[ovs.git] / lib / vlog.h

/*
 * Copyright (c) 2008, 2009, 2010 Nicira Networks.
 *
 * Licensed 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 VLOG_H
#define VLOG_H 1

#include <limits.h>
#include <stdarg.h>
#include <stdbool.h>
#include <time.h>
#include "util.h"

#ifdef  __cplusplus
extern "C" {
#endif

/* Logging importance levels. */
#define VLOG_LEVELS                             \
    VLOG_LEVEL(EMER, LOG_ALERT)                 \
    VLOG_LEVEL(ERR, LOG_ERR)                    \
    VLOG_LEVEL(WARN, LOG_WARNING)               \
    VLOG_LEVEL(INFO, LOG_NOTICE)                \
    VLOG_LEVEL(DBG, LOG_DEBUG)
enum vlog_level {
#define VLOG_LEVEL(NAME, SYSLOG_LEVEL) VLL_##NAME,
    VLOG_LEVELS
#undef VLOG_LEVEL
    VLL_N_LEVELS
};

const char *vlog_get_level_name(enum vlog_level);
enum vlog_level vlog_get_level_val(const char *name);

/* Facilities that we can log to. */
#define VLOG_FACILITIES                                         \
    VLOG_FACILITY(SYSLOG, "%05N|%c|%p|%m")                      \
    VLOG_FACILITY(CONSOLE, "%d{%b %d %H:%M:%S}|%05N|%c|%p|%m")  \
    VLOG_FACILITY(FILE, "%d{%b %d %H:%M:%S}|%05N|%c|%p|%m")
enum vlog_facility {
#define VLOG_FACILITY(NAME, PATTERN) VLF_##NAME,
    VLOG_FACILITIES
#undef VLOG_FACILITY
    VLF_N_FACILITIES,
    VLF_ANY_FACILITY = -1
};

const char *vlog_get_facility_name(enum vlog_facility);
enum vlog_facility vlog_get_facility_val(const char *name);

/* A log module. */
struct vlog_module {
    const char *name;             /* User-visible name. */
    int levels[VLF_N_FACILITIES]; /* Minimum log level for each facility. */
    int min_level;                /* Minimum log level for any facility. */
};

/* Creates and initializes a global instance of a module named MODULE. */
#if USE_LINKER_SECTIONS
#define VLOG_DEFINE_MODULE(MODULE)                                      \
        VLOG_DEFINE_MODULE__(MODULE)                                    \
        struct vlog_module *vlog_module_ptr_##MODULE                    \
            __attribute__((section("vlog_modules"))) = &VLM_##MODULE
#else
#define VLOG_DEFINE_MODULE(MODULE) extern struct vlog_module VLM_##MODULE
#endif

const char *vlog_get_module_name(const struct vlog_module *);
struct vlog_module *vlog_module_from_name(const char *name);

/* Rate-limiter for log messages. */
struct vlog_rate_limit {
    /* Configuration settings. */
    unsigned int rate;          /* Tokens per second. */
    unsigned int burst;         /* Max cumulative tokens credit. */

    /* Current status. */
    unsigned int tokens;        /* Current number of tokens. */
    time_t last_fill;           /* Last time tokens added. */
    time_t first_dropped;       /* Time first message was dropped. */
    unsigned int n_dropped;     /* Number of messages dropped. */
};

/* Number of tokens to emit a message.  We add 'rate' tokens per second, which
 * is 60 times the unit used for 'rate', thus 60 tokens are required to emit
 * one message. */
#define VLOG_MSG_TOKENS 60

/* Initializer for a struct vlog_rate_limit, to set up a maximum rate of RATE
 * messages per minute and a maximum burst size of BURST messages. */
#define VLOG_RATE_LIMIT_INIT(RATE, BURST)                   \
        {                                                   \
            RATE,                           /* rate */      \
            (MIN(BURST, UINT_MAX / VLOG_MSG_TOKENS)         \
             * VLOG_MSG_TOKENS),            /* burst */     \
            0,                              /* tokens */    \
            0,                              /* last_fill */ \
            0,                              /* first_dropped */ \
            0,                              /* n_dropped */ \
        }

