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hammer/blockarray.h

@@ -0,0 +1,101 @@
+//========= Copyright Valve Corporation, All rights reserved. ============//
+//
+// Purpose: 
+//
+// $NoKeywords: $
+//
+//=============================================================================//
+
+#ifndef _BLOCKARRAY_H
+#define _BLOCKARRAY_H
+
+#include "tier0/dbg.h"
+
+// memdbgon must be the last include file in a .cpp file!!!
+#include <tier0/memdbgon.h>
+
+template <class T, int nBlockSize, int nMaxBlocks>
+class BlockArray
+{
+public:
+	BlockArray()
+	{
+		nCount = nBlocks = 0;
+	}
+	~BlockArray()
+	{
+		GetBlocks(0);
+	}
+
+	T& operator[] (int iIndex);
+	
+	void SetCount(int nObjects);
+	int GetCount() { return nCount; }
+
+private:
+	T * Blocks[nMaxBlocks+1];
+	short nCount;
+	short nBlocks;
+	void GetBlocks(int nNewBlocks);
+};
+
+template <class T, int nBlockSize, int nMaxBlocks>
+void BlockArray<T,nBlockSize,nMaxBlocks>::
+	GetBlocks(int nNewBlocks)
+{
+	for(int i = nBlocks; i < nNewBlocks; i++)
+	{
+		Blocks[i] = new T[nBlockSize];
+	}
+	for(int i = nNewBlocks; i < nBlocks; i++)
+	{
+		delete[] Blocks[i];
+	}
+
+	nBlocks = nNewBlocks;
+}
+
+template <class T, int nBlockSize, int nMaxBlocks>
+void BlockArray<T,nBlockSize,nMaxBlocks>::
+	SetCount(int nObjects)
+{
+	if(nObjects == nCount)
+		return;
+
+	// find the number of blocks required by nObjects, checking for
+	// integer rounding error
+	int nNewBlocks = (nObjects / nBlockSize);
+	if ((nNewBlocks * nBlockSize) < nObjects)
+	{
+		nNewBlocks++;
+	}
+
+	if(nNewBlocks != nBlocks)
+	{
+		// Make sure we don't get an overrun.
+		if ( nNewBlocks > ARRAYSIZE( Blocks ) )
+		{
+			Error( "BlockArray< ?, %d, %d > - too many blocks needed.", nBlockSize, nMaxBlocks );
+		}
+		
+		GetBlocks(nNewBlocks);
+	}
+	nCount = nObjects;
+}
+
+template <class T, int nBlockSize, int nMaxBlocks>
+T& BlockArray<T,nBlockSize,nMaxBlocks>::operator[] (int iIndex)
+{
+	// Cast to unsigned so that this check will reject negative values as
+	// well as overly large values.
+	if((unsigned)iIndex >= (unsigned)nCount)
+	{
+		Error( "BlockArray< %d, %d > - invalid block index.", iIndex, nCount );
+		SetCount(iIndex+1);
+	}
+	return Blocks[iIndex / nBlockSize][iIndex % nBlockSize];
+}
+
+#include <tier0/memdbgoff.h>
+
+#endif // _BLOCKARRAY_H