Add support for ipv4 prefixes under 16

ipapi.py

@@ -23,7 +23,8 @@ parser.add_argument("--log-level", default = "INFO", help = "the log level use f
 parser.add_argument("-l", "--limit", default = 3600, type = int, help = "the number of requests per hour to limit usage of the api to (default: %(default)s)")
 parser.add_argument("-r", "--raws", help = "the path containing raw tile data (default: %(default)s)")
 parser.add_argument("-t", "--tile-size", default = 256, type = int, help = "the tile size to use (default: %(default)s)")
-parser.add_argument("-c", "--cache-size", default = 4096, type = int, help = "the number of tiles to keep in the cache (default: %(default)s)")
+parser.add_argument("-c", "--cache-size", default = 4096, type = int, help = "the number of compressed tiles to keep in the cache (default: %(default)s)")
+parser.add_argument("-d", "--decomp-cache-size", default = 1024, type = int, help = "the number of decompressed tiles to keep in the cache (default: %(default)s)")
 parser.add_argument("-v", "--variants", default = "density,rtt", help = "the variants to return data for (default: %(default)s)")
 args = parser.parse_args()
 
@@ -94,9 +95,15 @@ if args.raws:
     data_bytes = 4
     
     @lru_cache(args.cache_size)
-    def get_raw_data(path: Path):
+    def get_raw_data_compressed(path: Path):
         print(f"reading file '{path}'...")
-        return decompress(path.read_bytes())
+        return path.read_bytes()
+    
+    @lru_cache(args.decomp_cache_size)
+    def get_raw_data(path: Path):
+        compressed_data = get_raw_data_compressed(path)
+        print(f"decompressing file '{path}'...")
+        return decompress(compressed_data)
     
     @app.get("/api/scandata/:date/:variant/tile/:z/:y/:x")
     def get_info_tile(request: Request):
@@ -106,19 +113,27 @@ if args.raws:
         variant = unquote(request.path_params["variant"])
         if variant not in variants_set:
             return error_response("Invalid variant provided", 400)
+        try:
             z = int(unquote(request.path_params["z"]))
-        if z < 0:
+        except ValueError:
             return error_response("Invalid z value provided", 400)
+        try:
             y = int(unquote(request.path_params["y"]))
             if y < 0:
+                raise ValueError()
+        except ValueError:
             return error_response("Invalid y value provided", 400)
+        try:
             x = int(unquote(request.path_params["x"]))
             if x < 0:
+                raise ValueError()
+        except ValueError:
             return error_response("Invalid x value provided", 400)
         y_tile, y_off = divmod(y, tile_size)
         x_tile, x_off = divmod(x, tile_size)
-        off = y_off * tile_size * data_bytes + x_off * data_bytes
         path = raws_path / date / variant / f"{z}" / f"{y_tile}" / f"{x_tile}.bin"
+        img_size = (tile_size >> -z) if z < 0 else tile_size
+        off = y_off * img_size * data_bytes + x_off * data_bytes
         try:
             value = int.from_bytes(get_raw_data(path)[off : off + data_bytes], "little")
         except FileNotFoundError:
@@ -132,10 +147,13 @@ if args.raws:
     def get_info_range(request: Request):
         try:
             range = IPv4Network(unquote(request.path_params["range"]), strict = False)
-        except:
+        except ValueError:
             return error_response("Invalid IPv4 range", 400)
-        if range.prefixlen < 16:
-            return error_response("Prefix length of IPv4 range must be 16 or above", 400)
+        if range.prefixlen % 2 != 0:
+            return error_response("Prefix length of IPv4 range must be even", 400)
+        if range.prefixlen == 0:
+            x, y = 0, 0
+        else:
             x, y = HilbertCurve(range.prefixlen // 2, 2).point_from_distance(int(range.network_address) // (1 << (32 - range.prefixlen)))
         z = (range.prefixlen - 16) // 2
         request.path_params["x"] = str(x)