tools/src/dtnstream.cpp

Go to the documentation of this file.

/*
 * dtnstream.cpp
 *
 * The application dtnstream can transfer a data stream to another instance of dtnstream.
 * It uses an extension block to mark the sequence of the stream.
 *
 *  Created on: 23.03.2011
 *      Author: morgenro
 */

#include "config.h"
#include "BundleStream.h"
#include <ibrdtn/api/Client.h>
#include <ibrdtn/data/EID.h>
#include <ibrdtn/data/PayloadBlock.h>
#include <ibrcommon/net/tcpclient.h>
#include <ibrcommon/data/File.h>
#include <ibrcommon/TimeMeasurement.h>
#include <iostream>

unsigned int __timeout_receive__ = 0;

dtn::data::Block* StreamBlock::Factory::create()
{
        return new StreamBlock();
}

StreamBlock::StreamBlock()
: dtn::data::Block(StreamBlock::BLOCK_TYPE), _seq(0)
{
}

StreamBlock::~StreamBlock()
{

}

size_t StreamBlock::getLength() const
{
        return _seq.getLength();
}

std::ostream& StreamBlock::serialize(std::ostream &stream, size_t &length) const
{
        stream << _seq;
        return stream;
}

std::istream& StreamBlock::deserialize(std::istream &stream, const size_t length)
{
        stream >> _seq;
        return stream;
}

void StreamBlock::setSequenceNumber(size_t seq)
{
        _seq = seq;
}

size_t StreamBlock::getSequenceNumber() const
{
        return _seq.getValue();
}

StreamBundle::StreamBundle()
 : _ref(ibrcommon::StringBLOB::create())
{
        StreamBlock &block = _b.push_front<StreamBlock>();
        block.setSequenceNumber(0);

        _b.push_back(_ref);
}

StreamBundle::StreamBundle(const dtn::api::Bundle &b)
 : dtn::api::Bundle(b), _ref(getData())
{
}

StreamBundle::~StreamBundle()
{
}

void StreamBundle::append(const char* data, size_t length)
{
        ibrcommon::BLOB::iostream stream = _ref.iostream();
        (*stream).seekp(0, ios::end);
        (*stream).write(data, length);
}

void StreamBundle::clear()
{
        ibrcommon::BLOB::iostream stream = _ref.iostream();
        stream.clear();

        // increment the sequence number
        try {
                StreamBlock &block = _b.getBlock<StreamBlock>();
                block.setSequenceNumber(block.getSequenceNumber() + 1);
        } catch (const dtn::data::Bundle::NoSuchBlockFoundException&) { };
}

size_t StreamBundle::size()
{
        ibrcommon::BLOB::iostream stream = _ref.iostream();
        return stream.size();
}

size_t StreamBundle::getSequenceNumber(const StreamBundle &b)
{
        try {
                const StreamBlock &block = b._b.getBlock<StreamBlock>();
                return block.getSequenceNumber();
        } catch (const dtn::data::Bundle::NoSuchBlockFoundException&) {
                return 0;
        }
}

BundleStreamBuf::BundleStreamBuf(dtn::api::Client &client, StreamBundle &chunk, size_t buffer)
 : _in_buf(new char[BUFF_SIZE]), _out_buf(new char[BUFF_SIZE]), _client(client), _chunk(chunk),
   _buffer(buffer), _chunk_offset(0), _in_seq(0)
{
        // Initialize get pointer.  This should be zero so that underflow is called upon first read.
        setg(0, 0, 0);
        setp(_in_buf, _in_buf + BUFF_SIZE - 1);
};

BundleStreamBuf::~BundleStreamBuf()
{
        delete[] _in_buf;
        delete[] _out_buf;
};

int BundleStreamBuf::sync()
{
        int ret = std::char_traits<char>::eq_int_type(this->overflow(
                        std::char_traits<char>::eof()), std::char_traits<char>::eof()) ? -1
                        : 0;

        // send the current chunk and clear it
        _client << _chunk; _client.flush();
        _chunk.clear();

        return ret;
}

int BundleStreamBuf::overflow(int c)
{
        char *ibegin = _in_buf;
        char *iend = pptr();

