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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
{
// FILE_Cookie pure virtual destructor
FILE_Cookie::~FILE_Cookie() {
if (m_file) {
// Bug if neither ~iFILE_Cookie nor ~oFILE_Cookie closed the FILE*
dmnsn_error(DMNSN_SEVERITY_HIGH,
"FILE* not closed by FILE_Cookie destructor");
}
}
namespace
{
// Cookie read function
ssize_t
cookie_read(void* cookie, char* buf, size_t size)
{
FILE_Cookie* fcookie = reinterpret_cast<FILE_Cookie*>(cookie);
iFILE_Cookie& ifcookie = dynamic_cast<iFILE_Cookie&>(*fcookie);
// Do the unformatted read
ifcookie.istr().read(buf, size);
if (ifcookie.istr().eof() || ifcookie.istr().good()) {
return ifcookie.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* fcookie = reinterpret_cast<FILE_Cookie*>(cookie);
oFILE_Cookie& ofcookie = dynamic_cast<oFILE_Cookie&>(*fcookie);
// Do the unformatted write
ofcookie.ostr().write(buf, size);
if (ofcookie.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* fcookie = reinterpret_cast<FILE_Cookie*>(cookie);
iFILE_Cookie* ifcookie = dynamic_cast<iFILE_Cookie*>(fcookie);
oFILE_Cookie* ofcookie = dynamic_cast<oFILE_Cookie*>(fcookie);
if (ifcookie) {
// If we have an input stream, seek it
switch (whence) {
case SEEK_SET:
ifcookie->istr().seekg(*offset, std::ios::beg);
break;
case SEEK_CUR:
ifcookie->istr().seekg(*offset, std::ios::cur);
break;
case SEEK_END:
ifcookie->istr().seekg(*offset, std::ios::end);
break;
}
if (!ifcookie->istr().good()) {
// Seek failed
return 1;
}
}
if (ofcookie) {
// If we have an output stream, seek it
switch (whence) {
case SEEK_SET:
ofcookie->ostr().seekp(*offset, std::ios::beg);
break;
case SEEK_CUR:
ofcookie->ostr().seekp(*offset, std::ios::cur);
break;
case SEEK_END:
ofcookie->ostr().seekp(*offset, std::ios::end);
}
if (!ofcookie->ostr().good()) {
// Seek failed
return 1;
}
}
// Seek succeeded
return 0;
}
}
// Make an input FILE_Cookie
iFILE_Cookie::iFILE_Cookie(std::istream& istr)
: m_istr(&istr)
{
cookie_io_functions_t io_funcs;
io_funcs.read = &cookie_read;
io_funcs.write = 0;
io_funcs.seek = &cookie_seek;
io_funcs.close = 0;
// Set the FILE*
file(fopencookie(reinterpret_cast<void*>(static_cast<FILE_Cookie*>(this)),
"r", io_funcs));
}
// iFILE_Cookie destructor
iFILE_Cookie::~iFILE_Cookie()
{
if (file()) {
// If the FILE* is open, close it and set it to NULL
fclose(file());
file(0);
}
}
// Make an output FILE_Cookie
oFILE_Cookie::oFILE_Cookie(std::ostream& ostr)
: 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;
// Set the FILE*
file(fopencookie(reinterpret_cast<void*>(static_cast<FILE_Cookie*>(this)),
"w", io_funcs));
}
// oFILE_Cookie destructor
oFILE_Cookie::~oFILE_Cookie()
{
if (file()) {
// If the FILE* is open, close it and set it to NULL
fclose(file());
file(0);
}
}
// Make an I/O FILE_Cookie
ioFILE_Cookie::ioFILE_Cookie(std::iostream& iostr)
: iFILE_Cookie(iostr, 0), oFILE_Cookie(iostr, 0)
{
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;
file(fopencookie(reinterpret_cast<void*>(static_cast<FILE_Cookie*>(this)),
"r+", io_funcs));
}
// No-op ioFILE_Cookie destructor
ioFILE_Cookie::~ioFILE_Cookie() { }
}
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