iostream.h

/*
 *  Copyright (C) 2006  Helmut Grohne
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef LIBMUTH_IOSTREAM_H
#define LIBMUTH_IOSTREAM_H

#include <assert.h>
#include "iostream_decls.h"

template<class C, class T>
                BasicScheduledStreambuf<C, T>::BasicScheduledStreambuf(int f,
                BaseScheduler &s, std::ios_base::openmode m,
                std::streamsize insize, std::streamsize outsize) : fd(f),
                sched(s), mode(m) {
        // Do not allow opening a stream neither for reading nor for writing.
        assert(this->mode & (std::ios_base::in|std::ios_base::out));
        this->ibufsize = insize;
        if(this->mode & std::ios_base::in)
                this->ibuf = new char_type[insize];
        else
                this->ibuf = NULL;
        this->setg(this->ibuf, this->ibuf, this->ibuf);
        if(this->mode & std::ios_base::out) {
                this->obuf = new char_type[outsize];
                this->setp(this->obuf, this->obuf + outsize);
        } else {
                this->obuf = NULL;
                this->setp(NULL, NULL);
        }
}

template<class C, class T>
                BasicScheduledStreambuf<C, T>::~BasicScheduledStreambuf() {
        if(this->mode & std::ios_base::in)
                delete[] this->ibuf;
        if(this->mode & std::ios_base::out) {
                this->sync();
                delete[] this->obuf;
        }
}

template<class C, class T> typename BasicScheduledStreambuf<C, T>::int_type
                BasicScheduledStreambuf<C, T>::underflow() {
        assert(this->mode & std::ios_base::in);
        if(this->gptr() < this->egptr())
                return traits_type::to_int_type(*this->gptr());
        assert(this->ibufsize > 0);
        const int r(this->sched.read(this->fd, this->ibuf,
                        this->ibufsize * sizeof(char_type)));
        if(r <= 0)
                return traits_type::eof();
        /* FIXME: this will result in problems showed by assertions: */
        assert(r % sizeof(char_type) == 0);
        this->setg(this->ibuf, this->ibuf, static_cast<char_type*>(
                        static_cast<char*>(this->ibuf) + r));
        return traits_type::to_int_type(*this->gptr());
}

template<class C, class T> typename BasicScheduledStreambuf<C, T>::int_type
                BasicScheduledStreambuf<C, T>::pbackfail(int_type ch) {
        assert(this->mode & std::ios_base::in);
        if(this->gptr() != this->eback()) {
                this->gbump(-1);
                if(!traits_type::eq_int_type(ch, traits_type::eof()))
                        *this->gptr() = traits_type::not_eof(ch);
                return traits_type::not_eof(ch);
        }
        return traits_type::eof();
}

template<class C, class T> int BasicScheduledStreambuf<C, T>::sync() {
        assert(this->mode & std::ios_base::out);
        const int bump(static_cast<int>(this->pptr() - this->pbase()));
        char *data(static_cast<char*>(this->pbase()));
        size_t n(static_cast<size_t>(static_cast<char*>(this->pptr()) - data));
        if(n == 0)
                return 0;
        int r(this->sched.write(this->fd, data, n));
        if(r <= 0)
                return -1;
        assert(n >= (size_t)r);
        while((size_t)r != n) {
                r = this->sched.write(this->fd, data, n);
                if(r <= 0)
                        return -1;
                assert(n < (size_t)r);
                data += r;
                n -= r;
        }
        this->pbump(-bump);
        return 0;
}

template<class C, class T> typename BasicScheduledStreambuf<C, T>::int_type
                BasicScheduledStreambuf<C, T>::overflow(int_type ch) {
        assert(this->mode & std::ios_base::out);
        /* FIXME: maybe not really sync but write parts of the buffer. */
        if(this->sync() < 0)
                return traits_type::eof();
        if(traits_type::eq_int_type(ch, traits_type::eof()))
                /* FIXME: find out why we return not_eof(eof()). */
                return traits_type::not_eof(ch);
        return this->sputc(traits_type::to_char_type(ch));
}

#if 0
template<class C, class T> std::streamsize
                BasicScheduledStreambuf<C, T>::xsputn(const char_type *str,
                std::streamsize n) {
        assert(this->mode & std::ios_base::out);
        if(this->sync() < 0)
                return 0;
        const int r(this->sched.write(this->fd, str, n * sizeof(char_type)));
        if(r < 0)
                return 0;
        return r / sizeof(char_type);
}
#endif

template<class C, class T> inline BasicScheduledStreambuf<C, T>::operator int()
                const {
        return this->fd;
}

template<class C, class T> BasicScheduledIStream<C, T>::BasicScheduledIStream(
                int f, BaseScheduler &s, std::streamsize size)
                : std::basic_istream<C, T>(NULL),
                streambuf(f, s, std::ios_base::in, size) {
        this->init(&this->streambuf);
}

template<class C, class T> inline BasicScheduledIStream<C, T>::operator int()
                const {
        return (int)this->streambuf;
}

template<class C, class T> BasicScheduledOStream<C, T>::BasicScheduledOStream(
                int f, BaseScheduler &s, std::streamsize size)
                : std::basic_ostream<C, T>(NULL),
                streambuf(f, s, std::ios_base::out, 0, size) {
        this->init(&this->streambuf);
}

template<class C, class T> inline BasicScheduledOStream<C, T>::operator int()
                const {
        return (int)this->streambuf;
}

template<class C, class T> BasicScheduledIOStream<C, T>::BasicScheduledIOStream(
                int f, BaseScheduler &s, std::streamsize insize,
                std::streamsize outsize) : std::basic_iostream<C, T>(NULL),
                streambuf(f, s, std::ios_base::in | std::ios_base::out, insize,
                outsize) {
        this->init(&this->streambuf);
}

template<class C, class T> inline BasicScheduledIOStream<C, T>::operator int()
                const {
        return (int)this->streambuf;
}

#endif

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