+++ /dev/null
-/* LOCK THE ENTIRE HASH TABLE */
-#include "prelookup.h"
-
-prehashtable_t pflookup; //Global prefetch cache table
-
-unsigned int prehashCreate(unsigned int size, float loadfactor) {
- prehashlistnode_t *nodes;
- int i;
-
- // Allocate space for the hash table
- if((nodes = calloc(size, sizeof(prehashlistnode_t))) == NULL) {
- printf("Calloc error %s %d\n", __FILE__, __LINE__);
- return 1;
- }
-
- pflookup.table = nodes;
- pflookup.size = size;
- pflookup.numelements = 0; // Initial number of elements in the hash
- pflookup.loadfactor = loadfactor;
-
- //Intiliaze and set prefetch table mutex attribute
- pthread_mutexattr_init(&pflookup.prefetchmutexattr);
- //NOTE:PTHREAD_MUTEX_RECURSIVE is currently inside a #if_def UNIX98 in the pthread.h file
- //Therefore use PTHREAD_MUTEX_RECURSIVE_NP instead
- pthread_mutexattr_settype(&pflookup.prefetchmutexattr, PTHREAD_MUTEX_RECURSIVE_NP);
-
- //Initialize mutex var
- pthread_mutex_init(&pflookup.lock, &pflookup.prefetchmutexattr);
- //pthread_mutex_init(&pflookup.lock, NULL);
- pthread_cond_init(&pflookup.cond, NULL);
- return 0;
-}
-
-//Assign keys to bins inside hash table
-unsigned int prehashFunction(unsigned int key) {
- return ( key % (pflookup.size));
-}
-
-//Store oids and their pointers into hash
-unsigned int prehashInsert(unsigned int key, void *val) {
- unsigned int newsize;
- int index;
- prehashlistnode_t *ptr, *node;
-
- if(pflookup.numelements > (pflookup.loadfactor * pflookup.size)) {
- //Resize
- newsize = 2 * pflookup.size + 1;
- pthread_mutex_lock(&pflookup.lock);
- prehashResize(newsize);
- pthread_mutex_unlock(&pflookup.lock);
- }
-
- ptr = pflookup.table;
- pflookup.numelements++;
- index = prehashFunction(key);
-
- pthread_mutex_lock(&pflookup.lock);
- 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(prehashlistnode_t))) == NULL) {
- printf("Calloc error %s, %d\n", __FILE__, __LINE__);
- pthread_mutex_unlock(&pflookup.lock);
- return 1;
- }
- node->key = key;
- node->val = val ;
- node->next = ptr[index].next;
- ptr[index].next = node;
- }
- pthread_mutex_unlock(&pflookup.lock);
- return 0;
-}
-
-// Search for an address for a given oid
-void *prehashSearch(unsigned int key) {
- int index;
- prehashlistnode_t *ptr, *node;
-
- ptr = pflookup.table;
- index = prehashFunction(key);
- node = &ptr[index];
- pthread_mutex_lock(&pflookup.lock);
- while(node != NULL) {
- if(node->key == key) {
- pthread_mutex_unlock(&pflookup.lock);
- return node->val;
- }
- node = node->next;
- }
- pthread_mutex_unlock(&pflookup.lock);
- return NULL;
-}
-
-unsigned int prehashRemove(unsigned int key) {
- int index;
- prehashlistnode_t *curr, *prev;
- prehashlistnode_t *ptr, *node;
-
- ptr = pflookup.table;
- index = prehashFunction(key);
- curr = &ptr[index];
-
- pthread_mutex_lock(&pflookup.lock);
- for (; curr != NULL; curr = curr->next) {
- if (curr->key == key) { // Find a match in the hash table
- pflookup.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 prehashlistnode_t
- curr->key = 0;
- curr->val = NULL;
- } else if ((curr == &ptr[index]) && (curr->next != NULL)) { //Delete the first item with a linked list of prehashlistnode_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);
- }
- pthread_mutex_unlock(&pflookup.lock);
- return 0;
- }
- prev = curr;
- }
- pthread_mutex_unlock(&pflookup.lock);
- return 1;
-}
-
-unsigned int prehashResize(unsigned int newsize) {
- prehashlistnode_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 prehashlistnode_t for each bin in hashtable
- int i,index;
- prehashlistnode_t *newnode;
-
- ptr = pflookup.table;
- oldsize = pflookup.size;
-
- if((node = calloc(newsize, sizeof(prehashlistnode_t))) == NULL) {
- printf("Calloc error %s %d\n", __FILE__, __LINE__);
- return 1;
- }
-
- pflookup.table = node; //Update the global hashtable upon resize()
- pflookup.size = newsize;
- pflookup.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 = prehashFunction(curr->key);
- // Insert into the new table
- if(pflookup.table[index].next == NULL && pflookup.table[index].key == 0) {
- pflookup.table[index].key = curr->key;
- pflookup.table[index].val = curr->val;
- pflookup.numelements++;
- }else {
- if((newnode = calloc(1, sizeof(prehashlistnode_t))) == NULL) {
- printf("Calloc error %s, %d\n", __FILE__, __LINE__);
- return 1;
- }
- newnode->key = curr->key;
- newnode->val = curr->val;
- newnode->next = pflookup.table[index].next;
- pflookup.table[index].next = newnode;
- pflookup.numelements++;
- }
-
- //free the linked list of prehashlistnode_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;
-}
-
-/* Deletes the prefetch Cache */
-void prehashDelete() {
- int i, isFirst;
- prehashlistnode_t *ptr, *curr, *next;
- ptr = pflookup.table;
-
- for(i=0 ; i<pflookup.size ; i++) {
- curr = &ptr[i];
- isFirst = 1;
- while(curr != NULL) {
- next = curr->next;
- if(isFirst != 1) {
- free(curr);
- }
- isFirst = 0;
- curr = next;
- }
- }
-
- free(ptr);
-}
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