<?php

/**

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements. See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You 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 log4php

 */

/**

 * Pool implmentation for LoggerAppender instances.

 *

 * The pool is used when configuring log4php. First all appender instances

 * are created in the pool. Afterward, they are linked to loggers, each

 * appender can be linked to multiple loggers. This makes sure duplicate

 * appenders are not created.

 *

 * @version $Revision: 1350602 $

 * @package log4php

 */

class LoggerAppenderPool {

    /** Holds appenders indexed by their name */

    public static $appenders = array();

    /**

     * Adds an appender to the pool.

     * The appender must be named for this operation.

     * @param LoggerAppender $appender

     */

    public static function add(LoggerAppender $appender) {

        $name = $appender->getName();

        if (empty($name)) {

            trigger_error('log4php: Cannot add unnamed appender to pool.', E_USER_WARNING);

            return;

        }

        if (isset(self::$appenders[$name])) {

            trigger_error("log4php: Appender [$name] already exists in pool. Overwriting existing appender.", E_USER_WARNING);

        }

        self::$appenders[$name] = $appender;

    }

    /**

     * Retrieves an appender from the pool by name.

     * @param string $name Name of the appender to retrieve.

     * @return LoggerAppender The named appender or NULL if no such appender

     *  exists in the pool.

     */

    public static function get($name) {

        return isset(self::$appenders[$name]) ? self::$appenders[$name] : null;

    }

    /**

     * Removes an appender from the pool by name.

     * @param string $name Name of the appender to remove.

     */

    public static function delete($name) {

        unset(self::$appenders[$name]);

    }

    /**

     * Returns all appenders from the pool.

     * @return array Array of LoggerAppender objects.

     */

    public static function getAppenders() {

        return self::$appenders;

    }

    /**

     * Checks whether an appender exists in the pool.

     * @param string $name Name of the appender to look for.

     * @return boolean TRUE if the appender with the given name exists.

     */

    public static function exists($name) {

        return isset(self::$appenders[$name]);

    }

    /**

     * Clears all appenders from the pool.

     */

    public static function clear() {

        self::$appenders = array();

    }

}