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* Copyright 2011-2012 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
* 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.
#include <gnuradio/extras/stream_to_blob.h>
#include <gr_io_signature.h>
#include <cstring> //std::memcpy
#include <stdexcept>
using namespace gnuradio::extras;
static const pmt::pmt_t BLOB_KEY = pmt::pmt_string_to_symbol("blob_stream");
static const size_t POOL_SIZE = 64; //num pre-allocated blobs to acquire at once
class stream_to_blob_impl : public stream_to_blob{
const size_t item_size,
const size_t mtu,
const bool fixed
gr_make_io_signature(1, 1, item_size),
gr_make_io_signature(0, 0, 0),
msg_signature(false, 1)
if (mtu%item_size != 0) throw std::invalid_argument(
"stream_to_blob MTU is not a multiple of item size"
if (fixed) this->set_output_multiple(mtu/item_size);
std::stringstream str;
str << name() << unique_id();
_id = pmt::pmt_string_to_symbol(str.str());
//pre-allocate blobs
_mgr = pmt::pmt_mgr::make();
for (size_t i = 0; i < POOL_SIZE; i++){
bool stop(void){
//post an empty blob to mark stop
//this is used in the blob qa code to cause the blob to stream to exit work
pmt::pmt_t blob = pmt::pmt_make_blob(0);
this->post_msg(0, BLOB_KEY, blob, _id);
return true;
int work(
const InputItems &input_items,
const OutputItems &output_items
size_t ninput_items = input_items[0].size();
if (_fixed && ninput_items*_item_size < _mtu){
throw std::runtime_error("stream to blob made false assumption about set_output_multiple");
//cap the output items to the mtu size
ninput_items = std::min<size_t>(ninput_items, _mtu/_item_size);
//acquire blob and memcpy stream memory to the blob memory
pmt::pmt_t blob = _mgr->acquire(true /*block*/);
pmt::pmt_blob_resize(blob, ninput_items*_item_size);
std::memcpy(pmt::pmt_blob_rw_data(blob), input_items[0].get(), pmt::pmt_blob_length(blob));
//post the message to downstream subscribers
this->post_msg(0, BLOB_KEY, blob, _id);
//yield the number of consumed items
return ninput_items;
const size_t _item_size;
const size_t _mtu;
const bool _fixed;
pmt::pmt_t _id;
pmt::pmt_mgr::sptr _mgr;
stream_to_blob::sptr stream_to_blob::make(
const size_t item_size,
const size_t mtu_
const size_t mtu = (mtu_ == 0)? 2048 : mtu_;
const bool fixed = (mtu_ != 0);
return gnuradio::get_initial_sptr(new stream_to_blob_impl(item_size, mtu, fixed));