text: /* $Id: tif_open.c,v 1.46 2010-12-06 16:54:54 faxguy 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"
  
  /*
   * Dummy functions to fill the omitted client procedures.
   */
  static int
  _tiffDummyMapProc(thandle_t fd, void** pbase, toff_t* psize)
  {
    (void) fd; (void) pbase; (void) psize;
    return (0);
  }
  
  static void
  _tiffDummyUnmapProc(thandle_t fd, void* base, toff_t size)
  {
    (void) fd; (void) base; (void) size;
  }
  
  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:
      TIFFErrorExt(0, 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;
    const char* cp;
  
    /* The following are configuration checks. They should be redundant, but should not
     * compile to any actual code in an optimised release build anyway. If any of them
     * fail, (makefile-based or other) configuration is not correct */
    assert(sizeof(uint8)==1);
    assert(sizeof(int8)==1);
    assert(sizeof(uint16)==2);
    assert(sizeof(int16)==2);
    assert(sizeof(uint32)==4);
    assert(sizeof(int32)==4);
    assert(sizeof(uint64)==8);
    assert(sizeof(int64)==8);
    assert(sizeof(tmsize_t)==sizeof(void*));
    {
      union{
        uint8 a8[2];
        uint16 a16;
      } n;
      n.a8[0]=1;
      n.a8[1]=0;
      #ifdef WORDS_BIGENDIAN
      assert(n.a16==256);
      #else
      assert(n.a16==1);
      #endif
    }
  
    m = _TIFFgetMode(mode, module);
    if (m == -1)
      goto bad2;
    tif = (TIFF *)_TIFFmalloc((tmsize_t)(sizeof (TIFF) + strlen(name) + 1));
    if (tif == NULL) {
      TIFFErrorExt(clientdata, 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 = (uint16) -1;    /* non-existent directory */
    tif->tif_curoff = 0;
    tif->tif_curstrip = (uint32) -1;  /* invalid strip */
    tif->tif_row = (uint32) -1;    /* read/write pre-increment */
    tif->tif_clientdata = clientdata;
    if (!readproc || !writeproc || !seekproc || !closeproc || !sizeproc) {
      TIFFErrorExt(clientdata, 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
  
