cmd/pax/paxlib.c

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1987-2011 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                 Eclipse Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*          http://www.eclipse.org/org/documents/epl-v10.html           *
*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                                                                      *
***********************************************************************/
#pragma prototyped
/*
 * Glenn Fowler
 *
 * pax pax external library support
 */

#include "pax.h"

#undef  paxchecksum
#undef  paxcorrupt
#undef  paxdata
#undef  paxget
#undef  paxnext
#undef  paxnospace
#undef  paxpart
#undef  paxput
#undef  paxread
#undef  paxseek
#undef  paxstash
#undef  paxsync
#undef  paxunread
#undef  paxwrite

static const char   null[] = "";
static const char   sep[] = ": ";

#define TXT(s,m)    (s)?sep:null,(s)?(m):null

static int
paxdata(Pax_t* pax, Paxarchive_t* ap, Paxfile_t* f, int fd, void* b, off_t n)
{
    return holewrite(fd, b, n) == n ? 0 : -1;
}

static void*
paxget(Pax_t* pax, Paxarchive_t* ap, off_t n, off_t* p)
{
    return bget(ap, n, p);
}

static int
paxput(Pax_t* pax, Paxarchive_t* ap, off_t n)
{
    bput(ap, n);
    return 0;
}

static off_t
paxread(Pax_t* pax, Paxarchive_t* ap, void* b, off_t n, off_t m, int must)
{
    return bread(ap, b, n, m, must);
}

static off_t
paxseek(Pax_t* pax, Paxarchive_t* ap, off_t pos, int op, int hard)
{
    return bseek(ap, pos, op, hard);
}

static char*
paxstash(Pax_t* pax, Value_t* v, const char* s, size_t z)
{
    return stash(v, s, z);
}

static int
paxsync(Pax_t* pax, Paxarchive_t* ap, int hard)
{
    if (ap->io->mode == O_RDONLY)
        bflushin(ap, hard);
    else
        bflushout(ap);
    return 0;
}

static int
paxunread(Pax_t* pax, Paxarchive_t* ap, void* b, off_t n)
{
    bunread(ap, b, n);
    return 0;
}

static int
paxwrite(Pax_t* pax, Paxarchive_t* ap, const void* b, off_t n)
{
    bwrite(ap, (void*)b, n);
    return 0;
}

static int
paxnext(Pax_t* pax, Paxarchive_t* ap, size_t c, size_t n)
{
    newio(ap, c, n);
    return 0;
}

static int
paxcorrupt(Pax_t* pax, Paxarchive_t* ap, Paxfile_t* f, const char* msg)
{
    (*pax->errorf)(NiL, pax, 2, "%s%s%s: %s archive corrupt at %I*u%s%s", ap->name, TXT(f, f->name), ap->format->name, sizeof(off_t), paxseek(pax, ap, 0, SEEK_CUR, 0), TXT(msg, msg));
    return -1;
}

static int
paxchecksum(Pax_t* pax, Paxarchive_t* ap, Paxfile_t* f, unsigned long expected, unsigned long value)
{
    int z;

    if (expected != value)
    {
        z = ((expected | value) & 0xffff0000) ? 8 : 4;
        (*pax->errorf)(NiL, pax, 2, "%s%s%s: %s archive checksum error -- expected %0*lx != %0*lx", ap->name, TXT(f, f->name), ap->format->name, z, expected, z, value);
        return -1;
    }
    return 0;
}

static int
paxnospace(Pax_t* pax)
{
    (*pax->errorf)(NiL, pax, 2, "out of space");
    return -1;
}

/*
 * archive part sfio discipline
 */

static ssize_t
part_read(Sfio_t* sp, void* buf, size_t n, Sfdisc_t* disc)
{
    register Part_t*    part = (Part_t*)disc;
    ssize_t         r;

    if (part->n <= 0)
        return part->n;
    if (n > part->n)
        n = part->n;
    if ((r = paxread(part->pax, part->ap, buf, n, 0, 0)) > 0)
        part->n -= r;
    return r;
}

static ssize_t
part_write(Sfio_t* sp, const void* buf, size_t n, Sfdisc_t* disc)
{
    register Part_t*    part = (Part_t*)disc;
    ssize_t         r;

    if ((r = paxwrite(part->pax, part->ap, buf, n)) > 0)
        part->n += r;
    return r;
}

static Sfio_t*
paxpart(Pax_t* pax, Paxarchive_t* ap, off_t n)
{
    register Part_t*    part;

    static int      fd = -1;

    if (!(part = ap->partio))
    {
        if (!(part = newof(0, Part_t, 1, 0)) || !(part->sp = sfstropen()))
        {
            paxnospace(pax);
            return 0;
        }
        part->sp->_flags &= ~(SF_READ|SF_WRITE|SF_STRING);
        if (ap->flags & PAX_IN)
            part->sp->_flags |= SF_READ;
        else
            part->sp->_flags |= SF_WRITE;
        if (fd < 0)
            fd = open("/dev/null", O_RDWR);
        part->sp->_file = fd;
        part->disc.readf = part_read;
        part->disc.writef = part_write;
        if (sfdisc(part->sp, &part->disc) != &part->disc)
        {
            sfclose(part->sp);
            free(part);
            return 0;
        }
        part->pax = pax;
        part->ap = ap;
        ap->partio = part;
    }
    part->n = n;
    return part->sp;
}

/*
 * initialize the external library callbacks
 */

void
paxinit(register Pax_t* pax, const char* id)
{
    pax->id = id;
    pax->errorf = errorf;

    pax->dataf = paxdata;
    pax->getf = paxget;
    pax->partf = paxpart;
    pax->putf = paxput;
    pax->readf = paxread;
    pax->seekf = paxseek;
    pax->stashf = paxstash;
    pax->syncf = paxsync;
    pax->unreadf = paxunread;
    pax->writef = paxwrite;

    pax->corruptf = paxcorrupt;
    pax->checksumf = paxchecksum;
    pax->nospacef = paxnospace;

    pax->nextf = paxnext;
}