LOSCache.diff

diff --git a/common/ruletypes.h b/common/ruletypes.h
index b610c30..991240f 100644
--- a/common/ruletypes.h
+++ b/common/ruletypes.h
@@ -529,6 +529,11 @@ RULE_BOOL( QueryServ, MerchantLogTransactions, false) // Logs Merchant Transacti
 RULE_BOOL( QueryServ, PlayerLogPCCoordinates, false) // Logs Player Coordinates with certain events
 RULE_CATEGORY_END()
 
+RULE_CATEGORY ( Performance )
+RULE_BOOL ( Performance, LOSCacheEnabled, false )
+RULE_INT ( Performance, LOSCacheEntryMS, 3000 )
+RULE_CATEGORY_END()
+
 #undef RULE_CATEGORY
 #undef RULE_INT
 #undef RULE_REAL
diff --git a/zone/aggro.cpp b/zone/aggro.cpp
index 326e320..508ed22 100644
--- a/zone/aggro.cpp
+++ b/zone/aggro.cpp
@@ -998,14 +998,65 @@ bool Mob::CheckLos(Mob* other) {
 	return true;
 }
 
+// Added LOSEntry as a cache to slow down the attempts against los on the same mob in a short time frame
+bool Mob::FindLosCacheEntry(Mob *other, bool &inLOS, uint32 &hits)
+{
+	if (!other || !RuleB(Performance, LOSCacheEnabled))
+		return false;
+
+	auto it = m_LOSCache.find(other->GetID());
+	if (it != m_LOSCache.end()) {
+		if (it->second.entry == other) {
+			if (Timer::GetCurrentTime() < it->second.lastChecked) {
+				// Update hits
+				it->second.hits += 1;
+				// if loc still valid, extend
+				if (it->second.lastX == other->GetX() &&
+						it->second.lastY == other->GetY() &&
+						it->second.ourLastX == GetX() &&
+						it->second.ourLastY == GetY())
+					it->second.lastChecked = Timer::GetCurrentTime() + RuleI(Performance, LOSCacheEntryMS);
+				inLOS = it->second.isLOS;
+				hits = it->second.hits;
+				return true;
+			}
+		}
+	}
+
+	return false;
+}
 
 //Father Nitwit's LOS code
 bool Mob::CheckLosFN(Mob* other) {
 	bool Result = false;
 
-	if(other)
+	if (other == this) // checking self?
+		return true;
+
+	uint32 hits = 0;
+
+	if (FindLosCacheEntry(other, Result, hits))
+		return Result;
+
+	if (other) {
 		Result = CheckLosFN(other->GetX(), other->GetY(), other->GetZ(), other->GetSize());
 
+		if (RuleB(Performance, LOSCacheEnabled)) {
+			LOSEntry newEnt;
+			newEnt.entry = other;
+			newEnt.isLOS = Result;
+			newEnt.lastChecked = Timer::GetCurrentTime() + RuleI(Performance, LOSCacheEntryMS);
+			newEnt.hits = 1;
+			newEnt.lastX = other->GetX();
+			newEnt.lastY = other->GetY();
+			newEnt.lastZ = other->GetZ();
+			newEnt.ourLastX = GetX();
+			newEnt.ourLastY = GetY();
+			newEnt.ourLastZ = GetZ();
+			m_LOSCache[other->GetID()] = newEnt;
+		}
+	}
+
 	return Result;
 }
 
diff --git a/zone/command.cpp b/zone/command.cpp
index 1b8ce33..fa1de3b 100644
--- a/zone/command.cpp
+++ b/zone/command.cpp
@@ -6468,7 +6468,12 @@ void command_checklos(Client *c, const Seperator *sep)
 {
 	if(c->GetTarget())
 	{
-//		if(c->CheckLos(c->GetTarget()))
+		bool los = false;
+		uint32 hits = 0;
+		if (c->FindLosCacheEntry(c->GetTarget(), los, hits))
+			c->Message(12,"(Client->Mob) Cached entry exists with mob. LOSVisibleStatus: %i.  CacheEntryHits: %i.", los, hits);
+		if (c->GetTarget()->FindLosCacheEntry(c, los, hits))
+			c->Message(12,"(Mob->Client) Cached entry exists ON mob. LOSVisibleStatus: %i.  CacheEntryHits: %i.", los, hits);
 		if(c->CheckLosFN(c->GetTarget()))
 			c->Message(0, "You have LOS to %s", c->GetTarget()->GetName());
 		else
diff --git a/zone/mob.h b/zone/mob.h
index f636b5e..d2d5084 100644
--- a/zone/mob.h
+++ b/zone/mob.h
@@ -31,6 +31,23 @@ char* strn0cpy(char* dest, const char* source, uint32 size);
 
 #define MAX_SPECIAL_ATTACK_PARAMS 8
 
+struct LOSEntry {
+	Mob *entry;
+	bool isLOS;
+	uint32 lastChecked; // Timer::GetCurrentTime entry to compare
+	uint32 hits; // times the entry was hit in the timeframe of the cache
+
+	// target last location
+	float lastX;
+	float lastY;
+	float lastZ;
+
+	// our last location when we got this entry
+	float ourLastX;
+	float ourLastY;
+	float ourLastZ;
+};
+
 class EGNode;
 class MobFearState;
 class Mob : public Entity {
@@ -447,6 +464,7 @@ public:
 	void ClearFeignMemory();
 	void PrintHateListToClient(Client *who) { hate_list.PrintToClient(who); }
 	std::list<tHateEntry*>& GetHateList() { return hate_list.GetHateList(); }
+	bool FindLosCacheEntry(Mob *other, bool &inLOS, uint32 &hits);
 	bool CheckLos(Mob* other);
 	bool CheckLosFN(Mob* other);
 	bool CheckLosFN(float posX, float posY, float posZ, float mobSize);
@@ -887,6 +905,8 @@ protected:
 	std::vector<uint16> RampageArray;
 	std::map<std::string, std::string> m_EntityVariables;
 
+	std::map<uint16, LOSEntry> m_LOSCache;
+
 	int16 SkillDmgTaken_Mod[HIGHEST_SKILL+2];
 	int16 Vulnerability_Mod[HIGHEST_RESIST+2];
 	bool m_AllowBeneficial;