可扩散列--可扩散列实现文件C语言

/*extendible_hashing.c -- 可扩散列实现文件*/#include <stdio.h>#include <stdlib.h>#include "extendible_hashing.h"/*局部函数声明*/static char pow_base_two (const int power) ;/*接口函数定义*/int Hash (const Item * const pitem, const char constant){return *pitem >> constant ;}int InitializeTable (Table * const ptable){*ptable = (struct table *) malloc (sizeof (struct table)) ;if (NULL == *ptable){puts ("Out of space.[1]") ;return 0 ;}(*ptable) -> directory_size = M ;(*ptable) -> index_digit = M / 2 ;(*ptable) -> item_digit = LENTH ;(*ptable) -> array_size = M ;(*ptable) -> directory = (Subdirectories *) malloc (sizeof (Subdirectories) * M) ;if (NULL == (*ptable) -> directory){puts ("Out of space.[2]") ;free (*ptable) ;return 0 ;}(*ptable) -> directory[0].byte_index = 0 ;(*ptable) -> directory[0].point = NULL ;(*ptable) -> directory[0].point_to_itself = NO ;(*ptable) -> directory[1].byte_index = 1 ;(*ptable) -> directory[1].point = NULL ;(*ptable) -> directory[1].point_to_itself = NO ;(*ptable) -> directory[2].byte_index = 2 ;(*ptable) -> directory[2].point = NULL ;(*ptable) -> directory[2].point_to_itself = NO ;(*ptable) -> directory[3].byte_index = 3 ;(*ptable) -> directory[3].point = NULL ;(*ptable) -> directory[3].point_to_itself = NO ;return 1 ;}int Insert (const Table * const ptable, const Item * const pitem){Subdirectories * s_temp ;Item * arr_temp ;char * d_temp ;char key, constant, difference, index, step ;int ct_out, ct_lin, same_preamle, d_s_record, i_temp ;constant = (*ptable) -> item_digit - (*ptable) -> index_digit ;//取出前N位key = Hash (pitem, constant) ;/*如果索引空间为空(针对添加操作初期的情况) 或者 未指向其自身的数据空间 创建空间同时完成添加*/if (NULL == (*ptable) -> directory[key].point || NO == (*ptable) -> directory[key].point_to_itself){(*ptable) -> directory[key].point = (Unit *) malloc (sizeof (Unit)) ;if (NULL == (*ptable) -> directory[key].point){puts ("Out of space.[3]") ;return 0 ;}(*ptable) -> directory[key].point -> array = (Item *) malloc (sizeof (Item) * (*ptable) -> array_size) ;if (NULL == (*ptable) -> directory[key].point -> array){puts ("Out of space.[4]") ;free ((*ptable) -> directory[key].point) ;return 0 ;}(*ptable) -> directory[key].point -> sub = 0 ;(*ptable) -> directory[key].point -> array[0] = *pitem ;(*ptable) -> directory[key].point -> sub++ ;(*ptable) -> directory[key].point_to_itself = YES ;}//否则如果索引空间当前已满(隐式的条件是指向其自身空间)*/else if ((*ptable) -> array_size == (*ptable) -> directory[key].point -> sub){//重复数据检测.不添加重复数据for (ct_out = 0; ct_out < (*ptable) -> array_size; ct_out++)if (*pitem == (*ptable) -> directory[key].point -> array[ct_out])return 0 ;//记录目录中的索引值*/d_temp = (char *) malloc (sizeof (char) * (*ptable) -> directory_size) ;if (NULL == d_temp){puts ("Out of space.[5]") ;free ((*ptable) -> directory[key].point) ;free ((*ptable) -> directory[key].point -> array) ;return 0 ;}//利用了循环展开*/for (ct_out = 0, i_temp = (*ptable) -> directory_size; ct_out < i_temp; ct_out += 4){d_temp[ct_out + 0] = (*ptable) -> directory[ct_out + 0].byte_index ;d_temp[ct_out + 1] = (*ptable) -> directory[ct_out + 1].byte_index ;d_temp[ct_out + 2] = (*ptable) -> directory[ct_out + 2].byte_index ;d_temp[ct_out + 3] = (*ptable) -> directory[ct_out + 3].byte_index ;}//检测相同前导位数量*/arr_temp = (Item *) malloc (sizeof (Item) * (*ptable) -> array_size) ;if (NULL == arr_temp){puts ("Out of space.