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.encoder;
015
016import ch.qos.logback.core.spi.ContextAware;
017import ch.qos.logback.core.spi.LifeCycle;
018
019/**
020 * Encoders are responsible for transform an incoming event into a byte array
021 * 
022 * @author Ceki Gülcü
023 * @author Joern Huxhorn
024 * @author Maarten Bosteels
025 * 
026 * @param <E> event type
027 * @since 0.9.19
028 */
029public interface Encoder<E> extends ContextAware, LifeCycle {
030
031    /**
032     * Get header bytes. This method is typically called upon opening of an output
033     * stream.
034     * 
035     * @return header bytes. Null values are allowed.
036     */
037    byte[] headerBytes();
038
039    /**
040     * Encode an event as bytes.
041     * 
042     * @param event
043     */
044    byte[] encode(E event);
045
046    /**
047     * Get footer bytes. This method is typically called prior to the closing of the
048     * stream where events are written.
049     * 
050     * @return footer bytes. Null values are allowed.
051     */
052    byte[] footerBytes();
053}