[osm/polygons] Using an LRU cache for prepped polygons in the various PolygonIndex subclasses. That way can store less simplified polygons but keep frequently accessed ones (like countries) in memory

scripts/geodata/polygons/reverse_geocode.py

@@ -434,6 +434,9 @@ class QuattroshapesReverseGeocoder(RTreePolygonIndex):
 
     PRIORITIES_FILENAME = 'priorities.json'
 
+    persistent_polygons = True
+    cache_size = 100000
+
     sorted_levels = (COUNTRY,
                      ADMIN1_REGION,
                      ADMIN1,
@@ -648,6 +651,9 @@ class OSMReverseGeocoder(RTreePolygonIndex):
 
     polygon_reader = OSMAdminPolygonReader
 
+    persistent_polygons = True
+    cache_size = 100000
+
     include_property_patterns = set([
         'name',
         'name:*',
@@ -794,11 +800,15 @@ class OSMReverseGeocoder(RTreePolygonIndex):
 
 
 class OSMSubdivisionReverseGeocoder(OSMReverseGeocoder):
+    persistent_polygons = True
+    cache_size = 10000
     polygon_reader = OSMSubdivisionPolygonReader
     include_property_patterns = OSMReverseGeocoder.include_property_patterns | set(['landuse'])
 
 
 class OSMBuildingReverseGeocoder(OSMReverseGeocoder):
+    persistent_polygons = True
+    cache_size = 10000
     polygon_reader = OSMBuildingPolygonReader
     include_property_patterns = OSMReverseGeocoder.include_property_patterns | set(['building', 'building:levels'])