1HEADmaster

1 files changed, 117 insertions, 0 deletions

diff --git a/common/cstringhash.h b/common/cstringhash.h
new file mode 100644
index 0000000..7703f4c
--- /dev/null
+++ b/common/cstringhash.h
@@ -0,0 +1,117 @@
+//========= Copyright Valve Corporation, All rights reserved. ============//
+//
+// Purpose: 
+//
+// $NoKeywords: $
+//=============================================================================//
+
+#ifndef CSTRINGHASH_H
+#define CSTRINGHASH_H
+#pragma once
+
+#include "string.h"
+
+#define STRING_HASH_TABLE_SIZE 701
+
+template <class T> class CStringHash
+{
+public:
+	CStringHash() 
+	{
+		memset( m_HashTable, 0, sizeof( StringHashNode_t * ) * STRING_HASH_TABLE_SIZE );
+	}
+	~CStringHash()
+	{
+		int i;
+
+		for( i = 0; i < STRING_HASH_TABLE_SIZE; i++ )
+		{
+			StringHashNode_t *curEntry;
+			curEntry = m_HashTable[i];
+			if( curEntry )
+			{
+				StringHashNode_t *next;
+				next = curEntry->next;
+				delete curEntry;
+				curEntry = next;
+			}
+		}
+	}
+	// return false if it already exists
+	// there can only be one entry for each string.
+	bool Insert( const char *string, T val )
+	{
+		unsigned int hashID = HashString( string );
+		StringHashNode_t *newEntry;
+		if( !m_HashTable[hashID] )
+		{
+			// first on at this hashID
+			// fixme: need to make the allocation function configurable.
+			newEntry = m_HashTable[hashID] = new StringHashNode_t;
+			newEntry->next = NULL;
+		}
+		else
+		{
+			StringHashNode_t *curEntry;
+			curEntry = m_HashTable[hashID];
+			while( curEntry )
+			{
+				if( stricmp( curEntry->string, string ) == 0 )
+				{
+					// replace the data at the current entry with the enw data.
+					curEntry->data = val;
+					return false;
+				}
+				curEntry = curEntry->next;
+			}
+			newEntry = new StringHashNode_t;
+			newEntry->next = m_HashTable[hashID];
+			m_HashTable[hashID] = newEntry;
+		}
+		int len = strlen( string ) + 1;
+		newEntry->string = new char[len];
+		Q_strncpy( newEntry->string, string, len );
+		newEntry->data = val;
+		return true;
+	}
+
+	T Find( const char *string )
+	{
+		int hashID = HashString( string );
+		StringHashNode_t *curEntry;
+		curEntry = m_HashTable[hashID];
+		while( curEntry )
+		{
+			if( stricmp( curEntry->string, string ) == 0 )
+			{
+				return curEntry->data;
+			}
+			curEntry = curEntry->next;
+		}
+		return NULL;
+	}
+
+private:
+	unsigned int HashString( const char *string )
+	{
+		const char *s = string;
+		unsigned int result = 0;
+
+		while( *s )
+		{
+			result += tolower( ( int )*s ) * 6029;
+			result *= 5749;
+			s++;
+		}
+		return result % STRING_HASH_TABLE_SIZE;
+	}
+	typedef struct StringHashNode_s
+	{
+		char *string;
+		T data;
+		struct StringHashNode_s *next;
+	} StringHashNode_t;
+	StringHashNode_t *m_HashTable[STRING_HASH_TABLE_SIZE];
+};
+
+#endif // CSTRINGHASH_H