Improve memory load efficiency for shape_availability calculation

atlite/gis.py

@@ -426,15 +426,14 @@ def shape_availability(geometry, excluder):
         Affine transform of the mask.
 
     """
-    exclusions = []
     if not excluder.all_open:
         excluder.open_files()
     assert geometry.crs == excluder.crs
 
     bounds = rio.features.bounds(geometry)
     transform, shape = padded_transform_and_shape(bounds, res=excluder.res)
-    masked = geometry_mask(geometry, shape, transform).astype(int)
-    exclusions.append(masked)
+    masked = geometry_mask(geometry, shape, transform)
+    exclusions = masked
 
     # For the following: 0 is eligible, 1 in excluded
     raster = None
@@ -459,15 +458,15 @@ def shape_availability(geometry, excluder):
             masked_ = ~(masked_).astype(bool)
         if d["buffer"]:
             iterations = int(d["buffer"] / excluder.res) + 1
-            masked_ = dilation(masked_, iterations=iterations).astype(int)
+            masked_ = dilation(masked_, iterations=iterations)
 
-        exclusions.append(masked_.astype(int))
+        exclusions = exclusions | masked_
 
     for d in excluder.geometries:
         masked = ~geometry_mask(d["geometry"], shape, transform, invert=d["invert"])
-        exclusions.append(masked.astype(int))
+        exclusions = exclusions | masked
 
-    return (sum(exclusions) == 0).astype(float), transform
+    return ~exclusions, transform
 
 
 def shape_availability_reprojected(