From b00e97e222279fe558ef42598bedb6e89e5234ba Mon Sep 17 00:00:00 2001
From: codinablack <codinablack@gmail.com>
Date: Sat, 7 Dec 2024 00:31:07 -0600
Subject: [PATCH] Implemented Hash Cache for spectators.

Co-Authored-By: Sarah Wesker <sarahelizabetwesker@gmail.com>
---
 src/map.cpp  | 30 ++++++++++++++++++++++--------
 src/map.h    | 45 ++++++++++++++++++++++++++++++++++++++++++++-
 src/tile.cpp | 15 +++------------
 3 files changed, 69 insertions(+), 21 deletions(-)

diff --git a/src/map.cpp b/src/map.cpp
index de24d641..1f3b56f1 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -407,9 +407,27 @@ void Map::getSpectators(SpectatorVec& spectators, const Position& centerPos, boo
     minRangeY = (minRangeY == 0 ? -maxViewportY : -minRangeY);
     maxRangeY = (maxRangeY == 0 ? maxViewportY : maxRangeY);
 
-    std::array<int32_t, 4> cache_values{
-        -maxViewportX , maxViewportX , -maxViewportY , maxViewportY
-    };
+    chunkKey.minRangeX = minRangeX;
+	chunkKey.maxRangeX = maxRangeX;
+	chunkKey.minRangeY = minRangeY;
+	chunkKey.maxRangeY = maxRangeY;
+	chunkKey.x = centerPos.x;
+	chunkKey.y = centerPos.y;
+	chunkKey.z = centerPos.z;
+	chunkKey.multifloor = multifloor;
+	chunkKey.onlyPlayers = onlyPlayers;
+
+	auto it = chunksSpectatorCache.find(chunkKey);
+	if (it != chunksSpectatorCache.end()) {
+		if (!spectators.empty()) {
+			spectators.addSpectators(it->second);
+		} else {
+			spectators = it->second;
+		}
+		foundCache = true;
+	} else {
+		cacheResult = true;
+	}
 
     if (minRangeX == -maxViewportX && maxRangeX == maxViewportX && minRangeY == -maxViewportY && maxRangeY == maxViewportY && multifloor) {
         if (onlyPlayers) {
@@ -467,11 +485,7 @@ void Map::getSpectators(SpectatorVec& spectators, const Position& centerPos, boo
         getSpectatorsInternal(spectators, centerPos, minRangeX, maxRangeX, minRangeY, maxRangeY, minRangeZ, maxRangeZ, onlyPlayers);
 
         if (cacheResult) {
-            if (onlyPlayers) {
-                playersSpectatorCache[centerPos] = spectators;
-            } else {
-                spectatorCache[centerPos] = spectators;
-            }
+            chunksSpectatorCache.emplace(chunkKey, spectators);
         }
     }
 }
diff --git a/src/map.h b/src/map.h
index 5a7e824c..243a5b4f 100644
--- a/src/map.h
+++ b/src/map.h
@@ -34,6 +34,45 @@ static constexpr int32_t MAX_NODES = 512;
 static constexpr int32_t MAP_NORMALWALKCOST = 10;
 static constexpr int32_t MAP_DIAGONALWALKCOST = 25;
 
+struct alignas(16) ChunkKey {
+	int32_t minRangeX, maxRangeX, minRangeY, maxRangeY;
+	uint16_t x, y;
+	uint8_t z;
+	bool multifloor, onlyPlayers;
+
+	bool operator==(const ChunkKey& other) const noexcept {
+		return std::memcmp(this, &other, sizeof(ChunkKey)) == 0;
+	}
+};
+static ChunkKey chunkKey;
+struct ChunkKeyHash {
+	std::size_t operator()(const ChunkKey& key) const noexcept {
+		std::size_t hash = 0;
+		hash_combine(hash, key.minRangeX, key.maxRangeX, key.minRangeY, key.maxRangeY,
+					 key.x, key.y, key.z, key.multifloor, key.onlyPlayers);
+		return hash;
+	}
+
+private:
+	template <typename... Args>
+	static void hash_combine(std::size_t& seed, Args&&... args) {
+		(hash_combine_impl(seed, std::forward<Args>(args)), ...);
+	}
+
+	template <typename T>
+	static void hash_combine_impl(std::size_t& seed, const T& v) {
+		seed ^= std::hash<T>{}(v) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
+	}
+};
+
+struct ChunkKeyEqual {
+	bool operator()(const ChunkKey& lhs, const ChunkKey& rhs) const noexcept {
+		return std::memcmp(&lhs, &rhs, sizeof(ChunkKey)) == 0;
+	}
+};
+
+using ChunkCache = std::unordered_map<ChunkKey, SpectatorVec, ChunkKeyHash, ChunkKeyEqual>;
+
 class AStarNodes
 {
 	public:
@@ -169,6 +208,10 @@ class Map
 		  * \returns true if the map was loaded successfully
 		  */
 		bool loadMap(const std::string& identifier, bool loadHouses);
+		void clearChunkSpectatorCache()	{
+			playersSpectatorCache.clear();
+			chunksSpectatorCache.clear();
+		}
 
 		/**
 		  * Save a map.
@@ -268,7 +311,7 @@ class Map
 	private:
 		SpectatorCache spectatorCache;
 		SpectatorCache playersSpectatorCache;
-
+		ChunkCache chunksSpectatorCache;
 		QTreeNode root;
 
 		std::filesystem::path spawnfile;
diff --git a/src/tile.cpp b/src/tile.cpp
index e2f556c8..0cc640d5 100644
--- a/src/tile.cpp
+++ b/src/tile.cpp
@@ -902,10 +902,7 @@ void Tile::addThing(int32_t, Thing* thing)
 {
 	Creature* creature = thing->getCreature();
 	if (creature) {
-		g_game.map.clearSpectatorCache();
-		if (creature->getPlayer()) {
-			g_game.map.clearPlayersSpectatorCache();
-		}
+		g_game.map.clearChunkSpectatorCache();
 
 		creature->setParent(this);
 		CreatureVector* creatures = makeCreatures();
@@ -1111,10 +1108,7 @@ void Tile::removeThing(Thing* thing, uint32_t count)
 		if (creatures) {
 			auto it = std::find(creatures->begin(), creatures->end(), thing);
 			if (it != creatures->end()) {
-				g_game.map.clearSpectatorCache();
-				if (creature->getPlayer()) {
-					g_game.map.clearPlayersSpectatorCache();
-				}
+				g_game.map.clearChunkSpectatorCache();
 
 				creatures->erase(it);
 			}
@@ -1491,10 +1485,7 @@ void Tile::internalAddThing(uint32_t, Thing* thing)
 
 	Creature* creature = thing->getCreature();
 	if (creature) {
-		g_game.map.clearSpectatorCache();
-		if (creature->getPlayer()) {
-			g_game.map.clearPlayersSpectatorCache();
-		}
+		g_game.map.clearChunkSpectatorCache();
 
 		CreatureVector* creatures = makeCreatures();
 		creatures->insert(creatures->begin(), creature);