mirror of
https://github.com/pocoproject/poco.git
synced 2024-12-12 18:20:26 +01:00
628a06f718
Signed-off-by: Roger Meier <roger@bufferoverflow.ch>
175 lines
3.3 KiB
C++
Executable File
175 lines
3.3 KiB
C++
Executable File
//
|
|
// UnufferedStreamBuf.h
|
|
//
|
|
// $Id: //poco/1.4/Foundation/include/Poco/UnbufferedStreamBuf.h#1 $
|
|
//
|
|
// Library: Foundation
|
|
// Package: Streams
|
|
// Module: StreamBuf
|
|
//
|
|
// Definition of template BasicUnbufferedStreamBuf and class UnbufferedStreamBuf.
|
|
//
|
|
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
|
|
// and Contributors.
|
|
//
|
|
// SPDX-License-Identifier: BSL-1.0
|
|
//
|
|
|
|
|
|
#ifndef Foundation_UnbufferedStreamBuf_INCLUDED
|
|
#define Foundation_UnbufferedStreamBuf_INCLUDED
|
|
|
|
|
|
#include "Poco/Foundation.h"
|
|
#include "Poco/StreamUtil.h"
|
|
#include <streambuf>
|
|
#include <iosfwd>
|
|
#include <ios>
|
|
|
|
|
|
namespace Poco {
|
|
|
|
|
|
template <typename ch, typename tr>
|
|
class BasicUnbufferedStreamBuf: public std::basic_streambuf<ch, tr>
|
|
/// This is an implementation of an unbuffered streambuf
|
|
/// that greatly simplifies the implementation of
|
|
/// custom streambufs of various kinds.
|
|
/// Derived classes only have to override the methods
|
|
/// readFromDevice() or writeToDevice().
|
|
{
|
|
protected:
|
|
typedef std::basic_streambuf<ch, tr> Base;
|
|
typedef std::basic_ios<ch, tr> IOS;
|
|
typedef ch char_type;
|
|
typedef tr char_traits;
|
|
typedef typename Base::int_type int_type;
|
|
typedef typename Base::pos_type pos_type;
|
|
typedef typename Base::off_type off_type;
|
|
typedef typename IOS::openmode openmode;
|
|
|
|
public:
|
|
BasicUnbufferedStreamBuf():
|
|
_pb(char_traits::eof()),
|
|
_ispb(false)
|
|
{
|
|
this->setg(0, 0, 0);
|
|
this->setp(0, 0);
|
|
}
|
|
|
|
~BasicUnbufferedStreamBuf()
|
|
{
|
|
}
|
|
|
|
virtual int_type overflow(int_type c)
|
|
{
|
|
if (c != char_traits::eof())
|
|
return writeToDevice(char_traits::to_char_type(c));
|
|
else
|
|
return c;
|
|
}
|
|
|
|
virtual int_type underflow()
|
|
{
|
|
if (_ispb)
|
|
{
|
|
return _pb;
|
|
}
|
|
else
|
|
{
|
|
int_type c = readFromDevice();
|
|
if (c != char_traits::eof())
|
|
{
|
|
_ispb = true;
|
|
_pb = c;
|
|
}
|
|
return c;
|
|
}
|
|
}
|
|
|
|
virtual int_type uflow()
|
|
{
|
|
if (_ispb)
|
|
{
|
|
_ispb = false;
|
|
return _pb;
|
|
}
|
|
else
|
|
{
|
|
int_type c = readFromDevice();
|
|
if (c != char_traits::eof())
|
|
{
|
|
_pb = c;
|
|
}
|
|
return c;
|
|
}
|
|
}
|
|
|
|
virtual int_type pbackfail(int_type c)
|
|
{
|
|
if (_ispb)
|
|
{
|
|
return char_traits::eof();
|
|
}
|
|
else
|
|
{
|
|
_ispb = true;
|
|
_pb = c;
|
|
return c;
|
|
}
|
|
}
|
|
|
|
virtual std::streamsize xsgetn(char_type* p, std::streamsize count)
|
|
/// Some platforms (for example, Compaq C++) have buggy implementations of
|
|
/// xsgetn that handle null buffers incorrectly.
|
|
/// Anyway, it does not hurt to provide an optimized implementation
|
|
/// of xsgetn for this streambuf implementation.
|
|
{
|
|
std::streamsize copied = 0;
|
|
while (count > 0)
|
|
{
|
|
int_type c = uflow();
|
|
if (c == char_traits::eof()) break;
|
|
*p++ = char_traits::to_char_type(c);
|
|
++copied;
|
|
--count;
|
|
}
|
|
return copied;
|
|
}
|
|
|
|
protected:
|
|
static int_type charToInt(char_type c)
|
|
{
|
|
return char_traits::to_int_type(c);
|
|
}
|
|
|
|
private:
|
|
virtual int_type readFromDevice()
|
|
{
|
|
return char_traits::eof();
|
|
}
|
|
|
|
virtual int_type writeToDevice(char_type)
|
|
{
|
|
return char_traits::eof();
|
|
}
|
|
|
|
int_type _pb;
|
|
bool _ispb;
|
|
|
|
BasicUnbufferedStreamBuf(const BasicUnbufferedStreamBuf&);
|
|
BasicUnbufferedStreamBuf& operator = (const BasicUnbufferedStreamBuf&);
|
|
};
|
|
|
|
|
|
//
|
|
// We provide an instantiation for char
|
|
//
|
|
typedef BasicUnbufferedStreamBuf<char, std::char_traits<char> > UnbufferedStreamBuf;
|
|
|
|
|
|
} // namespace Poco
|
|
|
|
|
|
#endif // Foundation_UnbufferedStreamBuf_INCLUDED
|