Bound track history growth

src/data/Track.cpp

@@ -11,6 +11,7 @@
 #include "rapidjson/filewritestream.h"
 
 const uint64_t Track::MAX_INDEX = 65535;
+const uint64_t Track::MAX_HISTORY = 100;
 const std::string Track::STATE_ACTIVE = "ACTIVE";
 const std::string Track::STATE_TENTATIVE = "TENTATIVE";
 const std::string Track::STATE_COASTING = "COASTING";
@@ -36,12 +37,21 @@ std::string Track::uint2hex(uint64_t number)
 void Track::set_state(uint64_t index, std::string _state)
 {
   state.at(index).push_back(_state);
+  if (state.at(index).size() > MAX_HISTORY)
+  {
+    state.at(index).erase(state.at(index).begin());
+  }
 }
 
 void Track::set_current(uint64_t index, Detection smoothed)
 {
   current.at(index) = smoothed;
   associated.at(index).push_back(smoothed);
+  nAssociated.at(index)++;
+  if (associated.at(index).size() > MAX_HISTORY)
+  {
+    associated.at(index).erase(associated.at(index).begin());
+  }
 }
 
 void Track::set_acceleration(uint64_t index, double _acceleration)
@@ -92,6 +102,11 @@ uint64_t Track::get_nInactive(uint64_t index)
   return nInactive.at(index);
 }
 
+uint64_t Track::get_nAssociated(uint64_t index)
+{
+  return nAssociated.at(index);
+}
+
 uint64_t Track::add(Detection initial)
 {
   id.push_back(uint2hex(iNext));
@@ -103,6 +118,7 @@ uint64_t Track::add(Detection initial)
   std::vector<Detection> _associated;
   _associated.push_back(initial);
   associated.push_back(_associated);
+  nAssociated.push_back(1);
   nInactive.push_back(0);
   iNext++;
   if (iNext >= MAX_INDEX)
@@ -167,6 +183,12 @@ void Track::remove(uint64_t index)
   } else {
     throw std::out_of_range("Index out of bounds for 'associated' vector");
   }
+
+  if (index < nAssociated.size()) {
+    nAssociated.erase(nAssociated.begin() + index);
+  } else {
+    throw std::out_of_range("Index out of bounds for 'nAssociated' vector");
+  }
 }
 
 std::string Track::to_json(uint64_t timestamp)
@@ -195,7 +217,7 @@ std::string Track::to_json(uint64_t timestamp)
         document.GetAllocator());
       object1.AddMember("acceleration", 
         acceleration.at(i), document.GetAllocator());
-      object1.AddMember("n", associated.at(i).size(), 
+      object1.AddMember("n", get_nAssociated(i),
         document.GetAllocator());
       rapidjson::Value associatedDelay(rapidjson::kArrayType);
       rapidjson::Value associatedDoppler(rapidjson::kArrayType);
@@ -233,4 +255,4 @@ std::string Track::to_json(uint64_t timestamp)
   document.Accept(writer);
 
   return strbuf.GetString();
-}
+}

src/data/Track.h

@@ -28,7 +28,7 @@ class Track
   /// @brief Track ID (4 digit alpha-numeric).
   std::vector<std::string> id;
 
-  /// @brief State history for each track.
+  /// @brief State history for each track, most recent MAX_HISTORY entries only.
   std::vector<std::vector<std::string>> state;
 
   /// @brief Curent track position.
@@ -37,9 +37,12 @@ class Track
   /// @brief Current acceleration (Hz/s).
   std::vector<double> acceleration;
 
-  /// @brief Associated detections in track.
+  /// @brief Associated detections in track, most recent MAX_HISTORY entries only.
   std::vector<std::vector<Detection>> associated;
 
+  /// @brief Total number of detections ever associated with each track.
+  std::vector<uint64_t> nAssociated;
+
   /// @brief Number of updates the track has been tentative/coasting.
   /// @details Forms criteria for track deletion.
   std::vector<uint64_t> nInactive;
@@ -50,6 +53,9 @@ class Track
   /// @brief Maximum integer index to wrap around.
   static const uint64_t MAX_INDEX;
 
+  /// @brief Maximum retained state and associated detection history.
+  static const uint64_t MAX_HISTORY;
+
   /// @brief String for state ACTIVE.
   static const std::string STATE_ACTIVE;
 
@@ -127,6 +133,10 @@ class Track
   /// @return Number of updates track has been tentative/coasting.
   uint64_t get_nInactive(uint64_t index);
 
+  /// @brief Get total number of detections ever associated with a track.
+  /// @return Total number of associated detections.
+  uint64_t get_nAssociated(uint64_t index);
+
   /// @brief Update an associated detection.
   /// @param index Index of track to change.
   /// @param update New associated detection.

test/unit/process/tracker/TestTracker.cpp

@@ -10,6 +10,8 @@
 #include "process/tracker/Tracker.h"
 #include "data/meta/Constants.h"
 
+#include "rapidjson/document.h"
+
 #include <string>
 #include <vector>
 #include <random>
@@ -81,4 +83,31 @@ TEST_CASE("Test predict", "[predict]")
     Catch::Matchers::WithinAbs(prediction_truth.get_delay().front(), 0.01));
   CHECK_THAT(prediction.get_doppler().front(), 
     Catch::Matchers::WithinAbs(prediction_truth.get_doppler().front(), 0.01));
-}
+}
+
+/// @brief Test that long-lived track histories remain bounded.
+TEST_CASE("Track history is bounded for a long-lived track", "[track]")
+{
+  Track track;
+  Detection initial(10, -20, 0);
+  uint64_t index = track.add(initial);
+
+  uint32_t nCycles = 500;
+  for (uint32_t i = 0; i < nCycles; i++)
+  {
+    track.set_current(index, initial);
+    track.set_state(index, "ASSOCIATED");
+  }
+
+  CHECK(track.get_nAssociated(index) == nCycles + 1);
+
+  std::string json = track.to_json(0);
+  rapidjson::Document doc;
+  doc.Parse(json.c_str());
+  const rapidjson::Value& data = doc["data"][0];
+
+  CHECK(data["n"].GetUint64() == nCycles + 1);
+  CHECK(data["associated_delay"].Size() <= 100);
+  CHECK(data["associated_doppler"].Size() <= 100);
+  CHECK(data["associated_state"].Size() <= 100);
+}