log.c

来自「mms client」· C语言 代码 · 共 370 行

/*
 * log.c - implement logging functions
 */

#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <time.h>
#include <stdarg.h>
#include <string.h>

#if HAVE_SYSLOG_H
    #include <syslog.h>
#else

/*
 * If we don't have syslog.h, then we'll use the following dummy definitions
 * to avoid writing #if HAVE_SYSLOG_H everywhere.
 */

enum {
    LOG_PID, LOG_DAEMON, LOG_DEBUG, LOG_INFO, LOG_WARNING, LOG_ERR, LOG_ALERT
};

static void openlog(const char *ident, int option, int facility) {
}

static void syslog(int translog, const char *buf) {
}

#endif

#include "gwlib.h"


/*
 * List of currently open log files.
 */
#define MAX_LOGFILES 8
static struct {
    FILE *file;
    int minimum_output_level;
    char filename[FILENAME_MAX + 1]; /* to allow re-open */
} logfiles[MAX_LOGFILES];
static int num_logfiles = 0;


/*
 * List of places that should be logged at debug-level.
 */
#define MAX_LOGGABLE_PLACES (10*1000)
static char *loggable_places[MAX_LOGGABLE_PLACES];
static int num_places = 0;


/*
 * Syslog support.
 */
static int sysloglevel;
static int dosyslog = 0;


/*
 * Make sure stderr is included in the list.
 */
static void add_stderr(void) {
    int i;

    for (i = 0; i < num_logfiles; ++i)
        if (logfiles[i].file == stderr)
            return;
    logfiles[num_logfiles].file = stderr;
    logfiles[num_logfiles].minimum_output_level = GW_DEBUG;
    ++num_logfiles;
}


void log_set_output_level(enum output_level level) {
    int i;

    add_stderr();
    for (i = 0; i < num_logfiles; ++i) {
        if (logfiles[i].file == stderr) {
            logfiles[i].minimum_output_level = level;
            break;
        }
    }
}


void log_set_syslog(const char *ident, int syslog_level) {
    if (ident == NULL)
        dosyslog = 0;
    else {
        dosyslog = 1;
        sysloglevel = syslog_level;
        openlog(ident, LOG_PID, LOG_DAEMON);
        debug("gwlib.log", 0, "Syslog logging enabled.");
    }
}


void log_reopen(void) {
    int i;

    for (i = 0; i < num_logfiles; ++i) {
        if (logfiles[i].file != stderr) {
            fclose(logfiles[i].file);
            logfiles[i].file = fopen(logfiles[i].filename, "a");
            if (logfiles[i].file == NULL) {
                error(errno, "Couldn't re-open logfile `%s'.",
                      logfiles[i].filename);
            }
        }
    }       
}


void log_close_all(void) {
    while (num_logfiles > 0) {
        --num_logfiles;
        if (logfiles[num_logfiles].file != stderr)
            fclose(logfiles[num_logfiles].file);
        logfiles[num_logfiles].file = NULL;
    }
}


void log_open(char *filename, int level) {
    FILE *f;

    add_stderr();
    if (num_logfiles == MAX_LOGFILES) {
        error(0, "Too many log files already open, not adding `%s'", 
              filename);
        return;
    }

    if (strlen(filename) > FILENAME_MAX) {
        error(0, "Log filename too long: `%s'.", filename);
        return;
    }

    f = fopen(filename, "a");
    if (f == NULL) {
        error(errno, "Couldn't open logfile `%s'.", filename);
        return;
    }

    logfiles[num_logfiles].file = f;
    logfiles[num_logfiles].minimum_output_level = level;
    strcpy(logfiles[num_logfiles].filename, filename);
    ++num_logfiles;
    info(0, "Added logfile `%s' with level `%d'.", filename, level);
}


#define FORMAT_SIZE (1024)
static void format(char *buf, int level, const char *place, int e, 
                   const char *fmt) {
    static char *tab[] = {
        "DEBUG: ",
        "INFO: ",
        "WARNING: ",
        "ERROR: ",
        "PANIC: ",
        "LOG: "
    };
    static int tab_size = sizeof(tab) / sizeof(tab[0]);
    time_t t;
    struct tm tm;
    char *p, prefix[1024];

    p = prefix;
    time(&t);
#if LOG_TIMESTAMP_LOCALTIME
    tm = gw_localtime(t);
#else
    tm = gw_gmtime(t);
#endif
    sprintf(p, "%04d-%02d-%02d %02d:%02d:%02d ",
            tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
            tm.tm_hour, tm.tm_min, tm.tm_sec);

    p = strchr(p, '\0');
    sprintf(p, "[%ld] ", gwthread_self());

