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Diffstat (limited to 'lib/vlog.h')
| -rw-r--r-- | lib/vlog.h | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/lib/vlog.h b/lib/vlog.h new file mode 100644 index 000000000..87036151b --- /dev/null +++ b/lib/vlog.h @@ -0,0 +1,192 @@ +/* + * Copyright (c) 2008, 2009 Nicira Networks. + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#ifndef VLOG_H +#define VLOG_H 1 + +#include <limits.h> +#include <stdarg.h> +#include <stdbool.h> +#include <time.h> +#include "util.h" + +/* 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); + +/* VLM_ constant for each vlog module. */ +enum vlog_module { +#define VLOG_MODULE(NAME) VLM_##NAME, +#include "vlog-modules.def" + VLM_N_MODULES, + VLM_ANY_MODULE = -1 +}; + +const char *vlog_get_module_name(enum vlog_module); +enum vlog_module vlog_get_module_val(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(enum vlog_module, enum vlog_facility); +void vlog_set_levels(enum 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(enum vlog_module, enum vlog_level); +bool vlog_should_drop(enum 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(enum vlog_module, enum vlog_level, const char *format, ...) + __attribute__((format(printf, 3, 4))); +void vlog_valist(enum vlog_module, enum vlog_level, const char *, va_list) + __attribute__((format(printf, 3, 0))); +void vlog_rate_limit(enum vlog_module, enum vlog_level, + struct vlog_rate_limit *, const char *, ...) + __attribute__((format(printf, 4, 5))); + +/* Convenience macros. To use these, define THIS_MODULE as a macro that + * expands to the module used by the current source file, e.g. + * #include "vlog.h" + * #define THIS_MODULE VLM_netlink + * 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) + +/* 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 (min_vlog_levels[THIS_MODULE] >= LEVEL) { \ + vlog(THIS_MODULE, LEVEL, __VA_ARGS__); \ + } \ + } while (0) +#define VLOG_RL(RL, LEVEL, ...) \ + do { \ + if (min_vlog_levels[THIS_MODULE] >= LEVEL) { \ + vlog_rate_limit(THIS_MODULE, LEVEL, RL, __VA_ARGS__); \ + } \ + } while (0) +extern enum vlog_level min_vlog_levels[VLM_N_MODULES]; + + +#endif /* vlog.h */ |