req_source_impl.cc

/* -*- c++ -*- */
/*
 * Copyright 2013,2014 Free Software Foundation, Inc.
 *
 * This file is part of GNU Radio.
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "req_source_impl.h"
#include "tag_headers.h"
#include <gnuradio/io_signature.h>

namespace gr {
namespace zeromq {

req_source::sptr req_source::make(size_t itemsize,
                                  size_t vlen,
                                  char* address,
                                  int timeout,
                                  bool pass_tags,
                                  int hwm,
                                  bool bind)
{
    return gnuradio::make_block_sptr<req_source_impl>(
        itemsize, vlen, address, timeout, pass_tags, hwm, bind);
}

req_source_impl::req_source_impl(size_t itemsize,
                                 size_t vlen,
                                 char* address,
                                 int timeout,
                                 bool pass_tags,
                                 int hwm,
                                 bool bind)
    : gr::sync_block("req_source",
                     gr::io_signature::make(0, 0, 0),
                     gr::io_signature::make(1, 1, itemsize * vlen)),
      base_source_impl(ZMQ_REQ, itemsize, vlen, address, timeout, pass_tags, hwm, bind),
      d_req_pending(false)
{
    /* All is delegated */
}

int req_source_impl::work(int noutput_items,
                          gr_vector_const_void_star& input_items,
                          gr_vector_void_star& output_items)
{
#if 0
#endif
    uint8_t* out = (uint8_t*)output_items[0];
    bool first = true;
    int done = 0;

    /* Process as much as we can */
    while (1) {
        if (has_pending()) {
            /* Flush anything pending */
            done += flush_pending(
                out + (done * d_vsize), noutput_items - done, nitems_written(0) + done);

            /* No more space ? */
            if (done == noutput_items)
                break;

            /* Have some output to return: do not wait for more messages */
            first = false;
        } else {
            /* Send request if needed */
            if (!d_req_pending) {
                /* The REP/REQ pattern state machine guarantees we can send at this point
                 */
                uint32_t req_len = noutput_items - done;
                zmq::message_t request(sizeof(uint32_t));
                memcpy((void*)request.data(), &req_len, sizeof(uint32_t));
#if USE_NEW_CPPZMQ_SEND_RECV
                d_socket.send(request, zmq::send_flags::none);
#else
                d_socket.send(request);
#endif

                d_req_pending = true;
            }

            /* Try to get the next message */
            if (!load_message(first))
                break; /* No message, we're done for now */

            /* Got response */
            d_req_pending = false;

            /* Not the first anymore: do not wait for more messages */
            first = false;
        }
    }

    return done;

    return 0;
}

} /* namespace zeromq */
} /* namespace gr */

// vim: ts=2 sw=2 expandtab