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iftop

    1: /* hash table */
    2: 
    3: #include <stdio.h>
    4: #include <stdlib.h>
    5: #include "hash.h"
    6: #include "iftop.h"
    7: 
    8: hash_status_enum hash_insert(hash_type* hash_table, void* key, void* rec) {
    9:     hash_node_type *p, *p0;
   10:     int bucket;
   11: 
   12:    /************************************************
   13:     *  allocate node for data and insert in table  *
   14:     ************************************************/
   15: 
   16: 
   17:     /* insert node at beginning of list */
   18:     bucket = hash_table->hash(key);
   19:     p = xmalloc(sizeof *p);
   20:     p0 = hash_table->table[bucket];
   21:     hash_table->table[bucket] = p;
   22:     p->next = p0;
   23:     p->key = hash_table->copy_key(key);
   24:     p->rec = rec;
   25:     return HASH_STATUS_OK;
   26: }
   27: 
   28: hash_status_enum hash_delete(hash_type* hash_table, void* key) {
   29:     hash_node_type *p0, *p;
   30:     int bucket;
   31: 
   32:    /********************************************
   33:     *  delete node containing data from table  *
   34:     ********************************************/
   35: 
   36:     /* find node */
   37:     p0 = 0;
   38:     bucket = hash_table->hash(key);
   39:     p = hash_table->table[bucket];
   40:     while (p && !hash_table->compare(p->key, key)) {
   41:         p0 = p;
   42:         p = p->next;
   43:     }
   44:     if (!p) return HASH_STATUS_KEY_NOT_FOUND;
   45: 
   46:     /* p designates node to delete, remove it from list */
   47:     if (p0) {
   48:         /* not first node, p0 points to previous node */
   49:         p0->next = p->next;
   50:     }
   51:     else {
   52:         /* first node on chain */
   53:         hash_table->table[bucket] = p->next;
   54:     }
   55: 
   56:     hash_table->delete_key(p->key);
   57:     free (p);
   58:     return HASH_STATUS_OK;
   59: }
   60: 
   61: hash_status_enum hash_find(hash_type* hash_table, void* key, void **rec) {
   62:     hash_node_type *p;
   63: 
   64:    /*******************************
   65:     *  find node containing data  *
   66:     *******************************/
   67:     p = hash_table->table[hash_table->hash(key)];
   68: 
   69:     while (p && !hash_table->compare(p->key, key))  {
   70:         p = p->next;
   71:     }
   72:     if (!p) return HASH_STATUS_KEY_NOT_FOUND;
   73:     *rec = p->rec;
   74:     return HASH_STATUS_OK;
   75: }
   76: 
   77: hash_status_enum hash_next_item(hash_type* hash_table, hash_node_type** ppnode) {
   78:     int i;
   79:     if(*ppnode != NULL) {
   80:         if((*ppnode)->next != NULL) {
   81:             *ppnode = (*ppnode)->next;
   82:             return HASH_STATUS_OK;
   83:         }
   84:         i = hash_table->hash((*ppnode)->key) + 1;
   85:     }
   86:     else {
   87:         /* first node */
   88:         i = 0;
   89:     }
   90:     while(i < hash_table->size && hash_table->table[i] == NULL) {
   91:          i++; 
   92:     }
   93:     if(i == hash_table->size) {
   94:         *ppnode = NULL;
   95:         return HASH_STATUS_KEY_NOT_FOUND;
   96:     }
   97:     *ppnode = hash_table->table[i];
   98:     return HASH_STATUS_OK;
   99: }
  100: 
  101: void hash_delete_all(hash_type* hash_table) {
  102:     int i;
  103:     hash_node_type *n, *nn;
  104:     for(i = 0; i < hash_table->size; i++) {
  105:         n = hash_table->table[i];
  106:         while(n != NULL) {
  107:             nn = n->next;
  108:             hash_table->delete_key(n->key);
  109:             free(n);
  110:             n = nn;
  111:         }
  112:         hash_table->table[i] = NULL;
  113:     }
  114: }
  115: 
  116: 
  117: /*
  118:  * Allocate and return a hash
  119:  */
  120: hash_status_enum hash_initialise(hash_type* hash_table) {
  121:     hash_table->table = xcalloc(hash_table->size, sizeof *hash_table->table);
  122:     return HASH_STATUS_OK;
  123: }
  124: 
  125: hash_status_enum hash_destroy(hash_type* hash_table) {
  126:     free(hash_table->table);
  127:     return HASH_STATUS_OK;
  128: }
  129: