void HashTable_Rehash(wHashTable* table, long numOfBuckets)
{
int index;
long hashValue;
wKeyValuePair* pair;
wKeyValuePair* nextPair;
wKeyValuePair** newBucketArray;
if (numOfBuckets == 0)
numOfBuckets = calculateIdealNumOfBuckets(table);
if (numOfBuckets == table->numOfBuckets)
return; /* already the right size! */
newBucketArray = (wKeyValuePair**) malloc(numOfBuckets * sizeof(wKeyValuePair*));
if (newBucketArray == NULL)
{
/* Couldn't allocate memory for the new array. This isn't a fatal
* error; we just can't perform the rehash. */
return;
}
for (index = 0; index < numOfBuckets; index++)
newBucketArray[index] = NULL;
for (index = 0; index < table->numOfBuckets; index++)
{
pair = table->bucketArray[index];
while (pair != NULL)
{
nextPair = pair->next;
hashValue = table->hashFunction(pair->key) % numOfBuckets;
pair->next = newBucketArray[hashValue];
newBucketArray[hashValue] = pair;
pair = nextPair;
}
}
free(table->bucketArray);
table->bucketArray = newBucketArray;
table->numOfBuckets = numOfBuckets;
}
void HashTableRehash(HashTable *hashTable, long numOfBuckets) {
KeyValuePair **newBucketArray;
int i;
assert(numOfBuckets >= 0);
if (numOfBuckets == 0)
numOfBuckets = calculateIdealNumOfBuckets(hashTable);
if (numOfBuckets == hashTable->numOfBuckets)
return; /* already the right size! */
newBucketArray = (KeyValuePair **)
malloc(numOfBuckets * sizeof(KeyValuePair *));
if (newBucketArray == NULL) {
/* Couldn't allocate memory for the new array. This isn't a fatal
* error; we just can't perform the rehash. */
return;
}
for (i=0; i<numOfBuckets; i++)
newBucketArray[i] = NULL;
for (i=0; i<hashTable->numOfBuckets; i++) {
KeyValuePair *pair = hashTable->bucketArray[i];
while (pair != NULL) {
KeyValuePair *nextPair = pair->next;
long hashValue = hashTable->hashFunction(pair->key) % numOfBuckets;
pair->next = newBucketArray[hashValue];
newBucketArray[hashValue] = pair;
pair = nextPair;
}
}
free(hashTable->bucketArray);
hashTable->bucketArray = newBucketArray;
hashTable->numOfBuckets = numOfBuckets;
}
