[search][ugc] UGC ratings in search

21 files changed, 109 insertions, 42 deletions

diff --git a/android/jni/com/mapswithme/maps/SearchEngine.cpp b/android/jni/com/mapswithme/maps/SearchEngine.cpp
index 921d599b07..ad5c8e87de 100644
--- a/android/jni/com/mapswithme/maps/SearchEngine.cpp
+++ b/android/jni/com/mapswithme/maps/SearchEngine.cpp
@@ -4,6 +4,7 @@
 #include "com/mapswithme/platform/Platform.hpp"
 
 #include "map/everywhere_search_params.hpp"
+#include "map/place_page_info.hpp"
 #include "map/viewport_search_params.hpp"
 
 #include "search/hotels_filter.hpp"
@@ -331,8 +332,8 @@ jmethodID g_mapResultCtor;
 
 booking::AvailabilityParams g_lastBookingFilterParams;
 
-jobject ToJavaResult(Result & result, bool isLocalAdsCustomer, bool hasPosition, double lat,
-                     double lon)
+jobject ToJavaResult(Result & result, bool isLocalAdsCustomer, float ugcRating, bool hasPosition,
+                     double lat, double lon)
 {
   JNIEnv * env = jni::GetEnv();
   ::Framework * fr = g_framework->NativeFramework();
@@ -373,8 +374,13 @@ jobject ToJavaResult(Result & result, bool isLocalAdsCustomer, bool hasPosition,
   jni::TScopedLocalRef address(env, jni::ToJavaString(env, result.GetAddress()));
   jni::TScopedLocalRef dist(env, jni::ToJavaString(env, distance));
   jni::TScopedLocalRef cuisine(env, jni::ToJavaString(env, result.GetCuisine()));
-  jni::TScopedLocalRef rating(env, jni::ToJavaString(env, result.GetHotelRating()));
   jni::TScopedLocalRef pricing(env, jni::ToJavaString(env, result.GetHotelApproximatePricing()));
+
+  string ratingTmp = result.GetHotelRating();
+  if (ratingTmp.empty() && ugcRating > 0.f)
+    ratingTmp = place_page::rating::GetRatingFormatted(ugcRating);
+  jni::TScopedLocalRef rating(env, jni::ToJavaString(env, ratingTmp));
+
   jni::TScopedLocalRef desc(env, env->NewObject(g_descriptionClass, g_descriptionConstructor,
                                                 featureId.get(), featureType.get(), address.get(),
                                                 dist.get(), cuisine.get(),
@@ -391,7 +397,8 @@ jobject ToJavaResult(Result & result, bool isLocalAdsCustomer, bool hasPosition,
 }
 
 void OnResults(Results const & results, vector<bool> const & isLocalAdsCustomer,
-               long long timestamp, bool isMapAndTable, bool hasPosition, double lat, double lon)
+               vector<float> const & ugcRatings, long long timestamp, bool isMapAndTable,
+               bool hasPosition, double lat, double lon)
 {
   // Ignore results from obsolete searches.
   if (g_queryTimestamp > timestamp)
@@ -402,7 +409,7 @@ void OnResults(Results const & results, vector<bool> const & isLocalAdsCustomer,
   if (!results.IsEndMarker() || results.IsEndedNormal())
   {
     jni::TScopedLocalObjectArrayRef jResults(
-        env, BuildSearchResults(results, isLocalAdsCustomer, hasPosition, lat, lon));
+        env, BuildSearchResults(results, isLocalAdsCustomer, ugcRatings, hasPosition, lat, lon));
     env->CallVoidMethod(g_javaListener, g_updateResultsId, jResults.get(),
                         static_cast<jlong>(timestamp),
                         search::HotelsClassifier::IsHotelResults(results));
@@ -460,7 +467,8 @@ void OnBookingFilterResults(booking::AvailabilityParams const & params,
 }  // namespace
 
 jobjectArray BuildSearchResults(Results const & results, vector<bool> const & isLocalAdsCustomer,
-                                bool hasPosition, double lat, double lon)
+                                vector<float> const & ugcRatings, bool hasPosition, double lat,
+                                double lon)
 {
   JNIEnv * env = jni::GetEnv();
 
