Ejemplo n.º 1
0
static void
_parcHashMap_Resize(PARCHashMap *hashMap, size_t newCapacity)
{
    if (newCapacity < hashMap->minCapacity) {
        return;
    }

    PARCLinkedList **newBuckets = parcMemory_AllocateAndClear(newCapacity * sizeof(PARCLinkedList*));

    for (unsigned int i = 0; i < hashMap->capacity; i++) {
        if (hashMap->buckets[i] != NULL) {
            if (!parcLinkedList_IsEmpty(hashMap->buckets[i])) {
                PARCIterator *elementIt = parcLinkedList_CreateIterator(hashMap->buckets[i]);
                while (parcIterator_HasNext(elementIt)) {
                    _PARCHashMapEntry *entry = parcIterator_Next(elementIt);
                    PARCHashCode keyHash = parcObject_HashCode(entry->key);
                    int newBucket = keyHash % newCapacity;
                    if (newBuckets[newBucket] == NULL) {
                        newBuckets[newBucket] = parcLinkedList_Create();
                    }
                    parcLinkedList_Append(newBuckets[newBucket], entry);
                }
                parcIterator_Release(&elementIt);
            }
            parcLinkedList_Release(&hashMap->buckets[i]);
        }
    }
    PARCLinkedList **cleanupBuckets = hashMap->buckets;
    hashMap->buckets = newBuckets;
    hashMap->capacity = newCapacity;

    parcMemory_Deallocate(&cleanupBuckets);
}
Ejemplo n.º 2
0
bool
parcHashMap_Remove(PARCHashMap *hashMap, const PARCObject *key)
{
    PARCHashCode keyHash = parcObject_HashCode(key);

    int bucket = keyHash % hashMap->capacity;

    bool result = false;

    if (hashMap->buckets[bucket] != NULL) {
        PARCIterator *iterator = parcLinkedList_CreateIterator(hashMap->buckets[bucket]);

        while (parcIterator_HasNext(iterator)) {
            _PARCHashMapEntry *entry = parcIterator_Next(iterator);
            if (parcObject_Equals(key, entry->key)) {
                parcIterator_Remove(iterator);
                hashMap->size--;
                result = true;
                break;
            }
        }
        parcIterator_Release(&iterator);
    }

    // When expanded by 2 the load factor goes from .75 (3/4) to .375 (3/8), if
    // we compress by 2 when the load factor is .25 (1/4) the load
    // factor becomes .5 (1/2).
    double loadFactor = (double)hashMap->size/(double)hashMap->capacity;
    if (loadFactor <= (hashMap->minLoadFactor)) {
        _parcHashMap_Resize(hashMap, hashMap->capacity / 2);
    }

    return result;
}
Ejemplo n.º 3
0
static _PARCHashMapEntry *
_parcHashMap_GetEntry(const PARCHashMap *hashMap, const PARCObject *key)
{
    PARCHashCode keyHash = parcObject_HashCode(key);

    int bucket = keyHash % hashMap->capacity;

    _PARCHashMapEntry *result = NULL;

    if (hashMap->buckets[bucket] != NULL) {
        PARCIterator *iterator = parcLinkedList_CreateIterator(hashMap->buckets[bucket]);

        while (parcIterator_HasNext(iterator)) {
            _PARCHashMapEntry *entry = parcIterator_Next(iterator);
            if (parcObject_Equals(key, entry->key)) {
                result = entry;
                break;
            }
        }
        parcIterator_Release(&iterator);
    }

    return result;
}
Ejemplo n.º 4
0
PARCIterator *
parcSortedList_CreateIterator(PARCSortedList *instance)
{
    return parcLinkedList_CreateIterator(instance->list);
}