repos_ecs/其他2015后/日志库/log4cproj_c/Log4C/log4c/layout.h

/* $Id$
*
* layout.h
* 
* Copyright 2001-2003, Meiosys (www.meiosys.com). All rights reserved.
*
* See the COPYING file for the terms of usage and distribution.
*/

#ifndef log4c_layout_h
#define log4c_layout_h

/**
* @file layout.h
*
* @brief Interface for user specific layout format of log4c_logging_event
* events. 
*
* @todo the layout interface needs a better configuration system
* depending on the layout type. The udata field is a just a trick.
*
* @todo a pattern layout would be welcomed !!
**/

#include "log4c/defs.h"
#include "log4c/logging_event.h"
#include <stdio.h>

__LOG4C_BEGIN_DECLS

struct __log4c_layout;

/**
* log4c layout class 
**/
typedef struct __log4c_layout log4c_layout_t;

/**
* @brief log4c layout type class
*
* Attributes description:
* 
* @li @c name layout type name 
* @li @c format 
**/
typedef struct log4c_layout_type {
	const TCHAR* name;
	const TCHAR* (*format) (const log4c_layout_t*, const log4c_logging_event_t*);
} log4c_layout_type_t;

/**
* Get a pointer to an existing layout type.
*
* @param a_name the name of the layout type to return.  
* @returns a pointer to an existing layout type, or NULL if no layout
* type with the specified name exists.
**/
LOG4C_API const log4c_layout_type_t* log4c_layout_type_get(const TCHAR* a_name);

/**
* Use this function to register a layout type with log4c.
* Once this is done you may refer to this type by name both 
* programatically and in the log4c configuration file.
*
* @param a_type a pointer to the new layout type to set.
* @returns a pointer to the previous layout type of same name.
*
* Example code fragment: 
* @code
* 
* const log4c_layout_type_t log4c_layout_type_xml = {
*    "s13_xml",
*    xml_format,
* };
*  
* log4c_layout_type_set(&log4c_layout_type_xml);
*
* @endcode
**/
LOG4C_API const log4c_layout_type_t* log4c_layout_type_set(const log4c_layout_type_t* a_type);

/**
* Get a pointer to an existing layout.
*
* @param a_name the name of the layout to return.
* @returns a pointer to an existing layout, or NULL if no layout
* with the specfied name exists.
**/
LOG4C_API log4c_layout_t* log4c_layout_get(const TCHAR* a_name);

/**
* Constructor for layout. 
**/
LOG4C_API log4c_layout_t* log4c_layout_new(const TCHAR* a_name);

/**
* Destructor for layout.
**/
LOG4C_API void log4c_layout_delete(log4c_layout_t* a_layout);

/**
* @param a_layout the log4c_layout_t object
* @return the layout name
**/
LOG4C_API const TCHAR* log4c_layout_get_name(const log4c_layout_t* a_layout);

/**
* @param a_layout the log4c_layout_t object
* @return a log4c_layout_type_t object
**/
LOG4C_API const log4c_layout_type_t* log4c_layout_get_type(const log4c_layout_t* a_layout);

/**
* sets the layout type
*
* @param a_layout the log4c_layout_t object
* @param a_type the new layout type
* @return the previous layout type
*
**/
LOG4C_API const log4c_layout_type_t* log4c_layout_set_type(log4c_layout_t* a_layout,
	const log4c_layout_type_t* a_type);

/**
* @param a_layout the log4c_layout_t object
* @return the layout user data
**/
LOG4C_API void* log4c_layout_get_udata(const log4c_layout_t* a_layout);

/**
* sets the layout user data
*
* @param a_layout the log4c_layout_t object
* @param a_udata the new layout user data
* @return the previous layout user data
**/
LOG4C_API void* log4c_layout_set_udata(log4c_layout_t*	a_layout, void*		a_udata);
/**
* format a log4c_logging_event events to a string.
*
* @param a_layout the log4c_layout_t object
* @param a_event a logging_event_t object
* @returns an appendable string.
**/
LOG4C_API const TCHAR* log4c_layout_format(const log4c_layout_t* a_layout,const log4c_logging_event_t*	a_event);

/**
* prints the layout on a stream
* @param a_layout the log4c_layout_t object
* @param a_stream the stream
**/
LOG4C_API void log4c_layout_print(const log4c_layout_t* a_layout, FILE* a_stream);

/**
* prints all the current registered layout types on a stream
*
* @param fp the stream
**/                            
LOG4C_API void log4c_layout_types_print(FILE *fp);

/** 删除本layout.c文件中定义的全局和静态的指针指向的内存,防止内存泄漏
如：
1.gs_types.
2.
@return void.
作者：jesse 日期:2008.09.08
*/
LOG4C_API void log4c_layout_delete_global();


/**
* Helper macro to define static layout types.
*
* @param a_type the log4c_layout_type_t object to define
* @warning needs GCC support: otherwise this macro does nothing
* @deprecated This macro, and the static initialialization
* of layouts in general, is deprecated. Use rather
* the log4c_layout_type_set() function to initialize your appenders
* before calling log4c_init() 
**/
#ifdef __GNUC__
#   define log4c_layout_type_define(a_type) \
	typedef int log4c_layout_type_define_##a_type __attribute__((deprecated)); \
	static log4c_layout_type_define_##a_type __unsused_var __attribute__((unused));
#else
#   define log4c_layout_type_define(a_type)
#endif

/**
* @internal
**/
struct __sd_factory;
LOG4C_API struct __sd_factory* log4c_layout_factory;

__LOG4C_END_DECLS

#endif