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 ; else difference = 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 ; }