/* Configuring how each module logs messages. */
enum vlog_level vlog_get_level(const struct vlog_module *, enum vlog_facility);
void vlog_set_levels(struct vlog_module *,
                     enum vlog_facility, enum vlog_level);
char *vlog_set_levels_from_string(const char *);
char *vlog_get_levels(void);
bool vlog_is_enabled(const struct vlog_module *, enum vlog_level);
bool vlog_should_drop(const struct vlog_module *, enum vlog_level,
                      struct vlog_rate_limit *);
void vlog_set_verbosity(const char *arg);

/* Configuring log facilities. */
void vlog_set_pattern(enum vlog_facility, const char *pattern);
const char *vlog_get_log_file(void);
int vlog_set_log_file(const char *file_name);
int vlog_reopen_log_file(void);

/* Function for actual logging. */
void vlog_init(void);
void vlog_exit(void);
void vlog(const struct vlog_module *, enum vlog_level, const char *format, ...)
    __attribute__((format(printf, 3, 4)));
void vlog_valist(const struct vlog_module *, enum vlog_level,
                 const char *, va_list)
    __attribute__((format(printf, 3, 0)));
void vlog_rate_limit(const struct vlog_module *, enum vlog_level,
                     struct vlog_rate_limit *, const char *, ...)
    __attribute__((format(printf, 4, 5)));

/* Creates and initializes a global instance of a module named MODULE, and
 * defines a static variable named THIS_MODULE that points to it, for use with
 * the convenience macros below. */
#define VLOG_DEFINE_THIS_MODULE(MODULE)                                 \
        VLOG_DEFINE_MODULE(MODULE);                                     \
        static struct vlog_module *const THIS_MODULE = &VLM_##MODULE

/* Convenience macros.  These assume that THIS_MODULE points to a "struct
 * vlog_module" for the current module, as set up by e.g. the
 * VLOG_DEFINE_MODULE macro above.
 *
 * Guaranteed to preserve errno.
 */
#define VLOG_EMER(...) VLOG(VLL_EMER, __VA_ARGS__)
#define VLOG_ERR(...) VLOG(VLL_ERR, __VA_ARGS__)
#define VLOG_WARN(...) VLOG(VLL_WARN, __VA_ARGS__)
#define VLOG_INFO(...) VLOG(VLL_INFO, __VA_ARGS__)
#define VLOG_DBG(...) VLOG(VLL_DBG, __VA_ARGS__)

/* More convenience macros, for testing whether a given level is enabled in
 * THIS_MODULE.  When constructing a log message is expensive, this enables it
 * to be skipped. */
#define VLOG_IS_EMER_ENABLED() true
#define VLOG_IS_ERR_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_EMER)
#define VLOG_IS_WARN_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_WARN)
#define VLOG_IS_INFO_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_INFO)
#define VLOG_IS_DBG_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_DBG)

/* Convenience macros for rate-limiting.
 * Guaranteed to preserve errno.
 */
#define VLOG_ERR_RL(RL, ...) VLOG_RL(RL, VLL_ERR, __VA_ARGS__)
#define VLOG_WARN_RL(RL, ...) VLOG_RL(RL, VLL_WARN, __VA_ARGS__)
#define VLOG_INFO_RL(RL, ...) VLOG_RL(RL, VLL_INFO, __VA_ARGS__)
#define VLOG_DBG_RL(RL, ...) VLOG_RL(RL, VLL_DBG, __VA_ARGS__)

#define VLOG_DROP_ERR(RL) vlog_should_drop(THIS_MODULE, VLL_ERR, RL)
#define VLOG_DROP_WARN(RL) vlog_should_drop(THIS_MODULE, VLL_WARN, RL)
#define VLOG_DROP_INFO(RL) vlog_should_drop(THIS_MODULE, VLL_INFO, RL)
#define VLOG_DROP_DBG(RL) vlog_should_drop(THIS_MODULE, VLL_DBG, RL)

/* Macros for logging at most once per execution. */
#define VLOG_ERR_ONCE(...) VLOG_ONCE(VLL_ERR, __VA_ARGS__)
#define VLOG_WARN_ONCE(...) VLOG_ONCE(VLL_WARN, __VA_ARGS__)
#define VLOG_INFO_ONCE(...) VLOG_ONCE(VLL_INFO, __VA_ARGS__)
#define VLOG_DBG_ONCE(...) VLOG_ONCE(VLL_DBG, __VA_ARGS__)

/* Command line processing. */
#define VLOG_OPTION_ENUMS OPT_LOG_FILE
#define VLOG_LONG_OPTIONS                                   \
        {"verbose",     optional_argument, 0, 'v'},         \
        {"log-file",    optional_argument, 0, OPT_LOG_FILE}
#define VLOG_OPTION_HANDLERS                    \
        case 'v':                               \
            vlog_set_verbosity(optarg);         \
            break;                              \
        case OPT_LOG_FILE:                      \
            vlog_set_log_file(optarg);          \
            break;
void vlog_usage(void);

/* Implementation details. */
#define VLOG(LEVEL, ...)                            \
    do {                                            \
        if (THIS_MODULE->min_level >= LEVEL) {      \
            vlog(THIS_MODULE, LEVEL, __VA_ARGS__);  \
        }                                           \
    } while (0)
#define VLOG_RL(RL, LEVEL, ...)                                     \
    do {                                                            \
        if (THIS_MODULE->min_level >= LEVEL) {                      \
            vlog_rate_limit(THIS_MODULE, LEVEL, RL, __VA_ARGS__);   \
        }                                                           \
    } while (0)
#define VLOG_ONCE(LEVEL, ...)                       \
    do {                                            \
        static bool already_logged;                 \
        if (!already_logged) {                      \
            already_logged = true;                  \
            vlog(THIS_MODULE, LEVEL, __VA_ARGS__);  \
        }                                           \
    } while (0)

#define VLOG_DEFINE_MODULE__(MODULE)                                    \
        struct vlog_module VLM_##MODULE =                               \
        {                                                               \
            #MODULE,                                      /* name */    \
            { [ 0 ... VLF_N_FACILITIES - 1] = VLL_INFO }, /* levels */  \
            VLL_INFO,                                     /* min_level */ \
        };

