/* $Id: tif_open.c,v 1.5 2005/11/19 16:02:59 malaterre Exp $ */

/*
 * Copyright (c) 1988-1997 Sam Leffler
 * Copyright (c) 1991-1997 Silicon Graphics, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software and 
 * its documentation for any purpose is hereby granted without fee, provided
 * that (i) the above copyright notices and this permission notice appear in
 * all copies of the software and related documentation, and (ii) the names of
 * Sam Leffler and Silicon Graphics may not be used in any advertising or
 * publicity relating to the software without the specific, prior written
 * permission of Sam Leffler and Silicon Graphics.
 * 
 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 
 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 
 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  
 * 
 * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 
 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 
 * OF THIS SOFTWARE.
 */

/*
 * TIFF Library.
 */
#include "tiffiop.h"

void _TIFFSetDefaultCompressionState(TIFF* tif);

static const long typemask[13] = {
  (long)0L,    /* TIFF_NOTYPE */
  (long)0x000000ffL,  /* TIFF_BYTE */
  (long)0xffffffffL,  /* TIFF_ASCII */
  (long)0x0000ffffL,  /* TIFF_SHORT */
  (long)0xffffffffL,  /* TIFF_LONG */
  (long)0xffffffffL,  /* TIFF_RATIONAL */
  (long)0x000000ffL,  /* TIFF_SBYTE */
  (long)0x000000ffL,  /* TIFF_UNDEFINED */
  (long)0x0000ffffL,  /* TIFF_SSHORT */
  (long)0xffffffffL,  /* TIFF_SLONG */
  (long)0xffffffffL,  /* TIFF_SRATIONAL */
  (long)0xffffffffL,  /* TIFF_FLOAT */
  (long)0xffffffffL,  /* TIFF_DOUBLE */
};
static const int bigTypeshift[13] = {
  0,    /* TIFF_NOTYPE */
  24,    /* TIFF_BYTE */
  0,    /* TIFF_ASCII */
  16,    /* TIFF_SHORT */
  0,    /* TIFF_LONG */
  0,    /* TIFF_RATIONAL */
  24,    /* TIFF_SBYTE */
  24,    /* TIFF_UNDEFINED */
  16,    /* TIFF_SSHORT */
  0,    /* TIFF_SLONG */
  0,    /* TIFF_SRATIONAL */
  0,    /* TIFF_FLOAT */
  0,    /* TIFF_DOUBLE */
};
static const int litTypeshift[13] = {
  0,    /* TIFF_NOTYPE */
  0,    /* TIFF_BYTE */
  0,    /* TIFF_ASCII */
  0,    /* TIFF_SHORT */
  0,    /* TIFF_LONG */
  0,    /* TIFF_RATIONAL */
  0,    /* TIFF_SBYTE */
  0,    /* TIFF_UNDEFINED */
  0,    /* TIFF_SSHORT */
  0,    /* TIFF_SLONG */
  0,    /* TIFF_SRATIONAL */
  0,    /* TIFF_FLOAT */
  0,    /* TIFF_DOUBLE */
};

/*
 * Dummy functions to fill the omitted client procedures.
 */
static int
_tiffDummyMapProc(thandle_t d, tdata_t* pbase, toff_t* psize)
{
  (void)d;
  (void)pbase;
  (void)psize;
  return (0);
}

static void
_tiffDummyUnmapProc(thandle_t fd, tdata_t base, toff_t size)
{
  (void)fd;
  (void)base;
  (void)size;
}

