source: psi/trunk/cutestuff/util/bconsole.cpp

/*
 * bconsole.cpp - ByteStream wrapper for stdin/stdout
 * Copyright (C) 2003  Justin Karneges
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include"bconsole.h"

#include<qsocketnotifier.h>
#include<unistd.h>
#include<fcntl.h>

//----------------------------------------------------------------------------
// BConsole
//----------------------------------------------------------------------------
class BConsole::Private
{
public:
        Private() {}

        QSocketNotifier *r, *w;
        bool closing;
        bool closed;
};

BConsole::BConsole(QObject *parent)
:ByteStream(parent)
{
        d = new Private;
        d->closing = false;
        d->closed = false;

        // set stdin/stdout to non-block
        fcntl(0, F_SETFL, O_NONBLOCK);
        fcntl(1, F_SETFL, O_NONBLOCK);

        d->r = new QSocketNotifier(0, QSocketNotifier::Read);
        connect(d->r, SIGNAL(activated(int)), SLOT(sn_read()));
        d->w = 0;
}

BConsole::~BConsole()
{
        delete d->w;
        delete d->r;
        delete d;
}

bool BConsole::isOpen() const
{
        return (!d->closing && !d->closed);
}

void BConsole::close()
{
        if(d->closing || d->closed)
                return;

        if(bytesToWrite() > 0)
                d->closing = true;
        else {
                ::fclose(stdout);
                d->closed = true;
        }
}

void BConsole::sn_read()
{
        QByteArray a(1024);
        int r = ::read(0, a.data(), a.size());
        if(r < 0) {
                error(ErrRead);
        }
        else if(r == 0) {
                connectionClosed();
        }
        else {
                a.resize(r);
                appendRead(a);
                readyRead();
        }
}

void BConsole::sn_write()
{
        d->w->deleteLater();
        d->w = 0;

        if(bytesToWrite() > 0)
                tryWrite();
        if(bytesToWrite() == 0 && d->closing) {
                d->closing = false;
                d->closed = true;
                delayedCloseFinished();
        }
}

int BConsole::tryWrite()
{
        // try a section of the write buffer
        QByteArray a = takeWrite(1024, false);

        // write it
        int r = ::write(1, a.data(), a.size());
        if(r < 0) {
                error(ErrWrite);
                return -1;
        }

        d->w = new QSocketNotifier(1, QSocketNotifier::Write);
        connect(d->w, SIGNAL(activated(int)), SLOT(sn_write()));

        takeWrite(r);
        bytesWritten(r);
        return r;
}