BlockingStream.cc

// Copyright (c) 2013 by István Váradi
 
// This file is part of VSCPL, a simple cross-platform utility library
 
// 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 "Waiter.h"
 
#include <cstring>
#include <cstdio>
 
//------------------------------------------------------------------------------
 
using hu::varadiistvan::scpl::io::BlockingStream;
 
using std::min;
 
//------------------------------------------------------------------------------
 
inline bool BlockingStream::checkInterrupted()
{
    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 copied = readingBuffer.extract(d, length, readingOffset);
        readingOffset += copied;
        length -= copied;
        d += copied;
 
        if (length!=0) {
            if (!fill()) return false;
        }
    }
 
    return true;
}
 
//------------------------------------------------------------------------------
 
bool BlockingStream::skip(size_t length)
{
    ReadingBuffer& readingBuffer = stream.getReadingBuffer();
    while (length>0) {
        size_t toSkip = min(length, readingBuffer.getLength() - readingOffset);
        readingOffset += toSkip;
        length -= toSkip;
 
        if (length!=0) {
            if (!fill()) 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 copied = writingBuffer.append(s, length);
        length -= copied;
        s += copied;
 
        if (length==0) break;
        if (!flush()) return false;
    }
 
    return true;
}
 
//------------------------------------------------------------------------------
 
bool BlockingStream::flush()
{
    WritingBuffer& writingBuffer = stream.getWritingBuffer();
    while (*this) {
        if (checkInterrupted()) return false;
 
        if (writingBuffer.write()) {
            return true;
        } else if (writingBuffer.failed()) {
            setErrorCode(writingBuffer.getErrorCode());
        } else {
            Waiter* waiter = stream.getWaiter();
            waiter->wait();
            if (waiter->failed()) {
                setErrorCode(waiter->getErrorCode());
            }
        }
    }
    return false;
}
 
//------------------------------------------------------------------------------
 
bool BlockingStream::fill()
{
    ReadingBuffer& readingBuffer = stream.getReadingBuffer();
 
    readingBuffer.reset();
    readingOffset = 0;
    while (*this) {
        if (checkInterrupted()) return false;
 
        if (readingBuffer.read()) {
            eof = readingBuffer.isEmpty();
            return !eof;
        } else if (readingBuffer.failed()) {
            setErrorCode(readingBuffer.getErrorCode());
        } else {
            Waiter* waiter = stream.getWaiter();
            waiter->wait();
            if (waiter->failed()) {
                setErrorCode(waiter->getErrorCode());
                return false;
            }
        }
    }
    return false;
}
 
//------------------------------------------------------------------------------
 
// Local Variables:
// mode: C++
// c-basic-offset: 4
// indent-tabs-mode: nil
// End: