icd.c

早期freebsd实现

/*  $Revision: 1.26 $
**
**  Routines to read and write the active file.
*/
#include "innd.h"
#if	defined(ACT_MMAP)
#include <sys/mman.h>
#endif	/* defined(ACT_MMAP) */
#include <sys/uio.h>

typedef struct iovec	IOVEC;


STATIC char		ICDactpath[] = _PATH_ACTIVE;
STATIC char		*ICDactpointer;
STATIC int		ICDactfd;
STATIC int		ICDactsize;


/*
**  Set and unset (or copy) IOVEC elements.  We make copies to
**  avoid problems with mmap.
*/
#if	defined(ACT_MMAP)
#define ICDiovset(iovp, base, len)	\
	do { \
	    (iovp)->iov_len = len; \
	    (iovp)->iov_base = NEW(char, (iovp)->iov_len); \
	    (void)memcpy((POINTER)(iovp)->iov_base, (POINTER)base, \
		    (SIZE_T)(iovp)->iov_len); \
	} while (JUSTONCE)
#define ICDiovrelease(iovp)		DISPOSE((iovp)->iov_base)

#if	defined(MAP_FILE)
#define MAP__ARG	(MAP_FILE | MAP_SHARED)
#else
#define MAP__ARG	(MAP_SHARED)
#endif	/* defined(MAP_FILE) */

#else

#define ICDiovset(iovp, base, len)	\
	(iovp)->iov_base = base, (iovp)->iov_len = len
#define ICDiovrelease(iovp)		/* NULL */
#endif	/* defined(ACT_MMAP) */


/*
**  Close the active file, releasing its resources.
*/
STATIC void
ICDcloseactive()
{
    if (ICDactpointer) {
#if	defined(ACT_MMAP)
	if (munmap(ICDactpointer, ICDactsize) < 0)
	    syslog(L_ERROR, "%s cant munmap %m", LogName, ICDactpath);
#else
	DISPOSE(ICDactpointer);
#endif	/* defined(ACT_MMAP) */
	ICDactpointer = NULL;
	if (close(ICDactfd) < 0) {
	    syslog(L_FATAL, "%s cant close %s %m", LogName, ICDactpath);
	    exit(1);
	}
    }
}


/*
**  Set up the hash and in-core tables.
*/
void
ICDsetup(StartSites)
    BOOL	StartSites;
{
    ICDneedsetup = FALSE;
    ICDcloseactive();
    NGparsefile();
    if (NGfind("control") == NULL || NGfind("junk") == NULL) {
	syslog(L_FATAL, "%s internal no control and/or junk group", LogName);
	exit(1);
    }
#if	defined(DO_MERGE_TO_GROUPS)
    if (NGfind("to") == NULL) {
	syslog(L_FATAL, "%s internal no to group", LogName);
	exit(1);
    }
#endif	/* defined(DO_MERGE_TO_GROUPS) */
    SITEparsefile(StartSites);
}


/*
**  Write out all in-core data.
*/
void
ICDwrite()
{
    HISsync();

    if (ICDactivedirty) {
	ICDwriteactive();
	ICDactivedirty = 0;
    }

    /* Flush log and error log. */
    if (fflush(Log) == EOF)
	syslog(L_ERROR, "%s cant fflush log %m", LogName);
    if (fflush(Errlog) == EOF)
	syslog(L_ERROR, "%s cant fflush errlog %m", LogName);
}


/*
**  Close things down.
*/
void
ICDclose()
{
    ICDwrite();
    ICDcloseactive();
}


/*
**  Scan the active file, and renumber the min/max counts.
*/
void
ICDrenumberactive()
{
    register int	i;
    register NEWSGROUP	*ngp;

    for (i = nGroups, ngp = Groups; --i >= 0; ngp++)
	if (!NGrenumber(ngp))
	    break;
    if (i < 0)
	ICDwrite();
}


