Repo created

libs/map/gps_track_collection.cpp

@@ -0,0 +1,117 @@
+#include "map/gps_track_collection.hpp"
+
+#include "base/assert.hpp"
+
+#include <algorithm>
+
+namespace
+{
+
+// Simple rollbacker which restores deque state
+template <typename T>
+class Rollbacker
+{
+public:
+  Rollbacker(std::deque<T> & cont) : m_cont(&cont), m_size(cont.size()) {}
+  ~Rollbacker()
+  {
+    if (m_cont && m_cont->size() > m_size)
+      m_cont->erase(m_cont->begin() + m_size, m_cont->end());
+  }
+  void Reset() { m_cont = nullptr; }
+
+private:
+  std::deque<T> * m_cont;
+  size_t const m_size;
+};
+
+}  // namespace
+
+size_t const GpsTrackCollection::kInvalidId = std::numeric_limits<size_t>::max();
+
+GpsTrackCollection::GpsTrackCollection() : m_lastId(0), m_elevationInfoDirty(true) {}
+
+std::pair<size_t, size_t> GpsTrackCollection::Add(std::vector<TItem> const & items)
+{
+  size_t startId = m_lastId;
+  size_t added = 0;
+
+  // Rollbacker ensure strong guarantee if exception happens while adding items
+  Rollbacker<TItem> rollbacker(m_items);
+
+  for (auto const & item : items)
+  {
+    if (!m_items.empty() && m_items.back().m_timestamp > item.m_timestamp)
+      continue;
+
+    m_statistics.AddGpsInfoPoint(item);
+
+    m_items.emplace_back(item);
+    ++added;
+  }
+
+  m_elevationInfoDirty = true;
+
+  rollbacker.Reset();
+
+  if (0 == added)
+  {
+    // Invalid timestamp order
+    return std::make_pair(kInvalidId, kInvalidId);  // Nothing was added
+  }
+
+  m_lastId += added;
+
+  return std::make_pair(startId, startId + added - 1);
+}
+
+std::pair<size_t, size_t> GpsTrackCollection::Clear(bool resetIds)
+{
+  if (m_items.empty())
+  {
+    if (resetIds)
+      m_lastId = 0;
+
+    return std::make_pair(kInvalidId, kInvalidId);
+  }
+
+  ASSERT_GREATER_OR_EQUAL(m_lastId, m_items.size(), ());
+
+  // Range of evicted items
+  auto const res = std::make_pair(m_lastId - m_items.size(), m_lastId - 1);
+
+  m_items.clear();
+  m_items.shrink_to_fit();
+  m_statistics = {};
+  m_elevationInfo = {};
+
+  if (resetIds)
+    m_lastId = 0;
+
+  return res;
+}
+
+size_t GpsTrackCollection::GetSize() const
+{
+  return m_items.size();
+}
+
+ElevationInfo const & GpsTrackCollection::UpdateAndGetElevationInfo()
+{
+  if (!m_elevationInfoDirty)
+    return m_elevationInfo;
+
+  auto const elevationInfoSize = m_elevationInfo.GetSize();
+  if (elevationInfoSize < m_items.size())
+  {
+    std::vector<TItem> const missedPoints(m_items.begin() + elevationInfoSize, m_items.end());
+    m_elevationInfo.AddGpsPoints(missedPoints);
+  }
+  m_elevationInfoDirty = false;
+  return m_elevationInfo;
+}
+
+bool GpsTrackCollection::IsEmpty() const
+{
+  return m_items.size() < 2;
+}