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/*************************************************************************
* Copyright (C) 2009 Tavian Barnes <tavianator@gmail.com> *
* *
* This file is part of The Dimension Library. *
* *
* The Dimension Library is free software; you can redistribute it and/ *
* or modify it under the terms of the GNU Lesser General Public License *
* as published by the Free Software Foundation; either version 3 of the *
* License, or (at your option) any later version. *
* *
* The Dimension Library is distributed in the hope that it will be *
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty *
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
* Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU Lesser General Public *
* License along with this program. If not, see *
* <http://www.gnu.org/licenses/>. *
*************************************************************************/
#include "dimensionxx.hpp"
#ifndef _GNU_SOURCE
// For fopencookie()
#define _GNU_SOURCE
#endif
#include <stdio.h>
// The conundrum: libdimension uses C I/O, with FILE*'s. We want to use C++ I/O
// with std::i/ostreams. If present, we use the nonportable GNU stdio extension
// fopencookie(), which creates a FILE* with custom read/write/seek functions.
// BSD also has a similar function, funopen() which we should use too. Failing
// in all that, fall back on a tmpfile() buffer (see cookie-tmpfile.cpp).
namespace Dimension
{
namespace
{
// Cookie read function
ssize_t
cookie_read(void* cookie, char* buf, size_t size)
{
FILE_Cookie* streams = reinterpret_cast<FILE_Cookie*>(cookie);
// Do the unformatted read
streams->istr().read(buf, size);
if (streams->istr().eof() || streams->istr().good()) {
return streams->istr().gcount(); // This returns 0 on an immediate EOF
// for us.
} else {
// Some non-EOF error
return -1;
}
}
// Cookie write function
ssize_t
cookie_write(void* cookie, const char* buf, size_t size)
{
FILE_Cookie* streams = reinterpret_cast<FILE_Cookie*>(cookie);
// Do the unformatted write
streams->ostr().write(buf, size);
if (streams->ostr().good()) {
// Write operation succeeded, so we must've written size bytes
return size;
} else {
// Write operation failed
return -1;
}
}
// Cookie seek function
int
cookie_seek(void* cookie, off64_t* offset, int whence)
{
FILE_Cookie* streams = reinterpret_cast<FILE_Cookie*>(cookie);
if (streams->is_input()) {
// If we have an input stream, seek it
switch (whence) {
case SEEK_SET:
streams->istr().seekg(*offset, std::ios::beg);
break;
case SEEK_CUR:
streams->istr().seekg(*offset, std::ios::cur);
break;
case SEEK_END:
streams->istr().seekg(*offset, std::ios::end);
break;
}
if (!streams->istr().good()) {
// Seek failed
return 1;
}
}
if (streams->is_output()) {
// If we have an output stream, seek it
switch (whence) {
case SEEK_SET:
streams->ostr().seekp(*offset, std::ios::beg);
break;
case SEEK_CUR:
streams->ostr().seekp(*offset, std::ios::cur);
break;
case SEEK_END:
streams->ostr().seekp(*offset, std::ios::end);
}
if (!streams->ostr().good()) {
// Seek failed
return 1;
}
}
// Seek succeeded
return 0;
}
}
// Make an input FILE_Cookie
FILE_Cookie::FILE_Cookie(std::istream& istr)
: m_istr(&istr), m_ostr(0)
{
cookie_io_functions_t io_funcs;
io_funcs.read = &cookie_read;
io_funcs.write = 0;
io_funcs.seek = &cookie_seek;
io_funcs.close = 0;
m_file = fopencookie(reinterpret_cast<void*>(this), "r", io_funcs);
}
// Make an output FILE_Cookie
FILE_Cookie::FILE_Cookie(std::ostream& ostr)
: m_istr(0), m_ostr(&ostr)
{
cookie_io_functions_t io_funcs;
io_funcs.read = 0;
io_funcs.write = &cookie_write;
io_funcs.seek = &cookie_seek;
io_funcs.close = 0;
m_file = fopencookie(reinterpret_cast<void*>(this), "w", io_funcs);
}
// Make an I/O FILE_Cookie
FILE_Cookie::FILE_Cookie(std::iostream& iostr)
: m_istr(&iostr), m_ostr(&iostr)
{
cookie_io_functions_t io_funcs;
io_funcs.read = &cookie_read;
io_funcs.write = &cookie_write;
io_funcs.seek = &cookie_seek;
io_funcs.close = 0;
m_file = fopencookie(reinterpret_cast<void*>(this), "r+", io_funcs);
}
// Close the file
FILE_Cookie::~FILE_Cookie() { std::fclose(m_file); }
// Get the FILE*
FILE* FILE_Cookie::file() { return m_file; }
const FILE* FILE_Cookie::file() const { return m_file; }
bool FILE_Cookie::is_input() const { return m_istr; }
bool FILE_Cookie::is_output() const { return m_ostr; }
// Get the C++ streams
std::istream&
FILE_Cookie::istr()
{
if (is_input()) {
return *m_istr;
} else {
throw Dimension_Error("Attempted to get input stream from non-input"
" FILE_Cookie.");
}
}
const std::istream&
FILE_Cookie::istr() const
{
if (is_input()) {
return *m_istr;
} else {
throw Dimension_Error("Attempted to get input stream from non-input"
" FILE_Cookie.");
}
}
std::ostream&
FILE_Cookie::ostr()
{
if (is_output()) {
return *m_ostr;
} else {
throw Dimension_Error("Attempted to get output stream from non-input"
" FILE_Cookie.");
}
}
const std::ostream& FILE_Cookie::ostr() const
{
if (is_output()) {
return *m_ostr;
} else {
throw Dimension_Error("Attempted to get output stream from non-input"
" FILE_Cookie.");
}
}
}
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