Class IndexMap

src/main/java/pascal/taie/util/collection/IndexMap.java:51–354

Array-based implementation of the Map interface. This implementation requires a Indexer, which provides a unique index for each key object that could be put into this map. Since the indexer maintains the mappings between objects and indexes, this map does not need to store the ke

 * TODO: add mod count
 */
public class IndexMap<K, V> extends AbstractMap<K, V>
        implements Serializable {

    private static final String NULL_VALUE_MSG = "IndexMap does not permit null values";

    private final Indexer<K> indexer;

    private V[] values;

    private int size = 0;

    /**
     * The cache of {@link IndexMap#entrySet()}.
     */
    private transient Set<Entry<K, V>> entrySet;

    /**
     * The cache of {@link IndexMap#keySet()}.
     */
    private transient Set<K> keySet;

    public IndexMap(Indexer<K> indexer, int initialCapacity) {
        this.indexer = indexer;
        this.values = (V[]) new Object[initialCapacity];
    }

    public int capacity() {
        return values.length;
    }

    @Override
    public int size() {
        return size;
    }

    @Override
    public boolean isEmpty() {
        return size == 0;
    }

    @Override
    public boolean containsKey(Object key) {
        int index = indexer.getIndex((K) key);
        return isValidIndex(index) && values[index] != null;
    }

    private boolean isValidIndex(int index) {
        return 0 <= index && index < values.length;
    }

    @Override
    public V get(Object key) {
        int index = indexer.getIndex((K) key);
        return isValidIndex(index) ? values[index] : null;
    }

    @Override
    public V put(K key, V value) {