+++ /dev/null
- #include "clookup.h"
-
-chashtable_t *chashCreate(unsigned int size, float loadfactor) {
- chashtable_t *ctable;
- chashlistnode_t *nodes;
- int i;
-
- if((ctable = calloc(1, sizeof(chashtable_t))) == NULL) {
- printf("Calloc error %s %d\n", __FILE__, __LINE__);
- return NULL;
- }
-
- // Allocate space for the hash table
- if((nodes = calloc(size, sizeof(chashlistnode_t))) == NULL) {
- printf("Calloc error %s %d\n", __FILE__, __LINE__);
- free(ctable);
- return NULL;
- }
-
- ctable->table = nodes;
- ctable->size = size;
- ctable->numelements = 0; // Initial number of elements in the hash
- ctable->loadfactor = loadfactor;
-
- return ctable;
-}
-
-//Finds the right bin in the hash table
-unsigned int chashFunction(chashtable_t *table, unsigned int key) {
- return ( key % (table->size));
-}
-
-//Store objects and their pointers into hash
-unsigned int chashInsert(chashtable_t *table, unsigned int key, void *val) {
- unsigned int newsize;
- int index;
- chashlistnode_t *ptr, *node;
-
- if(table->numelements > (table->loadfactor * table->size)) {
- //Resize
- newsize = 2 * table->size + 1;
- chashResize(table,newsize);
- }
-
- ptr = table->table;
- table->numelements++;
- index = chashFunction(table, key);
-#ifdef DEBUG
- printf("chashInsert(): DEBUG -> index = %d, key = %d, val = %x\n", index, key, val);
-#endif
- if(ptr[index].next == NULL && ptr[index].key == 0) { // Insert at the first position in the hashtable
- ptr[index].key = key;
- ptr[index].val = val;
- } else { // Insert in the beginning of linked list
- if ((node = calloc(1, sizeof(chashlistnode_t))) == NULL) {
- printf("Calloc error %s, %d\n", __FILE__, __LINE__);
- return 1;
- }
- node->key = key;
- node->val = val;
- node->next = ptr[index].next;
- ptr[index].next = node;
- }
- return 0;
-}
-
-// Search for an address for a given oid
-void *chashSearch(chashtable_t *table, unsigned int key) {
- int index;
- chashlistnode_t *ptr, *node;
-
- ptr = table->table;
- index = chashFunction(table, key);
- node = &ptr[index];
- while(node != NULL) {
- if(node->key == key) {
- return node->val;
- }
- node = node->next;
- }
- return NULL;
-}
-
-unsigned int chashRemove(chashtable_t *table, unsigned int key) {
- int index;
- chashlistnode_t *curr, *prev;
- chashlistnode_t *ptr, *node;
-
- ptr = table->table;
- index = chashFunction(table,key);
- curr = &ptr[index];
-
- for (; curr != NULL; curr = curr->next) {
- if (curr->key == key) { // Find a match in the hash table
- table->numelements--; // Decrement the number of elements in the global hashtable
- if ((curr == &ptr[index]) && (curr->next == NULL)) { // Delete the first item inside the hashtable with no linked list of chashlistnode_t
- curr->key = 0;
- curr->val = NULL;
- } else if ((curr == &ptr[index]) && (curr->next != NULL)) { //Delete the first item with a linked list of chashlistnode_t connected
- curr->key = curr->next->key;
- curr->val = curr->next->val;
- node = curr->next;
- curr->next = curr->next->next;
- free(node);
- } else { // Regular delete from linked listed
- prev->next = curr->next;
- free(curr);
- }
- return 0;
- }
- prev = curr;
- }
- return 1;
-}
-
-unsigned int chashResize(chashtable_t *table, unsigned int newsize) {
- chashlistnode_t *node, *ptr, *curr, *next; // curr and next keep track of the current and the next chashlistnodes in a linked list
- unsigned int oldsize;
- int isfirst; // Keeps track of the first element in the chashlistnode_t for each bin in hashtable
- int i,index;
- chashlistnode_t *newnode;
-
- ptr = table->table;
- oldsize = table->size;
-
- if((node = calloc(newsize, sizeof(chashlistnode_t))) == NULL) {
- printf("Calloc error %s %d\n", __FILE__, __LINE__);
- return 1;
- }
-
- table->table = node; //Update the global hashtable upon resize()
- table->size = newsize;
- table->numelements = 0;
-
- for(i = 0; i < oldsize; i++) { //Outer loop for each bin in hash table
- curr = &ptr[i];
- isfirst = 1;
- while (curr != NULL) { //Inner loop to go through linked lists
- if (curr->key == 0) { //Exit inner loop if there the first element for a given bin/index is NULL
- break; //key = val =0 for element if not present within the hash table
- }
- next = curr->next;
-
- index = chashFunction(table, curr->key);
-#ifdef DEBUG
- printf("DEBUG(resize) -> index = %d, key = %d, val = %x\n", index, curr->key, curr->val);
-#endif
- // Insert into the new table
- if(table->table[index].next == NULL && table->table[index].key == 0) {
- table->table[index].key = curr->key;
- table->table[index].val = curr->val;
- table->numelements++;
- }else {
- if((newnode = calloc(1, sizeof(chashlistnode_t))) == NULL) {
- printf("Calloc error %s, %d\n", __FILE__, __LINE__);
- return 1;
- }
- newnode->key = curr->key;
- newnode->val = curr->val;
- newnode->next = table->table[index].next;
- table->table[index].next = newnode;
- table->numelements++;
- }
-
- //free the linked list of chashlistnode_t if not the first element in the hash table
- if (isfirst != 1) {
- free(curr);
- }
-
- isfirst = 0;
- curr = next;
- }
- }
-
- free(ptr); //Free the memory of the old hash table
- return 0;
-}
-
-//Delete the entire hash table
-void chashDelete(chashtable_t *table) {
- int i, isFirst;
- chashlistnode_t *ptr, *curr, *next;
- ptr = table->table;
-
- for(i=0 ; i<table->size ; i++) {
- curr = &ptr[i];
- isFirst = 1 ;
- while(curr != NULL) {
- next = curr->next;
- if(isFirst != 1) {
- free(curr);
- }
- isFirst = 0;
- curr = next;
- }
- }
-
- free(ptr);
- free(table);
- table = NULL;
-}
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