com.firefly.net.buffer.IOBufferPool Maven / Gradle / Ivy

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package com.firefly.net.buffer;

import com.firefly.net.BufferPool;
import com.firefly.utils.io.BufferUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.lang.ref.SoftReference;
import java.nio.ByteBuffer;

public class IOBufferPool implements BufferPool {
    private static Logger log = LoggerFactory.getLogger("firefly-system");

    private static final int POOL_SIZE = 8;

    @SuppressWarnings("unchecked")
    private final SoftReference[] pool = new SoftReference[POOL_SIZE];

    @Override
    public final ByteBuffer acquire(int size) {
        final SoftReference[] pool = this.pool;
        for (int i = 0; i < POOL_SIZE; i++) {
            SoftReference ref = pool[i];
            if (ref == null) {
                continue;
            }

            ByteBuffer buf = ref.get();
            if (buf == null) {
                pool[i] = null;
                continue;
            }

            if (buf.capacity() < size) {
                continue;
            }

            pool[i] = null;

            buf.clear();
            return buf;
        }

        int allocateSize = BufferUtils.normalizeBufferSize(size);
        log.debug("acquire read size: {}", allocateSize);

        ByteBuffer buf = ByteBuffer.allocateDirect(allocateSize);
        buf.clear();
        return buf;
    }

    @Override
    public final void release(ByteBuffer buffer) {
        final SoftReference[] pool = this.pool;
        for (int i = 0; i < POOL_SIZE; i++) {
            SoftReference ref = pool[i];
            if (ref == null || ref.get() == null) {
                pool[i] = new SoftReference<>(buffer);
                return;
            }
        }

        // pool is full - replace one
        final int capacity = buffer.capacity();
        for (int i = 0; i < POOL_SIZE; i++) {
            SoftReference ref = pool[i];
            ByteBuffer pooled = ref.get();
            if (pooled == null) {
                pool[i] = null;
                continue;
            }

            if (pooled.capacity() < capacity) {
                pool[i] = new SoftReference<>(buffer);
                return;
            }
        }
    }

}