seshashmap.h

在LINUX环境下

/****************************************************************************
 *
 *         (c) Copyright 2006 by SCADA Enterprise Solutions Inc
 *         All rights reserved
 *
 * NAME:
 *
 *         sesHashMap.H -- This is the header file for declaring all data
 *                         of a hashmap which takes a string as key and
 *                         returns an integer.
 *
 * AUTHOR: Wai Tse
 *
 * DESCRIPTION:
 *
 *         This file contains all data structures used by a hashmap
 *
 * RESTRICTION:
 *         None
 *
 * REVISION HISTORY:
 *
 *         10-Mar-2006    Wai Tse    Created the initial version.
 *
 ***************************************************************************/
#ifndef HASHMAP_H
#define HASHMAP_H

#include <malloc.h>
#include <stdlib.h>
#include "sesConst.H"
#include "sesDbg.H"
#include "sesLogErr.H"

#define MAP_EXIST -3    // Element exists
#define MAP_MISSING -3  // No such element
#define MAP_FULL -2 	// Hashmap is full
#define MAP_OMEM -1 	// Out of Memory
#define MAP_OK 0 	// OK
#define SIZE_FACTOR 4   // Factor to set the size of a hash map
#define KEY_SIZE 20     // Size of the hash key

// any_t is a pointer of any type.
typedef void *any_t;

// PFany is a pointer to a function that can take two any_t arguments
// and return an integer. Returns status code..
//typedef int (*PFany)(any_t, any_t);

// map_t is a pointer to an internally maintained data structure.
typedef any_t map_t;

// Data structure stores in a map
// For shared memory, we must use save the content instead of the pointer 
// of a key.
// Note that when changing the size of an alias (dtAlias), we need to  
// change the size of the key.
typedef struct {
  char  key[KEY_SIZE];
  short in_use;
  short data;
} hashmap_element;

// Header of a hashmap and its data
typedef struct {
	int table_size;
	int size;
        int collision;
} hashmap_map;

class sesHashMap
{
public:
     sesHashMap(int mapEntries);
     sesHashMap(int mapEntries, void *ptrMap, int reset);
     virtual ~sesHashMap();
     void put(const char *key, int value);
     void get(const char *key, int *value);
     void remove(char *key);
     int size() { return _m->size; }
     int tableSize() { return _m->table_size; }
     int collision() { return _m->collision; }

private:
     int hash(const char *key);
     unsigned int hash_char(const char *key);
     unsigned int hash_char1(const char *key);
     unsigned int hash_char2(const char *key);
     unsigned int hash_char3(const char *key);
     unsigned int hash_char4(const char *key);
     unsigned int hash_char5(const char *key);
     unsigned int hash_char6(const char *key);
     unsigned int hash_char7(const char *key);
     unsigned int hash_char8(const char *key);
     void rehash();
     hashmap_map     *_m;      // pointer of a hashmap
     hashmap_element *_data; // hash map data block pointer
     int             _shared;  // 1=shared memory mode, for controlling free()
     int             _semid;   // semaphore ID
};

#endif // HASHMAP_H