[6]") ;free ((*ptable) -> directory[key].point) ;free ((*ptable) -> directory[key].point -> array) ;free (d_temp) ;return 0 ;}//记录数据空间内数据*/for (ct_out = 0, i_temp = (*ptable) -> array_size; ct_out < i_temp; ct_out++)arr_temp[ct_out] = (*ptable) -> directory[key].point -> array[ct_out] ;/*得到相同前导位数dL*/for (same_preamle = (*ptable) -> index_digit; same_preamle <= LENTH; same_preamle++){if ((arr_temp[0] >> (LENTH - same_preamle) ^ arr_temp[1] >> (LENTH - same_preamle)) != 0){same_preamle-- ;break ;}if ((arr_temp[0] >> (LENTH - same_preamle) ^ arr_temp[2] >> (LENTH - same_preamle)) != 0){same_preamle-- ;break ;}if ((arr_temp[0] >> (LENTH - same_preamle) ^ arr_temp[3] >> (LENTH - same_preamle)) != 0){same_preamle-- ;break ;}}//相同前导位数同原索引位数的差*/difference = same_preamle - (*ptable) -> index_digit ;//更新目录索引位数(因为数据空间满的情况下必然至少要将目录扩充一位)*/(*ptable) -> index_digit = same_preamle + 1 ;//如果dL > d*/if (difference > 0)difference += 1 ;elsedifference = 1 ;//创建新目录*/s_temp = (*ptable) -> directory ;d_s_record = (*ptable) -> directory_size ;//记录原目录长度(*ptable) -> directory_size = (*ptable) -> directory_size * 2 * difference ;//更新目录长度//更新索引值*/key = key * 2 * difference ;(*ptable) -> directory = (Subdirectories *) malloc (sizeof (Subdirectories) * (*ptable) -> directory_size) ;if (NULL == (*ptable) -> directory){puts ("Out of space.[6]") ;free ((*ptable) -> directory[key].point) ;free ((*ptable) -> directory[key].point -> array) ;free (d_temp) ;free (arr_temp) ;return 0 ;}//更新目录*/for (ct_out = 0, step = pow_base_two ((*ptable) -> index_digit) / 4; ct_out < d_s_record; ct_out++){ct_lin = ct_out * step ;(*ptable) -> directory[ct_lin].byte_index = s_temp[ct_out].byte_index * step ;(*ptable) -> directory[ct_lin].point = s_temp[ct_out].point ;(*ptable) -> directory[ct_lin].point_to_itself = s_temp[ct_out].point_to_itself ;ct_lin++ ;while (ct_lin < ct_out * step + step){(*ptable) -> directory[ct_lin].byte_index = (*ptable) -> directory[ct_lin - 1].byte_index + 1 ;(*ptable) -> directory[ct_lin].point = s_temp[ct_out].point ;(*ptable) -> directory[ct_lin].point_to_itself = NO ;ct_lin++ ;}}/*完成最后的对单元内数据的处理(此时数据单元内一定有 (*ptable) -> array_size 个数据)*///调整数据空间内所有数据for (ct_out = 0, i_temp = (*ptable) -> array_size; ct_out < i_temp; ct_out++){index = (*ptable) -> directory[key].point -> array[ct_out] >> (LENTH - same_preamle - 1) ;if (NO == (*ptable) -> directory[index].point_to_itself){(*ptable) -> directory[index].point = (Unit *) malloc (sizeof (Unit)) ;if (NULL == (*ptable) -> directory[index].point){puts ("Out of space.[7]") ;free ((*ptable) -> directory[key].point -> array) ;free ((*ptable) -> directory[key].point) ;free (d_temp) ;free (arr_temp) ;free ((*ptable) -> directory) ;return 0 ;}(*ptable) -> directory[index].point -> array = (Item *) malloc (sizeof (Item) * (*ptable) -> array_size) ;if (NULL == (*ptable) -> directory[index].point -> array){puts ("Ouf of space.[8]") ;free ((*ptable) -> directory[key].point -> array) ;free ((*ptable) -> directory[key].point) ;free (d_temp) ;free (arr_temp) ;free ((*ptable) -> directory[index].point -> array) ;free ((*ptable) -> directory) ;return 0 ;}//初始化新的数据空间(*ptable) -> directory[index].point -> sub = 0 ;//将数据添加到新的数据空间中(*ptable) -> directory[index].point -> array[0] = (*ptable) -> directory[key].point -> array[ct_out] ;(*ptable) -> directory[index].point -> sub++ ;(*ptable) -> directory[index].point_to_itself = YES ;//对原数据空间内数据进行处理(将最后一个数据替换到移走数据的位置)(*ptable) -> directory[key].point -> array[ct_out] = (*ptable) -> directory[key].point -> array[(*ptable) -> directory[key].point -> sub - 1] ;(*ptable) -> directory[key].point -> sub-- ;}}//将新数据添加到数据空间中constant = (*ptable) -> item_digit - (*ptable) -> index_digit ;key = Hash (pitem, constant) ;if (NO == (*ptable) -> directory[key].point){(*ptable) -> directory[key].point = (Unit *) malloc (sizeof (Unit)) ;if (NULL == (*ptable) -> directory[key].point){puts ("Out of space.