        // mark the buffer as free
        setp(_in_buf, _in_buf + BUFF_SIZE - 1);

        if (!std::char_traits<char>::eq_int_type(c, std::char_traits<char>::eof()))
        {
                *iend++ = std::char_traits<char>::to_char_type(c);
        }

        // if there is nothing to send, just return
        if ((iend - ibegin) == 0)
        {
                return std::char_traits<char>::not_eof(c);
        }

        // copy data into the bundles payload
        _chunk.append(_in_buf, iend - ibegin);

        // if size exceeds chunk limit, send it
        if (_chunk.size() > _buffer)
        {
                _client << _chunk; _client.flush();
                _chunk.clear();
        }

        return std::char_traits<char>::not_eof(c);
}

void BundleStreamBuf::received(const dtn::api::Bundle &b)
{
        ibrcommon::MutexLock l(_chunks_cond);

        if (StreamBundle::getSequenceNumber(b) < _in_seq) return;

        _chunks.insert(Chunk(b));
        _chunks_cond.signal(true);

        // bundle received
//      std::cerr << ". " << StreamBundle::getSequenceNumber(b) << std::flush;
}

int BundleStreamBuf::underflow()
{
        ibrcommon::MutexLock l(_chunks_cond);

        return __underflow();
}

int BundleStreamBuf::__underflow()
{
        // receive chunks until the next sequence number is received
        while (_chunks.empty())
        {
                // wait for the next bundle
                _chunks_cond.wait();
        }

        ibrcommon::TimeMeasurement tm;
        tm.start();

        // while not the right sequence number received -> wait
        while (_in_seq != (*_chunks.begin())._seq)
        {
                try {
                        // wait for the next bundle
                        _chunks_cond.wait(1000);
                } catch (const ibrcommon::Conditional::ConditionalAbortException&) { };

                tm.stop();
                if ((__timeout_receive__ > 0) && (tm.getSeconds() > __timeout_receive__))
                {
                        // skip the missing bundles and proceed with the last received one
                        _in_seq = (*_chunks.begin())._seq;
                }
        }

        // get the first chunk in the buffer
        const Chunk &c = (*_chunks.begin());

        dtn::api::Bundle b = c._bundle;
        ibrcommon::BLOB::Reference r = b.getData();

        // get stream lock
        ibrcommon::BLOB::iostream stream = r.iostream();

        // jump to the offset position
        (*stream).seekg(_chunk_offset, ios::beg);

        // copy the data of the last received bundle into the buffer
        (*stream).read(_out_buf, BUFF_SIZE);

        // get the read bytes
        size_t bytes = (*stream).gcount();

        if ((*stream).eof())
        {
                // bundle consumed
//              std::cerr << std::endl << "# " << c._seq << std::endl << std::flush;

                // delete the last chunk
                _chunks.erase(c);

                // reset the chunk offset
                _chunk_offset = 0;

                // increment sequence number
                _in_seq++;

                // if no more bytes are read, get the next bundle -> call underflow() recursive
                if (bytes == 0)
                {
                        return __underflow();
                }
        }
        else
        {
                // increment the chunk offset
                _chunk_offset += bytes;
        }
        
        // Since the input buffer content is now valid (or is new)
        // the get pointer should be initialized (or reset).
        setg(_out_buf, _out_buf, _out_buf + bytes);

        return std::char_traits<char>::not_eof(_out_buf[0]);
}

BundleStreamBuf::Chunk::Chunk(const dtn::api::Bundle &b)
 : _bundle(b), _seq(StreamBundle::getSequenceNumber(b))
{
}

BundleStreamBuf::Chunk::~Chunk()
{
}

bool BundleStreamBuf::Chunk::operator==(const Chunk& other) const
{
        return (_seq == other._seq);
}

bool BundleStreamBuf::Chunk::operator<(const Chunk& other) const
{
        return (_seq < other._seq);
}