    /*
     * 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
     * 'h' read TIFF header only, do not load the first IFD
     * '4' ClassicTIFF for creating a file (default)
     * '8' BigTIFF for creating a file
     *
     * 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':
          #ifndef WORDS_BIGENDIAN
          if (m&O_CREAT)
            tif->tif_flags |= TIFF_SWAB;
          #endif
          break;
        case 'l':
          #ifdef WORDS_BIGENDIAN
          if ((m&O_CREAT))
            tif->tif_flags |= TIFF_SWAB;
          #endif
          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;
        case 'h':
          tif->tif_flags |= TIFF_HEADERONLY;
          break;
        case '8':
          if (m&O_CREAT)
            tif->tif_flags |= TIFF_BIGTIFF;
          break;
      }
    /*
     * Read in TIFF header.
     */
    if ((m & O_TRUNC) ||
        !ReadOK(tif, &tif->tif_header, sizeof (TIFFHeaderClassic))) {
      if (tif->tif_mode == O_RDONLY) {
        TIFFErrorExt(tif->tif_clientdata, name,
            "Cannot read TIFF header");
        goto bad;
      }
      /*
       * Setup header and write.
       */
      #ifdef WORDS_BIGENDIAN
      tif->tif_header.common.tiff_magic = tif->tif_flags & TIFF_SWAB
          ? TIFF_LITTLEENDIAN : TIFF_BIGENDIAN;
      #else
      tif->tif_header.common.tiff_magic = tif->tif_flags & TIFF_SWAB
          ? TIFF_BIGENDIAN : TIFF_LITTLEENDIAN;
      #endif
      if (!(tif->tif_flags&TIFF_BIGTIFF))
      {
        tif->tif_header.common.tiff_version = TIFF_VERSION_CLASSIC;
        tif->tif_header.classic.tiff_diroff = 0;
        if (tif->tif_flags & TIFF_SWAB)
          TIFFSwabShort(&tif->tif_header.common.tiff_version);
        tif->tif_header_size = sizeof(TIFFHeaderClassic);
      }
      else
      {
        tif->tif_header.common.tiff_version = TIFF_VERSION_BIG;
        tif->tif_header.big.tiff_offsetsize = 8;
        tif->tif_header.big.tiff_unused = 0;
        tif->tif_header.big.tiff_diroff = 0;
        if (tif->tif_flags & TIFF_SWAB)
        {
          TIFFSwabShort(&tif->tif_header.common.tiff_version);
          TIFFSwabShort(&tif->tif_header.big.tiff_offsetsize);
        }
        tif->tif_header_size = sizeof (TIFFHeaderBig);
      }
      /*
       * The doc for "fopen" for some STD_C_LIBs says that if you
       * open a file for modify ("+"), then you must fseek (or
       * fflush?) between any freads and fwrites.  This is not
       * necessary on most systems, but has been shown to be needed
       * on Solaris.
       */
      TIFFSeekFile( tif, 0, SEEK_SET );
      if (!WriteOK(tif, &tif->tif_header, (tmsize_t)(tif->tif_header_size))) {
        TIFFErrorExt(tif->tif_clientdata, name,
            "Error writing TIFF header");
        goto bad;
      }
      /*
       * Setup the byte order handling.
       */
      if (tif->tif_header.common.tiff_magic == TIFF_BIGENDIAN) {
        #ifndef WORDS_BIGENDIAN
        tif->tif_flags |= TIFF_SWAB;
        #endif
      } else {
        #ifdef WORDS_BIGENDIAN
        tif->tif_flags |= TIFF_SWAB;
        #endif
      }
      /*
       * Setup default directory.
       */
      if (!TIFFDefaultDirectory(tif))
        goto bad;
      tif->tif_diroff = 0;
      tif->tif_dirlist = NULL;
      tif->tif_dirlistsize = 0;
      tif->tif_dirnumber = 0;
      return (tif);
    }
    /*
     * Setup the byte order handling.
     */
    if (tif->tif_header.common.tiff_magic != TIFF_BIGENDIAN &&
        tif->tif_header.common.tiff_magic != TIFF_LITTLEENDIAN
        #if MDI_SUPPORT
        &&
        #if HOST_BIGENDIAN
        tif->tif_header.common.tiff_magic != MDI_BIGENDIAN
        #else
        tif->tif_header.common.tiff_magic != MDI_LITTLEENDIAN
        #endif
        ) {
      TIFFErrorExt(tif->tif_clientdata, name,
          "Not a TIFF or MDI file, bad magic number %d (0x%x)",
        #else
        ) {
      TIFFErrorExt(tif->tif_clientdata, name,
          "Not a TIFF file, bad magic number %d (0x%x)",
        #endif
          tif->tif_header.common.tiff_magic,
          tif->tif_header.common.tiff_magic);
      goto bad;
    }
    if (tif->tif_header.common.tiff_magic == TIFF_BIGENDIAN) {
      #ifndef WORDS_BIGENDIAN
      tif->tif_flags |= TIFF_SWAB;
      #endif
    } else {
      #ifdef WORDS_BIGENDIAN
      tif->tif_flags |= TIFF_SWAB;
      #endif
    }
    if (tif->tif_flags & TIFF_SWAB)
      TIFFSwabShort(&tif->tif_header.common.tiff_version);
    if ((tif->tif_header.common.tiff_version != TIFF_VERSION_CLASSIC)&&
        (tif->tif_header.common.tiff_version != TIFF_VERSION_BIG)) {
      TIFFErrorExt(tif->tif_clientdata, name,
          "Not a TIFF file, bad version number %d (0x%x)",
          tif->tif_header.common.tiff_version,
          tif->tif_header.common.tiff_version);
      goto bad;
    }
    if (tif->tif_header.common.tiff_version == TIFF_VERSION_CLASSIC)
    {
      if (tif->tif_flags & TIFF_SWAB)
        TIFFSwabLong(&tif->tif_header.classic.tiff_diroff);
      tif->tif_header_size = sizeof(TIFFHeaderClassic);
    }
    else
    {
      if (!ReadOK(tif, ((uint8*)(&tif->tif_header) + sizeof(TIFFHeaderClassic)), (sizeof(TIFFHeaderBig)-sizeof(TIFFHeaderClassic))))
      {
        TIFFErrorExt(tif->tif_clientdata, name,
            "Cannot read TIFF header");
        goto bad;
      }
      if (tif->tif_flags & TIFF_SWAB)
      {
        TIFFSwabShort(&tif->tif_header.big.tiff_offsetsize);
        TIFFSwabLong8(&tif->tif_header.big.tiff_diroff);
      }
      if (tif->tif_header.big.tiff_offsetsize != 8)
      {
        TIFFErrorExt(tif->tif_clientdata, name,
            "Not a TIFF file, bad BigTIFF offsetsize %d (0x%x)",
            tif->tif_header.big.tiff_offsetsize,
            tif->tif_header.big.tiff_offsetsize);
        goto bad;
      }
      if (tif->tif_header.big.tiff_unused != 0)
      {
        TIFFErrorExt(tif->tif_clientdata, name,
            "Not a TIFF file, bad BigTIFF unused %d (0x%x)",
            tif->tif_header.big.tiff_unused,
            tif->tif_header.big.tiff_unused);
        goto bad;
      }
      tif->tif_header_size = sizeof(TIFFHeaderBig);
      tif->tif_flags |= TIFF_BIGTIFF;
    }
    tif->tif_flags |= TIFF_MYBUFFER;
    tif->tif_rawcp = tif->tif_rawdata = 0;
    tif->tif_rawdatasize = 0;
          tif->tif_rawdataoff = 0;
          tif->tif_rawdataloaded = 0;
  