/*
 * Initialize the shift & mask tables, and the
 * byte swapping state according to the file
 * contents and the machine architecture.
 */
static void
TIFFInitOrder(TIFF* tif, int magic, int bigendian)
{
  tif->tif_typemask = typemask;
  if (magic == TIFF_BIGENDIAN) {
    tif->tif_typeshift = bigTypeshift;
    if (!bigendian)
      tif->tif_flags |= TIFF_SWAB;
  } else {
    tif->tif_typeshift = litTypeshift;
    if (bigendian)
      tif->tif_flags |= TIFF_SWAB;
  }
}

int
_TIFFgetMode(const char* mode, const char* module)
{
  int m = -1;

  switch (mode[0]) {
  case 'r':
    m = O_RDONLY;
    if (mode[1] == '+')
      m = O_RDWR;
    break;
  case 'w':
  case 'a':
    m = O_RDWR|O_CREAT;
    if (mode[0] == 'w')
      m |= O_TRUNC;
    break;
  default:
    TIFFError(module, "\"%s\": Bad mode", mode);
    break;
  }
  return (m);
}

TIFF*
TIFFClientOpen(
  const char* name, const char* mode,
  thandle_t clientdata,
  TIFFReadWriteProc readproc,
  TIFFReadWriteProc writeproc,
  TIFFSeekProc seekproc,
  TIFFCloseProc closeproc,
  TIFFSizeProc sizeproc,
  TIFFMapFileProc mapproc,
  TIFFUnmapFileProc unmapproc
)
{
  static const char module[] = "TIFFClientOpen";
  TIFF *tif;
  int m, bigendian;
  const char* cp;

  m = _TIFFgetMode(mode, module);
  if (m == -1)
    goto bad2;
  tif = (TIFF *)_TIFFmalloc(sizeof (TIFF) + strlen(name) + 1);
  if (tif == NULL) {
    TIFFError(module, "%s: Out of memory (TIFF structure)", name);
    goto bad2;
  }
  _TIFFmemset(tif, 0, sizeof (*tif));
  tif->tif_name = (char *)tif + sizeof (TIFF);
  strcpy(tif->tif_name, name);
  tif->tif_mode = m &~ (O_CREAT|O_TRUNC);
  tif->tif_curdir = (tdir_t) -1;    /* non-existent directory */
  tif->tif_curoff = 0;
  tif->tif_curstrip = (tstrip_t) -1;  /* invalid strip */
  tif->tif_row = (uint32) -1;    /* read/write pre-increment */
  tif->tif_clientdata = clientdata;
  if (!readproc || !writeproc || !seekproc || !closeproc || !sizeproc) {
    TIFFError(module,
        "One of the client procedures is NULL pointer.");
    goto bad2;
  }
  tif->tif_readproc = readproc;
  tif->tif_writeproc = writeproc;
  tif->tif_seekproc = seekproc;
  tif->tif_closeproc = closeproc;
  tif->tif_sizeproc = sizeproc;
        if (mapproc)
    tif->tif_mapproc = mapproc;
  else
    tif->tif_mapproc = _tiffDummyMapProc;
  if (unmapproc)
    tif->tif_unmapproc = unmapproc;
  else
    tif->tif_unmapproc = _tiffDummyUnmapProc;
  _TIFFSetDefaultCompressionState(tif);  /* setup default state */
  /*
   * Default is to return data MSB2LSB and enable the
   * use of memory-mapped files and strip chopping when
   * a file is opened read-only.
   */
  tif->tif_flags = FILLORDER_MSB2LSB;
  if (m == O_RDONLY )
            tif->tif_flags |= TIFF_MAPPED;

#ifdef STRIPCHOP_DEFAULT
  if (m == O_RDONLY || m == O_RDWR)
    tif->tif_flags |= STRIPCHOP_DEFAULT;
#endif

