1 files changed, 96 insertions, 0 deletions
diff --git a/src/engine/shared/memheap.cpp b/src/engine/shared/memheap.cpp
new file mode 100644
index 00000000..6661962b
--- /dev/null
+++ b/src/engine/shared/memheap.cpp
@@ -0,0 +1,96 @@
+// copyright (c) 2007 magnus auvinen, see licence.txt for more info
+#include <base/system.h>
+#include "memheap.h"
+
+static const int CHUNK_SIZE = 1024*64;
+
+// allocates a new chunk to be used
+void CHeap::NewChunk()
+{
+	CChunk *pChunk;
+	char *pMem;
+	
+	// allocate memory
+	pMem = (char*)mem_alloc(sizeof(CChunk)+CHUNK_SIZE, 1);
+	if(!pMem)
+		return;
+
+	// the chunk structure is located in the begining of the chunk
+	// init it and return the chunk
+	pChunk = (CChunk*)pMem;
+	pChunk->m_pMemory = (char*)(pChunk+1);
+	pChunk->m_pCurrent = pChunk->m_pMemory;
+	pChunk->m_pEnd = pChunk->m_pMemory + CHUNK_SIZE;
+	pChunk->m_pNext = (CChunk *)0x0;
+
+	pChunk->m_pNext = m_pCurrent;
+	m_pCurrent = pChunk;	
+}
+
+//****************
+void *CHeap::AllocateFromChunk(unsigned int Size)
+{
+	char *pMem;
+	
+	// check if we need can fit the allocation
+	if(m_pCurrent->m_pCurrent + Size > m_pCurrent->m_pEnd)
+		return (void*)0x0;
+
+	// get memory and move the pointer forward
+	pMem = m_pCurrent->m_pCurrent;
+	m_pCurrent->m_pCurrent += Size;
+	return pMem;
+}
+
+// creates a heap
+CHeap::CHeap()
+{
+	m_pCurrent = 0x0;
+	Reset();
+}
+
+CHeap::~CHeap()
+{
+	Clear();
+}
+
+void CHeap::Reset()
+{
+	Clear();
+	NewChunk();
+}
+
+// destroys the heap
+void CHeap::Clear()
+{
+	CChunk *pChunk = m_pCurrent;
+	CChunk *pNext;
+	
+	while(pChunk)
+	{
+		pNext = pChunk->m_pNext;
+		mem_free(pChunk);
+		pChunk = pNext;
+	}
+	
+	m_pCurrent = 0x0;
+}
+
+//
+void *CHeap::Allocate(unsigned Size)
+{
+	char *pMem;
+
+	// try to allocate from current chunk
+	pMem = (char *)AllocateFromChunk(Size);
+	if(!pMem)
+	{
+		// allocate new chunk and add it to the heap
+		NewChunk();
+		
+		// try to allocate again
+		pMem = (char *)AllocateFromChunk(Size);
+	}
+	
+	return pMem;
+}