binary_o_socket.cpp

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/** @file
 *  @author Bram de Greve (bram@cocamware.com)
 *  @author Tom De Muer (tom@cocamware.com)
 *
 *  *** BEGIN LICENSE INFORMATION ***
 *  
 *  The contents of this file are subject to the Common Public Attribution License 
 *  Version 1.0 (the "License"); you may not use this file except in compliance with 
 *  the License. You may obtain a copy of the License at 
 *  http://lass.sourceforge.net/cpal-license. The License is based on the 
 *  Mozilla Public License Version 1.1 but Sections 14 and 15 have been added to cover 
 *  use of software over a computer network and provide for limited attribution for 
 *  the Original Developer. In addition, Exhibit A has been modified to be consistent 
 *  with Exhibit B.
 *  
 *  Software distributed under the License is distributed on an "AS IS" basis, WITHOUT 
 *  WARRANTY OF ANY KIND, either express or implied. See the License for the specific 
 *  language governing rights and limitations under the License.
 *  
 *  The Original Code is LASS - Library of Assembled Shared Sources.
 *  
 *  The Initial Developer of the Original Code is Bram de Greve and Tom De Muer.
 *  The Original Developer is the Initial Developer.
 *  
 *  All portions of the code written by the Initial Developer are:
 *  Copyright (C) 2004-2011 the Initial Developer.
 *  All Rights Reserved.
 *  
 *  Contributor(s):
 *
 *  Alternatively, the contents of this file may be used under the terms of the 
 *  GNU General Public License Version 2 or later (the GPL), in which case the 
 *  provisions of GPL are applicable instead of those above.  If you wish to allow use
 *  of your version of this file only under the terms of the GPL and not to allow 
 *  others to use your version of this file under the CPAL, indicate your decision by 
 *  deleting the provisions above and replace them with the notice and other 
 *  provisions required by the GPL License. If you do not delete the provisions above,
 *  a recipient may use your version of this file under either the CPAL or the GPL.
 *  
 *  *** END LICENSE INFORMATION ***
 */
 
#include "lass_common.h"
#include "binary_o_socket.h"
#include "socket.h"
#include "../util/callback_0.h"
#include "../util/thread_fun.h"
#include "../num/num_cast.h"
#include <string.h>
 
namespace lass
{
namespace io
{
 
// --- public --------------------------------------------------------------------------------------
 
BinaryOSocket::BinaryOSocket(size_t bufferSize, unsigned long flushPeriod):
    BinaryOStream(),
    socket_(0),
    requestedBufferSize_(bufferSize),
    current_(0),
    flushPeriod_(flushPeriod),
    stopFlushThread_(false),
    skipABeat_(false)
{
    init();
}
 
 
 
/**
 *  @param socket [in] BinaryISocket does _not_ take ownership of socket, and it must be alive as long as BinaryISocket needs it 
 *      (until BinaryISocket goes out of scope, or another socket is installed).
 */
BinaryOSocket::BinaryOSocket(Socket* socket, size_t bufferSize, unsigned long flushPeriod):
    BinaryOStream(),
    socket_(socket),
    requestedBufferSize_(bufferSize),
    current_(0),
    flushPeriod_(flushPeriod),
    stopFlushThread_(false),
    skipABeat_(false)
{
    init();
}
 
 
 
BinaryOSocket::~BinaryOSocket()
{
    stopFlushThread_ = true;
    skipABeat_ = false;
    try
    {
        LASS_LOCK(bufferLock_)
        {
            flushImpl();
        }
        flushCondition_.signal();
        flushThread_->join();
    }
    catch (std::exception& error)
    {
        std::cerr << "[LASS RUN MSG] UNDEFINED BEHAVIOUR WARNING: exception thrown in ~BinaryOSocket(): " << error.what() << std::endl;
    }
    catch (...)
    {
        std::cerr << "[LASS RUN MSG] UNDEFINED BEHAVIOUR WARNING: unknown exception thrown in ~BinaryOSocket()" << std::endl;
    }
}
 
 
 