#ifdef  __cplusplus
}
#endif


#endif /* vlog.h */
Commit	Line	Data
064af421	1	/*
5136ce49	2	* Copyright (c) 2008, 2009, 2010 Nicira Networks.
064af421	3	*
a14bc59f BP	4	* Licensed under the Apache License, Version 2.0 (the "License");
	5	* you may not use this file except in compliance with the License.
	6	* You may obtain a copy of the License at:
064af421	7	*
a14bc59f BP	8	* http://www.apache.org/licenses/LICENSE-2.0
	9	*
	10	* Unless required by applicable law or agreed to in writing, software
	11	* distributed under the License is distributed on an "AS IS" BASIS,
	12	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	13	* See the License for the specific language governing permissions and
	14	* limitations under the License.
064af421 BP	15	*/
	16
	17	#ifndef VLOG_H
	18	#define VLOG_H 1
	19
	20	#include <limits.h>
	21	#include <stdarg.h>
	22	#include <stdbool.h>
	23	#include <time.h>
	24	#include "util.h"
d295e8e9	25
f4ade105 JG	26	#ifdef __cplusplus
	27	extern "C" {
	28	#endif
064af421 BP	29
	30	/* Logging importance levels. */
	31	#define VLOG_LEVELS \
	32	VLOG_LEVEL(EMER, LOG_ALERT) \
	33	VLOG_LEVEL(ERR, LOG_ERR) \
	34	VLOG_LEVEL(WARN, LOG_WARNING) \
	35	VLOG_LEVEL(INFO, LOG_NOTICE) \
	36	VLOG_LEVEL(DBG, LOG_DEBUG)
	37	enum vlog_level {
	38	#define VLOG_LEVEL(NAME, SYSLOG_LEVEL) VLL_##NAME,
	39	VLOG_LEVELS
	40	#undef VLOG_LEVEL
	41	VLL_N_LEVELS
	42	};
	43
	44	const char *vlog_get_level_name(enum vlog_level);
	45	enum vlog_level vlog_get_level_val(const char *name);
	46
	47	/* Facilities that we can log to. */
	48	#define VLOG_FACILITIES \
	49	VLOG_FACILITY(SYSLOG, "%05N\|%c\|%p\|%m") \
	50	VLOG_FACILITY(CONSOLE, "%d{%b %d %H:%M:%S}\|%05N\|%c\|%p\|%m") \
	51	VLOG_FACILITY(FILE, "%d{%b %d %H:%M:%S}\|%05N\|%c\|%p\|%m")
	52	enum vlog_facility {
	53	#define VLOG_FACILITY(NAME, PATTERN) VLF_##NAME,
	54	VLOG_FACILITIES
	55	#undef VLOG_FACILITY
	56	VLF_N_FACILITIES,
	57	VLF_ANY_FACILITY = -1
	58	};
	59
	60	const char *vlog_get_facility_name(enum vlog_facility);
	61	enum vlog_facility vlog_get_facility_val(const char *name);
	62
480ce8ab BP	63	/* A log module. */
	64	struct vlog_module {
	65	const char name; / User-visible name. */
	66	int levels[VLF_N_FACILITIES]; /* Minimum log level for each facility. */
	67	int min_level; /* Minimum log level for any facility. */
064af421 BP	68	};
064af421 BP	69
480ce8ab BP	70	/* Creates and initializes a global instance of a module named MODULE. */
	71	#if USE_LINKER_SECTIONS
	72	#define VLOG_DEFINE_MODULE(MODULE) \
	73	VLOG_DEFINE_MODULE__(MODULE) \
	74	struct vlog_module *vlog_module_ptr_##MODULE \
d98e6007	75	__attribute__((section("vlog_modules"))) = &VLM_##MODULE
480ce8ab	76	#else
d98e6007	77	#define VLOG_DEFINE_MODULE(MODULE) extern struct vlog_module VLM_##MODULE
480ce8ab BP	78	#endif
	79
	80	const char vlog_get_module_name(const struct vlog_module );
	81	struct vlog_module vlog_module_from_name(const char name);
064af421 BP	82
	83	/* Rate-limiter for log messages. */
	84	struct vlog_rate_limit {
	85	/* Configuration settings. */
	86	unsigned int rate; /* Tokens per second. */
	87	unsigned int burst; /* Max cumulative tokens credit. */
	88
	89	/* Current status. */
