source: xplcommon/src/xplcommon/BlockingStream.cc@ 29:54c2d451f8a0

// Copyright (c) 2013 by István Váradi

// This file is part of libxplcommon, a common utility library for
// development related to X-Plane

// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:

// 1. Redistributions of source code must retain the above copyright notice, this
//    list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
//    and/or other materials provided with the distribution.

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// The views and conclusions contained in the software and documentation are those
// of the authors and should not be interpreted as representing official policies,
// either expressed or implied, of the FreeBSD Project.

//------------------------------------------------------------------------------

#include "BlockingStream.h"

#include "ReadingBuffer.h"
#include "WritingBuffer.h"

#include <cstring>
#include <cstdio>

//------------------------------------------------------------------------------

using xplcommon::BlockingStream;

using std::min;

//------------------------------------------------------------------------------

bool BlockingStream::isInterrupted()
{
    if (failed()) return false;

    if (!interrupted) {
        interrupted = event.check();
        if (!interrupted && event.failed()) {
            setErrorCode(event.getErrorCode());
        }
    }

    return interrupted;
}

//------------------------------------------------------------------------------

bool BlockingStream::read(void* dest, size_t length)
{
    unsigned char* d = reinterpret_cast<unsigned char*>(dest);

    ReadingBuffer& readingBuffer = stream.getReadingBuffer();
    while (length>0) {
        size_t toCopy = min(readingBuffer.getLength() - readingOffset, length);
        if (toCopy>0) {
            memcpy(d, readingBuffer.getData() + readingOffset, toCopy);
            readingOffset += toCopy;
            length -= toCopy;
            d += toCopy;
        }

        if (length==0) break;

        readingBuffer.reset();
        readingOffset = 0;
        while (!failed()) {
            if (isInterrupted()) return false;

            if (readingBuffer.read()) {
                if (readingBuffer.isEmpty()) return false;
                break;
            } else if (readingBuffer.failed()) {
                setErrorCode(readingBuffer.getErrorCode());
            } else {
                Waiter* waiter = stream.getWaiter();
                waiter->wait();
                if (waiter->failed()) {
                    setErrorCode(waiter->getErrorCode());
                }
            }
        }
        if (failed()) return false;
    }

    return true;
}

//------------------------------------------------------------------------------

bool BlockingStream::write(const void* src, size_t length)
{
    const unsigned char* s = reinterpret_cast<const unsigned char*>(src);

    WritingBuffer& writingBuffer = stream.getWritingBuffer();
    while(length>0) {
        size_t toCopy = min(length, writingBuffer.getAvailable());
        if (toCopy>0) {
            memcpy(writingBuffer.getData() + writingBuffer.getLength(),
                   s, toCopy);
            writingBuffer.addLength(toCopy);
            length -= toCopy;
            s += toCopy;
        }

        if (length==0) break;
        if (!flush()) return false;
    }

    return true;
}

//------------------------------------------------------------------------------

bool BlockingStream::flush()
{
    WritingBuffer& writingBuffer = stream.getWritingBuffer();
    while (!failed()) {
        if (isInterrupted()) return false;

        if (writingBuffer.write()) {
            return true;
        } else if (writingBuffer.failed()) {
            setErrorCode(writingBuffer.getErrorCode());
            return false;
        } else {
            Waiter* waiter = stream.getWaiter();
            waiter->wait();
            if (waiter->failed()) {
                setErrorCode(waiter->getErrorCode());
            }
        }
    }
    return false;
}

//------------------------------------------------------------------------------

// Local Variables:
// mode: C++
// c-basic-offset: 4
// indent-tabs-mode: nil
// End: