static void *find_fit(size_t asize)
{
/* First fit search */
void* bp;
// print_list();
int offset = get_offset(asize);
//printf("in first fit search \n");
for (int i = offset; i < 9; i++)
{
//printf ("In bucket %d \n",i);
for (bp =((void*) (*(long*)GET_BUCKET(root, i)));
bp != NULL ; bp = get_succ(bp) )
{
// printf("bp %p \n",bp);
REQUIRES ((void*)bp != NULL);
REQUIRES (((size_t)(bp))%8 == 0);
size_t size = GET_SIZE(HDRP((bp)));
if (!GET_ALLOC( HDRP(((bp) ) )) &&
(asize <= size))
{
ENSURES ( (size_t)(bp)%8 == 0);
size_t diff = size - asize;
return first_best_fit((void*)bp,asize, diff) ;
}
}
}
return NULL; /* No fit */
}
void
hash_destroy (HTAB *hashp)
{
/* cannot destroy a shared memory hash table */
Assert(! hashp->segbase);
if (hashp != NULL) {
register SEG_OFFSET segNum;
SEGMENT segp;
int nsegs = hashp->hctl->nsegs;
int j;
BUCKET_INDEX *elp,p,q;
ELEMENT *curr;
for (segNum = 0; nsegs > 0; nsegs--, segNum++) {
segp = GET_SEG(hashp,segNum);
for (j = 0, elp = segp; j < hashp->hctl->ssize; j++, elp++) {
for ( p = *elp; p != INVALID_INDEX; p = q ){
curr = GET_BUCKET(hashp,p);
q = curr->next;
MEM_FREE((char *) curr);
}
}
free((char *)segp);
}
(void) MEM_FREE( (char *) hashp->dir);
(void) MEM_FREE( (char *) hashp->hctl);
hash_stats("destroy",hashp);
(void) MEM_FREE( (char *) hashp);
}
}
static void remove_block(void *bp, size_t size)
{
//printf ("remove block\n");
REQUIRES ( bp != NULL );
REQUIRES ( (size_t)(bp) % 8 == 0);
int offset = get_offset(size);
void *pred = get_pred(bp);
void *succ = get_succ(bp);
if ( pred == NULL && succ != NULL)
//block to be removed is the first block in the list
{
SET_SUCC(bp) = 0;
SET_PRED(succ) = 0;
SET_ROOT(GET_BUCKET(root, offset)) = (long)succ;
}
else if (pred != NULL && succ == NULL)
//block to be removed is the last block in the list
{
SET_SUCC(pred) = 0;
SET_PRED(bp) = 0;
}
else if (pred != NULL && succ != NULL)
//block to be removed is located somewhere within the list.
{
SET_SUCC(pred) = (int)( (long)succ - BASE);
SET_PRED(succ) = (int)((long)pred - BASE);
SET_PRED(bp) = 0;
SET_SUCC(bp) = 0;
}
else if ( pred == NULL && succ == NULL)
{
//printf("resetting root\n");
SET_ROOT(GET_BUCKET(root, offset)) = 0;
}
print_list();
return;
}
// Returns 0 if no errors were found, otherwise returns the error
int mm_checkheap(int verbose) {
// char *bp = heap_listp;
if (verbose)
printf("Heap (%p):\n", heap_listp);
if ((GET_SIZE(HDRP(heap_listp)) != DSIZE) || !GET_ALLOC(HDRP(heap_listp)))
printf("Bad prologue header\n");
checkblock(heap_listp);
void* list;
int count_free_in_list = 0;
int count_free_in_heap = 0;
for (int i =0; i < 9; i++)
{
for (list = (void*)(*(long*)GET_BUCKET(root,i)); list != NULL;
list = get_succ(list) ) {
if (verbose)
printblock(list);
checkblock(list);
if ( get_succ(list) != NULL && get_pred(list) !=NULL)
check_succ_pred(list);
check_address(list);
count_free_in_list++;
check_in_correct_bucket(list, i);
}
}
char *bp;
for (bp = heap_listp; GET_SIZE(HDRP(bp)) > 0; bp = NEXT_BLKP(bp)) {
if (verbose)
{
if (GET_ALLOC(HDRP(bp)) == 0)
count_free_in_heap ++;
printblock(bp);
checkblock(bp);
check_coalescing( (void*)bp);
}
}
if (count_free_in_heap != count_free_in_list)
printf ("Number of free block not consistent in heap and list list \n");
if (verbose)
printblock(bp);
if ((GET_SIZE(HDRP(bp)) != 0) || !(GET_ALLOC(HDRP(bp))))
{
printf("Bad epilogue header\n");
if (GET_SIZE(HDRP(bp)) != 0)
printf ("size is not 0\n");
if (!(GET_ALLOC(HDRP(bp))) )
printf ("not allocated properly\n");
}
return 0;
}
bool
hashmap_has_key(hashmap_t* map, hash_t key) {
/*lint --e{613} */
size_t ibucket = GET_BUCKET(map, key);
hashmap_node_t* bucket = map->bucket[ibucket];
size_t inode, nsize;
for (inode = 0, nsize = array_size(bucket); inode < nsize; ++inode) {
if (bucket[inode].key == key)
return true;
}
return false;
}
void*
hashmap_lookup(hashmap_t* map, hash_t key) {
/*lint --e{613} */
size_t ibucket = GET_BUCKET(map, key);
hashmap_node_t* bucket = map->bucket[ibucket];
size_t inode, nsize;
for (inode = 0, nsize = array_size(bucket); inode < nsize; ++inode) {
if (bucket[inode].key == key)
return bucket[inode].value;
}
return 0;
}
static void add_block(void *bp, size_t size)
{
// printf ("in add block\n");
REQUIRES ( bp != NULL ) ;
REQUIRES ((size_t)(bp) % 8 == 0);
int offset = get_offset(size);
if ( (*(long*)GET_BUCKET(root, offset) != 0))
{
//printf ("replacing root\n");
SET_PRED((void*)(*(long*)GET_BUCKET(root, offset))) =
(int)( (long)bp -BASE );
}
int val = (int)(*(long*)GET_BUCKET(root,offset) - BASE);
//printf ("val = 0x%x \n",val);
SET_SUCC(bp) = val;
SET_PRED(bp) = 0;
SET_ROOT(GET_BUCKET(root, offset)) = (long)bp;
//print_list();
//printf("returned from adding block\n");
return;
}
void*
hashmap_erase(hashmap_t* map, hash_t key) {
/*lint --e{613} */
size_t ibucket = GET_BUCKET(map, key);
hashmap_node_t* bucket = map->bucket[ibucket];
size_t inode, nsize;
for (inode = 0, nsize = array_size(bucket); inode < nsize; ++inode) {
if (bucket[inode].key == key) {
void* prev = bucket[inode].value;
array_erase(map->bucket[ibucket], inode);
--map->num_nodes;
return prev;
}
}
return 0;
}
/*
* allocate some new buckets and link them into the free list
*/
static int
bucket_alloc(HTAB *hashp)
{
int i;
ELEMENT *tmpBucket;
long bucketSize;
BUCKET_INDEX tmpIndex,lastIndex;
bucketSize =
sizeof(BUCKET_INDEX) + hashp->hctl->keysize + hashp->hctl->datasize;
/* make sure its aligned correctly */
bucketSize += sizeof(long *) - (bucketSize % sizeof(long *));
/* tmpIndex is the shmem offset into the first bucket of
* the array.
*/
tmpBucket = (ELEMENT *)
hashp->alloc((unsigned long) BUCKET_ALLOC_INCR*bucketSize);
if (! tmpBucket) {
return(0);
}
tmpIndex = MAKE_HASHOFFSET(hashp,tmpBucket);
/* set the freebucket list to point to the first bucket */
lastIndex = hashp->hctl->freeBucketIndex;
hashp->hctl->freeBucketIndex = tmpIndex;
/* initialize each bucket to point to the one behind it */
for (i=0;i<(BUCKET_ALLOC_INCR-1);i++) {
tmpBucket = GET_BUCKET(hashp,tmpIndex);
tmpIndex += bucketSize;
tmpBucket->next = tmpIndex;
}
/* the last bucket points to the old freelist head (which is
* probably invalid or we wouldnt be here)
*/
tmpBucket->next = lastIndex;
return(1);
}
void*
hashmap_insert(hashmap_t* map, hash_t key, void* value) {
/*lint --e{613} */
size_t ibucket = GET_BUCKET(map, key);
hashmap_node_t* bucket = map->bucket[ibucket];
size_t inode, nsize;
for (inode = 0, nsize = array_size(bucket); inode < nsize; ++inode) {
if (bucket[inode].key == key) {
void* prev = bucket[inode].value;
bucket[inode].value = value;
return prev;
}
}
{
hashmap_node_t node = { key, value };
array_push(map->bucket[ibucket], node);
++map->num_nodes;
}
return 0;
}
/********************************* UTILITIES ************************/
