/* $Id: tif_stream.cxx,v 1.11 2010-12-11 23:12:29 faxguy Exp $ */
/*
* 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
* 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 UNIX-specific Routines.
*/
#include "tiffiop.h"
#include <iostream>
#ifndef __VMS
using namespace std;
#endif
/*
ISO C++ uses a 'std::streamsize' type to define counts. This makes
it similar to, (but perhaps not the same as) size_t.
The std::ios::pos_type is used to represent stream positions as used
by tellg(), tellp(), seekg(), and seekp(). This makes it similar to
(but perhaps not the same as) 'off_t'. The std::ios::streampos type
is used for character streams, but is documented to not be an
integral type anymore, so it should *not* be assigned to an integral
type.
The std::ios::off_type is used to specify relative offsets needed by
the variants of seekg() and seekp() which accept a relative offset
argument.
Useful prototype knowledge:
Obtain read position
ios::pos_type basic_istream::tellg()
Set read position
basic_istream& basic_istream::seekg(ios::pos_type)
basic_istream& basic_istream::seekg(ios::off_type, ios_base::seekdir)
Read data
basic_istream& istream::read(char *str, streamsize count)
Number of characters read in last unformatted read
streamsize istream::gcount();
Obtain write position
ios::pos_type basic_ostream::tellp()
Set write position
basic_ostream& basic_ostream::seekp(ios::pos_type)
basic_ostream& basic_ostream::seekp(ios::off_type, ios_base::seekdir)
Write data
basic_ostream& ostream::write(const char *str, streamsize count)
*/
struct tiffis_data;
struct tiffos_data;
extern "C" {
static tmsize_t _tiffosReadProc(thandle_t, void*, tmsize_t);
static tmsize_t _tiffisReadProc(thandle_t fd, void* buf, tmsize_t size);
static tmsize_t _tiffosWriteProc(thandle_t fd, void* buf, tmsize_t size);
static tmsize_t _tiffisWriteProc(thandle_t, void*, tmsize_t);
static uint64 _tiffosSeekProc(thandle_t fd, uint64 off, int whence);
static uint64 _tiffisSeekProc(thandle_t fd, uint64 off, int whence);
static uint64 _tiffosSizeProc(thandle_t fd);
static uint64 _tiffisSizeProc(thandle_t fd);
static int _tiffosCloseProc(thandle_t fd);
static int _tiffisCloseProc(thandle_t fd);
static int _tiffDummyMapProc(thandle_t , void** base, toff_t* size );
static void _tiffDummyUnmapProc(thandle_t , void* base, toff_t size );
static TIFF* _tiffStreamOpen(const char* name, const char* mode, void *fd);
struct tiffis_data
{
istream *stream;
ios::pos_type start_pos;
};
struct tiffos_data
{
ostream *stream;
ios::pos_type start_pos;
};
static tmsize_t
_tiffosReadProc(thandle_t, void*, tmsize_t)
{
return 0;
}
static tmsize_t
_tiffisReadProc(thandle_t fd, void* buf, tmsize_t size)
{
tiffis_data *data = reinterpret_cast<tiffis_data *>(fd);
// Verify that type does not overflow.
streamsize request_size = size;
if (static_cast<tmsize_t>(request_size) != size)
return static_cast<tmsize_t>(-1);
data->stream->read((char *) buf, request_size);
return static_cast<tmsize_t>(data->stream->gcount());
}
static tmsize_t
_tiffosWriteProc(thandle_t fd, void* buf, tmsize_t size)
{
tiffos_data *data = reinterpret_cast<tiffos_data *>(fd);
ostream *os = data->stream;
ios::pos_type pos = os->tellp();
// Verify that type does not overflow.
streamsize request_size = size;
if (static_cast<tmsize_t>(request_size) != size)
return static_cast<tmsize_t>(-1);
os->write(reinterpret_cast<const char *>(buf), request_size);
return static_cast<tmsize_t>(os->tellp() - pos);
}
static tmsize_t
_tiffisWriteProc(thandle_t, void*, tmsize_t)
{
return 0;
}
static uint64
_tiffosSeekProc(thandle_t fd, uint64 off, int whence)
{
tiffos_data *data = reinterpret_cast<tiffos_data *>(fd);
ostream *os = data->stream;
// if the stream has already failed, don't do anything
if( os->fail() )
return static_cast<uint64>(-1);
switch(whence) {
case SEEK_SET:
{
// Compute 64-bit offset
uint64 new_offset = static_cast<uint64>(data->start_pos) + off;
// Verify that value does not overflow
ios::off_type offset = static_cast<ios::off_type>(new_offset);
if (static_cast<uint64>(offset) != new_offset)
return static_cast<uint64>(-1);
os->seekp(offset, ios::beg);
break;
}
case SEEK_CUR:
{
// Verify that value does not overflow
ios::off_type offset = static_cast<ios::off_type>(off);
if (static_cast<uint64>(offset) != off)
return static_cast<uint64>(-1);
os->seekp(offset, ios::cur);
break;
}
case SEEK_END:
{
// Verify that value does not overflow
ios::off_type offset = static_cast<ios::off_type>(off);
if (static_cast<uint64>(offset) != off)
return static_cast<uint64>(-1);
os->seekp(offset, ios::end);
break;
}
}
// Attempt to workaround problems with seeking past the end of the
// stream. ofstream doesn't have a problem with this but
// ostrstream/ostringstream does. In that situation, add intermediate
// '\0' characters.