BundleStream::BundleStream(ibrcommon::tcpstream &stream, size_t chunk_size, const std::string &app)
 : dtn::api::Client(app, stream), _stream(stream), _buf(*this, _chunk, chunk_size)
{};

BundleStream::~BundleStream() {};

BundleStreamBuf& BundleStream::rdbuf()
{
        return _buf;
}

dtn::api::Bundle& BundleStream::base()
{
        return _chunk;
}

void BundleStream::received(const dtn::api::Bundle &b)
{
        _buf.received(b);
}

void print_help()
{
        std::cout << "-- dtnstream (IBR-DTN) --" << std::endl;
        std::cout << "Syntax: dtnstream [options]"  << std::endl;
        std::cout << "* optional parameters *" << std::endl;
        std::cout << " -h               display this text" << std::endl;
        std::cout << " -d <destination> set the destination eid (e.g. dtn://node/stream)" << std::endl;
        std::cout << " -s <identifier>  set the source identifier (e.g. stream)" << std::endl;
        std::cout << " -c <bytes>       set the chunk size (max. size of each bundle)" << std::endl;
        std::cout << " -t <seconds>     set the timeout of the buffer" << std::endl;
        std::cout << " -l <seconds>     set the lifetime of stream chunks default: 30" << std::endl;
        std::cout << " -E               request encryption on the bundle layer" << std::endl;
        std::cout << " -S               request signature on the bundle layer" << std::endl;
        std::cout << " -U <socket>      use UNIX domain sockets" << std::endl;
}

int main(int argc, char *argv[])
{
        int opt = 0;
        dtn::data::EID _destination;
        std::string _source = "stream";
        unsigned int _lifetime = 30;
        size_t _chunk_size = 4096;
        bool _bundle_encryption = false;
        bool _bundle_signed = false;
        ibrcommon::File _unixdomain;

        while((opt = getopt(argc, argv, "hd:t:s:c:l:ESU:")) != -1)
        {
                switch (opt)
                {
                case 'h':
                        print_help();
                        return 0;

                case 'd':
                        _destination = std::string(optarg);
                        break;

                case 's':
                        _source = optarg;
                        break;

                case 'c':
                        _chunk_size = atoi(optarg);
                        break;

                case 't':
                        __timeout_receive__ = atoi(optarg);
                        break;

                case 'l':
                        _lifetime = atoi(optarg);
                        break;

                case 'E':
                        _bundle_encryption = true;
                        break;

                case 'S':
                        _bundle_signed = true;
                        break;

                case 'U':
                        _unixdomain = ibrcommon::File(optarg);
                        break;

                default:
                        std::cout << "unknown command" << std::endl;
                        return -1;
                }
        }

        try {
                // Create a stream to the server using TCP.
                ibrcommon::tcpclient conn;

                // check if the unixdomain socket exists
                if (_unixdomain.exists())
                {
                        // connect to the unix domain socket
                        conn.open(_unixdomain);
                }
                else
                {
                        // connect to the standard local api port
                        conn.open("127.0.0.1", 4550);

                        // enable nodelay option
                        conn.enableNoDelay();
                }

                // Initiate a derivated client
                BundleStream bs(conn, _chunk_size, _source);

                // Connect to the server. Actually, this function initiate the
                // stream protocol by starting the thread and sending the contact header.
                bs.connect();

                // transmitter mode
                if (_destination != dtn::data::EID())
                {
                        bs.base().setDestination(_destination);
                        bs.base().setLifetime(_lifetime);
                        if (_bundle_encryption) bs.base().requestEncryption();
                        if (_bundle_signed) bs.base().requestSigned();
                        std::ostream stream(&bs.rdbuf());
                        stream << std::cin.rdbuf() << std::flush;
                }
                // receiver mode
                else
                {
                        std::istream stream(&bs.rdbuf());
                        std::cout << stream.rdbuf() << std::flush;
                }

                // Shutdown the client connection.
                bs.close();
                conn.close();
        } catch (const ibrcommon::tcpclient::SocketException&) {
                std::cerr << "Can not connect to the daemon. Does it run?" << std::endl;
                return -1;
        } catch (...) {

        }

}