static int
expand_table(HTAB *hashp)
{
HHDR *hctl;
SEGMENT old_seg,new_seg;
long old_bucket, new_bucket;
long new_segnum, new_segndx;
long old_segnum, old_segndx;
ELEMENT *chain;
BUCKET_INDEX *old,*newbi;
register BUCKET_INDEX chainIndex,nextIndex;
#ifdef HASH_STATISTICS
hash_expansions++;
#endif
hctl = hashp->hctl;
new_bucket = ++hctl->max_bucket;
old_bucket = (hctl->max_bucket & hctl->low_mask);
new_segnum = new_bucket >> hctl->sshift;
new_segndx = MOD ( new_bucket, hctl->ssize );
if ( new_segnum >= hctl->nsegs ) {
/* Allocate new segment if necessary */
if (new_segnum >= hctl->dsize) {
dir_realloc(hashp);
}
if (! (hashp->dir[new_segnum] = seg_alloc(hashp))) {
return (0);
}
hctl->nsegs++;
}
if ( new_bucket > hctl->high_mask ) {
/* Starting a new doubling */
hctl->low_mask = hctl->high_mask;
hctl->high_mask = new_bucket | hctl->low_mask;
}
/*
* Relocate records to the new bucket
*/
old_segnum = old_bucket >> hctl->sshift;
old_segndx = MOD(old_bucket, hctl->ssize);
old_seg = GET_SEG(hashp,old_segnum);
new_seg = GET_SEG(hashp,new_segnum);
old = &old_seg[old_segndx];
newbi = &new_seg[new_segndx];
for (chainIndex = *old;
chainIndex != INVALID_INDEX;
chainIndex = nextIndex){
chain = GET_BUCKET(hashp,chainIndex);
nextIndex = chain->next;
if ( call_hash(hashp,
(char *)&(chain->key),
hctl->keysize) == old_bucket ) {
*old = chainIndex;
old = &chain->next;
} else {
*newbi = chainIndex;
newbi = &chain->next;
}
chain->next = INVALID_INDEX;
}
return (1);
}
/*
* hash_seq -- sequentially search through hash table and return
* all the elements one by one, return NULL on error and
* return TRUE in the end.
*
*/
long *
hash_seq(HTAB *hashp)
{
static uint32 curBucket = 0;
static BUCKET_INDEX curIndex;
ELEMENT *curElem;
long segment_num;
long segment_ndx;
SEGMENT segp;
HHDR *hctl;
if (hashp == NULL)
{
/*
* reset static state
*/
curBucket = 0;
curIndex = INVALID_INDEX;
return((long *) NULL);
}
hctl = hashp->hctl;
while (curBucket <= hctl->max_bucket) {
if (curIndex != INVALID_INDEX) {
curElem = GET_BUCKET(hashp, curIndex);
curIndex = curElem->next;
if (curIndex == INVALID_INDEX) /* end of this bucket */
++curBucket;
return(&(curElem->key));
}
/*
* initialize the search within this bucket.
*/
segment_num = curBucket >> hctl->sshift;
segment_ndx = curBucket & ( hctl->ssize - 1 );
/*
* first find the right segment in the table directory.
*/
segp = GET_SEG(hashp, segment_num);
if (segp == NULL)
/* this is probably an error */
return((long *) NULL);
/*
* now find the right index into the segment for the first
* item in this bucket's chain. if the bucket is not empty
* (its entry in the dir is valid), we know this must
* correspond to a valid element and not a freed element
* because it came out of the directory of valid stuff. if
* there are elements in the bucket chains that point to the
* freelist we're in big trouble.
*/
curIndex = segp[segment_ndx];
if (curIndex == INVALID_INDEX) /* empty bucket */
++curBucket;
}
return((long *) TRUE); /* out of buckets */
}
/*
* hash_search -- look up key in table and perform action
*
* action is one of HASH_FIND/HASH_ENTER/HASH_REMOVE
*
* RETURNS: NULL if table is corrupted, a pointer to the element
* found/removed/entered if applicable, TRUE otherwise.
* foundPtr is TRUE if we found an element in the table
* (FALSE if we entered one).
