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;
+ 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));
+ 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;
+ 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;
+ 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;
+ 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;
+ 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);
+ 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);
}
//Note: This is based on the implementation of the inserting a key in the first position of the hashtable
void prehashClear() {
int i, isFirstBin;
prehashlistnode_t *ptr, *prev, *curr;
-
+
pthread_mutex_lock(&pflookup.lock);
ptr = pflookup.table;
for(i = 0; i < pflookup.size; i++) {
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