tagged_stream_mux.h

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/* -*- c++ -*- */
/* Copyright 2012 Free Software Foundation, Inc.
 *
 * This file is part of GNU Radio
 *
 * GNU Radio 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 3, or (at your option)
 * any later version.
 *
 * GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#ifndef INCLUDED_TAGGED_STREAM_MUX_H
#define INCLUDED_TAGGED_STREAM_MUX_H

#include <gnuradio/blocks/api.h>
#include <gnuradio/tagged_stream_block.h>

namespace gr {
namespace blocks {

/*!
 * \brief Combines tagged streams.
 * \ingroup stream_operators_blk
 *
 * \details
 * Takes N streams as input. Each stream is tagged with packet lengths.
 * Packets are output sequentially from each input stream.
 *
 * The output signal has a new length tag, which is the sum of all
 * individual length tags. The old length tags are discarded.
 *
 * All other tags are propagated as expected, i.e. they stay associated
 * with the same input item.
 * There are cases when this behaviour is undesirable. One special case
 * is when a tag at the first element (the head item) of one input port
 * must stay on the head item of the output port. To achieve this,
 * set \p tag_preserve_head_pos to the port that will receive these special
 * tags.
 */
class BLOCKS_API tagged_stream_mux : virtual public tagged_stream_block
{
public:
    typedef boost::shared_ptr<tagged_stream_mux> sptr;

    /*!
     * Make a tagged stream mux block.
     *
     * \param itemsize Items size (number of bytes per item)
     * \param lengthtagname Length tag key
     * \param tag_preserve_head_pos Preserves the head position of tags on this input port
     */
    static sptr make(size_t itemsize,
                     const std::string& lengthtagname,
                     unsigned int tag_preserve_head_pos = 0);
};

} // namespace blocks
} // namespace gr

#endif /* INCLUDED_TAGGED_STREAM_MUX_H */