@@ -470,10 +478,12 @@ jobjectArray BuildSearchResults(Results const & results, vector<bool> const & is
   jobjectArray const jResults = env->NewObjectArray(count, g_resultClass, nullptr);
 
   ASSERT_EQUAL(results.GetCount(), isLocalAdsCustomer.size(), ());
+  ASSERT_EQUAL(results.GetCount(), ugcRatings.size(), ());
+
   for (int i = 0; i < count; i++)
   {
-    jni::TScopedLocalRef jRes(
-      env, ToJavaResult(g_results[i], isLocalAdsCustomer[i], hasPosition, lat, lon));
+    jni::TScopedLocalRef jRes(env, ToJavaResult(g_results[i], isLocalAdsCustomer[i], ugcRatings[i],
+                                                hasPosition, lat, lon));
     env->SetObjectArrayElement(jResults, i, jRes.get());
   }
   return jResults;
@@ -519,7 +529,7 @@ extern "C"
     search::EverywhereSearchParams params;
     params.m_query = jni::ToNativeString(env, bytes);
     params.m_inputLocale = jni::ToNativeString(env, lang);
-    params.m_onResults = bind(&OnResults, _1, _2, timestamp, false, hasPosition, lat, lon);
+    params.m_onResults = bind(&OnResults, _1, _2, _3, timestamp, false, hasPosition, lat, lon);
     params.m_hotelsFilter = g_hotelsFilterBuilder.Build(env, hotelsFilter);
     g_lastBookingFilterParams = g_bookingAvailabilityParamsBuilder.Build(env, bookingFilterParams);
     params.m_bookingFilterParams.m_params = g_lastBookingFilterParams;
@@ -553,7 +563,7 @@ extern "C"
       search::EverywhereSearchParams eparams;
       eparams.m_query = vparams.m_query;
       eparams.m_inputLocale = vparams.m_inputLocale;
-      eparams.m_onResults = bind(&OnResults, _1, _2, timestamp, isMapAndTable,
+      eparams.m_onResults = bind(&OnResults, _1, _2, _3, timestamp, isMapAndTable,
                                  false /* hasPosition */, 0.0 /* lat */, 0.0 /* lon */);
       eparams.m_hotelsFilter = vparams.m_hotelsFilter;
       if (g_framework->NativeFramework()->SearchEverywhere(eparams))
diff --git a/android/jni/com/mapswithme/maps/SearchEngine.hpp b/android/jni/com/mapswithme/maps/SearchEngine.hpp
index 949c289a32..7942b95342 100644
--- a/android/jni/com/mapswithme/maps/SearchEngine.hpp
+++ b/android/jni/com/mapswithme/maps/SearchEngine.hpp
@@ -8,4 +8,5 @@
 
