Repo created

libs/routing/data_source.hpp

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+#pragma once
+#include "routing/routing_exceptions.hpp"
+
+#include "routing_common/num_mwm_id.hpp"
+
+#include "indexer/data_source.hpp"
+
+#include "base/lru_cache.hpp"
+
+#include <map>
+#include <unordered_map>
+
+namespace routing
+{
+// Main purpose is to take and hold MwmHandle-s here (readers and caches).
+// Routing works in a separate threads and doesn't interfere within route calculation process.
+/// @note Should add additional thread's caches in case of concurrent routing process.
+class MwmDataSource
+{
+  DataSource & m_dataSource;
+  std::shared_ptr<NumMwmIds> m_numMwmIDs;
+  std::unordered_map<NumMwmId, MwmSet::MwmHandle> m_handles;
+
+  // Used for FeaturesRoadGraph in openlr only.
+  std::map<MwmSet::MwmId, MwmSet::MwmHandle> m_handles2;
+
+  // Cache is important for Cross-Mwm routing, where we need at least 2 sources simultaneously.
+  LruCache<MwmSet::MwmId, std::unique_ptr<FeatureSource>> m_featureSources{4};
+
+  MwmSet::MwmHandle const * GetHandleSafe(NumMwmId numMwmId)
+  {
+    ASSERT(m_numMwmIDs, ());
+    auto it = m_handles.find(numMwmId);
+    if (it == m_handles.end())
+    {
+      auto handle = m_dataSource.GetMwmHandleByCountryFile(m_numMwmIDs->GetFile(numMwmId));
+      if (!handle.IsAlive())
+        return nullptr;
+
+      it = m_handles.emplace(numMwmId, std::move(handle)).first;
+    }
+    return &(it->second);
+  }
+
+public:
+  /// @param[in]  numMwmIDs Can be null, if won't call NumMwmId functions.
+  MwmDataSource(DataSource & dataSource, std::shared_ptr<NumMwmIds> numMwmIDs)
+    : m_dataSource(dataSource)
+    , m_numMwmIDs(std::move(numMwmIDs))
+  {}
+
+  void FreeHandles()
+  {
+    m_featureSources.Clear();
+    m_handles.clear();
+    m_handles2.clear();
+  }
+
+  bool IsLoaded(platform::CountryFile const & file) const { return m_dataSource.IsLoaded(file); }
+
+  enum SectionStatus
+  {
+    MwmNotLoaded,
+    SectionExists,
+    NoSection,
+  };
+
+  MwmSet::MwmHandle const & GetHandle(NumMwmId numMwmId)
+  {
+    ASSERT(m_numMwmIDs, ());
+    auto it = m_handles.find(numMwmId);
+    if (it == m_handles.end())
+    {
+      auto const file = m_numMwmIDs->GetFile(numMwmId);
+      auto handle = m_dataSource.GetMwmHandleByCountryFile(file);
+      if (!handle.IsAlive())
+        MYTHROW(RoutingException, ("Mwm", file, "cannot be loaded."));
+
+      it = m_handles.emplace(numMwmId, std::move(handle)).first;
+    }
+    return it->second;
+  }
+
+  MwmValue const & GetMwmValue(NumMwmId numMwmId) { return *GetHandle(numMwmId).GetValue(); }
+
+  SectionStatus GetSectionStatus(NumMwmId numMwmId, std::string const & section)
+  {
+    auto const * handle = GetHandleSafe(numMwmId);
+    if (!handle)
+      return MwmNotLoaded;
+    return handle->GetValue()->m_cont.IsExist(section) ? SectionExists : NoSection;
+  }
+
+  MwmSet::MwmId GetMwmId(NumMwmId numMwmId) const
+  {
+    ASSERT(m_numMwmIDs, ());
+    return m_dataSource.GetMwmIdByCountryFile(m_numMwmIDs->GetFile(numMwmId));
+  }
+
+  template <class FnT>
+  void ForEachStreet(FnT && fn, m2::RectD const & rect)
+  {
+    m_dataSource.ForEachInRect(fn, rect, scales::GetUpperScale());
+  }
+
+  MwmSet::MwmHandle const & GetHandle(MwmSet::MwmId const & mwmId)
+  {
+    if (m_numMwmIDs)
+    {
+      return GetHandle(m_numMwmIDs->GetId(mwmId.GetInfo()->GetLocalFile().GetCountryFile()));
+    }
+    else
+    {
+      auto it = m_handles2.find(mwmId);
+      if (it == m_handles2.end())
+      {
+        auto handle = m_dataSource.GetMwmHandleById(mwmId);
+        if (!handle.IsAlive())
+          MYTHROW(RoutingException, ("Mwm", mwmId.GetInfo()->GetCountryName(), "cannot be loaded."));
+
+        it = m_handles2.emplace(mwmId, std::move(handle)).first;
+      }
+      return it->second;
+    }
+  }
+
+  std::unique_ptr<FeatureType> GetFeature(FeatureID const & id)
+  {
+    bool found = false;
+    auto & ptr = m_featureSources.Find(id.m_mwmId, found);
+    if (!found)
+      ptr = m_dataSource.CreateFeatureSource(GetHandle(id.m_mwmId));
+
+    /// @todo Should we also retrieve "modified" features here?
+    return ptr->GetOriginalFeature(id.m_index);
+  }
+};
+}  // namespace routing