    switch (mode[0]) {
      case 'r':
        if (!(tif->tif_flags&TIFF_BIGTIFF))
          tif->tif_nextdiroff = tif->tif_header.classic.tiff_diroff;
        else
          tif->tif_nextdiroff = tif->tif_header.big.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)
        {
          toff_t n;
          if (TIFFMapFileContents(tif,(void**)(&tif->tif_base),&n))
          {
            tif->tif_size=(tmsize_t)n;
            assert((toff_t)tif->tif_size==n);
          }
          else
            tif->tif_flags &= ~TIFF_MAPPED;
        }
        /*
         * Sometimes we do not want to read the first directory (for example,
         * it may be broken) and want to proceed to other directories. I this
         * case we use the TIFF_HEADERONLY flag to open file and return
         * immediately after reading TIFF header.
         */
        if (tif->tif_flags & TIFF_HEADERONLY)
          return (tif);
  
        /*
         * Setup initial directory.
         */
        if (TIFFReadDirectory(tif)) {
          tif->tif_rawcc = (tmsize_t)-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.
   */
  uint16
  TIFFCurrentDirectory(TIFF* tif)
  {
    return (tif->tif_curdir);
  }
  
  /*
   * Return current strip.
   */
  uint32
  TIFFCurrentStrip(TIFF* tif)
  {
    return (tif->tif_curstrip);
  }
  
  /*
   * Return current tile.
   */
  uint32
  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.common.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);
  }
  
  /* vim: set ts=8 sts=8 sw=8 noet: */
  /*
   * Local Variables:
   * mode: c
   * c-basic-offset: 8
   * fill-column: 78
   * End:
   */
  