 jobjectArray BuildSearchResults(search::Results const & results,
                                 std::vector<bool> const & isLocalAdsCustomer,
-                                bool hasPosition, double lat, double lon);
+                                std::vector<float> const & ugcRatings, bool hasPosition, double lat,
+                                double lon);
diff --git a/android/jni/com/mapswithme/maps/discovery/DiscoveryManager.cpp b/android/jni/com/mapswithme/maps/discovery/DiscoveryManager.cpp
index 2118b82a3c..963218e1e3 100644
--- a/android/jni/com/mapswithme/maps/discovery/DiscoveryManager.cpp
+++ b/android/jni/com/mapswithme/maps/discovery/DiscoveryManager.cpp
@@ -69,9 +69,9 @@ struct DiscoveryCallback
     auto const lat = MercatorBounds::YToLat(viewportCenter.y);
     auto const lon = MercatorBounds::XToLon(viewportCenter.x);
     std::vector<bool> customers(results.GetCount(), false);
-    jni::TScopedLocalObjectArrayRef jResults(env, BuildSearchResults(results, customers,
-                                                                     true /* hasPosition */,
-                                                                     lat, lon));
+    std::vector<float> ugcRatings(results.GetCount(), -1.f);
+    jni::TScopedLocalObjectArrayRef jResults(
+        env, BuildSearchResults(results, customers, ugcRatings, true /* hasPosition */, lat, lon));
     jobject discoveryManagerInstance = env->GetStaticObjectField(g_discoveryManagerClass,
                                                                  g_discoveryManagerInstanceField);
     env->CallVoidMethod(discoveryManagerInstance, g_onResultReceivedMethod,
diff --git a/iphone/Maps/Core/Search/MWMSearch.h b/iphone/Maps/Core/Search/MWMSearch.h
index b73e917b63..36f96d6799 100644
--- a/iphone/Maps/Core/Search/MWMSearch.h
+++ b/iphone/Maps/Core/Search/MWMSearch.h
@@ -22,6 +22,7 @@ class Result;
 + (NSUInteger)containerIndexWithRow:(NSUInteger)row;
 + (search::Result const &)resultWithContainerIndex:(NSUInteger)index;
 + (BOOL)isLocalAdsWithContainerIndex:(NSUInteger)index;
++ (CGFloat)ugcRatingWithContainerIndex:(NSUInteger)index;
 + (id<MWMBanner>)adWithContainerIndex:(NSUInteger)index;
 + (BOOL)isBookingAvailableWithContainerIndex:(NSUInteger)index;
 
diff --git a/iphone/Maps/Core/Search/MWMSearch.mm b/iphone/Maps/Core/Search/MWMSearch.mm
index a4407dc490..2b57ea788c 100644
--- a/iphone/Maps/Core/Search/MWMSearch.mm
+++ b/iphone/Maps/Core/Search/MWMSearch.mm
@@ -51,6 +51,7 @@ using Observers = NSHashTable<Observer>;
   search::Results m_viewportResults;
   std::vector<bool> m_isLocalAdsCustomer;
   std::vector<FeatureID> m_bookingAvailableFeatureIDs;
+  std::vector<float> m_ugcRatings;
 }
 
 #pragma mark - Instance
@@ -81,12 +82,14 @@ using Observers = NSHashTable<Observer>;
   self.lastSearchTimestamp += 1;
   NSUInteger const timestamp = self.lastSearchTimestamp;
   m_everywhereParams.m_onResults = [self, timestamp](search::Results const & results,
-                                                     vector<bool> const & isLocalAdsCustomer) {
+                                                     vector<bool> const & isLocalAdsCustomer,
+                                                     vector<float> const & ugcRatings) {
 
     if (timestamp == self.lastSearchTimestamp)
     {
       self->m_everywhereResults = results;
       self->m_isLocalAdsCustomer = isLocalAdsCustomer;
+      self->m_ugcRatings = ugcRatings;
       self.suggestionsCount = results.GetSuggestsCount();
 
       [self onSearchResultsUpdated];
@@ -218,6 +221,11 @@ using Observers = NSHashTable<Observer>;
   return [MWMSearch manager]->m_isLocalAdsCustomer[index];
 }
 
++ (CGFloat)ugcRatingWithContainerIndex:(NSUInteger)index
+{
+  return [MWMSearch manager]->m_ugcRatings[index];
+}
+
 + (id<MWMBanner>)adWithContainerIndex:(NSUInteger)index
 {
   return [[MWMSearch manager].banners bannerAtIndex:index];
diff --git a/iphone/Maps/UI/Search/TableView/MWMSearchCommonCell.h b/iphone/Maps/UI/Search/TableView/MWMSearchCommonCell.h
index 1807591968..decf8114f9 100644
--- a/iphone/Maps/UI/Search/TableView/MWMSearchCommonCell.h
+++ b/iphone/Maps/UI/Search/TableView/MWMSearchCommonCell.h
@@ -6,6 +6,7 @@
 
