Source: ../../libxorp/xlog.h
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/* -*- c-basic-offset: 4; tab-width: 8; indent-tabs-mode: t -*- */
/*
* Copyright (c) 2001-2004 International Computer Science Institute
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software")
* to deal in the Software without restriction, subject to the conditions
* listed in the XORP LICENSE file. These conditions include: you must
* preserve this copyright notice, and you cannot mention the copyright
* holders in advertising related to the Software without their permission.
* The Software is provided WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED. This
* notice is a summary of the XORP LICENSE file; the license in that file is
* legally binding.
*/
/*
* $XORP: xorp/libxorp/xlog.h,v 1.10 2004/06/10 22:41:23 hodson Exp $
*/
#ifndef __LIBXORP_XLOG_H__
#define __LIBXORP_XLOG_H__
#include <stdio.h>
#include <stdarg.h>
#include "config.h"
/*
* The following defines and notes we defined __printfike if it does not
* already exist. The expansion of this macro uses a gcc extension to
* check format strings.
*/
#ifndef __printflike
#ifdef __GNUC__
#define __printflike(fmt,va1) __attribute__((__format__(printf, fmt, va1)))
#define __libxorp_xlog_defined_printflike
#else
#define __printflike(fmt, va1)
#define __libxorp_xlog_defined_printflike
#endif /* __GNUC__ */
#endif /* __printflike */
/**
* @short XORP logging functions.
*
* The xlog functions provide a similar role to syslog. The log
* messages may be output to multiple output streams simulataneously.
*/
# ifdef __cplusplus
extern "C" {
# endif
/**
* The log levels. Typically used only by @ref xlog_enable()
* and @ref xlog_disable()
*/
typedef enum {
XLOG_LEVEL_FATAL = 0, /* 0 */
XLOG_LEVEL_ERROR, /* 1 */
XLOG_LEVEL_WARNING, /* 2 */
XLOG_LEVEL_INFO, /* 3 */
XLOG_LEVEL_TRACE, /* 4 */
XLOG_LEVEL_MAX
} xlog_level_t;
/**
* The messages verbose level. Typically used only by @ref xlog_set_verbose()
* and @ref xlog_level_set_verbose()
*/
typedef enum {
XLOG_VERBOSE_LOW = 0, /* 0 */
XLOG_VERBOSE_MEDIUM, /* 1 */
XLOG_VERBOSE_HIGH, /* 2 */
XLOG_VERBOSE_MAX
} xlog_verbose_t;
/**
* The type of add-on functions to process the log messages.
*/
typedef int (*xlog_output_func_t)(void *obj, const char *msg);
/**
* A macro used for internal purpose to generate the appropriate xlog code
*/
#if (!defined XORP_MODULE_NAME) && (!defined XORP_LIBRARY_NAME)
#error You MUST have in your local directory a file like
#error "foo_module.h" that has defined inside the module
#error or library name. E.g.: #define XORP_MODULE_NAME "BGP"
#error or #define XORP_LIBRARY_NAME
#error This "foo_module.h" must be the first included by
#error each *.c and *.cc file.
#endif
#ifdef XORP_LIBRARY_NAME
# define _XLOG_MODULE_NAME XORP_LIBRARY_NAME
#else
# define _XLOG_MODULE_NAME XORP_MODULE_NAME
#endif
#define XLOG_FN(fn, fmt...) \
do { \
char xlog_where_buf[8000]; \
sprintf(xlog_where_buf, "+%d %s %s", __LINE__, __FILE__, __FUNCTION__);\
xlog_##fn(_XLOG_MODULE_NAME, xlog_where_buf, fmt); \
} while (0)
/**
* Initialize the log utility.
*
* As part of the initialization, the preamble string will be set to
* <@ref process_name><@ref preamble_message>
* Use in preference to @ref xlog_set_preamble which will be removed.
*
* @param argv0 the path of the process executable from which the program name
* will be extract to become part of the preamble string.
*
* @param preamble_message a string that will become part of the
* preamble string.
*
* @return 0 on success, otherwise -1.
*/
int xlog_init(const char *argv0, const char *preamble_message);
/**
* Gracefully exit logging.
*
* @return 0 on success, otherwise -1.
*/
int xlog_exit(void);
/**
* Start logging.
*
* @return 0 on success, otherwise -1.
*/
int xlog_start(void);
/**
* Stop logging.
*
* @return 0 on success, otherwise -1.
*/
int xlog_stop(void);
/**
* Check if xlog is running.
*
* @return non-zero if xlog is running, otherwise 0.
*/
int xlog_is_running(void);
/**
* Enable logging for messages of a given type (@ref log_level_t).
*
* By default, all message types are enabled.
*
* @param log_level the message type @ref xlog_level_t
* (e.g., @ref XLOG_LEVEL_WARNING) to enable the logging for.
* @return 0 on success, otherwise -1.
*/
int xlog_enable(xlog_level_t log_level);
/**
* Disable logging for messages of a given type (@ref log_level_t).