/*
**  Use writev() to replace the active file.
*/
STATIC BOOL
ICDwritevactive(vp, vpcount)
    IOVEC		*vp;
    int			vpcount;
{
    static char		BACKUP[] = _PATH_OLDACTIVE;
    static char		WHEN[] = "backup active";
    register int	fd;
    char		*dummy;

    /* Write the current file to a backup. */
    if (unlink(BACKUP) < 0 && errno != ENOENT) {
	IOError(WHEN);
	syslog(L_ERROR, "%s cant unlink %s %m", LogName, BACKUP);
    }
    if ((fd = open(BACKUP, O_WRONLY | O_TRUNC | O_CREAT, 0664)) < 0) {
	IOError(WHEN);
	syslog(L_ERROR, "%s cant open %s %m", LogName, BACKUP);
    }
    else if (xwrite(fd, ICDactpointer, ICDactsize) < 0) {
	IOError(WHEN);
	syslog(L_ERROR, "%s cant write %s %m", LogName, BACKUP);
	(void)close(fd);
    }
    else if (close(fd) < 0) {
	IOError(WHEN);
	syslog(L_ERROR, "%s cant close %s %m", LogName, BACKUP);
    }

    /* Open the active file. */
    fd = open(ICDactpath, O_WRONLY | O_TRUNC | O_CREAT, ARTFILE_MODE);
    if (fd < 0) {
	IOError(WHEN);
	syslog(L_ERROR, "%s cant open %s %m", LogName, ICDactpath);
	return FALSE;
    }

    /* Write it. */
    if (xwritev(fd, vp, vpcount) < 0) {
	IOError(WHEN);
	syslog(L_ERROR, "%s cant write %s %m", LogName, ICDactpath);
	(void)close(fd);
	return FALSE;
    }

    /* Close it. */
    (void)close(fd);
    if (AmRoot)
	xchown(ICDactpath);

    /* Invalidate in-core pointers. */
    ICDcloseactive();

    /* Restore in-core pointers. */
    if (Mode != OMrunning) {
	ICDneedsetup = TRUE;
	/* Force the active file into memory. */
	(void)ICDreadactive(&dummy);
    }
    else
	ICDsetup(TRUE);
    return TRUE;
}


/*
**  Change the flag on a newsgroup.  Fairly easy.
*/
BOOL
ICDchangegroup(ngp, Rest)
    NEWSGROUP		*ngp;
    char		*Rest;
{
    static char		NEWLINE[] = "\n";
    register int	i;
    IOVEC		iov[3];
    BOOL		ret;

    /* Set up the scatter/gather vectors. */
    ICDiovset(&iov[0], ICDactpointer, ngp->Rest - ICDactpointer);
    ICDiovset(&iov[1], Rest, strlen(Rest));
    if (++ngp < &Groups[nGroups]) {
	/* Not the last group, keep the \n from the next line. */
	i = ngp->Start;
	ICDiovset(&iov[2], &ICDactpointer[i - 1], ICDactsize - i + 1);
    }
    else {
	/* Last group -- append a newline. */
	ICDiovset(&iov[2], NEWLINE, STRLEN(NEWLINE));
    }
    ret = ICDwritevactive(iov, 3);
    ICDiovrelease(&iov[0]);
    ICDiovrelease(&iov[1]);
    ICDiovrelease(&iov[2]);
    return ret;
}


/*
**  Add a newsgroup.  Append a line to the end of the active file and reload.
*/
BOOL
ICDnewgroup(Name, Rest)
    char		*Name;
    char		*Rest;
{
    char		buff[SMBUF];
    IOVEC		iov[2];
    BOOL		ret;

