/*

 * 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.

 */

#ifndef _LOG4CXX_APPENDER_H

#define _LOG4CXX_APPENDER_H

#include <log4cxx/spi/optionhandler.h>

#include <log4cxx/helpers/object.h>

#include <vector>

namespace LOG4CXX_NS

{

// Forward declarations

namespace spi

{

class LoggingEvent;

typedef std::shared_ptr<LoggingEvent> LoggingEventPtr;

class Filter;

typedef std::shared_ptr<Filter> FilterPtr;

class ErrorHandler;

typedef std::shared_ptr<ErrorHandler> ErrorHandlerPtr;

}

class Layout;

typedef std::shared_ptr<Layout> LayoutPtr;

/**

Implement this interface for your own strategies for outputting log

statements.

*/

class LOG4CXX_EXPORT Appender :

  public virtual spi::OptionHandler

{

  public:

    DECLARE_ABSTRACT_LOG4CXX_OBJECT(Appender)

    virtual ~Appender() {}

    /**

     Add a filter to the end of the filter list.

    */

    virtual void addFilter(const spi::FilterPtr newFilter) = 0;

    /**

     Returns the head Filter. The Filters are organized in a linked list

     and so all Filters on this Appender are available through the result.

     @return the head Filter or null, if no Filters are present

     */

    virtual spi::FilterPtr getFilter() const = 0;

    /**

     Clear the list of filters by removing all the filters in it.

    */

    virtual void clearFilters() = 0;

    /**

     Release any resources allocated within the appender such as file

     handles, network connections, etc.

     <p>It is a programming error to append to a closed appender.

    */

    virtual void close() = 0;

    /**

     Log in <code>Appender</code> specific way. When appropriate,

     Loggers will call the <code>doAppend</code> method of appender

     implementations in order to log.

    */

    virtual void doAppend(const spi::LoggingEventPtr& event,

      LOG4CXX_NS::helpers::Pool& pool) = 0;

    /**

     Get the name of this appender. The name uniquely identifies the

     appender.

    */

    virtual LogString getName() const = 0;

    /**

     Set the Layout for this appender.

    */

    virtual void setLayout(const LayoutPtr layout) = 0;

    /**

     Returns this appenders layout.

    */

    virtual LayoutPtr getLayout() const = 0;

    /**

     Set the name of this appender. The name is used by other

     components to identify this appender.

    */

    virtual void setName(const LogString& name) = 0;

    /**

     Configurators call this method to determine if the appender

     requires a layout. If this method returns <code>true</code>,

     meaning that layout is required, then the configurator will

     configure an layout using the configuration information at its

     disposal.  If this method returns <code>false</code>, meaning that

     a layout is not required, then layout configuration will be

     skipped even if there is available layout configuration

     information at the disposal of the configurator..

     <p>In the rather exceptional case, where the appender

     implementation admits a layout but can also work without it, then

     the appender should return <code>true</code>.

    */

    virtual bool requiresLayout() const = 0;

};

LOG4CXX_PTR_DEF(Appender);

LOG4CXX_LIST_DEF(AppenderList, AppenderPtr);

}

#endif //_LOG4CXX_APPENDER_H