New cChunkStay class for temporarily keeping chunks loaded even when then have no clients. For now unused, will be used by generator and lighting in the future.

git-svn-id: http://mc-server.googlecode.com/svn/trunk@330 0a769ca7-a7f5-676a-18bf-c427514a06d6

source/cChunk.cpp

@@ -85,6 +85,7 @@ cChunk::cChunk(int a_X, int a_Y, int a_Z, cChunkMap * a_ChunkMap, cWorld * a_Wor
 	, m_IsValid(false)
 	, m_IsDirty(false)
 	, m_IsSaving(false)
+	, m_StayCount(0)
 {
 	// LOGINFO("### new cChunk (%i, %i) at %p, thread 0x%x ###", a_X, a_Z, this, GetCurrentThreadId());
 }
@@ -164,7 +165,7 @@ void cChunk::SetValid(bool a_SendToClients)
 
 bool cChunk::CanUnload(void)
 {
-	return m_LoadedByClient.empty() && !m_IsDirty;
+	return m_LoadedByClient.empty() && !m_IsDirty && (m_StayCount == 0);
 }
 
 
@@ -298,6 +299,17 @@ bool cChunk::HasBlockEntityAt(int a_BlockX, int a_BlockY, int a_BlockZ)
 
 
 
+/// Sets or resets the internal flag that prevents chunk from being unloaded
+void cChunk::Stay(bool a_Stay)
+{
+	m_StayCount += (a_Stay ? 1 : -1);
+	ASSERT(m_StayCount >= 0);
+}
+
+
+
+
+
 void cChunk::Tick(float a_Dt, MTRand & a_TickRandom)
 {
 	if (m_bCalculateLighting)

source/cChunk.h

@@ -146,6 +146,9 @@ public:
 	/// Returns true if there is a block entity at the coords specified
 	bool HasBlockEntityAt(int a_BlockX, int a_BlockY, int a_BlockZ);
 	
+	/// Sets or resets the internal flag that prevents chunk from being unloaded
+	void Stay(bool a_Stay = true);
+	
 	void Tick(float a_Dt, MTRand & a_TickRandom);
 
 	int GetPosX() { return m_PosX; }
@@ -239,6 +242,9 @@ private:
 	cEntityList        m_Entities;
 	cBlockEntityList   m_BlockEntities;
 	
+	/// Number of times the chunk has been requested to stay (by various cChunkStay objects); if zero, the chunk can be unloaded
+	int m_StayCount;
+
 	bool m_bCalculateLighting;
 
 	int m_PosX, m_PosY, m_PosZ;

source/cChunkMap.cpp

@@ -755,6 +755,21 @@ void cChunkMap::UpdateSign(int a_X, int a_Y, int a_Z, const AString & a_Line1, c
 
 
 
+void cChunkMap::ChunkStay(int a_ChunkX, int a_ChunkY, int a_ChunkZ, bool a_Stay)
+{
+	cCSLock Lock(m_CSLayers);
+	cChunkPtr Chunk = GetChunkNoGen(a_ChunkX, a_ChunkY, a_ChunkZ);
+	if (Chunk == NULL)
+	{
+		return;
+	}
+	Chunk->Stay(a_Stay);
+}
+
+
+
+
+
 void cChunkMap::Tick( float a_Dt, MTRand & a_TickRandom )
 {
 	cCSLock Lock(m_CSLayers);
@@ -939,3 +954,79 @@ void cChunkMap::ChunkValidated(void)
 
 
 