	90	unsigned int tokens; /* Current number of tokens. */
	91	time_t last_fill; /* Last time tokens added. */
	92	time_t first_dropped; /* Time first message was dropped. */
	93	unsigned int n_dropped; /* Number of messages dropped. */
	94	};
	95
	96	/* Number of tokens to emit a message. We add 'rate' tokens per second, which
	97	* is 60 times the unit used for 'rate', thus 60 tokens are required to emit
	98	* one message. */
	99	#define VLOG_MSG_TOKENS 60
	100
	101	/* Initializer for a struct vlog_rate_limit, to set up a maximum rate of RATE
	102	* messages per minute and a maximum burst size of BURST messages. */
	103	#define VLOG_RATE_LIMIT_INIT(RATE, BURST) \
	104	{ \
	105	RATE, /* rate */ \
	106	(MIN(BURST, UINT_MAX / VLOG_MSG_TOKENS) \
	107	* VLOG_MSG_TOKENS), /* burst */ \
	108	0, /* tokens */ \
	109	0, /* last_fill */ \
	110	0, /* first_dropped */ \
	111	0, /* n_dropped */ \
	112	}
	113
	114	/* Configuring how each module logs messages. */
480ce8ab BP	115	enum vlog_level vlog_get_level(const struct vlog_module *, enum vlog_facility);
	116	void vlog_set_levels(struct vlog_module *,
	117	enum vlog_facility, enum vlog_level);
064af421 BP	118	char vlog_set_levels_from_string(const char );
064af421 BP	119	char *vlog_get_levels(void);
480ce8ab BP	120	bool vlog_is_enabled(const struct vlog_module *, enum vlog_level);
480ce8ab BP	121	bool vlog_should_drop(const struct vlog_module *, enum vlog_level,
064af421 BP	122	struct vlog_rate_limit *);
	123	void vlog_set_verbosity(const char *arg);
	124
	125	/* Configuring log facilities. */
	126	void vlog_set_pattern(enum vlog_facility, const char *pattern);
	127	const char *vlog_get_log_file(void);
	128	int vlog_set_log_file(const char *file_name);
	129	int vlog_reopen_log_file(void);
	130
	131	/* Function for actual logging. */
	132	void vlog_init(void);
	133	void vlog_exit(void);
480ce8ab	134	void vlog(const struct vlog_module , enum vlog_level, const char format, ...)
064af421	135	__attribute__((format(printf, 3, 4)));
480ce8ab BP	136	void vlog_valist(const struct vlog_module *, enum vlog_level,
480ce8ab BP	137	const char *, va_list)
064af421	138	__attribute__((format(printf, 3, 0)));
480ce8ab	139	void vlog_rate_limit(const struct vlog_module *, enum vlog_level,
064af421 BP	140	struct vlog_rate_limit , const char , ...)
	141	__attribute__((format(printf, 4, 5)));
	142
480ce8ab BP	143	/* Creates and initializes a global instance of a module named MODULE, and
	144	* defines a static variable named THIS_MODULE that points to it, for use with
	145	* the convenience macros below. */
	146	#define VLOG_DEFINE_THIS_MODULE(MODULE) \
d98e6007 BP	147	VLOG_DEFINE_MODULE(MODULE); \
d98e6007 BP	148	static struct vlog_module *const THIS_MODULE = &VLM_##MODULE
5136ce49	149
480ce8ab BP	150	/* Convenience macros. These assume that THIS_MODULE points to a "struct
	151	* vlog_module" for the current module, as set up by e.g. the
	152	* VLOG_DEFINE_MODULE macro above.
5136ce49	153	*
064af421 BP	154	* Guaranteed to preserve errno.
	155	*/
	156	#define VLOG_EMER(...) VLOG(VLL_EMER, __VA_ARGS__)
	157	#define VLOG_ERR(...) VLOG(VLL_ERR, __VA_ARGS__)
