RecyclingSupplierBuilder.java

/*
 * Copyright (c) 2001-2017, Zoltan Farkas All Rights Reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * Additionally licensed with:
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.spf4j.recyclable.impl;

import org.spf4j.base.AbstractRunnable;
import org.spf4j.recyclable.ObjectCreationException;
import org.spf4j.recyclable.ObjectDisposeException;
import org.spf4j.recyclable.RecyclingSupplier;
import org.spf4j.recyclable.Scanable;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import javax.annotation.Nonnull;
import org.spf4j.base.Handler;

/**
 *
 * @author zoly
 */
public final class RecyclingSupplierBuilder<T> {

    private final int maxSize;
    private final RecyclingSupplier.Factory<T> factory;
    private boolean fair;
    private ScheduledExecutorService maintenanceExecutor;
    private long maintenanceIntervalMillis;
    private Handler<T, ? extends Exception> borrowHook;
    private Handler<T, ? extends Exception> returnHook;
    private int initialSize;
    private boolean collectBorrowed;

    public RecyclingSupplierBuilder(final int maxSize, @Nonnull final RecyclingSupplier.Factory<T> factory) {
        this.fair = true;
        this.maxSize = maxSize;
        this.factory = factory;
        this.initialSize = 0;
    }

    public RecyclingSupplierBuilder<T> unfair() {
        this.fair = false;
        return this;
    }

    public RecyclingSupplierBuilder<T> withInitialSize(final int pinitialSize) {
        this.initialSize = pinitialSize;
        return this;
    }


    public RecyclingSupplierBuilder<T> withMaintenance(final ScheduledExecutorService pexec,
            final long pmaintenanceIntervalMillis, final boolean pcollectBorrowed) {
        this.maintenanceExecutor = pexec;
        this.maintenanceIntervalMillis = pmaintenanceIntervalMillis;
        this.collectBorrowed = pcollectBorrowed;
        return this;
    }

    public RecyclingSupplierBuilder<T> withGetHook(final Handler<T, ? extends Exception> phook) {
        this.borrowHook = phook;
        return this;
    }

    public RecyclingSupplierBuilder<T> withRecycleHook(final Handler<T, ? extends Exception> phook) {
        this.returnHook = phook;
        return this;
    }

    public RecyclingSupplier<T> build() throws ObjectCreationException {
        final ScalableObjectPool<T> underlyingPool =
                new ScalableObjectPool<>(initialSize, maxSize, factory, fair);
        final RecyclingSupplier<T> pool;
        if (borrowHook != null || returnHook != null) {
            pool = new ObjectPoolWrapper<>(underlyingPool, borrowHook, returnHook);
        } else {
            pool = underlyingPool;
        }
        if (maintenanceExecutor != null) {
            maintenanceExecutor.scheduleWithFixedDelay(new MaintenanceRunner<>(underlyingPool, collectBorrowed),
                    maintenanceIntervalMillis, maintenanceIntervalMillis, TimeUnit.MILLISECONDS);
        }
        return pool;
    }

    private static final class MaintenanceRunner<T> extends AbstractRunnable {

        private final ScalableObjectPool<T> underlyingPool;
        private final boolean collectBorrowed;

        MaintenanceRunner(final ScalableObjectPool<T> underlyingPool, final boolean collectBorrowed) {
            super(true);
            this.underlyingPool = underlyingPool;
            this.collectBorrowed = collectBorrowed;
        }

        @Override
        public void doRun() throws Exception {
                if (collectBorrowed) {
                    underlyingPool.requestReturnFromBorrowersIfNotInUse();
                }
                underlyingPool.scan(new Scanable.ScanHandler<ObjectHolder<T>>() {
                    @Override
                    public boolean handle(final ObjectHolder<T> object) throws ObjectDisposeException {
                        object.validateObjectIfNotBorrowed();
                        return true;
                    }
                });

        }
    }

    @Override
    public String toString() {
        return "RecyclingSupplierBuilder{" + "maxSize=" + maxSize + ", factory=" + factory + ", fair="
                + fair + ", maintenanceExecutor=" + maintenanceExecutor + ", maintenanceIntervalMillis="
                + maintenanceIntervalMillis + ", borrowHook=" + borrowHook + ", returnHook=" + returnHook
                + ", initialSize=" + initialSize + ", collectBorrowed=" + collectBorrowed + '}';
    }



}