    p = strchr(p, '\0');
    if (level < 0 || level >= tab_size)
        sprintf(p, "UNKNOWN: ");
    else
        sprintf(p, "%s", tab[level]);

    p = strchr(p, '\0');
    if (place != NULL && *place != '\0')
        sprintf(p, "%s: ", place);

    if (strlen(prefix) + strlen(fmt) > FORMAT_SIZE / 2) {
        sprintf(buf, "%s <OUTPUT message too long>\n", prefix);
        return;
    }

    if (e == 0)
        sprintf(buf, "%s%s\n", prefix, fmt);
    else
        sprintf(buf, "%s%s\n%sSystem error %d: %s\n",
                prefix, fmt, prefix, e, strerror(e));
}


static void output(FILE *f, char *buf, va_list args) {
    vfprintf(f, buf, args);
    fflush(f);
}


static void kannel_syslog(char *format, va_list args, int level) {
    char buf[4096]; /* Trying to syslog more than 4K could be bad */
    int translog;

    if (level >= sysloglevel && dosyslog) {
        if (args == NULL) {
            strncpy(buf, format, sizeof(buf));
            buf[sizeof(buf) - 1] = '\0';
        } else {
            vsnprintf(buf, sizeof(buf), format, args);
            /* XXX vsnprint not 100% portable */
        }

        switch (level) {
            case GW_DEBUG:
                translog = LOG_DEBUG;
                break;
            case GW_INFO:
                translog = LOG_INFO;
                break;
            case GW_WARNING:
                translog = LOG_WARNING;
                break;
            case GW_ERROR:
                translog = LOG_ERR;
                break;
            case GW_PANIC:
                translog = LOG_ALERT;
                break;
            default:
                translog = LOG_INFO;
                break;
        }
        syslog(translog, buf);
    }
}


/*
 * Almost all of the message printing functions are identical, except for
 * the output level they use. This macro contains the identical parts of
 * the functions so that the code needs to exist only once. It's a bit
 * more awkward to edit, but that can't be helped. The "do {} while (0)"
 * construct is a gimmick to be more like a function call in all syntactic
 * situation.
 */

#define FUNCTION_GUTS(level, place) \
	do { \
	    int i; \
	    char buf[FORMAT_SIZE]; \
	    va_list args; \
	    \
	    add_stderr(); \
	    format(buf, level, place, e, fmt); \
	    for (i = 0; i < num_logfiles; ++i) { \
		if (level >= logfiles[i].minimum_output_level) { \
		    va_start(args, fmt); \
		    output(logfiles[i].file, buf, args); \
		    va_end(args); \
		} \
	    } \
	    if (dosyslog) { \
		va_start(args, fmt); \
		kannel_syslog(buf,args,level); \
		va_end(args); \
	    } \
	} while (0)


void gw_panic(int e, const char *fmt, ...) {
    FUNCTION_GUTS(GW_PANIC, "");
    exit(EXIT_FAILURE);
}


void error(int e, const char *fmt, ...) {
    FUNCTION_GUTS(GW_ERROR, "");
}


void warning(int e, const char *fmt, ...) {
    FUNCTION_GUTS(GW_WARNING, "");
}


void info(int e, const char *fmt, ...) {
    FUNCTION_GUTS(GW_INFO, "");
}


static int place_matches(const char *place, const char *pat) {
    size_t len;

    len = strlen(pat);
    if (pat[len-1] == '*')
        return(strncasecmp(place, pat, len - 1) == 0);
    return(strcasecmp(place, pat) == 0);
}


static int place_should_be_logged(const char *place) {
    int i;

    if (num_places == 0)
        return 1;
    for (i = 0; i < num_places; ++i) {
        if (*loggable_places[i] != '-' && 
            place_matches(place, loggable_places[i]))
            return 1;
    }
    return 0;
}


static int place_is_not_logged(const char *place) {
    int i;

    if (num_places == 0)
        return 0;
    for (i = 0; i < num_places; ++i) {
        if (*loggable_places[i] == '-' &&
            place_matches(place, loggable_places[i]+1))
            return 1;
    }
    return 0;
}


void debug(const char *place, int e, const char *fmt, ...) {
    if (place_should_be_logged(place) && place_is_not_logged(place) == 0) {
        FUNCTION_GUTS(GW_DEBUG, place);
        /*
         * Note: giving `place' to FUNCTION_GUTS makes log lines
             * too long and hard to follow. We'll rely on an external
             * list of what places are used instead of reading them
             * from the log file.
         */
    }
}


void log_set_debug_places(const char *places) {
    char *p;

    p = strtok(gw_strdup(places), " ,");
    num_places = 0;
    while (p != NULL && num_places < MAX_LOGGABLE_PLACES) {
        loggable_places[num_places++] = p;
        p = strtok(NULL, " ,");
    }
}