--- /dev/null
+ #include "clookup.h"
+
+cachehashtable_t *cachehashCreate(unsigned int size, float loadfactor) {
+ cachehashtable_t *ctable;
+ cachehashlistnode_t *nodes;
+ int i;
+
+ if((ctable = calloc(1, sizeof(cachehashtable_t))) == NULL) {
+ printf("Calloc error %s %d\n", __FILE__, __LINE__);
+ return NULL;
+ }
+
+ // Allocate space for the hash table
+ if((nodes = calloc(HASH_SIZE, sizeof(cachehashlistnode_t))) == NULL) {
+ printf("Calloc error %s %d\n", __FILE__, __LINE__);
+ 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 cachehashFunction(cachehashtable_t *table, unsigned int key) {
+ return ( key % (table->size));
+}
+
+//Store objects and their pointers into hash
+unsigned int cachehashInsert(cachehashtable_t *table, unsigned int key, void *val) {
+ unsigned int newsize;
+ int index;
+ cachehashlistnode_t *ptr, *node;
+
+ if(table->numelements > (table->loadfactor * table->size)) {
+ //Resize
+ newsize = 2 * table->size + 1;
+ cachehashResize(table,newsize);
+ }
+
+ ptr = table->table;
+ table->numelements++;
+ index = cachehashFunction(table, key);
+#ifdef DEBUG
+ printf("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(cachehashlistnode_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 *cachehashSearch(cachehashtable_t *table, unsigned int key) {
+ int index;
+ cachehashlistnode_t *ptr, *node;
+
+ ptr = table->table;
+ index = cachehashFunction(table, key);
+ node = &ptr[index];
+ while(node != NULL) {
+ if(node->key == key) {
+ return node->val;
+ }
+ node = node->next;
+ }
+ return NULL;
+}
+
+unsigned int cachehashRemove(cachehashtable_t *table, unsigned int key) {
+ int index;
+ cachehashlistnode_t *curr, *prev;
+ cachehashlistnode_t *ptr, *node;
+
+ ptr = table->table;
+ index = cachehashFunction(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 cachehashlistnode_t
+ curr->key = 0;
+ curr->val = NULL;
+ } else if ((curr == &ptr[index]) && (curr->next != NULL)) { //Delete the first item with a linked list of cachehashlistnode_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 cachehashResize(cachehashtable_t *table, unsigned int newsize) {
+ cachehashlistnode_t *node, *ptr, *curr, *next; // curr and next keep track of the current and the next cachehashlistnodes in a linked list
+ unsigned int oldsize;
+ int isfirst; // Keeps track of the first element in the cachehashlistnode_t for each bin in hashtable
+ int i,index;
+ cachehashlistnode_t *newnode;
+
+ ptr = table->table;
+ oldsize = table->size;
+
+ if((node = calloc(newsize, sizeof(cachehashlistnode_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 = cachehashFunction(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(cachehashlistnode_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 cachehashlistnode_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 cachehashDelete(cachehashtable_t *table) {
+ int i, isFirst;
+ cachehashlistnode_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);
+}
--- /dev/null
+#include <stdio.h>
+#include "clookup.h"
+
+main()
+{
+ int i;
+ void *val;
+ cachehashtable_t *ctable;
+
+ if (( ctable = cachehashCreate(20, 0.50)) == NULL) {
+ printf("cachehashCreate error\n"); //creates hashtable
+ }
+
+ for (i = 1; i <= 10; i++) { // Checks the insert() and resize()
+ if (cachehashInsert(ctable, 10*i, &i) == 1)
+ printf("cachehashInsert error\n");
+ }
+
+ i = cachehashRemove(ctable, 10);//Delete first element in the hashtable
+ if(i == 1)
+ printf("cachehashRemove error ");
+
+ for (i = 1; i <= 10; i++) { // Check if it can search for all keys in hash table
+ val = cachehashSearch(ctable, 10*i);
+ if (val != &i)
+ printf("cachehashSearch error - val = %d\n", val);
+ else
+ printf("cachehashSearch key = %d val = %x\n",10*i, val);
+ }
+
+ i = cachehashRemove(ctable, 30);
+ if(i == 1)
+ printf("cachehashRemove error\n ");
+ i = cachehashRemove(ctable, 40);
+ if(i == 1)
+ printf("cachehashRemove error\n ");
+ i = cachehashRemove(ctable, 80);
+ if(i == 1)
+ printf("cachehashRemove error\n ");
+ i = cachehashRemove(ctable, 100);
+ if(i == 1)
+ printf("cachehashRemove error\n ");
+ i = cachehashRemove(ctable, 90);
+ if(i == 1)
+ printf("cachehashRemove error\n ");
+
+ for (i = 1; i <= 10; i++) { //Prints all left over elements inside hash after deletion and prints error if element not found in hash
+ val = cachehashSearch(ctable, 10*i);
+ if (val != &i)
+ printf("cachehashSearch error - val = %d\n", val);
+ else
+ printf("cachehashSearch key = %d val = %x\n",10*i, val);
+ }
+
+ printf("The total number of elements in table : %d\n", ctable->numelements);
+
+}
+
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