1 files changed, 176 insertions, 0 deletions
diff --git a/Minecraft.Client/Common/C4JMemoryPool.h b/Minecraft.Client/Common/C4JMemoryPool.h
new file mode 100644
index 00000000..e1e795ec
--- /dev/null
+++ b/Minecraft.Client/Common/C4JMemoryPool.h
@@ -0,0 +1,176 @@
+
+#pragma once
+ 
+
+#include <stdlib.h>
+
+class C4JMemoryPool
+{
+public:
+	unsigned int Align(unsigned int val, unsigned int align) { 		return int((val+(align-1))/align) * align; }
+	virtual void* Alloc(size_t size) = 0;
+	virtual void Free(void* ptr) = 0;
+};
+
+
+
+// Fast Efficient Fixed-Size Memory Pool : No Loops and No Overhead
+// http://www.alogicalmind.com/memory_pools/index.htm
+class C4JMemoryPoolFixed : public C4JMemoryPool
+{ 
+	// Basic type define
+	typedef unsigned int uint;
+	typedef unsigned char uchar;
+	uint m_numOfBlocks; // Num of blocks
+	uint m_sizeOfEachBlock; // Size of each block
+	uint m_numFreeBlocks; // Num of remaining blocks
+	uint m_numInitialized; // Num of initialized blocks
+	uchar* m_memStart; // Beginning of memory pool
+	uchar* m_memEnd; // End of memory pool
+	uchar* m_next; // Num of next free block
+// 	CRITICAL_SECTION m_CS;
+public:
+	C4JMemoryPoolFixed()
+	{
+		m_numOfBlocks = 0;
+		m_sizeOfEachBlock = 0;
+		m_numFreeBlocks = 0;
+		m_numInitialized = 0;
+		m_memStart = NULL;
+		m_memEnd = NULL;
+		m_next = 0;
+	}
+
+	C4JMemoryPoolFixed(uint sizeOfEachBlock,	uint numOfBlocks)
+	{
+		CreatePool(sizeOfEachBlock, numOfBlocks);
+	}
+
+	~C4JMemoryPoolFixed() { DestroyPool(); }
+
+	void CreatePool(uint sizeOfEachBlock,	uint numOfBlocks)
+	{
+		assert(sizeOfEachBlock >= 4); // has to be at least the size of an int, for book keeping
+		m_numOfBlocks = numOfBlocks;
+		m_sizeOfEachBlock = sizeOfEachBlock;
+		m_numFreeBlocks = numOfBlocks;
+		m_numInitialized = 0;
+		m_memStart = new uchar[ m_sizeOfEachBlock *
+			m_numOfBlocks ];
+		m_memEnd = m_memStart + (m_sizeOfEachBlock * m_numOfBlocks);
+		m_next = m_memStart;
+// 		InitializeCriticalSection(&m_CS);
+	}
+
+	void DestroyPool()
+	{
+		delete[] m_memStart;
+		m_memStart = NULL;
+	}
+
+	uchar* AddrFromIndex(uint i) const
+	{
+		return m_memStart + ( i * m_sizeOfEachBlock );
+	}
+
+	uint IndexFromAddr(const uchar* p) const
+	{
+		return (((uint)(p - m_memStart)) / m_sizeOfEachBlock);
+	}
+
+	virtual void* Alloc(size_t size)
+	{
+		if(size > m_sizeOfEachBlock)
+			return ::malloc(size);
+// 		EnterCriticalSection(&m_CS);
+		if (m_numInitialized < m_numOfBlocks )
+		{
+			uint* p = (uint*)AddrFromIndex( m_numInitialized );
+			*p = m_numInitialized + 1;
+			m_numInitialized++;
+		}
+		void* ret = NULL;
+		if ( m_numFreeBlocks > 0 )
+		{
+			ret = (void*)m_next;
+			--m_numFreeBlocks;
+			if (m_numFreeBlocks!=0)
+			{
+				m_next = AddrFromIndex( *((uint*)m_next) );
+			}
+			else
+			{
+				m_next = NULL;
+			}
+		}
+// 		LeaveCriticalSection(&m_CS);
+		return ret;
+	}
+
+	virtual void Free(void* ptr)
+	{
+		if(ptr < m_memStart || ptr > m_memEnd)
+		{
+			::free(ptr);
+			return;
+		}
+// 		EnterCriticalSection(&m_CS);
+		if (m_next != NULL)
+		{
+			(*(uint*)ptr) = IndexFromAddr( m_next );
+			m_next = (uchar*)ptr;
+		}
+		else
+		{
+			*((uint*)ptr) = m_numOfBlocks;
+			m_next = (uchar*)ptr;
+		}
+		++m_numFreeBlocks;
+// 		LeaveCriticalSection(&m_CS);
+	}
+}; // End pool class
+
+
+// this pool will constantly grow until it is reset (automatically when all allocs have been "freed")
+class C4JMemoryPoolGrow : public C4JMemoryPool
+{
+	uint32_t	m_totalSize;
+	uint32_t	m_memUsed;
+	uint32_t	m_numAllocations;
+	uint8_t*	m_pMemory;
+	uint32_t	m_currentOffset;
+
+public:
+	C4JMemoryPoolGrow(uint32_t size = 64*1024)
+	{
+		size = Align(size, 4);
+		m_totalSize = size;
+		m_pMemory = new uint8_t[size];
+		m_currentOffset = 0;
+		m_memUsed = 0;
+		m_numAllocations = 0;
+	}
+
+	virtual void* Alloc(size_t size)
+	{
+		size = Align(size, 4);								// 4 byte align the memory
+		assert((m_currentOffset + size) < m_totalSize);		// make sure we haven't ran out of space
+		void* returnMem = &m_pMemory[m_currentOffset];		// grab the return memory
+		m_currentOffset += size;							
+		m_numAllocations++;
+		return returnMem;
+	}
+	virtual void Free(void* ptr)
+	{
+		m_numAllocations--;
+		if(m_numAllocations == 0)
+			m_currentOffset = 0;		// reset the pool when we reach zero allocations
+	}
+};
+
+
+
+
+
+
+