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public/tier1/stringpool.h

@@ -0,0 +1,91 @@
+//========= Copyright Valve Corporation, All rights reserved. ============//
+//
+// Purpose:
+//
+// $NoKeywords: $
+//=============================================================================//
+
+#ifndef STRINGPOOL_H
+#define STRINGPOOL_H
+
+#if defined( _WIN32 )
+#pragma once
+#endif
+
+#include "utlrbtree.h"
+#include "utlvector.h"
+
+//-----------------------------------------------------------------------------
+// Purpose: Allocates memory for strings, checking for duplicates first,
+//			reusing exising strings if duplicate found.
+//-----------------------------------------------------------------------------
+
+class CStringPool
+{
+public:
+	CStringPool();
+	~CStringPool();
+
+	unsigned int Count() const;
+
+	const char * Allocate( const char *pszValue );
+	void FreeAll();
+
+	// searches for a string already in the pool
+	const char * Find( const char *pszValue );
+
+protected:
+	typedef CUtlRBTree<const char *, unsigned short> CStrSet;
+
+	CStrSet m_Strings;
+};
+
+//-----------------------------------------------------------------------------
+// Purpose: A reference counted string pool.  
+//
+// Elements are stored more efficiently than in the conventional string pool, 
+// quicker to look up, and storage is tracked via reference counts.  
+//
+// At some point this should replace CStringPool
+//-----------------------------------------------------------------------------
+class CCountedStringPool
+{
+public: // HACK, hash_item_t structure should not be public.
+
+	struct hash_item_t
+	{
+		char*			pString;
+		unsigned short	nNextElement;
+		unsigned char	nReferenceCount;
+		unsigned char	pad;
+	};
+
+	enum
+	{
+		INVALID_ELEMENT = 0,
+		MAX_REFERENCE   = 0xFF,
+		HASH_TABLE_SIZE = 1024
+	};
+
+	CUtlVector<unsigned short>	m_HashTable;	// Points to each element
+	CUtlVector<hash_item_t>		m_Elements;
+	unsigned short				m_FreeListStart;
+
+public:
+	CCountedStringPool();
+	virtual ~CCountedStringPool();
+
+	void			FreeAll();
+
+	char			*FindString( const char* pIntrinsic ); 
+	char			*ReferenceString( const char* pIntrinsic );
+	void			DereferenceString( const char* pIntrinsic );
+
+	// These are only reliable if there are less than 64k strings in your string pool
+	unsigned short	FindStringHandle( const char* pIntrinsic ); 
+	unsigned short	ReferenceStringHandle( const char* pIntrinsic );
+	char			*HandleToString( unsigned short handle );
+	void			SpewStrings();
+};
+
+#endif // STRINGPOOL_H