def _query_sources(self, query):
"""
Query all sources and return the results as a single ImageSource.
Multiple sources will be merged into a single image.
"""
# directly return get_map without merge if ...
if (len(self.sources) == 1 and
not self.image_merger and # no special image_merger (like BandMerger)
not (self.sources[0].coverage and # no clipping coverage
self.sources[0].coverage.clip and
self.sources[0].coverage.intersects(query.bbox, query.srs))
):
try:
return self.sources[0].get_map(query)
except BlankImage:
return None
def get_map_from_source(source):
try:
img = source.get_map(query)
except BlankImage:
return None, None
else:
return (img, source.coverage)
layers = []
for layer in async_.imap(get_map_from_source, self.sources):
if layer[0] is not None:
layers.append(layer)
return merge_images(layers, size=query.size, bbox=query.bbox, bbox_srs=query.srs,
image_opts=self.tile_mgr.image_opts, merger=self.image_merger)
def test_map_with_exception(self):
def func(x):
raise Exception()
try:
list(imap(func, list(range(40))))
except Exception:
pass
else:
assert False, 'exception expected'
def test_map(self):
def func(x):
time.sleep(0.05)
return x
start = time.time()
result = list(imap(func, list(range(40))))
stop = time.time()
duration = stop - start
assert duration < 0.5, "took %s" % duration
assert len(result) == 40