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-rw-r--r--libtiff/tif_open.c149
1 files changed, 111 insertions, 38 deletions
diff --git a/libtiff/tif_open.c b/libtiff/tif_open.c
index 80788556..6ae2c130 100644
--- a/libtiff/tif_open.c
+++ b/libtiff/tif_open.c
@@ -1,8 +1,8 @@
-/* $Header: /usr/people/sam/tiff/libtiff/RCS/tif_open.c,v 1.59 1995/07/20 16:38:53 sam Exp $ */
+/* $Header: /usr/people/sam/tiff/libtiff/RCS/tif_open.c,v 1.63 1996/01/10 19:33:07 sam Exp $ */
/*
- * Copyright (c) 1988-1995 Sam Leffler
- * Copyright (c) 1991-1995 Silicon Graphics, Inc.
+ * Copyright (c) 1988-1996 Sam Leffler
+ * Copyright (c) 1991-1996 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
@@ -76,27 +76,13 @@ static const int litTypeshift[13] = {
};
/*
- * Initialize the bit fill order, the
- * shift & mask tables, and the byte
- * swapping state according to the file
+ * Initialize the shift & mask tables, and the
+ * byte swapping state according to the file
* contents and the machine architecture.
*/
static void
-TIFFInitOrder(register TIFF* tif, int magic, int bigendian)
+TIFFInitOrder(TIFF* tif, int magic, int bigendian)
{
-#ifdef notdef
- /*
- * NB: too many applications assume that data is returned
- * by the library in MSB2LSB bit order to change the
- * default bit order to reflect the native cpu. This
- * may change in the future in which case applications
- * will need to check the value of the FillOrder tag.
- */
- tif->tif_flags = (tif->tif_flags &~ TIFF_FILLORDER) | HOST_FILLORDER;
-#else
- tif->tif_flags = (tif->tif_flags &~ TIFF_FILLORDER) | FILLORDER_MSB2LSB;
-#endif
-
tif->tif_typemask = typemask;
if (magic == TIFF_BIGENDIAN) {
tif->tif_typeshift = bigTypeshift;
@@ -149,6 +135,7 @@ TIFFClientOpen(
static const char module[] = "TIFFClientOpen";
TIFF *tif;
int m, bigendian;
+ const char* cp;
m = _TIFFgetMode(mode, module);
if (m == -1)
@@ -174,28 +161,106 @@ TIFFClientOpen(
tif->tif_sizeproc = sizeproc;
tif->tif_mapproc = mapproc;
tif->tif_unmapproc = unmapproc;
+ /*
+ * 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|TIFF_STRIPCHOP;
{ union { int32 i; char c[4]; } u; u.i = 1; bigendian = u.c[0] == 0; }
-#ifdef ENDIANHACK_SUPPORT
/*
- * Numerous vendors, typically on the PC, do not correctly
- * support TIFF; they only support the Intel little-endian
- * byte order. If this hack is enabled, then applications
- * can open a file with a specific byte-order by specifying
- * either "wl" (for litt-endian byte order) or "wb" for
- * (big-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.
+ * 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
*
- * 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 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 probabyl 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.
*/
- if ((m&O_CREAT) &&
- ((bigendian && mode[1] == 'l') || (!bigendian && mode[1] == 'b')))
- tif->tif_flags |= TIFF_SWAB;
+ 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;
+#ifdef STRIPCHOP_SUPPORT
+ case 'C':
+ if (m == O_RDONLY)
+ tif->tif_flags |= TIFF_STRIPCHOP;
+ break;
+ case 'c':
+ if (m == O_RDONLY)
+ tif->tif_flags &= ~TIFF_STRIPCHOP;
+ break;
#endif
+ }
/*
* Read in TIFF header.
*/
@@ -211,6 +276,8 @@ TIFFClientOpen(
? (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");
@@ -267,8 +334,14 @@ TIFFClientOpen(
switch (mode[0]) {
case 'r':
tif->tif_nextdiroff = tif->tif_header.tiff_diroff;
- if (TIFFMapFileContents(tif, (tdata_t*) &tif->tif_base, &tif->tif_size))
- tif->tif_flags |= TIFF_MAPPED;
+ /*
+ * 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;
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