if( os->fail() ) {
#ifdef __VMS
int old_state;
#else
ios::iostate old_state;
#endif
ios::pos_type origin;
old_state = os->rdstate();
// reset the fail bit or else tellp() won't work below
os->clear(os->rdstate() & ~ios::failbit);
switch( whence ) {
case SEEK_SET:
default:
origin = data->start_pos;
break;
case SEEK_CUR:
origin = os->tellp();
break;
case SEEK_END:
os->seekp(0, ios::end);
origin = os->tellp();
break;
}
// restore original stream state
os->clear(old_state);
// only do something if desired seek position is valid
if( (static_cast<uint64>(origin) + off) > static_cast<uint64>(data->start_pos) ) {
uint64 num_fill;
// clear the fail bit
os->clear(os->rdstate() & ~ios::failbit);
// extend the stream to the expected size
os->seekp(0, ios::end);
num_fill = (static_cast<uint64>(origin)) + off - os->tellp();
for( uint64 i = 0; i < num_fill; i++ )
os->put('\0');
// retry the seek
os->seekp(static_cast<ios::off_type>(static_cast<uint64>(origin) + off), ios::beg);
}
}
return static_cast<uint64>(os->tellp());
}
static uint64
_tiffisSeekProc(thandle_t fd, uint64 off, int whence)
{
tiffis_data *data = reinterpret_cast<tiffis_data *>(fd);
switch(whence) {
case SEEK_SET:
{
// Compute 64-bit offset
uint64 new_offset = static_cast<uint64>(data->start_pos) + off;
// Verify that value does not overflow
ios::off_type offset = static_cast<ios::off_type>(new_offset);
if (static_cast<uint64>(offset) != new_offset)
return static_cast<uint64>(-1);
data->stream->seekg(offset, ios::beg);
break;
}
case SEEK_CUR:
{
// Verify that value does not overflow
ios::off_type offset = static_cast<ios::off_type>(off);
if (static_cast<uint64>(offset) != off)
return static_cast<uint64>(-1);
data->stream->seekg(offset, ios::cur);
break;
}
case SEEK_END:
{
// Verify that value does not overflow
ios::off_type offset = static_cast<ios::off_type>(off);
if (static_cast<uint64>(offset) != off)
return static_cast<uint64>(-1);
data->stream->seekg(offset, ios::end);
break;
}
}
return (uint64) (data->stream->tellg() - data->start_pos);
}
static uint64
_tiffosSizeProc(thandle_t fd)
{
tiffos_data *data = reinterpret_cast<tiffos_data *>(fd);
ostream *os = data->stream;
ios::pos_type pos = os->tellp();
ios::pos_type len;
os->seekp(0, ios::end);
len = os->tellp();
os->seekp(pos);
return (uint64) len;
}
static uint64
_tiffisSizeProc(thandle_t fd)
{
tiffis_data *data = reinterpret_cast<tiffis_data *>(fd);
ios::pos_type pos = data->stream->tellg();
ios::pos_type len;
data->stream->seekg(0, ios::end);
len = data->stream->tellg();
data->stream->seekg(pos);
return (uint64) len;
}
static int
_tiffosCloseProc(thandle_t fd)
{
// Our stream was not allocated by us, so it shouldn't be closed by us.
delete reinterpret_cast<tiffos_data *>(fd);
return 0;
}
static int
_tiffisCloseProc(thandle_t fd)
{
// Our stream was not allocated by us, so it shouldn't be closed by us.
delete reinterpret_cast<tiffis_data *>(fd);
return 0;
}
static int
_tiffDummyMapProc(thandle_t , void** base, toff_t* size )
{
return (0);
}
static void
_tiffDummyUnmapProc(thandle_t , void* base, toff_t size )
{
}
/*
* Open a TIFF file descriptor for read/writing.
*/
static TIFF*
_tiffStreamOpen(const char* name, const char* mode, void *fd)
{
TIFF* tif;
if( strchr(mode, 'w') ) {
tiffos_data *data = new tiffos_data;
data->stream = reinterpret_cast<ostream *>(fd);
data->start_pos = data->stream->tellp();
// Open for writing.
tif = TIFFClientOpen(name, mode,
reinterpret_cast<thandle_t>(data),
_tiffosReadProc,
_tiffosWriteProc,
_tiffosSeekProc,
_tiffosCloseProc,
_tiffosSizeProc,
_tiffDummyMapProc,
_tiffDummyUnmapProc);
} else {
tiffis_data *data = new tiffis_data;
data->stream = reinterpret_cast<istream *>(fd);
data->start_pos = data->stream->tellg();
// Open for reading.
tif = TIFFClientOpen(name, mode,
reinterpret_cast<thandle_t>(data),
_tiffisReadProc,
_tiffisWriteProc,
_tiffisSeekProc,
_tiffisCloseProc,
_tiffisSizeProc,
_tiffDummyMapProc,
_tiffDummyUnmapProc);
}
return (tif);
}
} /* extern "C" */
TIFF*
TIFFStreamOpen(const char* name, ostream *os)
{
// If os is either a ostrstream or ostringstream, and has no data
// written to it yet, then tellp() will return -1 which will break us.
// We workaround this by writing out a dummy character and
// then seek back to the beginning.
if( !os->fail() && static_cast<int>(os->tellp()) < 0 ) {
*os << '\0';
os->seekp(0);
}
// NB: We don't support mapped files with streams so add 'm'
return _tiffStreamOpen(name, "wm", os);
}
TIFF*
TIFFStreamOpen(const char* name, istream *is)
{
// NB: We don't support mapped files with streams so add 'm'
return _tiffStreamOpen(name, "rm", is);
}
/* vim: set ts=8 sts=8 sw=8 noet: */
/*
Local Variables:
mode: c
indent-tabs-mode: true
c-basic-offset: 8
End:
*/