Robust/src/Runtime/DSTM/interface/clookup.c

   1  #include "clookup.h"
   2
   3 chashtable_t *chashCreate(unsigned int size, float loadfactor) {
   4         chashtable_t *ctable;
   5         chashlistnode_t *nodes;
   6         int i;
   7
   8         if((ctable = calloc(1, sizeof(chashtable_t))) == NULL) {
   9                 printf("Calloc error %s %d\n", __FILE__, __LINE__);
  10                 return NULL;
  11         }
  12
  13         // Allocate space for the hash table
  14         if((nodes = calloc(size, sizeof(chashlistnode_t))) == NULL) {
  15                 printf("Calloc error %s %d\n", __FILE__, __LINE__);
  16                 free(ctable);
  17                 return NULL;
  18         }
  19
  20         ctable->table = nodes;
  21         ctable->size = size;
  22         ctable->numelements = 0; // Initial number of elements in the hash
  23         ctable->loadfactor = loadfactor;
  24
  25         return ctable;
  26 }
  27
  28 //Finds the right bin in the hash table
  29 unsigned int chashFunction(chashtable_t *table, unsigned int key) {
  30         return ( key % (table->size));
  31 }
  32
  33 //Store objects and their pointers into hash
  34 unsigned int chashInsert(chashtable_t *table, unsigned int key, void *val) {
  35         unsigned int newsize;
  36         int index;
  37         chashlistnode_t *ptr, *node;
  38
  39         if(table->numelements > (table->loadfactor * table->size)) {
  40                 //Resize
  41                 newsize = 2 * table->size + 1;
  42                 chashResize(table,newsize);
  43         }
  44
  45         ptr = table->table;
  46         table->numelements++;
  47         index = chashFunction(table, key);
  48 #ifdef DEBUG
  49         printf("chashInsert(): DEBUG -> index = %d, key = %d, val = %x\n", index, key, val);
  50 #endif
  51         if(ptr[index].next == NULL && ptr[index].key == 0) {    // Insert at the first position in the hashtable
  52                 ptr[index].key = key;
  53                 ptr[index].val = val;
  54         } else {                        // Insert in the beginning of linked list
  55                 if ((node = calloc(1, sizeof(chashlistnode_t))) == NULL) {
  56                         printf("Calloc error %s, %d\n", __FILE__, __LINE__);
  57                         return 1;
  58                 }
  59                 node->key = key;
  60                 node->val = val;
  61                 node->next = ptr[index].next;
  62                 ptr[index].next = node;
  63         }
  64         return 0;
  65 }
  66
  67 // Search for an address for a given oid
  68 void *chashSearch(chashtable_t *table, unsigned int key) {
  69         int index = chashFunction(table, key);
  70         chashlistnode_t *ptr =table -> table;
  71         chashlistnode_t *node = &ptr[index];
  72
  73         while(node != NULL) {
  74                 if(node->key == key) {
  75                         return node->val;
  76                 }
  77                 node = node->next;
  78         }
  79         return NULL;
  80 }
  81
  82 unsigned int chashRemove(chashtable_t *table, unsigned int key) {
  83         int index;
  84         chashlistnode_t *curr, *prev;
  85         chashlistnode_t *ptr, *node;
  86
  87         ptr = table->table;
  88         index = chashFunction(table,key);
  89         curr = &ptr[index];
  90
  91         for (; curr != NULL; curr = curr->next) {
  92                 if (curr->key == key) {         // Find a match in the hash table
  93                         table->numelements--;  // Decrement the number of elements in the global hashtable
  94                         if ((curr == &ptr[index]) && (curr->next == NULL))  { // Delete the first item inside the hashtable with no linked list of chashlistnode_t
  95                                 curr->key = 0;
  96                                 curr->val = NULL;
  97                         } else if ((curr == &ptr[index]) && (curr->next != NULL)) { //Delete the first item with a linked list of chashlistnode_t  connected
  98                                 curr->key = curr->next->key;
  99                                 curr->val = curr->next->val;
 100                                 node = curr->next;
 101                                 curr->next = curr->next->next;
 102                                 free(node);
 103                         } else {                                                // Regular delete from linked listed
 104                                 prev->next = curr->next;
 105                                 free(curr);
 106                         }
 107                         return 0;
 108                 }
 109                 prev = curr;
 110         }
 111         return 1;
 112 }
 113
 114 unsigned int chashResize(chashtable_t *table, unsigned int newsize) {
 115         chashlistnode_t *node, *ptr, *curr, *next;      // curr and next keep track of the current and the next chashlistnodes in a linked list
 116         unsigned int oldsize;
 117         int isfirst;    // Keeps track of the first element in the chashlistnode_t for each bin in hashtable
 118         int i,index;
 119         chashlistnode_t *newnode;
 120
 121         ptr = table->table;
 122         oldsize = table->size;
 123
 124         if((node = calloc(newsize, sizeof(chashlistnode_t))) == NULL) {
 125                 printf("Calloc error %s %d\n", __FILE__, __LINE__);
 126                 return 1;
 127         }
 128
 129         table->table = node;            //Update the global hashtable upon resize()
 130         table->size = newsize;
 131         table->numelements = 0;
 132
 133         for(i = 0; i < oldsize; i++) {                  //Outer loop for each bin in hash table
 134                 curr = &ptr[i];
 135                 isfirst = 1;
 136                 while (curr != NULL) {                  //Inner loop to go through linked lists
 137                         if (curr->key == 0) {           //Exit inner loop if there the first element for a given bin/index is NULL
 138                                 break;                  //key = val =0 for element if not present within the hash table
 139                         }
 140                         next = curr->next;
 141
 142                         index = chashFunction(table, curr->key);
 143 #ifdef DEBUG
 144                         printf("DEBUG(resize) -> index = %d, key = %d, val = %x\n", index, curr->key, curr->val);
 145 #endif
 146                         // Insert into the new table
 147                         if(table->table[index].next == NULL && table->table[index].key == 0) {
 148                                 table->table[index].key = curr->key;
 149                                 table->table[index].val = curr->val;
 150                                 table->numelements++;
 151                         }else {
 152                                 if((newnode = calloc(1, sizeof(chashlistnode_t))) == NULL) {
 153                                         printf("Calloc error %s, %d\n", __FILE__, __LINE__);
 154                                         return 1;
 155                                 }
 156                                 newnode->key = curr->key;
 157                                 newnode->val = curr->val;
 158                                 newnode->next = table->table[index].next;
 159                                 table->table[index].next = newnode;
 160                                 table->numelements++;
 161                         }
 162
 163                         //free the linked list of chashlistnode_t if not the first element in the hash table
 164                         if (isfirst != 1) {
 165                                 free(curr);
 166                         }
 167
 168                         isfirst = 0;
 169                         curr = next;
 170                 }
 171         }
 172
 173         free(ptr);              //Free the memory of the old hash table
 174         return 0;
 175 }
 176
 177 //Delete the entire hash table
 178 void chashDelete(chashtable_t *ctable) {
 179         int i, isFirst;
 180         chashlistnode_t *ptr, *curr, *next;
 181         ptr = ctable->table;
 182
 183         for(i=0 ; i<ctable->size ; i++) {
 184                 curr = &ptr[i];
 185                 isFirst = 1 ;
 186                 while(curr  != NULL) {
 187                         next = curr->next;
 188                         if(isFirst != 1) {
 189                                 free(curr);
 190                         }
 191                         isFirst = 0;
 192                         curr = next;
 193                 }
 194         }
 195
 196         free(ptr);
 197         ptr = NULL;
 198         free(ctable);
 199         ctable = NULL;
 200 }