3 * Copyright 2004 Free Software Foundation, Inc.
5 * This file is part of GNU Radio
7 * GNU Radio is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2, or (at your option)
12 * GNU Radio is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with GNU Radio; see the file COPYING. If not, write to
19 * the Free Software Foundation, Inc., 51 Franklin Street,
20 * Boston, MA 02110-1301, USA.
27 #include <gr_io_signature.h>
29 gr_head::gr_head (size_t sizeof_stream_item, int nitems)
30 : gr_sync_block ("head",
31 gr_make_io_signature (1, 1, sizeof_stream_item),
32 gr_make_io_signature (1, 1, sizeof_stream_item)),
33 d_nitems (nitems), d_ncopied_items (0)
38 gr_make_head (size_t sizeof_stream_item, int nitems)
40 return gr_block_sptr (new gr_head (sizeof_stream_item, nitems));
44 gr_head::work (int noutput_items,
45 gr_vector_const_void_star &input_items,
46 gr_vector_void_star &output_items)
48 if (d_ncopied_items >= d_nitems)
51 unsigned n = std::min (d_nitems - d_ncopied_items, noutput_items);
56 memcpy (output_items[0], input_items[0], n * input_signature()->sizeof_stream_item (0));