*/
long *
hash_search(HTAB *hashp,
char *keyPtr,
HASHACTION action, /*
* HASH_FIND / HASH_ENTER / HASH_REMOVE
* HASH_FIND_SAVE / HASH_REMOVE_SAVED
*/
bool *foundPtr)
{
uint32 bucket;
long segment_num;
long segment_ndx;
SEGMENT segp;
register ELEMENT *curr;
HHDR *hctl;
BUCKET_INDEX currIndex;
BUCKET_INDEX *prevIndexPtr;
char * destAddr;
static struct State {
ELEMENT *currElem;
BUCKET_INDEX currIndex;
BUCKET_INDEX *prevIndex;
} saveState;
Assert((hashp && keyPtr));
Assert((action == HASH_FIND) || (action == HASH_REMOVE) || (action == HASH_ENTER) || (action == HASH_FIND_SAVE) || (action == HASH_REMOVE_SAVED));
hctl = hashp->hctl;
# if HASH_STATISTICS
hash_accesses++;
hashp->hctl->accesses++;
# endif
if (action == HASH_REMOVE_SAVED)
{
curr = saveState.currElem;
currIndex = saveState.currIndex;
prevIndexPtr = saveState.prevIndex;
/*
* Try to catch subsequent errors
*/
Assert(saveState.currElem && !(saveState.currElem = 0));
}
else
{
bucket = call_hash(hashp, keyPtr, hctl->keysize);
segment_num = bucket >> hctl->sshift;
segment_ndx = bucket & ( hctl->ssize - 1 );
segp = GET_SEG(hashp,segment_num);
Assert(segp);
prevIndexPtr = &segp[segment_ndx];
currIndex = *prevIndexPtr;
/*
* Follow collision chain
*/
for (curr = NULL;currIndex != INVALID_INDEX;) {
/* coerce bucket index into a pointer */
curr = GET_BUCKET(hashp,currIndex);
if (! memcmp((char *)&(curr->key), keyPtr, hctl->keysize)) {
break;
}
prevIndexPtr = &(curr->next);
currIndex = *prevIndexPtr;
# if HASH_STATISTICS
hash_collisions++;
hashp->hctl->collisions++;
# endif
}
}
/*
* if we found an entry or if we weren't trying
* to insert, we're done now.
*/
*foundPtr = (bool) (currIndex != INVALID_INDEX);
switch (action) {
case HASH_ENTER:
if (currIndex != INVALID_INDEX)
return(&(curr->key));
break;
case HASH_REMOVE:
case HASH_REMOVE_SAVED:
if (currIndex != INVALID_INDEX) {
Assert(hctl->nkeys > 0);
hctl->nkeys--;
/* add the bucket to the freelist for this table. */
*prevIndexPtr = curr->next;
curr->next = hctl->freeBucketIndex;
hctl->freeBucketIndex = currIndex;
/* better hope the caller is synchronizing access to
* this element, because someone else is going to reuse
* it the next time something is added to the table
*/
return (&(curr->key));
}
return((long *) TRUE);
case HASH_FIND:
if (currIndex != INVALID_INDEX)
return(&(curr->key));
return((long *)TRUE);
case HASH_FIND_SAVE:
if (currIndex != INVALID_INDEX)
{
saveState.currElem = curr;
saveState.prevIndex = prevIndexPtr;
saveState.currIndex = currIndex;
return(&(curr->key));
}
return((long *)TRUE);
default:
/* can't get here */
return (NULL);
}
/*
If we got here, then we didn't find the element and
we have to insert it into the hash table
*/
Assert(currIndex == INVALID_INDEX);
/* get the next free bucket */
currIndex = hctl->freeBucketIndex;
if (currIndex == INVALID_INDEX) {
/* no free elements. allocate another chunk of buckets */
if (! bucket_alloc(hashp)) {
return(NULL);
}
currIndex = hctl->freeBucketIndex;
}
Assert(currIndex != INVALID_INDEX);
curr = GET_BUCKET(hashp,currIndex);
hctl->freeBucketIndex = curr->next;
/* link into chain */
*prevIndexPtr = currIndex;
/* copy key and data */
destAddr = (char *) &(curr->key);
memmove(destAddr,keyPtr,hctl->keysize);
curr->next = INVALID_INDEX;
/* let the caller initialize the data field after
* hash_search returns.
*/
/* memmove(destAddr,keyPtr,hctl->keysize+hctl->datasize);*/
/*
* Check if it is time to split the segment
*/
if (++hctl->nkeys / (hctl->max_bucket+1) > hctl->ffactor) {
/*
fprintf(stderr,"expanding on '%s'\n",keyPtr);
hash_stats("expanded table",hashp);
*/
if (! expand_table(hashp))
return(NULL);
}
return (&(curr->key));
}