 - (void)config:(search::Result const &)result
      isLocalAds:(BOOL)isLocalAds
-    isAvailable:(BOOL)isAvailable;
+     isAvailable:(BOOL)isAvailable
+     ugcRating:(CGFloat)ugcRating;
 
 @end
diff --git a/iphone/Maps/UI/Search/TableView/MWMSearchCommonCell.mm b/iphone/Maps/UI/Search/TableView/MWMSearchCommonCell.mm
index c443107b4d..41a50817d3 100644
--- a/iphone/Maps/UI/Search/TableView/MWMSearchCommonCell.mm
+++ b/iphone/Maps/UI/Search/TableView/MWMSearchCommonCell.mm
@@ -3,8 +3,11 @@
 #import "MWMLocationManager.h"
 
 #include "geometry/mercator.hpp"
+
 #include "platform/measurement_utils.hpp"
 
+#include "map/place_page_info.hpp"
+
 @interface MWMSearchCommonCell ()
 
 @property(nonatomic) IBOutletCollection(UIImageView) NSArray * infoRatingStars;
@@ -27,11 +30,14 @@
 
 - (void)config:(search::Result const &)result
      isLocalAds:(BOOL)isLocalAds
-    isAvailable:(BOOL)isAvailable
+     isAvailable:(BOOL)isAvailable
+     ugcRating:(CGFloat)ugcRating
 {
   [super config:result];
   self.typeLabel.text = @(result.GetFeatureTypeName().c_str()).capitalizedString;
-  auto const & ratingStr = result.GetHotelRating();
+  auto ratingStr = result.GetHotelRating();
+  if (ratingStr.empty() && ugcRating > 0.f)
+    ratingStr = place_page::rating::GetRatingFormatted(ugcRating);
   self.ratingLabel.text =
       ratingStr.empty() ? @"" : [NSString stringWithFormat:L(@"place_page_booking_rating"),
                                                             ratingStr.c_str()];
diff --git a/iphone/Maps/UI/Search/TableView/MWMSearchTableViewController.mm b/iphone/Maps/UI/Search/TableView/MWMSearchTableViewController.mm
index 6366b747ea..dd80ad164b 100644
--- a/iphone/Maps/UI/Search/TableView/MWMSearchTableViewController.mm
+++ b/iphone/Maps/UI/Search/TableView/MWMSearchTableViewController.mm
@@ -89,7 +89,8 @@
     auto const & result = [MWMSearch resultWithContainerIndex:containerIndex];
     auto const isLocalAds = [MWMSearch isLocalAdsWithContainerIndex:containerIndex];
     auto const isBookingAvailable = [MWMSearch isBookingAvailableWithContainerIndex:containerIndex];
-    [cell config:result isLocalAds:isLocalAds isAvailable:isBookingAvailable];
+    auto const ugcRating = [MWMSearch ugcRatingWithContainerIndex:containerIndex];
+    [cell config:result isLocalAds:isLocalAds isAvailable:isBookingAvailable ugcRating:ugcRating];
     return cell;
   }
   case MWMSearchItemTypeMopub:
diff --git a/map/everywhere_search_params.hpp b/map/everywhere_search_params.hpp
index 49f8c6ce00..ec1226e4ee 100644
--- a/map/everywhere_search_params.hpp
+++ b/map/everywhere_search_params.hpp
@@ -15,7 +15,8 @@ namespace search
 struct EverywhereSearchParams
 {
   using OnResults =
-      std::function<void(Results const & results, std::vector<bool> const & isLocalAdsCustomer)>;
+      std::function<void(Results const & results, std::vector<bool> const & isLocalAdsCustomer,
+                         std::vector<float> const & ugcRatings)>;
 
   std::string m_query;
   std::string m_inputLocale;
diff --git a/map/framework.cpp b/map/framework.cpp
index c912a36fb1..607471b84c 100644
--- a/map/framework.cpp
+++ b/map/framework.cpp
@@ -3256,6 +3256,18 @@ bool Framework::IsLocalAdsCustomer(search::Result const & result) const
   return m_localAdsManager.Contains(result.GetFeatureID());
 }
 
