1 files changed, 114 insertions, 0 deletions
diff --git a/gr-blocks/lib/stream_demux_impl.cc b/gr-blocks/lib/stream_demux_impl.cc
new file mode 100644
index 0000000000..a7298a78df
--- /dev/null
+++ b/gr-blocks/lib/stream_demux_impl.cc
@@ -0,0 +1,114 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2020 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "stream_demux_impl.h"
+#include <gnuradio/io_signature.h>
+#include <cstring>
+
+namespace gr {
+namespace blocks {
+
+stream_demux::sptr stream_demux::make(size_t itemsize, const std::vector<int>& lengths)
+{
+    return gnuradio::make_block_sptr<stream_demux_impl>(itemsize, lengths);
+}
+
+stream_demux_impl::stream_demux_impl(size_t itemsize, const std::vector<int>& lengths)
+    : gr::block("stream_demux",
+                gr::io_signature::make(1, 1, itemsize),
+                gr::io_signature::make(1, -1, itemsize)),
+      d_itemsize(itemsize),
+      d_lengths(lengths)
+{
+    while (d_lengths[d_stream] == 0) {
+        d_stream++;
+        if (d_stream == d_lengths.size()) {
+            throw std::invalid_argument("At least one size must be non-zero.");
+        }
+    }
+    d_residual = d_lengths[d_stream];
+    set_tag_propagation_policy(TPP_DONT);
+}
+
+void stream_demux_impl::forecast(int noutput_items, gr_vector_int& ninput_items_required)
+{
+    std::fill(ninput_items_required.begin(), ninput_items_required.end(), 1);
+}
+
+int stream_demux_impl::general_work(int noutput_items,
+                                    gr_vector_int& ninput_items,
+                                    gr_vector_const_void_star& input_items,
+                                    gr_vector_void_star& output_items)
+{
+    int input_index = 0;                          // Items read
+    gr_vector_int output_index(d_lengths.size()); // Items written
+
+    while (input_index < ninput_items[0]) {
+        if (noutput_items <= output_index[d_stream]) {
+            break;
+        }
+        const int space_left_in_buffers =
+            std::min(ninput_items[0] - input_index,         // Space left in input buffer
+                     noutput_items - output_index[d_stream] // Space left in output buffer
+            );
+        const int items_to_copy = std::min(space_left_in_buffers, d_residual);
+        const char* in =
+            reinterpret_cast<const char*>(input_items[0]) + input_index * d_itemsize;
+        char* out = reinterpret_cast<char*>(output_items[d_stream]);
+        memcpy(&out[output_index[d_stream] * d_itemsize], in, items_to_copy * d_itemsize);
+
+        std::vector<gr::tag_t> stream_t;
+        get_tags_in_window(stream_t, 0, input_index, input_index + items_to_copy);
+        for (auto& t : stream_t) {
+            t.offset = t.offset - nitems_read(0) - input_index +
+                       nitems_written(d_stream) + output_index[d_stream];
+            add_item_tag(d_stream, t);
+        }
+
+        output_index[d_stream] += items_to_copy;
+        input_index += items_to_copy;
+        d_residual -= items_to_copy;
+        if (d_residual == 0) {
+            do { // Skip all those outputs with zero length
+                d_stream = (d_stream + 1) % d_lengths.size();
+            } while (d_lengths[d_stream] == 0);
+            d_residual = d_lengths[d_stream];
+        } else {
+            break;
+        }
+    } // while
+
+    consume(0, input_index);
+
+    for (size_t i = 0; i < output_index.size(); i++) {
+        produce((int)i, output_index[i]);
+    }
+
+    return WORK_CALLED_PRODUCE;
+}
+
+} /* namespace blocks */
+} /* namespace gr */