Socket* BinaryOSocket::socket() const
{
    return socket_;
}
 
 
 
/**
 *  @param socket [in] BinaryISocket does _not_ take ownership of socket, and it must be alive as long as BinaryISocket needs it 
 *      (until BinaryISocket goes out of scope, or another socket is installed).
 */
void BinaryOSocket::setSocket(Socket* socket)
{
    LASS_LOCK(bufferLock_)
    {
        flushImpl();
        socket_ = socket;
        init();
    }
}
 
 
 
// --- private -------------------------------------------------------------------------------------
 
BinaryOSocket::pos_type BinaryOSocket::doTellp() const
{
    LASS_THROW("no position in network streams");
}
 
 
 
void BinaryOSocket::doSeekp(pos_type)
{
    LASS_THROW("no seeking in network streams");
}
 
 
 
void BinaryOSocket::doSeekp(off_type, std::ios_base::seekdir)
{
    LASS_THROW("no seeking in network streams");
}
 
 
 
void BinaryOSocket::doFlush()
{
    LASS_LOCK(bufferLock_)
    {
        flushImpl();
    }
}
 
 
 
/** write a buffer of bytes to the stream
 *  @par begin pointer to buffer.
 *  @par numberOfBytes length of buffer in bytes.
 */
size_t BinaryOSocket::doWrite(const void* begin, size_t numberOfBytes)
{
    LASS_LOCK(bufferLock_)
    {
        if (!socket_)
        {
            setstate(std::ios_base::badbit); // we won't be able to flush this data as there's nothing to flush it to ...
            return 0;
        }
        const char* first = static_cast<const char*>(begin);
        size_t bytesToWrite = numberOfBytes;
        while (bytesToWrite > 0)
        {
            if (current_ == buffer_.size())
            {
                flushImpl();
            }
 
            if (!good())
            {
                return 0;
            }
 
            LASS_ASSERT(current_ < buffer_.size());
            const size_t freeSize = buffer_.size() - current_;
            const size_t writeSize = std::min(bytesToWrite, freeSize);
 
            ::memcpy(&buffer_[current_], first, writeSize);
            current_ += writeSize;
            first += writeSize;
            bytesToWrite -= writeSize;
        }
        skipABeat_ = true;
    }
 
    return numberOfBytes;
}
 
 
 
void BinaryOSocket::init()
{
    size_t size = requestedBufferSize_;
    if (socket_)
    {
        const size_t maxSize = num::numCast<size_t>(socket_->sizeSendBuffer());
        if (size)
        {
            size = std::min(size, maxSize);
        }
        else
        {
            size = maxSize;
        }
    }
    buffer_.resize(size);
    current_ = 0;
 
    if (!flushThread_)
    {
        flushThread_.reset(util::threadMemFun(this, &BinaryOSocket::flusher, util::threadJoinable));
        flushThread_->run();
    }
}
 
 
 
void BinaryOSocket::flusher()
{
    while (!stopFlushThread_)
    {
        LASS_TRY_LOCK( bufferLock_ )
        {
            if (!skipABeat_)
            {
                flushImpl();
            }
            skipABeat_ = false;
        }
        flushCondition_.wait(flushPeriod_);
    }
}
 
 
void BinaryOSocket::flushImpl()
{
    if (!good() || !socket_ || buffer_.empty())
    {
        return;
    }
 
    const char* begin = &buffer_[0];
    const size_t nMax = static_cast<size_t>(num::NumTraits<int>::max);
 
    while (current_ > 0)
    {
        const int n = static_cast<int>(current_ > nMax ? nMax : current_);
        LASS_ASSERT(n > 0 && static_cast<size_t>(n) <= current_);
        try
        {
            const int sent = socket_->send(begin, n);
            LASS_ASSERT(sent >= 0 && sent <= n);
            begin += sent;
            current_ -= static_cast<size_t>(sent);
        }
        catch (const util::Exception&)
        {
            setstate(std::ios_base::badbit);
            return;
        }
    }
}
 
 
}
 
}
 
// EOF