/*
 * Adapted from The MIT License (MIT)
 *
 * Copyright (c) 2018-2025 DaPorkchop_
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy,
 * modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software
 * is furnished to do so, subject to the following conditions:
 *
 * Any persons and/or organizations using this software must include the above copyright notice and this permission notice,
 * provide sufficient credit to the original authors of the project (IE: DaPorkchop_), as well as provide a link to the original project.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

package net.daporkchop.lib.common.pool.array;

import lombok.NonNull;
import net.daporkchop.lib.common.math.BinMath;
import net.daporkchop.lib.common.reference.ReferenceStrength;
import net.daporkchop.lib.common.util.PArrays;

import java.lang.ref.Reference;
import java.lang.reflect.Array;
import java.util.ArrayDeque;
import java.util.Deque;
import java.util.function.IntFunction;

import static net.daporkchop.lib.common.util.PValidation.*;
import static net.daporkchop.lib.common.util.PorkUtil.*;

/**
 * Simple implementation of {@link ArrayAllocator} which caches arrays by their size in powers of 2.
 *
 * @author DaPorkchop_
 */
final class CollectablePow2ArrayAllocator<V> extends AbstractArrayAllocator<V> {
    private final Deque<Reference<V>>[] arenas = uncheckedCast(PArrays.filledFrom(StrongPow2ArrayAllocator.NUM_ARENAS, Deque.class, ArrayDeque::new));
    private final ReferenceStrength strength;
    private final int maxCapacity;

    public CollectablePow2ArrayAllocator(@NonNull IntFunction<V> lambda, @NonNull ReferenceStrength strength, int maxCapacity) {
        super(lambda);

        this.strength = strength;
        this.maxCapacity = positive(maxCapacity, "maxCapacity");
    }

    public CollectablePow2ArrayAllocator(@NonNull Class<?> componentClass, @NonNull ReferenceStrength strength, int maxCapacity) {
        super(componentClass);

        this.strength = strength;
        this.maxCapacity = positive(maxCapacity, "maxCapacity");
    }

    @Override
    public V atLeast(int length) {
        return this.getPooled(notNegative(length, "size"));
    }

    @Override
    public V exactly(int length) {
        notNegative(length, "size");
        if (!BinMath.hasSingleBit(length)) {
            //requested size is not a power of 2, we can't return a pooled array
            return this.createArray(length);
        }
        return this.getPooled(length);
    }

    private V getPooled(int length) {
        int arenaIndex = StrongPow2ArrayAllocator.arenaIndex(length);
        Deque<Reference<V>> arena = this.arenas[arenaIndex];
        V value = null;
        Reference<V> ref;
        synchronized (arena) {
            while ((ref = arena.poll()) != null && (value = ref.get()) == null) {
            }
        }
        if (value == null) {
            value = this.createArray(StrongPow2ArrayAllocator.arrayLengthInArena(arenaIndex));
        }
        return value;
    }

    @Override
    public void release(@NonNull V array) {
        int length = Array.getLength(array);
        if (BinMath.hasSingleBit(length)) {
            int arenaIndex = StrongPow2ArrayAllocator.arenaIndex(length);
            Deque<Reference<V>> arena = this.arenas[arenaIndex];
            synchronized (arena) {
                if (arena.size() < this.maxCapacity) {
                    arena.addFirst(this.strength.createReference(array));
                }
            }
        }
    }
}