+
+///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// cChunkStay:
+
+cChunkStay::cChunkStay(cWorld * a_World) :
+	m_World(a_World)
+{
+}
+
+
+
+
+
+cChunkStay::~cChunkStay()
+{
+	Clear();
+}
+
+
+
+
+
+void cChunkStay::Clear(void)
+{
+	cChunkCoordsList Chunks;
+	{
+		cCSLock Lock(m_CS);
+		std::swap(Chunks, m_Chunks);
+	}
+	
+	// Un-"stay" all chunks:
+	for (cChunkCoordsList::const_iterator itr = Chunks.begin(); itr != Chunks.end(); ++itr)
+	{
+		m_World->ChunkStay(itr->m_ChunkX, itr->m_ChunkY, itr->m_ChunkZ, false);
+	}  // for itr - Chunks[]
+}
+
+
+
+
+
+void cChunkStay::Add(int a_ChunkX, int a_ChunkY, int a_ChunkZ)
+{
+	cCSLock Lock(m_CS);
+	for (cChunkCoordsList::const_iterator itr = m_Chunks.begin(); itr != m_Chunks.end(); ++itr)
+	{
+		if ((itr->m_ChunkX == a_ChunkX) && (itr->m_ChunkY == a_ChunkY) && (itr->m_ChunkZ == a_ChunkZ))
+		{
+			// Already "stayed"
+			return;
+		}
+	}  // for itr - Chunks[]
+	m_World->ChunkStay(a_ChunkX, a_ChunkY, a_ChunkZ);
+}
+
+
+
+
+
+void cChunkStay::Remove(int a_ChunkX, int a_ChunkY, int a_ChunkZ)
+{
+	cCSLock Lock(m_CS);
+	for (cChunkCoordsList::const_iterator itr = m_Chunks.begin(); itr != m_Chunks.end(); ++itr)
+	{
+		if ((itr->m_ChunkX == a_ChunkX) && (itr->m_ChunkY == a_ChunkY) && (itr->m_ChunkZ == a_ChunkZ))
+		{
+			// Found, un-"stay"
+			m_World->ChunkStay(a_ChunkX, a_ChunkY, a_ChunkZ, false);
+			return;
+		}
+	}  // for itr - Chunks[]
+}
+
+
+
+

source/cChunkMap.h

@@ -15,6 +15,7 @@ class cWorld;
 class cEntity;
 class cItem;
 class MTRand;
+class cChunkStay;
 
 
 
@@ -84,6 +85,9 @@ public:
 	
 	void UpdateSign(int a_X, int a_Y, int a_Z, const AString & a_Line1, const AString & a_Line2, const AString & a_Line3, const AString & a_Line4);
 	
+	/// Marks (a_Stay == true) or unmarks (a_Stay == false) a chunk as non-unloadable; to be used only by cChunkStay!
+	void ChunkStay(int a_ChunkX, int a_ChunkY, int a_ChunkZ, bool a_Stay = true);
+
 	void Tick( float a_Dt, MTRand & a_TickRand );
 
 	void UnloadUnusedChunks();
@@ -173,3 +177,29 @@ private:
 
 
 
+
+/** Makes chunks stay loaded until this object is cleared or destroyed
+Works by setting internal flags in the cChunk that it should not be unloaded
+*/
+class cChunkStay
+{
+public:
+	cChunkStay(cWorld * a_World);
+	~cChunkStay();
+	
+	void Clear(void);
+	
+	void Add(int a_ChunkX, int a_ChunkY, int a_ChunkZ);
+	void Remove(int a_ChunkX, int a_ChunkY, int a_ChunkZ);
+	
+protected:
+
+	cWorld * m_World;
+	
+	cCriticalSection m_CS;
+	cChunkCoordsList m_Chunks;
+} ;
+
+
+
+

source/cWorld.cpp

@@ -1297,6 +1297,15 @@ void cWorld::UpdateSign(int a_X, int a_Y, int a_Z, const AString & a_Line1, cons
 
 
 
+void cWorld::ChunkStay(int a_ChunkX, int a_ChunkY, int a_ChunkZ, bool a_Stay)
+{
+	m_ChunkMap->ChunkStay(a_ChunkX, a_ChunkY, a_ChunkZ, a_Stay);
+}
+
+
+
+
+
 void cWorld::SaveAllChunks()
 {
 	LOG("Saving all chunks...");

source/cWorld.h

@@ -129,6 +129,9 @@ public:
 	
 	void UpdateSign(int a_X, int a_Y, int a_Z, const AString & a_Line1, const AString & a_Line2, const AString & a_Line3, const AString & a_Line4);
 
+	/// Marks (a_Stay == true) or unmarks (a_Stay == false) a chunk as non-unloadable; to be used only by cChunkStay!
+	void ChunkStay(int a_ChunkX, int a_ChunkY, int a_ChunkZ, bool a_Stay = true);
+
 	// TODO: Export to Lua
 	bool DoWithEntity( int a_UniqueID, cEntityCallback & a_Callback );