/* virtual-backup.c

Copyright (c) 2000-2004 Craig Condit, Stefan Hülswitt.

Redistribution and use in source and binary forms, with or without

modification, are permitted provided that the following conditions are met: 

1. Redistributions of source code must retain the above copyright notice,

   this list of conditions and the following disclaimer. 

2. Redistributions in binary form must reproduce the above copyright notice,

   this list of conditions and the following disclaimer in the documentation

   and/or other materials provided with the distribution. 

THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS

OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR

ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR

SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER

CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

SUCH DAMAGE.

*/

#define _LARGEFILE64_SOURCE

#define _GNU_SOURCE

#include <stdlib.h>

#include <stdio.h>

#include <unistd.h>

#include <fcntl.h>

#include <errno.h>

#include <string.h>

#include <sys/wait.h>

#include <sys/stat.h>

#include "virtual.h"

#include "cdbackup.h"

#include "cdrom.h"

#include "misc.h"

#include "debug.h"

//#define DEBUGOUT

extern int virtual, multi;

extern int fd;

extern struct virt_header *virt_header;

extern int virtualMissing;

extern char *real_virt_name;

#ifndef DEBUGOUT

static pid_t childpid;

#endif

static int vfd=-1;

/****************************************************************************/

void VnewTrack(void)

{

  if(virtual) {

    long long pos;

    if(virtualMissing) {

      if((fd=open64(real_virt_name,O_RDWR|O_CREAT,S_IRUSR|S_IWUSR|S_IRGRP| S_IROTH))<0) error("Open failed (new track)");

      if(write(fd,virt_header,CD_FRAMESIZE)!=CD_FRAMESIZE) error("Write failed (new track)");

      virtualMissing=0;

      }

    if(virt_header->tracks>=MAX_VIRT_TRACKS-1) serror("Maximum number of virtual tracks reached");

    pos=(long long)(virt_header->start[virt_header->tracks]=virt_header->leadout)*CD_FRAMESIZE;

    virt_header->tracks++;

    if(lseek64(fd,pos,SEEK_SET)<0) error("Seek failed (new track)");

    }

  else {

#ifndef DEBUGOUT

    int pd[2];

    Vclose();

    if(pipe(pd)<0) error("Pipe failed (new track)");

    if((childpid=fork())<0) error("Fork failed (new track)");

    if(childpid==0) { /* child */

      close(pd[1]);

      close(0);

      dup2(pd[0],0);

      start_cdrecord(); /* doesn't returns */

      }

    close(pd[0]); fd=pd[1];

#else

    /* debug code; send data to /dev/null. */

    Vclose();

    fprintf(stderr,"DEBUG CODE: NO recording, sending data to /dev/null!\n");

    if((fd=open("/dev/null",O_WRONLY))<0) error("Open failed (/dev/null)");

#endif

    cd_avail-=padsize*CD_FRAMESIZE;

    }

}

/****************************************************************************/

int Vsize(void)

{

  return virt_header->leadout;

}

/****************************************************************************/

int VhasCont(void)

{

  return virt_header->has_cont;

}

/****************************************************************************/

void VprepareDump(void)

{

  if((vfd=dup(fd))<0) error("Dup failed");

  Vclose();

}

/****************************************************************************/

void VvirtRead(void *buf)

{

  if(full_read(vfd,buf,CD_FRAMESIZE)!=CD_FRAMESIZE)

    serror("Unexpected EOF reading data");

}

/****************************************************************************/

void VcloseTrack(int cont)

{

  if(virtual) {

    if(lseek64(fd,0,SEEK_SET)<0) error("Seek failed (close track)");

    virt_header->has_cont=cont;

    if(write(fd,virt_header,CD_FRAMESIZE)!=CD_FRAMESIZE) error("Write failed (close track)");

    Vclose();

    }

  else {

    Vclose();

#ifndef DEBUGOUT

    DEBUG("VcloseTrack: waiting for child termination\n");

    while(wait(0)!=childpid);

#endif

    }

  if(vfd>=0) { close(vfd); vfd=-1; }

}

/****************************************************************************/

void Vwrite(const void *buf)

{

  if(write(fd,buf,CD_FRAMESIZE)!=CD_FRAMESIZE) error("Write failed");

  if(virtual) virt_header->leadout++;

  cd_avail-=CD_FRAMESIZE;

}