	158	#define VLOG_WARN(...) VLOG(VLL_WARN, __VA_ARGS__)
	159	#define VLOG_INFO(...) VLOG(VLL_INFO, __VA_ARGS__)
	160	#define VLOG_DBG(...) VLOG(VLL_DBG, __VA_ARGS__)
	161
	162	/* More convenience macros, for testing whether a given level is enabled in
	163	* THIS_MODULE. When constructing a log message is expensive, this enables it
	164	* to be skipped. */
	165	#define VLOG_IS_EMER_ENABLED() true
	166	#define VLOG_IS_ERR_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_EMER)
	167	#define VLOG_IS_WARN_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_WARN)
	168	#define VLOG_IS_INFO_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_INFO)
	169	#define VLOG_IS_DBG_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_DBG)
	170
	171	/* Convenience macros for rate-limiting.
	172	* Guaranteed to preserve errno.
	173	*/
	174	#define VLOG_ERR_RL(RL, ...) VLOG_RL(RL, VLL_ERR, __VA_ARGS__)
	175	#define VLOG_WARN_RL(RL, ...) VLOG_RL(RL, VLL_WARN, __VA_ARGS__)
	176	#define VLOG_INFO_RL(RL, ...) VLOG_RL(RL, VLL_INFO, __VA_ARGS__)
	177	#define VLOG_DBG_RL(RL, ...) VLOG_RL(RL, VLL_DBG, __VA_ARGS__)
	178
	179	#define VLOG_DROP_ERR(RL) vlog_should_drop(THIS_MODULE, VLL_ERR, RL)
	180	#define VLOG_DROP_WARN(RL) vlog_should_drop(THIS_MODULE, VLL_WARN, RL)
	181	#define VLOG_DROP_INFO(RL) vlog_should_drop(THIS_MODULE, VLL_INFO, RL)
	182	#define VLOG_DROP_DBG(RL) vlog_should_drop(THIS_MODULE, VLL_DBG, RL)
	183
5136364f BP	184	/* Macros for logging at most once per execution. */
	185	#define VLOG_ERR_ONCE(...) VLOG_ONCE(VLL_ERR, __VA_ARGS__)
	186	#define VLOG_WARN_ONCE(...) VLOG_ONCE(VLL_WARN, __VA_ARGS__)
	187	#define VLOG_INFO_ONCE(...) VLOG_ONCE(VLL_INFO, __VA_ARGS__)
	188	#define VLOG_DBG_ONCE(...) VLOG_ONCE(VLL_DBG, __VA_ARGS__)
	189
064af421 BP	190	/* Command line processing. */
	191	#define VLOG_OPTION_ENUMS OPT_LOG_FILE
	192	#define VLOG_LONG_OPTIONS \
	193	{"verbose", optional_argument, 0, 'v'}, \
	194	{"log-file", optional_argument, 0, OPT_LOG_FILE}
	195	#define VLOG_OPTION_HANDLERS \
	196	case 'v': \
	197	vlog_set_verbosity(optarg); \
	198	break; \
	199	case OPT_LOG_FILE: \
	200	vlog_set_log_file(optarg); \
	201	break;
	202	void vlog_usage(void);
	203
	204	/* Implementation details. */
480ce8ab BP	205	#define VLOG(LEVEL, ...) \
	206	do { \
	207	if (THIS_MODULE->min_level >= LEVEL) { \
	208	vlog(THIS_MODULE, LEVEL, __VA_ARGS__); \
	209	} \
064af421 BP	210	} while (0)
	211	#define VLOG_RL(RL, LEVEL, ...) \
	212	do { \
480ce8ab	213	if (THIS_MODULE->min_level >= LEVEL) { \
064af421 BP	214	vlog_rate_limit(THIS_MODULE, LEVEL, RL, __VA_ARGS__); \
	215	} \
	216	} while (0)
5136364f BP	217	#define VLOG_ONCE(LEVEL, ...) \
	218	do { \
	219	static bool already_logged; \
	220	if (!already_logged) { \
	221	already_logged = true; \
	222	vlog(THIS_MODULE, LEVEL, __VA_ARGS__); \
	223	} \
	224	} while (0)
	225
480ce8ab BP	226	#define VLOG_DEFINE_MODULE__(MODULE) \
	227	struct vlog_module VLM_##MODULE = \
	228	{ \
	229	#MODULE, /* name */ \
	230	{ [ 0 ... VLF_N_FACILITIES - 1] = VLL_INFO }, /* levels */ \
	231	VLL_INFO, /* min_level */ \
	232	};
	233
f4ade105 JG	234	#ifdef __cplusplus
	235	}
	236	#endif
064af421 BP	237
	238
	239	#endif /* vlog.h */