme=scheme,
zoom_level=zoom_level,
x=t[0],
y=t[1])
tile.decoded_data = decoded_data
cached_tiles.append(tile)
tiles_to_ignore.add((tile.column, tile.row))
else:
tiles_to_load.add(t)
remaining_nr_of_tiles = len(tiles_to_load)
if max_tiles:
if len(cached_tiles) + len(tiles_to_load) >= max_tiles:
remaining_nr_of_tiles = clamp(max_tiles -
len(cached_tiles),
low=0)
info("{} tiles in cache. Max. {} will be loaded additionally.",
len(cached_tiles), remaining_nr_of_tiles)
if len(cached_tiles) > 0:
if not self.cancel_requested:
self._process_tiles(cached_tiles, layer_filter)
self._all_tiles.extend(cached_tiles)
debug("Loading data for zoom level '{}' source '{}'", zoom_level,
self._source.name())
if remaining_nr_of_tiles:
tile_data_tuples = self._source.load_tiles(
zoom_level=zoom_level,
tiles_to_load=tiles_to_load,
max_tiles=remaining_nr_of_tiles)
if len(tile_data_tuples) > 0 and not self.cancel_requested:
tiles = self._decode_tiles(tile_data_tuples)
self._process_tiles(tiles, layer_filter)
for t in tiles:
cache_tile(cache_name=source_name,
zoom_level=zoom_level,
x=t.column,
y=t.row,
decoded_data=t.decoded_data)
self._all_tiles.extend(tiles)
self._continue_loading()
except Exception as e:
tb = ""
if traceback:
tb = traceback.format_exc()
critical("An exception occured: {}, {}", e, tb)
self.cancelled.emit()
def _get_clamped_zoom_level(self):
zoom_level = self._loading_options["zoom_level"]
min_zoom = self._source.min_zoom()
max_zoom = self._source.max_zoom()
zoom_level = clamp(zoom_level, low=min_zoom, high=max_zoom)
return zoom_level