PostgreSQL/src/backend/utils/error/elog.c

/*-------------------------------------------------------------------------
 *
 * elog.c--
 *    error logger
 *
 * Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    $Header: /cvsroot/pgsql/src/backend/utils/error/elog.c,v 1.17 1997/08/12 22:54:44 momjian Exp $
 *
 *-------------------------------------------------------------------------
 */
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <fcntl.h>
#ifndef O_RDONLY
#include <sys/file.h>
#endif /* O_RDONLY */
#include <sys/types.h>
#include <stdarg.h>
#include <errno.h>
#include <unistd.h>
#include <signal.h>

#include "postgres.h"
#include "miscadmin.h"
#include "libpq/libpq.h"
#include "storage/proc.h"

static int	Debugfile = -1;
static int	Err_file = -1;
static int	ElogDebugIndentLevel = 0;

extern char	OutputFileName[];

/*
 * elog --
 *	Old error logging function.
 */
void
elog(int lev, const char *fmt, ... )
{
    va_list ap;
    char		buf[ELOG_MAXLEN], line[ELOG_MAXLEN];
    register char	*bp;
    register const char *cp;
    extern	int	errno, sys_nerr;
#ifndef PG_STANDALONE
    extern	FILE	*Pfout;
#endif /* !PG_STANDALONE */
#ifdef ELOG_TIMESTAMPS
    time_t	tim;
#endif
    int		len;
    int		i = 0;
    
    va_start(ap, fmt);
    if (lev == DEBUG && Debugfile < 0) {
	return;
    }
    switch (lev) {
    case NOIND:
	i = ElogDebugIndentLevel-1;
	if (i < 0) i = 0;
	if (i > 30) i = i%30;
	cp = "DEBUG:";
	break;
    case DEBUG:
	i = ElogDebugIndentLevel;
	if (i < 0) i = 0;
	if (i > 30) i = i%30;
	cp = "DEBUG:";
	break;
    case NOTICE:
	cp = "NOTICE:";
	break;
    case WARN:
	cp = "WARN:";
	break;
    default:
	sprintf(line, "FATAL %d:", lev);
	cp = line;
    }
#ifdef ELOG_TIMESTAMPS
    time(&tim);
    strcat(strcpy(buf, cp), ctime(&tim)+4);
    bp = buf+strlen(buf)-6;
    *bp++ = ':';
#else
    strcpy(buf,cp);
    bp = buf+strlen(buf);
#endif
    while (i-- >0) *bp++ = ' ';
    for (cp = fmt; *cp; cp++)
	if (*cp == '%' && *(cp+1) == 'm') {
	    if (errno < sys_nerr && errno >= 0)
		strcpy(bp, strerror(errno));
	    else
		sprintf(bp, "error %d", errno);
	    bp += strlen(bp);
	    cp++;
	} else
	    *bp++ = *cp;
    *bp = '\0';
    vsprintf(line, buf, ap);
    va_end(ap);
    len = strlen(strcat(line, "\n"));
    if (Debugfile > -1)
	write(Debugfile, line, len);
    if (lev == DEBUG || lev == NOIND)
	return;
    
    /*
     *  If there's an error log file other than our channel to the
     *  front-end program, write to it first.  This is important
     *  because there's a bug in the socket code on ultrix.  If the
     *  front end has gone away (so the channel to it has been closed
     *  at the other end), then writing here can cause this backend
     *  to exit without warning -- that is, write() does an exit().
     *  In this case, our only hope of finding out what's going on
     *  is if Err_file was set to some disk log.  This is a major pain.
     */
    
    if (Err_file > -1 && Debugfile != Err_file) {
	if (write(Err_file, line, len) < 0) {
	    write(open("/dev/console", O_WRONLY, 0666), line, len);
	    fflush(stdout);
	    fflush(stderr);
	    exitpg(lev);
	}
	fsync(Err_file);
    }
    
#ifndef PG_STANDALONE
    /* Send IPC message to the front-end program */
    if (Pfout != NULL && lev > DEBUG) {
	/* notices are not exactly errors, handle it differently */
	if (lev == NOTICE) 
	    pq_putnchar("N", 1);
	else
	    pq_putnchar("E", 1);
	/* pq_putint(-101, 4);*/	/* should be query id */ 
	pq_putstr(line);
	pq_flush();
    }
#endif /* !PG_STANDALONE */
    
    if (lev == WARN) {
        extern int InWarn;
	ProcReleaseSpins(NULL);	/* get rid of spinlocks we hold */
        if (!InWarn) {
	    kill(getpid(), 1);	/* abort to traffic cop */
	    pause();
        }
	/*
	 * The pause(3) is just to avoid race conditions where the
	 * thread of control on an MP system gets past here (i.e.,
	 * the signal is not received instantaneously).
	 */
    }
    
    if (lev == FATAL) {
	/*
	 * Assume that if we have detected the failure we can
	 * exit with a normal exit status.  This will prevent
	 * the postmaster from cleaning up when it's not needed.
	 */
	fflush(stdout);
	fflush(stderr);
	ProcReleaseSpins(NULL);	/* get rid of spinlocks we hold */
	ProcReleaseLocks();	/* get rid of real locks we hold */
	exitpg(0);
    }
    
    if (lev > FATAL) {
	fflush(stdout);
	fflush(stderr);
	exitpg(lev);
    }
}

#ifndef PG_STANDALONE
int
DebugFileOpen(void)
{
    int fd, istty;
    
    Err_file = Debugfile = -1;
    ElogDebugIndentLevel = 0;
    
    if (OutputFileName[0]) {
	OutputFileName[MAXPGPATH-1] = '\0';
	if ((fd = open(OutputFileName, O_CREAT|O_APPEND|O_WRONLY,
		       0666)) < 0)
	    elog(FATAL, "DebugFileOpen: open of %s: %m",
		 OutputFileName);
	istty = isatty(fd);
	close(fd);
	/* If the file is a tty and we're running under the
	 * postmaster, try to send stdout there as well (if it
	 * isn't a tty then stderr will block out stdout, so we
	 * may as well let stdout go wherever it was going before).
	 */
	if (istty &&
	    IsUnderPostmaster &&
	    !freopen(OutputFileName, "a", stdout))
	    elog(FATAL, "DebugFileOpen: %s reopen as stdout: %m",
		 OutputFileName);
	if (!freopen(OutputFileName, "a", stderr))
	    elog(FATAL, "DebugFileOpen: %s reopen as stderr: %m",
		 OutputFileName);
	Err_file = Debugfile = fileno(stderr);
	return(Debugfile);
    }
    /* If no filename was specified, send debugging output to stderr.
     * If stderr has been hosed, try to open a file.
     */
    fd = fileno(stderr);
    if (fcntl(fd, F_GETFD, 0) < 0) {
	sprintf(OutputFileName, "%s/pg.errors.%d",
                DataDir, (int)getpid());
	fd = open(OutputFileName, O_CREAT|O_APPEND|O_WRONLY, 0666);
    }
    if (fd < 0)
	elog(FATAL, "DebugFileOpen: could not open debugging file");
    
    Err_file = Debugfile = fd;
    return(Debugfile);
}
#endif