    /* Set up the scatter/gather vectors. */
    if (strlen(Name) + strlen(Rest) > (SIZE_T)(SMBUF - 24)) {
	syslog(L_ERROR, "%s too_long %s", LogName, MaxLength(Name, Name));
	return FALSE;
    }
    (void)sprintf(buff, "%s 0000000000 0000000001 %s\n", Name, Rest);
    ICDiovset(&iov[0], ICDactpointer, ICDactsize);
    ICDiovset(&iov[1], buff, strlen(buff));

    ret = ICDwritevactive(iov, 2);
    ICDiovrelease(&iov[0]);
    ICDiovrelease(&iov[1]);
    return ret;
}


/*
**  Remove a newsgroup.  Splice the line out of the active file and reload.
*/
BOOL
ICDrmgroup(ngp)
    NEWSGROUP	*ngp;
{
    IOVEC	iov[2];
    int		i;
    BOOL	ret;

    /* If this is the first group in the file, write everything after. */
    if (ngp == &Groups[0]) {
	i = ngp[1].Start;
	ICDiovset(&iov[0], &ICDactpointer[i], ICDactsize - i);
	ret = ICDwritevactive(iov, 1);
	ICDiovrelease(&iov[0]);
	return ret;
    }

    /* Write everything up to this group. */
    ICDiovset(&iov[0], ICDactpointer, ngp->Start);

    /* If this is the last group, that's all we have to write. */
    if (ngp == &Groups[nGroups - 1]) {
	ret = ICDwritevactive(iov, 1);
	ICDiovrelease(&iov[0]);
	return ret;
    }

    /* Write everything after this group. */
    i = ngp[1].Start;
    ICDiovset(&iov[1], &ICDactpointer[i], ICDactsize - i);
    ret = ICDwritevactive(iov, 2);
    ICDiovrelease(&iov[0]);
    ICDiovrelease(&iov[1]);
    return ret;
}



/*
**  Open the active file and "map" it into memory.
*/
char *
ICDreadactive(endp)
    char		**endp;
{
    struct stat		Sb;

    if (ICDactpointer) {
	*endp = ICDactpointer + ICDactsize;
	return ICDactpointer;
    }

    if ((ICDactfd = open(ICDactpath, O_RDWR)) < 0) {
	syslog(L_FATAL, "%s cant open %s %m", LogName, ICDactpath);
	exit(1);
    }
    CloseOnExec(ICDactfd, TRUE);

#if	defined(ACT_MMAP)
    if (fstat(ICDactfd, &Sb) < 0) {
	syslog(L_FATAL, "%s cant fstat %d %s %m",
	    LogName, ICDactfd, ICDactpath);
	exit(1);
    }
    ICDactsize = Sb.st_size;
    ICDactpointer = mmap((caddr_t)0, ICDactsize, PROT_READ|PROT_WRITE,
			MAP__ARG, ICDactfd, (off_t)0);
    if (ICDactpointer == (char *)-1) {
	syslog(L_FATAL, "%s cant mmap %d %s %m",
	    LogName, ICDactfd, ICDactpath);
	exit(1);
    }

#else

    if ((ICDactpointer = ReadInDescriptor(ICDactfd, &Sb)) == NULL) {
	syslog(L_FATAL, "%s cant read %s %m", LogName, ICDactpath);
	exit(1);
    }
    ICDactsize = Sb.st_size;
#endif	/* defined(ACT_MMAP) */

    *endp = ICDactpointer + ICDactsize;
    return ICDactpointer;
}


/*
**  Write the active file out.
*/
void
ICDwriteactive()
{
#if	defined(ACT_MMAP)
    /* No-op. */

#else

    if (lseek(ICDactfd, 0L, SEEK_SET) == -1) {
	syslog(L_FATAL, "%s cant rewind %s %m", LogName, ICDactpath);
	exit(1);
    }
    if (xwrite(ICDactfd, ICDactpointer, ICDactsize) < 0) {
	syslog(L_FATAL, "%s cant write %s %m", LogName, ICDactpath);
	exit(1);
    }
#endif	/* defined(ACT_MMAP) */
}