  { union { int32 i; char c[4]; } u; u.i = 1; bigendian = u.c[0] == 0; }
  /*
   * Process library-specific flags in the open mode string.
   * The following flags may be used to control intrinsic library
   * behaviour that may or may not be desirable (usually for
   * compatibility with some application that claims to support
   * TIFF but only supports some braindead idea of what the
   * vendor thinks TIFF is):
   *
   * 'l'    use little-endian byte order for creating a file
   * 'b'    use big-endian byte order for creating a file
   * 'L'    read/write information using LSB2MSB bit order
   * 'B'    read/write information using MSB2LSB bit order
   * 'H'    read/write information using host bit order
   * 'M'    enable use of memory-mapped files when supported
   * 'm'    disable use of memory-mapped files
   * 'C'    enable strip chopping support when reading
   * 'c'    disable strip chopping support
   *
   * The use of the 'l' and 'b' flags is strongly discouraged.
   * These flags are provided solely because numerous vendors,
   * typically on the PC, do not correctly support TIFF; they
   * only support the Intel little-endian byte order.  This
   * support is not configured by default because it supports
   * the violation of the TIFF spec that says that readers *MUST*
   * support both byte orders.  It is strongly recommended that
   * you not use this feature except to deal with busted apps
   * that write invalid TIFF.  And even in those cases you should
   * bang on the vendors to fix their software.
   *
   * The 'L', 'B', and 'H' flags are intended for applications
   * that can optimize operations on data by using a particular
   * bit order.  By default the library returns data in MSB2LSB
   * bit order for compatibiltiy with older versions of this
   * library.  Returning data in the bit order of the native cpu
   * makes the most sense but also requires applications to check
   * the value of the FillOrder tag; something they probably do
   * not do right now.
   *
   * The 'M' and 'm' flags are provided because some virtual memory
   * systems exhibit poor behaviour when large images are mapped.
   * These options permit clients to control the use of memory-mapped
   * files on a per-file basis.
   *
   * The 'C' and 'c' flags are provided because the library support
   * for chopping up large strips into multiple smaller strips is not
   * application-transparent and as such can cause problems.  The 'c'
   * option permits applications that only want to look at the tags,
   * for example, to get the unadulterated TIFF tag information.
   */
  for (cp = mode; *cp; cp++)
    switch (*cp) {
    case 'b':
      if ((m&O_CREAT) && !bigendian)
        tif->tif_flags |= TIFF_SWAB;
      break;
    case 'l':
      if ((m&O_CREAT) && bigendian)
        tif->tif_flags |= TIFF_SWAB;
      break;
    case 'B':
      tif->tif_flags = (tif->tif_flags &~ TIFF_FILLORDER) |
          FILLORDER_MSB2LSB;
      break;
    case 'L':
      tif->tif_flags = (tif->tif_flags &~ TIFF_FILLORDER) |
          FILLORDER_LSB2MSB;
      break;
    case 'H':
      tif->tif_flags = (tif->tif_flags &~ TIFF_FILLORDER) |
          HOST_FILLORDER;
      break;
    case 'M':
      if (m == O_RDONLY)
        tif->tif_flags |= TIFF_MAPPED;
      break;
    case 'm':
      if (m == O_RDONLY)
        tif->tif_flags &= ~TIFF_MAPPED;
      break;
    case 'C':
      if (m == O_RDONLY)
        tif->tif_flags |= TIFF_STRIPCHOP;
      break;
    case 'c':
      if (m == O_RDONLY)
        tif->tif_flags &= ~TIFF_STRIPCHOP;
      break;
    }
  /*
   * Read in TIFF header.
   */
  if (!ReadOK(tif, &tif->tif_header, sizeof (TIFFHeader))) {
    if (tif->tif_mode == O_RDONLY) {
      TIFFError(name, "Cannot read TIFF header");
      goto bad;
    }
    /*
     * Setup header and write.
     */
    tif->tif_header.tiff_magic = tif->tif_flags & TIFF_SWAB
        ? (bigendian ? TIFF_LITTLEENDIAN : TIFF_BIGENDIAN)
        : (bigendian ? TIFF_BIGENDIAN : TIFF_LITTLEENDIAN);
    tif->tif_header.tiff_version = TIFF_VERSION;
    if (tif->tif_flags & TIFF_SWAB)
      TIFFSwabShort(&tif->tif_header.tiff_version);
    tif->tif_header.tiff_diroff = 0;  /* filled in later */

