tif_open.c

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/*
 * 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 <precomp.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.");
        _TIFFfree(tif);
        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 brain dead 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
         * 'D' enable use of deferred strip/tile offset/bytecount array loading.
         * 'O' on-demand loading of values instead of whole array loading (implies D)
     *
     * 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 compatibility 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;
            case 'D':
                    tif->tif_flags |= TIFF_DEFERSTRILELOAD;
                break;
            case 'O':
                if( m == O_RDONLY )
                    tif->tif_flags |= (TIFF_LAZYSTRILELOAD | TIFF_DEFERSTRILELOAD);
                break;
        }

#ifdef DEFER_STRILE_LOAD
        /* Compatibility with old DEFER_STRILE_LOAD compilation flag */
        /* Probably unneeded, since to the best of my knowledge (E. Rouault) */
        /* GDAL was the only user of this, and will now use the new 'D' flag */
        tif->tif_flags |= TIFF_DEFERSTRILELOAD;
#endif

    /*
     * 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:
 */