001/**
002 * Logback: the reliable, generic, fast and flexible logging framework.
003 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
004 *
005 * This program and the accompanying materials are dual-licensed under
006 * either the terms of the Eclipse Public License v1.0 as published by
007 * the Eclipse Foundation
008 *
009 *   or (per the licensee's choosing)
010 *
011 * under the terms of the GNU Lesser General Public License version 2.1
012 * as published by the Free Software Foundation.
013 */
014package ch.qos.logback.core.rolling;
015
016import java.io.File;
017import java.util.concurrent.atomic.AtomicLong;
018import java.util.concurrent.atomic.LongAdder;
019
020import ch.qos.logback.core.spi.LifeCycle;
021
022/**
023 * A <code>TriggeringPolicy</code> controls the conditions under which roll-over
024 * occurs. Such conditions include time of day, file size, an external event,
025 * the log request or a combination thereof.
026 *
027 * @author Ceki G&uuml;lc&uuml;
028 */
029
030public interface TriggeringPolicy<E> extends LifeCycle {
031
032    /**
033     *  Return the {@link LengthCounter} instance associated with this triggering
034     *  policy. The returned value may be null.
035     *
036     * @return a LengthCounter instance, may be null
037     * @since 1.5.8
038     */
039    default LengthCounter getLengthCounter() {
040        return null;
041    }
042
043    /**
044     * Should roll-over be triggered at this time?
045     * 
046     * @param activeFile A reference to the currently active log file.
047     * @param event      A reference to the current event.
048     * @return true if a roll-over should occur.
049     */
050    boolean isTriggeringEvent(final File activeFile, final E event);
051}