    if (!WriteOK(tif, &tif->tif_header, sizeof (TIFFHeader))) {
      TIFFError(name, "Error writing TIFF header");
      goto bad;
    }
    /*
     * Setup the byte order handling.
     */
    TIFFInitOrder(tif, tif->tif_header.tiff_magic, bigendian);
    /*
     * Setup default directory.
     */
    if (!TIFFDefaultDirectory(tif))
      goto bad;
    tif->tif_diroff = 0;
    tif->tif_dirlist = NULL;
    tif->tif_dirnumber = 0;
    return (tif);
  }
  /*
   * Setup the byte order handling.
   */
  if (tif->tif_header.tiff_magic != TIFF_BIGENDIAN &&
      tif->tif_header.tiff_magic != TIFF_LITTLEENDIAN) {
    TIFFError(name,  "Not a TIFF file, bad magic number %d (0x%x)",
        tif->tif_header.tiff_magic,
        tif->tif_header.tiff_magic);
    goto bad;
  }
  TIFFInitOrder(tif, tif->tif_header.tiff_magic, bigendian);
  /*
   * Swap header if required.
   */
  if (tif->tif_flags & TIFF_SWAB) {
    TIFFSwabShort(&tif->tif_header.tiff_version);
    TIFFSwabLong(&tif->tif_header.tiff_diroff);
  }
  /*
   * Now check version (if needed, it's been byte-swapped).
   * Note that this isn't actually a version number, it's a
   * magic number that doesn't change (stupid).
   */
  if (tif->tif_header.tiff_version == TIFF_BIGTIFF_VERSION) {
    TIFFError(name,
                          "This is a BigTIFF file.  This format not supported\n"
                          "by this version of libtiff." );
    goto bad;
  }
  if (tif->tif_header.tiff_version != TIFF_VERSION) {
    TIFFError(name,
        "Not a TIFF file, bad version number %d (0x%x)",
        tif->tif_header.tiff_version,
        tif->tif_header.tiff_version); 
    goto bad;
  }
  tif->tif_flags |= TIFF_MYBUFFER;
  tif->tif_rawcp = tif->tif_rawdata = 0;
  tif->tif_rawdatasize = 0;
  /*
   * Setup initial directory.
   */
  switch (mode[0]) {
  case 'r':
    tif->tif_nextdiroff = tif->tif_header.tiff_diroff;
    /*
     * Try to use a memory-mapped file if the client
     * has not explicitly suppressed usage with the
     * 'm' flag in the open mode (see above).
     */
    if ((tif->tif_flags & TIFF_MAPPED) &&
  !TIFFMapFileContents(tif, (tdata_t*) &tif->tif_base, &tif->tif_size))
      tif->tif_flags &= ~TIFF_MAPPED;
    if (TIFFReadDirectory(tif)) {
      tif->tif_rawcc = -1;
      tif->tif_flags |= TIFF_BUFFERSETUP;
      return (tif);
    }
    break;
  case 'a':
    /*
     * New directories are automatically append
     * to the end of the directory chain when they
     * are written out (see TIFFWriteDirectory).
     */
    if (!TIFFDefaultDirectory(tif))
      goto bad;
    return (tif);
  }
bad:
  tif->tif_mode = O_RDONLY;  /* XXX avoid flush */
        TIFFCleanup(tif);
bad2:
  return ((TIFF*)0);
}

/*
 * Query functions to access private data.
 */

/*
 * Return open file's name.
 */
const char *
TIFFFileName(TIFF* tif)
{
  return (tif->tif_name);
}

/*
 * Set the file name.
 */
const char *
TIFFSetFileName(TIFF* tif, const char *name)
{
  const char* old_name = tif->tif_name;
  tif->tif_name = (char *)name;
  return (old_name);
}

/*
 * Return open file's I/O descriptor.
 */
int
TIFFFileno(TIFF* tif)
{
  return (tif->tif_fd);
}

