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+ fix writing to std::stringstream

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* if seeking pass the end  - grow buffer (stringstream!)
* seekp beyond current buffer size doesn't set failbit (clang/libcxx)
This commit is contained in:
artemp 2013-05-10 16:50:28 +01:00
parent 3223836874
commit e9733d8a9b
1 changed files with 75 additions and 20 deletions
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95
include/mapnik/tiff_io.hpp
View file

@ -24,8 +24,7 @@
#define MAPNIK_TIFF_IO_HPP
#include <mapnik/global.hpp>
#include <iostream>
#include <mapnik/image_util.hpp>
extern "C"
{
@ -45,37 +44,89 @@ namespace mapnik {
static tsize_t tiff_write_proc(thandle_t fd, tdata_t buf, tsize_t size)
{
std::ostream* out = (std::ostream*)fd;
std::ostream* out = reinterpret_cast<std::ostream*>(fd);
std::ios::pos_type pos = out->tellp();
std::streamsize request_size = size;
if (static_cast<tsize_t>(request_size) != size)
return static_cast<tsize_t>(-1);
out->write(reinterpret_cast<const char*>(buf), size);
out->write((const char*)buf, size);
return size;
if( static_cast<std::streamsize>(pos) == -1 )
{
return size;
}
else
{
return static_cast<tsize_t>(out->tellp()-pos);
}
}
static toff_t tiff_seek_proc(thandle_t fd, toff_t off, int whence)
{
if (off == 0xFFFFFFFF)
{
return 0xFFFFFFFF;
}
std::ostream* out = reinterpret_cast<std::ostream*>(fd);
std::ostream* out = (std::ostream*)fd;
if( out->fail() )
return static_cast<toff_t>(-1);
if( static_cast<std::streamsize>(out->tellp()) == -1)
return static_cast< toff_t >( 0 );
switch(whence)
{
case SEEK_SET:
out->seekp(off, std::ios_base::beg);
break;
case SEEK_CUR:
out->seekp(off, std::ios_base::cur);
break;
case SEEK_END:
out->seekp(off, std::ios_base::end);
break;
case SEEK_SET:
default:
out->seekp(off, std::ios_base::beg);
break;
}
// grow std::stringstream buffer (re: libtiff/tif_stream.cxx)
std::ios::pos_type pos = out->tellp();
// second check needed for clang (libcxx doesn't set failbit when seeking beyond the current buffer size
if( out->fail() || off != pos)
{
std::ios::iostate old_state;
std::ios::pos_type origin;
old_state = out->rdstate();
// reset the fail bit or else tellp() won't work below
out->clear(out->rdstate() & ~std::ios::failbit);
switch( whence )
{
case SEEK_SET:
default:
origin = 0L;
break;
case SEEK_CUR:
origin = out->tellp();
break;
case SEEK_END:
out->seekp(0, std::ios::end);
origin = out->tellp();
break;
}
// restore original stream state
out->clear(old_state);
return (toff_t)out->tellp();
// only do something if desired seek position is valid
if( (static_cast<uint64_t>(origin) + off) > 0L)
{
uint64_t num_fill;
// clear the fail bit
out->clear(out->rdstate() & ~std::ios::failbit);
// extend the stream to the expected size
out->seekp(0, std::ios::end);
num_fill = (static_cast<uint64_t>(origin)) + off - out->tellp();
for( uint64_t i = 0; i < num_fill; ++i)
out->put('\0');
// retry the seek
out->seekp(static_cast<std::ios::off_type>(static_cast<uint64_t>(origin) + off), std::ios::beg);
}
}
return static_cast<toff_t>(out->tellp());
}
static int tiff_close_proc(thandle_t fd)
@ -87,8 +138,12 @@ static int tiff_close_proc(thandle_t fd)
static toff_t tiff_size_proc(thandle_t fd)
{
std::ostream* out = (std::ostream*)fd;
return (toff_t)out->tellp();
std::ostream* out = reinterpret_cast<std::ostream*>(fd);
std::ios::pos_type pos = out->tellp();
out->seekp(0, std::ios::end);
std::ios::pos_type len = out->tellp();
out->seekp(pos);
return (toff_t)len;
}
static tsize_t tiff_dummy_read_proc(thandle_t fd, tdata_t buf, tsize_t size)
@ -113,7 +168,7 @@ void save_as_tiff(T1 & file, T2 const& image)
const int scanline_size = sizeof(unsigned char) * width * 3;
TIFF* output = RealTIFFOpen("mapnik_tiff_stream",
"w",
"wm",
(thandle_t)&file,
tiff_dummy_read_proc,
tiff_write_proc,
@ -124,7 +179,7 @@ void save_as_tiff(T1 & file, T2 const& image)
tiff_dummy_unmap_proc);
if (! output)
{
// throw ?
throw ImageWriterException("Could not write TIFF");
}
TIFFSetField(output, TIFFTAG_IMAGEWIDTH, width);