ste.xtest.nio.WatchServiceMock Maven / Gradle / Ivy

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/*
 * xTest
 * Copyright (C) 2013 Stefano Fornari
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Affero General Public License version 3 as published by
 * the Free Software Foundation with the addition of the following permission
 * added to Section 15 as permitted in Section 7(a): FOR ANY PART OF THE COVERED
 * WORK IN WHICH THE COPYRIGHT IS OWNED BY Stefano Fornari, Stefano Fornari
 * DISCLAIMS THE WARRANTY OF NON INFRINGEMENT OF THIRD PARTY RIGHTS.
 *
 * This program 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 Affero General Public License
 * along with this program; if not, see http://www.gnu.org/licenses or write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301 USA.
 */
package ste.xtest.nio;

import static java.nio.file.StandardWatchEventKinds.*;
import java.io.IOException;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.WatchEvent;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.concurrent.TimeUnit;

/**
 * WhatService with the following characteristics:
 *
 * - interruptible (set interrupt to true)
 * - generates an event every x milliseconds (set interval)
 *
 * @author ste
 */
public class WatchServiceMock implements WatchService {

    public boolean interrupt;
    public int interruptAfterNPolls;
    public long interval;
    public LinkedList paths = null;

    private boolean closed;

    public WatchServiceMock(String[] paths) {
        if (paths == null) {
            throw new IllegalArgumentException("paths cannot be null");
        }
        interrupt = closed = false;
        interval = 1000;
        interruptAfterNPolls = -1;

        this.paths = new LinkedList<>();
        for (String path: paths) {
            this.paths.push(newWatchKeyMock(path));
        }

    }

    @Override
    public void close() throws IOException {
        closed = true;
    }

    @Override
    public WatchKey poll() {
        if (closed) {
            throw new IllegalStateException("the service is closed");
        }

        return paths.peek();
    }

    @Override
    public WatchKey poll(long timeout, TimeUnit unit) throws InterruptedException {
        //
        // TODO: mock better the poll method
        //
        return take();
    }

    @Override
    public WatchKey take() throws InterruptedException {
        if (closed) {
            throw new IllegalStateException("the service is closed");
        }

        if (interruptAfterNPolls == 0) {
            throw new InterruptedException("mocked interrumption");
        } else if (interruptAfterNPolls > 0) {
            --interruptAfterNPolls;
        }

        Thread.sleep(interval);

        return paths.peek();
    }

    /**
     * @return true if previously closed, false otherwise
     */
    public boolean isClosed() {
        return closed;
    }

    // --------------------------------------------------------- Private methods

    private WatchKeyMock newWatchKeyMock(final String path) {

        WatchEventMock event = new WatchEventMock();
        event.context = Paths.get(path);
        event.kind = ENTRY_MODIFY;

        WatchKeyMock watchKey = new WatchKeyMock();
        watchKey.valid = true;
        watchKey.path = event.context;
        watchKey.events = new ArrayList>();

        watchKey.events.add(event);

        return watchKey;
    }


}