shz.cache.MapCache Maven / Gradle / Ivy

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package shz.cache;

import java.lang.ref.Reference;
import java.lang.ref.ReferenceQueue;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

public final class MapCache extends LocalCache {
    private final ConcurrentHashMap> cache;

    public MapCache(int capacity, RefType refType, ReferenceQueue queue) {
        super(refType, queue);
        cache = new ConcurrentHashMap<>(capacity);
    }

    public MapCache(int capacity, RefType refType) {
        this(capacity, refType, null);
    }

    public MapCache(int capacity) {
        this(capacity, RefType.SOFT);
    }

    @Override
    public V get(K key) {
        Reference ref = cache.get(key);
        if (ref == null || ref.isEnqueued()) {
            cache.remove(key);
            return null;
        }
        return ref.get();
    }

    @Override
    public void put(K key, V val) {
        cache.put(key, getReference(val));
    }

    @Override
    public boolean containsKey(K key) {
        return cache.containsKey(key);
    }

    @Override
    public int size() {
        int size = 0;
        for (Map.Entry> kv : cache.entrySet()) {
            Reference ref = kv.getValue();
            if (ref == null || ref.isEnqueued()) cache.remove(kv.getKey());
            else ++size;
        }
        return size;
    }

    @Override
    public void delete(K key) {
        Reference ref = cache.get(key);
        if (ref != null) ref.clear();
        cache.remove(key);
    }

    @Override
    public void clear() {
        cache.forEach((key, ref) -> {
            if (ref != null) ref.clear();
        });
        cache.clear();
    }
}