+float Framework::GetUgcRating(search::Result const & result) const
+{
+  ASSERT(m_ugcApi, ());
+
+  if (result.GetResultType() != search::Result::Type::Feature)
+    return -1.f;
+
+  auto const ugc = m_ugcApi->GetLoader().GetUGC(result.GetFeatureID());
+
+  return ugc.m_totalRating;
+}
+
 double Framework::GetMinDistanceBetweenResults() const
 {
   return m_searchMarks.GetMaxDimension(m_currentModelView);
diff --git a/map/framework.hpp b/map/framework.hpp
index 5c1a4db61e..13c7f84d63 100644
--- a/map/framework.hpp
+++ b/map/framework.hpp
@@ -359,6 +359,7 @@ public:
   boost::optional<m2::PointD> GetCurrentPosition() const override;
   bool ParseSearchQueryCommand(search::SearchParams const & params) override;
   bool IsLocalAdsCustomer(search::Result const & result) const override;
+  float GetUgcRating(search::Result const & result) const override;
   double GetMinDistanceBetweenResults() const override;
 
 private:
diff --git a/map/search_api.cpp b/map/search_api.cpp
index de3bd15661..7136831a64 100644
--- a/map/search_api.cpp
+++ b/map/search_api.cpp
@@ -176,10 +176,11 @@ bool SearchAPI::SearchEverywhere(EverywhereSearchParams const & params)
 
   p.m_onResults = EverywhereSearchCallback(
       static_cast<EverywhereSearchCallback::Delegate &>(*this),
-      [this, params](Results const & results, vector<bool> const & isLocalAdsCustomer) {
+      [this, params](Results const & results, vector<bool> const & isLocalAdsCustomer,
+                     vector<float> const & ugcRatings) {
         if (params.m_onResults)
-          RunUITask([params, results, isLocalAdsCustomer] {
-            params.m_onResults(results, isLocalAdsCustomer);
+          RunUITask([params, results, isLocalAdsCustomer, ugcRatings] {
+            params.m_onResults(results, isLocalAdsCustomer, ugcRatings);
           });
         if (results.IsEndedNormal() && !params.m_bookingFilterParams.IsEmpty())
         {
@@ -339,6 +340,11 @@ bool SearchAPI::IsLocalAdsCustomer(Result const & result) const
   return m_delegate.IsLocalAdsCustomer(result);
 }
 
+float SearchAPI::GetUgcRating(search::Result const & result) const
+{
+  return m_delegate.GetUgcRating(result);
+}
+
 void SearchAPI::OnBookmarksCreated(vector<pair<df::MarkID, BookmarkData>> const & marks)
 {
   vector<BookmarkIdDoc> data;
diff --git a/map/search_api.hpp b/map/search_api.hpp
index 20a3d4ec65..e81783e8b9 100644
--- a/map/search_api.hpp
+++ b/map/search_api.hpp
@@ -94,9 +94,9 @@ public:
     {
     }
 
-    virtual void OnBookingFilterParamsUpdate(booking::AvailabilityParams const & params)
-    {
-    }
+    virtual void OnBookingFilterParamsUpdate(booking::AvailabilityParams const & params) {}
+
+    virtual float GetUgcRating(search::Result const & /* result */) const { return -1.f; }
   };
 