*
* Note: @ref XLOG_LEVEL_FATAL cannot be disabled.
*
* @param log_level the message type @ref xlog_level_t
* (e.g., @ref XLOG_LEVEL_WARNING) to disable the logging for.
* @return 0 on success, otherwise -1.
*/
int xlog_disable(xlog_level_t log_level);
/**
* Set the preamble string for the log entries.
*
* @param text the preamble string, or NULL if no preamble.
*/
void xlog_set_preamble(const char *text);
/**
* Get process name as set with xlog_init.
*
* @return pointer to name on success, NULL otherwise.
*/
const char* xlog_process_name(void);
/**
* Set the level of verbosity (@ref xlog_verbose_t) for the log entries.
*
* Applies for all type of messages except for @ref XLOG_LEVEL_FATAL
* which always is set to the most verbose level.
*
* @param verbose_level the level of verbosity @ref xlog_verbose_t
* (higher is more verbose).
*/
void xlog_set_verbose(xlog_verbose_t verbose_level);
/**
* Set the level of verbosity (@ref xlog_verbose_t) for the log entries
* of messages of a given type (@ref xlog_level_t).
*
* Note: @ref XLOG_LEVEL_FATAL verbosity cannot be changed, and is
* always set to the most verbose level.
*
* @param log_level the message type @ref xlog_level_t to set the
* verbosity of.
* @param verbose_level the level of verbosity @ref xlog_verbose_t
* (higher is more verbose).
*/
void xlog_level_set_verbose(xlog_level_t log_level,
xlog_verbose_t verbose_level);
/**
* Add a file descriptor to the set of output streams.
*
* @param fp the file descriptor to add to the set of output streams.
* @return 0 on success, otherwise -1.
*/
int xlog_add_output(FILE *fp);
/**
* Remove a file descriptor from the set of output streams.
*
* @param fp the file descriptor to remove from the set of output streams.
* @return 0 on success, otherwise -1.
*/
int xlog_remove_output(FILE *fp);
/**
* Add a processing function and an object to the set of output streams.
*
* @param func the function to add to the set of output streams.
* @param obj the object to supply @ref func with when called.
*
* @return 0 on success, otherwise -1.
*/
int xlog_add_output_func(xlog_output_func_t func, void *obj);
/**
* Remove a processing function and an object from the set of output streams.
*
* @param func the function to remove from the set of output streams.
* @param obj the object that @ref func was supplied with.
*
* @return 0 on success, otherwise -1.
*/
int xlog_remove_output_func(xlog_output_func_t func, void *obj);
/**
* Add default output stream to list of output streams.
*
* XXX: right now the default is '/dev/stderr', but it should eventually be:
* `/dev/console' if the process has sufficient permissions,
* and `/dev/stderr' otherwise.
*
* @return 0 on success, otherwise -1.
*/
int xlog_add_default_output(void);
/**
* Remove the default output stream from the set of output streams.
*
* @return 0 on success, otherwise -1.
*/
int xlog_remove_default_output(void);
/**
* Write a FATAL message to the xlog output streams and aborts the program.
*
* Note that FATAL messages cannot be disabled by @ref xlog_disable().
*
* @param module_name the name of the module this message applies to.
* @param format the printf()-style format of the message to write.
* Note that a trailing newline is added if none is present.
* @param ... the arguments for @ref format.
*/
void xlog_fatal(const char *module_name, const char *where,
const char *format, ...) __printflike(3,4);
#define XLOG_FATAL(fmt...) XLOG_FN(fatal, fmt)
/**
* Write an ERROR message to the xlog output streams.
*
* @param module_name the name of the module this message applies to.
* @param format the printf()-style format of the message to write.
* Note that a trailing newline is added if none is present.
* @param ... the arguments for @ref format.
*/
void xlog_error(const char *module_name, const char *where,
const char *format, ...) __printflike(3,4);
#define XLOG_ERROR(fmt...) XLOG_FN(error, fmt)
/**
* Write a WARNING message to the xlog output streams.
*
* @param module_name the name of the module this message applies to.
* @param format the printf()-style format of the message to write.
* Note that a trailing newline is added if none is present.
* @param ... the arguments for @ref format.
*/
void xlog_warning(const char *module_name, const char *where,
const char *format, ...) __printflike(3,4);
#define XLOG_WARNING(fmt...) XLOG_FN(warning, fmt)
/**
* Write an INFO message to the xlog output streams.
*
* @param module_name the name of the module this message applies to.
* @param format the printf()-style format of the message to write.
* Note that a trailing newline is added if none is present.
* @param ... the arguments for @ref format.
*/
void xlog_info(const char *module_name, const char *where,
const char *format, ...) __printflike(3,4);
#define XLOG_INFO(fmt...) XLOG_FN(info, fmt)
/**
* XORP replacement for assert(3).
*
* Note that it cannot be conditionally disabled and logs error through
* the standard XLOG mechanism.
