Added a crude limiter for explosions sent to client.

Now the client can survive even 3000k TNT blocks exploding without jerking much.

git-svn-id: http://mc-server.googlecode.com/svn/trunk@1606 0a769ca7-a7f5-676a-18bf-c427514a06d6

source/ClientHandle.cpp

@@ -47,6 +47,12 @@
 /// If the number of queued outgoing packets reaches this, the client will be kicked
 #define MAX_OUTGOING_PACKETS 2000
 
+/// How many explosions per single game tick are allowed
+static const int MAX_EXPLOSIONS_PER_TICK = 100;
+
+/// How many explosions in the recent history are allowed
+static const int MAX_RUNNING_SUM_EXPLOSIONS = cClientHandle::NUM_CHECK_EXPLOSIONS_TICKS * MAX_EXPLOSIONS_PER_TICK / 8;
+
 
 
 
@@ -87,6 +93,8 @@ cClientHandle::cClientHandle(const cSocket * a_Socket, int a_ViewDistance)
 	, m_UniqueID(0)
 	, m_BlockDigAnimStage(-1)
 	, m_HasStartedDigging(false)
+	, m_CurrentExplosionTick(0)
+	, m_RunningSumExplosions(0)
 {
 	m_Protocol = new cProtocolRecognizer(this);
 	
@@ -1310,6 +1318,11 @@ void cClientHandle::Tick(float a_Dt)
 			m_Player->GetWorld()->BroadcastBlockBreakAnimation(m_UniqueID, m_BlockDigAnimX, m_BlockDigAnimY, m_BlockDigAnimZ, (char)(m_BlockDigAnimStage / 1000), this);
 		}
 	}
+	
+	// Update the explosion statistics:
+	m_CurrentExplosionTick = (m_CurrentExplosionTick + 1) % ARRAYCOUNT(m_NumExplosionsPerTick);
+	m_RunningSumExplosions -= m_NumExplosionsPerTick[m_CurrentExplosionTick];
+	m_NumExplosionsPerTick[m_CurrentExplosionTick] = 0;
 }
 
 
@@ -1563,7 +1576,20 @@ void cClientHandle::SendEntityStatus(const cEntity & a_Entity, char a_Status)
 
 void cClientHandle::SendExplosion(double a_BlockX, double a_BlockY, double a_BlockZ, float a_Radius, const cVector3iArray & a_BlocksAffected, const Vector3d & a_PlayerMotion)
 {
-	m_Protocol->SendExplosion(a_BlockX,a_BlockY,a_BlockZ,a_Radius, a_BlocksAffected, a_PlayerMotion);
+	if (
+		(m_NumExplosionsPerTick[m_CurrentExplosionTick] > MAX_EXPLOSIONS_PER_TICK) ||  // Too many explosions in this tick
+		(m_RunningSumExplosions > MAX_RUNNING_SUM_EXPLOSIONS)  // Too many explosions in the recent history
+	)
+	{
+		LOGD("Dropped %u explosions", a_BlocksAffected.size());
+		return;
+	}
+	
+	// Update the statistics:
+	m_NumExplosionsPerTick[m_CurrentExplosionTick] += a_BlocksAffected.size();
+	m_RunningSumExplosions += a_BlocksAffected.size();
+	
+	m_Protocol->SendExplosion(a_BlockX, a_BlockY, a_BlockZ, a_Radius, a_BlocksAffected, a_PlayerMotion);
 }
 
 

source/ClientHandle.h

@@ -56,7 +56,10 @@ public:
 #endif
 	static const int MAX_VIEW_DISTANCE = 10;
 	static const int MIN_VIEW_DISTANCE = 4;
-
+	
+	/// How many ticks should be checked for a running average of explosions, for limiting purposes
+	static const int NUM_CHECK_EXPLOSIONS_TICKS = 20;
+	
 	cClientHandle(const cSocket * a_Socket, int a_ViewDistance);
 	virtual ~cClientHandle();
 
@@ -258,6 +261,17 @@ private:
 	/// If set to true during csDownloadingWorld, the tick thread calls CheckIfWorldDownloaded()
 	bool m_ShouldCheckDownloaded;
 
+	/// Stores the recent history of the number of explosions per tick
+	int m_NumExplosionsPerTick[NUM_CHECK_EXPLOSIONS_TICKS];
+	
+	/// Points to the current tick in the m_NumExplosionsPerTick[] array
+	int m_CurrentExplosionTick;
+	
+	/// Running sum of m_NumExplosionsPerTick[]
+	int m_RunningSumExplosions;
+	
+
+
 	/// Returns true if the rate block interactions is within a reasonable limit (bot protection)
 	bool CheckBlockInteractionsRate(void);