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/* Copyright (C) 2004 The glibmm Development Team
*
* This 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 2.1 of the License, or (at your option) any later version.
*
* This 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 library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
* The fdstream/fdstreambuf example classes provide a streambuffer
* interface for Glib::IOChannel, so that standard iostreams can be
* used with fifos, pipes and sockets, with safe temporary files
* opened with mkstemp() and with files opened with other system
* functions such as Unix open().
*
* It does not make use of the Glib::IOChannel automatic charset code
* conversion facilities (which when enabled will convert from UTF-8
* to the locale codeset when writing out, and vice-versa when reading
* in). Such automatic codeset conversion is usually undesirable as
* it makes the target file unportable - a file written out in the
* locale charset can only be used by those expecting the same locale
* codeset. It is also unnecessary as the <<() and >>() operators for
* Glib::ustring already carry out this codeset conversion (to avoid
* this use Glib::ustring::raw() when writing out to a stream via
* operator <<(), and read in via a std::string object with operator
* >>()).
*
* If an automatic codeset conversion option is thought to be
* valuable, it would be possible to provide this by having a read
* buffer in fdstreambuf large enough to take and putback six bytes
* (the largest space occupied by a UTF-8 character). This would
* require rewriting fdstreambuf::underflow(), but in compensation
* fdstreambuf::xsgetn() could be omitted, as if a read buffer were
* provided then std::streambuf::xsgetn() would be adequate for the
* purpose by itself.
*
* A serious implementation would probably also provide separate
* read-only ifdstream classes and write-only ofdstream classes, as
* fdstream provides both read and write facilities.
*/
#ifndef GLIBMMEXAMPLE_FDSTREAM_H
#define GLIBMMEXAMPLE_FDSTREAM_H
#include <istream>
#include <ostream>
#include <streambuf>
#include <glibmm/iochannel.h>
struct fdstream_error
{
bool error;
Glib::IOChannelError::Code code;
};
class fdstreambuf: public std::streambuf
{
public:
fdstreambuf(int fd, bool manage);
fdstreambuf();
~fdstreambuf();
void create_iochannel(int fd, bool manage);
void detach_fd();
void close_iochannel();
void connect(const sigc::slot<bool, Glib::IOCondition>& callback, Glib::IOCondition condition);
fdstream_error get_error() const;
protected:
int_type underflow() override;
std::streamsize xsgetn(char* dest, std::streamsize num) override;
int sync() override;
int_type overflow(int_type c) override;
std::streamsize xsputn(const char* source, std::streamsize num) override;
private:
Glib::RefPtr<Glib::IOChannel> iochannel_;
fdstream_error error_condition;
// putback_buffer does not do any buffering: it reserves one character
// for putback and one character for a peek() and/or for bumping
// with sbumpc/uflow()
char putback_buffer[2];
void reset();
};
class fdstream :
public std::istream,
public std::ostream
{
public:
explicit fdstream(int fd, bool manage = true);
fdstream();
// If fdstream is managing a file descriptor, attaching a new
// one will close the old one - call detach() to unmanage it
void attach(int fd, bool manage = true);
void detach();
void close();
void connect(const sigc::slot<bool, Glib::IOCondition>& callback,
Glib::IOCondition condition);
fdstream_error get_error() const;
private:
fdstreambuf buf;
};
#endif /*GLIBMMEXAMPLE_FDSTREAM_H*/
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