* Calls XLOG_FATAL if assertion fails.
*
* @param assertion the assertion condition.
*/
#define XLOG_ASSERT(assertion) \
do { \
if (!(assertion)) \
XLOG_FATAL("Assertion (%s) failed", #assertion); \
} while (0)
/**
* A marker that can be used to indicate code that should never be executed.
*
* Note that it cannot be conditionally disabled and logs error through
* the standard XLOG mechanism.
* Always calls XLOG_FATAL.
*/
#define XLOG_UNREACHABLE() \
do { \
XLOG_FATAL("Internal fatal error: unreachable code reached"); \
exit(1); /* unreached: keep the compiler happy */ \
} while (0)
/**
* A marker that can be used to indicate code that is not yet
* implemented and hence should not be run.
*
* Note that it cannot be conditionally disabled and logs error through
* the standard XLOG mechanism.
* Always calls XLOG_FATAL.
*/
#define XLOG_UNFINISHED() \
do { \
XLOG_FATAL("Internal fatal error: unfinished code reached"); \
exit(1); /* unreached: keep the compiler happy */ \
} while (0)
/*
* The macros below define the XLOG_TRACE(), the macro responsible for
* generating trace messages. It takes the same arguments as
* printf(), except that the very first argument is a boolean
* that defines whether the trace message will be output.
* Note that a trailing newline is added if none is present.
* E.g.,
*
* XLOG_TRACE(cond_variable, "The number is %d", 5);
*
* There is some additional unpleasantness in this header for
* `configure' related magic.
*
* The macro CPP_SUPPORTS_VA_ARGS is defined by `configure' tests if the
* C preprocessor supports macros with variable length arguments. We
* use the GNU specific (args...) syntax for variable length arguments
* as the c9x standard (__VA_ARGS__) breaks when the preprocessor is
* invoked via g++.
* TODO: the magic below should be used for the other XLOG_* entries
* as well.
*/
#ifdef CPP_SUPPORTS_GNU_VA_ARGS
# define XLOG_TRACE(args...) \
_xcond_trace_msg_long(XORP_MODULE_NAME, __FILE__, __LINE__, __FUNCTION__, args)
#else
# define XLOG_TRACE \
_xcond_trace_entry(XORP_MODULE_NAME, __FILE__, __LINE__, __FUNCTION__), \
_xcond_trace_msg_short
#endif
/* Function for systems with variable argument macros */
void _xcond_trace_msg_long(const char *module_name,
const char *file,
int line,
const char *fn,
int flag,
const char *format, ...) __printflike(6,7);
/* Functions for systems without variable argument macros */
void _xcond_trace_entry(const char *module_name, const char *file,
int line, const char *fn);
void _xcond_trace_msg_short(int flag,
const char *format, ...) __printflike(2,3);
/**
* Compute the current local time and return it as a string.
*
* The return string has the format:
* Year/Month/Day Hour:Minute:Second.Microsecond
* Example: 2002/02/05 20:22:09.808632
* Note that the returned string uses statically allocated memory,
* and does not need to be de-allocated.
*
* @return a statically allocated string with the local time using
* the format described above.
*/
const char *xlog_localtime2string(void);
/**
* A local implementation of vasprintf(3).
*
* If vasprintf(3) is available, it is called instead.
*
* @param ret a pointer to the string pointer to store the result.
* @param format the printf(3)-style format.
* @param ap the variable arguments for @ref format.
*
* @return (From FreeBSD vasprintf(3) manual page):
* The number of characters printed (not including the trailing '\0'
* used to end output to strings). Also, set the value pointed to by
* ret to be a pointer to a buffer sufficiently large to hold the
* formatted string. This pointer should be passed to free(3) to
* release the allocated storage when it is no longer needed. If
* sufficient space cannot be allocated, will return -1 and set @ref ret
* to be a NULL pointer.
*/
int x_vasprintf(char **ret, const char *format, va_list ap);
/**
* A local implementation of asprintf(3).
*
* @param ret a pointer to the string pointer to store the result.
* @param format the printf(3)-style format.
* @param ... the variable arguments for @ref format.
*
* @return (From FreeBSD asprintf(3) manual page):
* The number of characters printed (not including the
* trailing '\0' used to end output to strings). Also, set ret to be
* a pointer to a buffer sufficiently large to hold the formatted string.
* This pointer should be passed to free(3) to release the allocated
* storage when it is no longer needed. If sufficient space cannot
* be allocated, will return -1 and set @ref ret to be a NULL pointer.
*/
int x_asprintf(char **ret, const char *format, ...);
/* Undefine __printflike if we defined it */
#ifdef __libxorp_xlog_defined_printflike
#undef __libxorp_xlog_defined_printflike
#undef __printflike
#endif /* __libxorp_xlog_defined_printflike */
# ifdef __cplusplus
}
# endif
#endif /* __LIBXORP_XLOG_H__ */
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