   SearchAPI(Index & index, storage::Storage const & storage,
@@ -141,6 +141,7 @@ public:
   void ShowViewportSearchResults(bool clear, search::Results::ConstIter begin,
                                  search::Results::ConstIter end) override;
   bool IsLocalAdsCustomer(search::Result const & result) const override;
+  float GetUgcRating(search::Result const & result) const override;
 
   void OnBookmarksCreated(std::vector<std::pair<df::MarkID, BookmarkData>> const & marks);
   void OnBookmarksUpdated(std::vector<std::pair<df::MarkID, BookmarkData>> const & marks);
diff --git a/qt/search_panel.cpp b/qt/search_panel.cpp
index bb30680135..c39e619205 100644
--- a/qt/search_panel.cpp
+++ b/qt/search_panel.cpp
@@ -261,7 +261,8 @@ void SearchPanel::OnSearchTextChanged(QString const & str)
     m_params.m_query = normalized.toUtf8().constData();
     auto const timestamp = ++m_timestamp;
     m_params.m_onResults = [this, timestamp](search::Results const & results,
-                                             vector<bool> const & /* isLocalAdsCustomer */) {
+                                             vector<bool> const & /* isLocalAdsCustomer */,
+                                             vector<float> const & /* ugcRatings */) {
       GetPlatform().RunTask(Platform::Thread::Gui, bind(&SearchPanel::OnSearchResults, this,
                                                         timestamp, results));
     };
diff --git a/search/everywhere_search_callback.cpp b/search/everywhere_search_callback.cpp
index 9b80cda188..52b9db7d9b 100644
--- a/search/everywhere_search_callback.cpp
+++ b/search/everywhere_search_callback.cpp
@@ -12,13 +12,18 @@ EverywhereSearchCallback::EverywhereSearchCallback(Delegate & delegate, OnResult
 
 void EverywhereSearchCallback::operator()(Results const & results)
 {
+  ASSERT_EQUAL(m_isLocalAdsCustomer.size(), m_ugcRatings.size(), ());
+
   auto const prevSize = m_isLocalAdsCustomer.size();
   ASSERT_LESS_OR_EQUAL(prevSize, results.GetCount(), ());
 
   for (size_t i = prevSize; i < results.GetCount(); ++i)
+  {
     m_isLocalAdsCustomer.push_back(m_delegate.IsLocalAdsCustomer(results[i]));
+    m_ugcRatings.push_back(m_delegate.GetUgcRating(results[i]));
+  }
 
   ASSERT_EQUAL(m_isLocalAdsCustomer.size(), results.GetCount(), ());
-  m_onResults(results, m_isLocalAdsCustomer);
+  m_onResults(results, m_isLocalAdsCustomer, m_ugcRatings);
 }
 }  // namespace search
diff --git a/search/everywhere_search_callback.hpp b/search/everywhere_search_callback.hpp
index a31e5abd02..3d9e39b31b 100644
--- a/search/everywhere_search_callback.hpp
+++ b/search/everywhere_search_callback.hpp
@@ -20,12 +20,14 @@ public:
     virtual ~Delegate() = default;
 
     virtual bool IsLocalAdsCustomer(Result const & result) const = 0;
+    virtual float GetUgcRating(Result const & result) const = 0;
   };
 
   // The signature of the callback should be the same as EverywhereSaerchParams::OnResults, but
   // EverywhereSaerchParams is located in map project and we do not need dependency.
   using OnResults =
-    std::function<void(Results const & results, std::vector<bool> const & isLocalAdsCustomer)>;
+      std::function<void(Results const & results, std::vector<bool> const & isLocalAdsCustomer,
+                         std::vector<float> const & ugcRatings)>;
 
   EverywhereSearchCallback(Delegate & delegate, OnResults onResults);
 
