cdev-1.7.2n

extensions/cdevGenericServer/common/StringHash.h

@@ -0,0 +1,235 @@
+#ifndef _VAR_STRING_HASH_H_
+#define _VAR_STRING_HASH_H_ 1
+
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+class StringHashNode
+{
+friend class StringHash;
+friend class StringHashIterator;
+
+private:
+	int              copyKeyFlag;
+	char           * hashString;
+	void           * hashData;
+	StringHashNode * next;
+
+	StringHashNode  ( char * HashString, void * HashData, int copyKey=1);
+	~StringHashNode ( void );
+};
+
+
+class StringHash
+{
+friend class StringHashIterator;
+
+private:
+	int               tableSize;
+	int               copyKeyFlag;
+	StringHashNode ** nodes;
+	
+public:
+	StringHash  (int copyKey = 1, int TableSize = 255 );
+	~StringHash ( void );
+
+	inline unsigned int stringHash ( char * hashString );
+
+	inline void insert ( char * hashString, void * hashData );
+	inline void remove ( char * hashString );
+	inline void * find ( char * hashString );
+};
+
+
+class StringHashIterator
+{
+private:
+	StringHash     * hashTbl;
+	StringHashNode * node;
+	int              idx;	
+
+public:
+	StringHashIterator( StringHash * HashTbl );	
+	~StringHashIterator( void );
+	
+	inline void * first       ( void );
+	inline void * operator ++ ( void );
+	inline void * operator ++ ( int x );
+	inline char * key         ( void );
+	inline void * data        ( void );
+};
+
+
+inline StringHashNode::StringHashNode ( char * HashString, void * HashData, int copyKey )
+	: next(NULL), copyKeyFlag(copyKey)
+	{
+	if(copyKeyFlag) hashString = strdup(HashString);
+	else            hashString = HashString;
+        hashData  = HashData;
+	}
+
+
+inline StringHashNode::~StringHashNode ( void )
+	{
+	if(copyKeyFlag) delete hashString;
+        }
+
+
+inline StringHash::StringHash  ( int copyKey, int TableSize ) 
+	: copyKeyFlag(copyKey), tableSize (TableSize)
+	{
+	nodes = new StringHashNode * [tableSize];
+	memset(nodes, 0, sizeof(StringHashNode *) * tableSize );
+	}
+
+
+inline StringHash::~StringHash ( void )
+	{
+	for(int i=0; i<tableSize; i++)
+		{
+		while(nodes[i]!=NULL)
+			{
+			StringHashNode * node = nodes[i];
+			nodes[i] = node->next;
+			delete node;
+                        }
+		}
+	delete nodes;
+	}
+
+inline unsigned int StringHash::stringHash ( char * hashString )
+	{
+	unsigned int hash = 0, g;
+
+	for (int i = 0; hashString[i] != '\0'; i++)
+		{
+		hash = (hash << 4) + hashString[i];
+		if (g = hash & 0xf0000000)
+			{
+			hash ^= g >> 24;
+			hash ^= g;
+			}
+		}
+	return (hash % tableSize);
+	}
+
+inline void StringHash::insert (char * hashString, void * hashData )
+	{
+	unsigned int idx = stringHash(hashString);
+	StringHashNode * prev    = NULL, * node = nodes[idx];
+	StringHashNode * newNode = new StringHashNode(hashString, hashData, copyKeyFlag);
+
+	while(node!=NULL && strcmp(node->hashString, hashString))
+		{
+		prev = node;
+		node = prev->next;
+		}
+	if(node!=NULL)
+		{
+		newNode->next = node->next;
+		delete node;
+		}
+	if(prev!=NULL) prev->next = newNode;
+	else           nodes[idx] = newNode;
+	}
+
+inline void StringHash::remove ( char * hashString )
+	{
+	unsigned int idx = stringHash(hashString);
+	StringHashNode * prev = NULL, * node = nodes[idx];
+	while(node!=NULL && strcmp(node->hashString, hashString))
+		{
+		prev = node;
+		node = prev->next;
+		}
+	if(node!=NULL)
+		{
+		if(prev!=NULL) prev->next = node->next;
+		else           nodes[idx] = node->next;
+		delete node;
+		}
+	}
+
+inline void * StringHash::find ( char * hashString )
+	{
+	unsigned int idx = stringHash(hashString);
+	StringHashNode * prev = NULL, * node = nodes[idx];
+	while(node!=NULL && strcmp(node->hashString, hashString))
+		{
+		prev = node;
+		node = prev->next;
+		}
+	return node!=NULL?node->hashData:NULL;
+	}
+
+
+inline StringHashIterator::StringHashIterator(StringHash * HashTbl)
+	: hashTbl(HashTbl), idx(0), node(NULL)
+	{
+	}
+	
+inline StringHashIterator::~StringHashIterator( void ) 
+	{
+	}
+	
+inline void * StringHashIterator::first ( void )
+	{
+	if(hashTbl!=NULL)
+		{
+		for(idx = 0; idx<hashTbl->tableSize &&
+		   (node = hashTbl->nodes[idx])==NULL; idx++);
+		}
+	else node = NULL;
+	return (node!=NULL)?node->hashData:NULL;
+	}
+	
+inline void * StringHashIterator::operator ++ ( void )
+	{
+	if(hashTbl!=NULL)
+		{
+		if(node==NULL) first();
+		else if(node->next!=NULL) node = node->next;
+		else 
+			{
+			node = NULL;
+			do 	{
+				idx++;
+				} while(idx<hashTbl->tableSize && 
+				       (node = hashTbl->nodes[idx])==NULL);
+			}
+		}
+	else node = NULL;
+	return (node!=NULL)?node->hashData:NULL;
+	}
+	
+inline void * StringHashIterator::operator ++ ( int x )
+	{
+	if(hashTbl!=NULL && x==0)
+		{
+		if(node==NULL) first();
+		else if(node->next!=NULL) node = node->next;
+		else 
+			{
+			node = NULL;
+			do 	{
+				idx++;
+				} while(idx<hashTbl->tableSize && 
+				       (node = hashTbl->nodes[idx])==NULL);
+			}
+		}
+	else node = NULL;
+	return (node!=NULL)?node->hashData:NULL;
+	}
+
+inline char * StringHashIterator::key ( void )
+	{
+	return (node!=NULL)?node->hashString:(char *)NULL;
+	}
+	
+inline void * StringHashIterator::data ( void )
+	{
+	return (node!=NULL)?node->hashData:NULL;
+	}
+	
+#endif /* _VAR_STRING_HASH_H_ */