/*
 * Set open file's I/O descriptor, and return previous value.
 */
int
TIFFSetFileno(TIFF* tif, int fd)
{
        int old_fd = tif->tif_fd;
  tif->tif_fd = fd;
  return old_fd;
}

/*
 * Return open file's clientdata.
 */
thandle_t
TIFFClientdata(TIFF* tif)
{
  return (tif->tif_clientdata);
}

/*
 * Set open file's clientdata, and return previous value.
 */
thandle_t
TIFFSetClientdata(TIFF* tif, thandle_t newvalue)
{
  thandle_t m = tif->tif_clientdata;
  tif->tif_clientdata = newvalue;
  return m;
}

/*
 * Return read/write mode.
 */
int
TIFFGetMode(TIFF* tif)
{
  return (tif->tif_mode);
}

/*
 * Return read/write mode.
 */
int
TIFFSetMode(TIFF* tif, int mode)
{
  int old_mode = tif->tif_mode;
  tif->tif_mode = mode;
  return (old_mode);
}

/*
 * Return nonzero if file is organized in
 * tiles; zero if organized as strips.
 */
int
TIFFIsTiled(TIFF* tif)
{
  return (isTiled(tif));
}

/*
 * Return current row being read/written.
 */
uint32
TIFFCurrentRow(TIFF* tif)
{
  return (tif->tif_row);
}

/*
 * Return index of the current directory.
 */
tdir_t
TIFFCurrentDirectory(TIFF* tif)
{
  return (tif->tif_curdir);
}

/*
 * Return current strip.
 */
tstrip_t
TIFFCurrentStrip(TIFF* tif)
{
  return (tif->tif_curstrip);
}

/*
 * Return current tile.
 */
ttile_t
TIFFCurrentTile(TIFF* tif)
{
  return (tif->tif_curtile);
}

/*
 * Return nonzero if the file has byte-swapped data.
 */
int
TIFFIsByteSwapped(TIFF* tif)
{
  return ((tif->tif_flags & TIFF_SWAB) != 0);
}

/*
 * Return nonzero if the data is returned up-sampled.
 */
int
TIFFIsUpSampled(TIFF* tif)
{
  return (isUpSampled(tif));
}

/*
 * Return nonzero if the data is returned in MSB-to-LSB bit order.
 */
int
TIFFIsMSB2LSB(TIFF* tif)
{
  return (isFillOrder(tif, FILLORDER_MSB2LSB));
}

/*
 * Return nonzero if given file was written in big-endian order.
 */
int
TIFFIsBigEndian(TIFF* tif)
{
  return (tif->tif_header.tiff_magic == TIFF_BIGENDIAN);
}

/*
 * Return pointer to file read method.
 */
TIFFReadWriteProc
TIFFGetReadProc(TIFF* tif)
{
  return (tif->tif_readproc);
}

/*
 * Return pointer to file write method.
 */
TIFFReadWriteProc
TIFFGetWriteProc(TIFF* tif)
{
  return (tif->tif_writeproc);
}

/*
 * Return pointer to file seek method.
 */
TIFFSeekProc
TIFFGetSeekProc(TIFF* tif)
{
  return (tif->tif_seekproc);
}

/*
 * Return pointer to file close method.
 */
TIFFCloseProc
TIFFGetCloseProc(TIFF* tif)
{
  return (tif->tif_closeproc);
}

/*
 * Return pointer to file size requesting method.
 */
TIFFSizeProc
TIFFGetSizeProc(TIFF* tif)
{
  return (tif->tif_sizeproc);
}

/*
 * Return pointer to memory mapping method.
 */
TIFFMapFileProc
TIFFGetMapFileProc(TIFF* tif)
{
  return (tif->tif_mapproc);
}

/*
 * Return pointer to memory unmapping method.
 */
TIFFUnmapFileProc
TIFFGetUnmapFileProc(TIFF* tif)
{
  return (tif->tif_unmapproc);
}