@@ -35,5 +37,6 @@ private:
   Delegate & m_delegate;
   OnResults m_onResults;
   std::vector<bool> m_isLocalAdsCustomer;
+  std::vector<float> m_ugcRatings;
 };
 }  // namespace search
diff --git a/search/intermediate_result.cpp b/search/intermediate_result.cpp
index 10c5267fa8..374f42243f 100644
--- a/search/intermediate_result.cpp
+++ b/search/intermediate_result.cpp
@@ -1,6 +1,6 @@
-#include "intermediate_result.hpp"
-#include "geometry_utils.hpp"
-#include "reverse_geocoder.hpp"
+#include "search/intermediate_result.hpp"
+#include "search/geometry_utils.hpp"
+#include "search/reverse_geocoder.hpp"
 
 #include "storage/country_info_getter.hpp"
 
diff --git a/ugc/api.cpp b/ugc/api.cpp
index 65f77af714..f9b45acde3 100644
--- a/ugc/api.cpp
+++ b/ugc/api.cpp
@@ -44,6 +44,11 @@ void Api::SaveUGCOnDisk()
   m_thread.Push([this] { SaveUGCOnDiskImpl(); });
 }
 
+Loader & Api::GetLoader()
+{
+ return m_loader;
+}
+
 void Api::GetUGCImpl(FeatureID const & id, UGCCallbackUnsafe const & callback)
 {
   CHECK(callback, ());
diff --git a/ugc/api.hpp b/ugc/api.hpp
index 9af3ef365a..6b08de71b6 100644
--- a/ugc/api.hpp
+++ b/ugc/api.hpp
@@ -32,6 +32,8 @@ public:
   void SendingCompleted();
   void SaveUGCOnDisk();
 
+  Loader & GetLoader();
+
 private:
   void GetUGCImpl(FeatureID const & id, UGCCallbackUnsafe const & callback);
   Storage::SettingResult SetUGCUpdateImpl(FeatureID const & id, UGCUpdate const & ugc);
diff --git a/ugc/loader.cpp b/ugc/loader.cpp
index 6fa54deffb..ce57c4c5bc 100644
--- a/ugc/loader.cpp
+++ b/ugc/loader.cpp
@@ -21,17 +21,15 @@ UGC Loader::GetUGC(FeatureID const & featureId)
   if (!value.m_cont.IsExist(UGC_FILE_TAG))
     return {};
 
-  if (m_currentMwmId != featureId.m_mwmId)
+  UGC ugc;
   {
-    m_currentMwmId = featureId.m_mwmId;
-    m_d = binary::UGCDeserializer();
-  }
+    std::lock_guard<std::mutex> lock(m_mutex);
 
-  auto readerPtr = value.m_cont.GetReader(UGC_FILE_TAG);
+    auto deserializer = m_deserializers[featureId.m_mwmId];
+    auto readerPtr = value.m_cont.GetReader(UGC_FILE_TAG);
 
-  UGC ugc;
-  if (!m_d.Deserialize(*readerPtr.GetPtr(), featureId.m_index, ugc))
-    return {};
+    deserializer.Deserialize(*readerPtr.GetPtr(), featureId.m_index, ugc);
+  }
 
   return ugc;
 }
diff --git a/ugc/loader.hpp b/ugc/loader.hpp
index 0491fe8027..f141e841c7 100644
--- a/ugc/loader.hpp
+++ b/ugc/loader.hpp
@@ -5,11 +5,15 @@
 
 #include "indexer/mwm_set.hpp"
 
+#include <map>
+#include <mutex>
+
 class Index;
 struct FeatureID;
 
 namespace ugc
 {
+// *NOTE* This class IS thread-safe.
 class Loader
 {
 public:
@@ -18,7 +22,7 @@ public:
 
 private:
   Index const & m_index;
-  MwmSet::MwmId m_currentMwmId;
-  binary::UGCDeserializer m_d;
+  std::map<MwmSet::MwmId, binary::UGCDeserializer> m_deserializers;
+  std::mutex m_mutex;
 };
 }  // namespace ugc