[9]") ;free (d_temp) ;free (arr_temp) ;return 0 ;}(*ptable) -> directory[key].point -> array = (Item *) malloc (sizeof (Item) * (*ptable) -> array_size) ;if (NULL == (*ptable) -> directory[key].point -> array){puts ("Out of space.[10]") ;free (d_temp) ;free (arr_temp) ;free ((*ptable) -> directory[key].point) ;return 0 ;}(*ptable) -> directory[key].point -> array[0] = *pitem ;(*ptable) -> directory[key].point -> sub++ ;(*ptable) -> directory[key].point_to_itself = YES ;}else{(*ptable) ->directory[key].point -> array[(*ptable) -> directory[key].point -> sub] = *pitem ;(*ptable) ->directory[key].point -> sub++ ;}free (s_temp) ;free (arr_temp) ;free (d_temp) ;}//最期望出现的情况*/else{//重复数据检测.不添加重复数据for (ct_out = 0; ct_out < (*ptable) -> array_size; ct_out++)if (*pitem == (*ptable) -> directory[key].point -> array[ct_out])return 0 ;(*ptable) -> directory[key].point -> array[(*ptable) ->directory[key].point -> sub] = *pitem ;(*ptable) -> directory[key].point -> sub++ ;}return 1 ;}void Traversal (const Table * const ptable, void (* pfun) (const Subdirectories subdirectories)){int count, i_temp ;for (count = 0, i_temp = (*ptable) -> directory_size; count < i_temp; count++){if (YES == (*ptable) -> directory[count].point_to_itself)(*pfun) ((*ptable) -> directory[count]) ;}}int Find (const Table * const ptable, const Item * const pitem){Item * array ;int count, i_temp ;char key, constant ;constant = (*ptable) -> item_digit - (*ptable) -> index_digit ;key = Hash (pitem, constant) ;if (NULL == (*ptable) -> directory[key].point)return 0 ;array = (*ptable) -> directory[key].point -> array ;for (count = 0, i_temp = (*ptable) -> array_size; count < i_temp; count++){if (*pitem == (*ptable) -> directory[key].point -> array[count])return 1 ;}return 0 ;}int Delete (const Table * const ptable, const Item * const pitem){int count, i_temp ;char key, constant ;constant = (*ptable) -> item_digit - (*ptable) -> index_digit ;key = Hash (pitem, constant) ;if (NULL == (*ptable) -> directory[key].point)return 0 ;for (count = 0, i_temp = (*ptable) -> array_size; count < i_temp; count++){if (*pitem == (*ptable) -> directory[key].point -> array[count]){(*ptable) -> directory[key].point -> array[count] = (*ptable) -> directory[key].point -> array[(*ptable) -> directory[key].point -> sub - 1] ;(*ptable) -> directory[key].point -> sub-- ;return 1 ;}}return 0 ;}void Release (const Table * const ptable){int count ;for (count = (*ptable) -> directory_size - 1; count >= 0; count--){if ((*ptable) ->directory[count].point != NULL && YES == (*ptable) -> directory[count].point_to_itself){free ((*ptable) -> directory[count].point -> array) ;free ((*ptable) -> directory[count].point) ;}}free ((*ptable) -> directory) ;free (*ptable) ;}/*局部函数定义*/static char pow_base_two (const int power){char count, value ;for (count = 0, value = 1; count < power; count++)value *= 2 ;return value ;}