Adds a limit for number of results returned in Nearest service, resolves #2872

CHANGELOG.md

@@ -21,6 +21,8 @@
       - Fixed an issue that would detect turning circles as sliproads
       - Fixed a bug where post-processing instructions (e.g. left + left -> uturn) could result in false pronunciations
       - Fixes a bug where a bearing range of zero would cause exhaustive graph traversals
+    - Infrastructure:
+      - Adds a feature to limit results in nearest service with a default of 100 in `osrm-routed`
 
 # 5.3.0
   Changes from 5.3.0-rc.3

include/engine/engine_config.hpp

@@ -51,6 +51,7 @@ namespace engine
  *  - Route
  *  - Table
  *  - Match
+ *  - Nearest
  *
  * In addition, shared memory can be used for datasets loaded with osrm-datastore.
  *
@@ -65,6 +66,7 @@ struct EngineConfig final
     int max_locations_viaroute = -1;
     int max_locations_distance_table = -1;
     int max_locations_map_matching = -1;
+    int max_results_nearest = -1;
     bool use_shared_memory = true;
 };
 }

include/engine/plugins/nearest.hpp

@@ -15,9 +15,12 @@ namespace plugins
 class NearestPlugin final : public BasePlugin
 {
   public:
-    explicit NearestPlugin(datafacade::BaseDataFacade &facade);
+    explicit NearestPlugin(datafacade::BaseDataFacade &facade, const int max_results);
 
     Status HandleRequest(const api::NearestParameters &params, util::json::Object &result);
+
+  private:
+    const int max_results;
 };
 }
 }

src/engine/engine.cpp

@@ -146,7 +146,7 @@ Engine::Engine(EngineConfig &config)
 
     route_plugin = create<ViaRoutePlugin>(*query_data_facade, config.max_locations_viaroute);
     table_plugin = create<TablePlugin>(*query_data_facade, config.max_locations_distance_table);
-    nearest_plugin = create<NearestPlugin>(*query_data_facade);
+    nearest_plugin = create<NearestPlugin>(*query_data_facade, config.max_results_nearest);
     trip_plugin = create<TripPlugin>(*query_data_facade, config.max_locations_trip);
     match_plugin = create<MatchPlugin>(*query_data_facade, config.max_locations_map_matching);
     tile_plugin = create<TilePlugin>(*query_data_facade);

src/engine/engine_config.cpp

@@ -15,11 +15,15 @@ bool EngineConfig::IsValid() const
         storage_config.datasource_names_path.empty() &&
         storage_config.datasource_indexes_path.empty() && storage_config.names_data_path.empty();
 
-    const bool limits_valid =
+    const auto unlimited_or_more_than = [](const int v, const int limit) {
-        (max_locations_distance_table == -1 || max_locations_distance_table > 2) &&
+        return v == -1 || v > limit;
-        (max_locations_map_matching == -1 || max_locations_map_matching > 2) &&
+    };
-        (max_locations_trip == -1 || max_locations_trip > 2) &&
+
-        (max_locations_viaroute == -1 || max_locations_viaroute > 2);
+    const bool limits_valid = unlimited_or_more_than(max_locations_distance_table, 2) &&
+                              unlimited_or_more_than(max_locations_map_matching, 2) &&
+                              unlimited_or_more_than(max_locations_trip, 2) &&
+                              unlimited_or_more_than(max_locations_viaroute, 2) &&
+                              unlimited_or_more_than(max_results_nearest, 0);
 
     return ((use_shared_memory && all_path_are_empty) || storage_config.IsValid()) && limits_valid;
 }

src/engine/plugins/nearest.cpp

@@ -16,13 +16,24 @@ namespace engine
 namespace plugins
 {
 
-NearestPlugin::NearestPlugin(datafacade::BaseDataFacade &facade) : BasePlugin{facade} {}
+NearestPlugin::NearestPlugin(datafacade::BaseDataFacade &facade, const int max_results_)
+    : BasePlugin{facade}, max_results{max_results_}
+{
+}
 
 Status NearestPlugin::HandleRequest(const api::NearestParameters &params,
                                     util::json::Object &json_result)
 {
     BOOST_ASSERT(params.IsValid());
 
+    if (params.number_of_results > max_results)
+    {
+        return Error("TooBig",
+                     "Number of results " + std::to_string(params.number_of_results) +
+                         " is higher than current maximum (" + std::to_string(max_results) + ")",
+                     json_result);
+    }
+
     if (!CheckAllCoordinates(params.coordinates))
         return Error("InvalidOptions", "Coordinates are invalid", json_result);
 

src/tools/routed.cpp

@@ -63,7 +63,8 @@ inline unsigned generateServerProgramOptions(const int argc,
                                              int &max_locations_trip,
                                              int &max_locations_viaroute,
                                              int &max_locations_distance_table,
-                                             int &max_locations_map_matching)
+                                             int &max_locations_map_matching,
+                                             int &max_results_nearest)
 {
     using boost::program_options::value;
     using boost::filesystem::path;
@@ -100,7 +101,10 @@ inline unsigned generateServerProgramOptions(const int argc,
          "Max. locations supported in distance table query") //
         ("max-matching-size",
          value<int>(&max_locations_map_matching)->default_value(100),
-         "Max. locations supported in map matching query");
+         "Max. locations supported in map matching query") //
+        ("max-nearest-size",
+         value<int>(&max_results_nearest)->default_value(100),
+         "Max. results supported in nearest query");
 
     // hidden options, will be allowed on command line, but will not be shown to the user
     boost::program_options::options_description hidden_options("Hidden options");
@@ -189,7 +193,8 @@ int main(int argc, const char *argv[]) try
                                                               config.max_locations_trip,
                                                               config.max_locations_viaroute,
                                                               config.max_locations_distance_table,
-                                                              config.max_locations_map_matching);
+                                                              config.max_locations_map_matching,
+                                                              config.max_results_nearest);
     if (init_result == INIT_OK_DO_NOT_START_ENGINE)
     {
         return EXIT_SUCCESS;

unit_tests/library/limits.cpp

@@ -4,6 +4,7 @@
 #include "args.hpp"
 
 #include "osrm/match_parameters.hpp"
+#include "osrm/nearest_parameters.hpp"
 #include "osrm/route_parameters.hpp"
 #include "osrm/table_parameters.hpp"
 #include "osrm/trip_parameters.hpp"
@@ -136,4 +137,33 @@ BOOST_AUTO_TEST_CASE(test_match_limits)
     BOOST_CHECK(code == "TooBig"); // per the New-Server API spec
 }
 
+BOOST_AUTO_TEST_CASE(test_nearest_limits)
+{
+    const auto args = get_args();
+    BOOST_REQUIRE_EQUAL(args.size(), 1);
+
+    using namespace osrm;
+
+    EngineConfig config;
+    config.storage_config = {args[0]};
+    config.use_shared_memory = false;
+    config.max_results_nearest = 2;
+
+    OSRM osrm{config};
+
+    NearestParameters params;
+    params.coordinates.emplace_back(util::FloatLongitude{}, util::FloatLatitude{});
+    params.number_of_results = 10000;
+
+    json::Object result;
+
+    const auto rc = osrm.Nearest(params, result);
+
+    BOOST_CHECK(rc == Status::Error);
+
+    // Make sure we're not accidentally hitting a guard code path before
+    const auto code = result.values["code"].get<json::String>().value;
+    BOOST_CHECK(code == "TooBig"); // per the New-Server API spec
+}
+
 BOOST_AUTO_TEST_SUITE_END()