gambas-source-code/main/gbx/gbx_stream_arch.c

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

  stream_arch.c

  The archive stream management routines

  (c) 2000-2007 Benoit Minisini <gambas@users.sourceforge.net>

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 1, or (at your option)
  any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

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

#define __STREAM_IMPL_C

#include "gb_common.h"
#include "gb_error.h"
#include "gbx_value.h"
#include "gb_limit.h"

#include <fcntl.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <errno.h>

#include "gbx_archive.h"
#include "gbx_stream.h"


static int stream_open(STREAM *stream, const char *path, int mode)
{
  ARCHIVE_FIND find;

  if (ARCHIVE_get(NULL, &path, &find))
  {
    errno = ENOENT;
    return TRUE;
  }

  if (find.pos < 0)
  {
  	errno = EISDIR;
		return TRUE;
	}

  if ((mode & ST_ACCESS) != ST_READ)
  {
    errno = EACCES;
    return TRUE;
  }

	stream->common.available_now = TRUE;
  stream->arch.arch = find.arch;
  stream->arch.size = find.len;
  stream->arch.start = find.pos;
  stream->arch.pos = 0;

  return FALSE;
}


static int stream_close(STREAM *stream)
{
  return FALSE;
}


static int stream_read(STREAM *stream, char *buffer, int len)
{
  boolean strip = FALSE;
  int max;

  max = stream->arch.size - stream->arch.pos;

  if (len > max)
  {
    strip = TRUE;
    len = max;
    errno = 0;
  }

  if (ARCHIVE_read(stream->arch.arch, stream->arch.start + stream->arch.pos, buffer, len))
    strip = TRUE;

  stream->arch.pos += len;
  STREAM_eff_read = len;

  return strip;
}


static int stream_write(STREAM *stream, char *buffer, int len)
{
  return TRUE;
}


static int stream_seek(STREAM *stream, int64_t pos, int whence)
{
  int64_t new_pos;

  switch(whence)
  {
    case SEEK_SET:
      new_pos = pos;
      break;

    case SEEK_CUR:
      new_pos = stream->arch.pos + pos;
      break;

    case SEEK_END:
      new_pos = stream->arch.size - pos;
      break;

    default:
      return TRUE;
  }

  if (new_pos < 0 || new_pos > stream->arch.size)
    return TRUE;

  stream->arch.pos = (int)new_pos;
  return FALSE;
}

#define stream_getchar NULL


static int stream_tell(STREAM *stream, int64_t *pos)
{
  *pos = stream->arch.pos;
  return FALSE;
}


static int stream_flush(STREAM *stream)
{
  return FALSE;
}


static int stream_eof(STREAM *stream)
{
  return (stream->arch.pos >= stream->arch.size);
}


static int stream_lof(STREAM *stream, int64_t *len)
{
  *len = stream->arch.size;
  return FALSE;
}

static int stream_handle(STREAM *stream)
{
  return -1;
}


DECLARE_STREAM(STREAM_arch);