1 files changed, 129 insertions, 0 deletions
diff --git a/gnuradio-core/src/lib/general/gr_delay.cc b/gnuradio-core/src/lib/general/gr_delay.cc
new file mode 100644
index 000000000..8f728948d
--- /dev/null
+++ b/gnuradio-core/src/lib/general/gr_delay.cc
@@ -0,0 +1,129 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2007,2010,2012 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gr_delay.h>
+#include <gr_io_signature.h>
+#include <string.h>
+
+gr_delay_sptr
+gr_make_delay (size_t itemsize, int delay)
+{
+  return gnuradio::get_initial_sptr(new gr_delay (itemsize, delay));
+}
+
+gr_delay::gr_delay (size_t itemsize, int delay)
+  : gr_block ("delay",
+	      gr_make_io_signature (1, -1, itemsize),
+	      gr_make_io_signature (1, -1, itemsize)),
+    d_itemsize(itemsize)
+{
+  set_delay(delay);
+  d_delta = 0;
+}
+
+void
+gr_delay::forecast (int noutput_items, gr_vector_int &ninput_items_required)
+{
+  // make sure all inputs have noutput_items available
+  unsigned ninputs = ninput_items_required.size ();
+  for (unsigned i = 0; i < ninputs; i++)
+    ninput_items_required[i] = noutput_items;
+}
+
+void
+gr_delay::set_delay (int d)
+{
+  // only set a new delta if there is a change in the delay; this
+  // protects from quickly-repeated calls to this function that would
+  // end with d_delta=0.
+  if(d != delay()) {
+    gruel::scoped_lock l(d_mutex_delay);
+    int old = delay();
+    set_history(d+1);
+    d_delta += delay() - old;
+  }
+}
+
+int
+gr_delay::general_work (int noutput_items,
+			gr_vector_int &ninput_items,
+			gr_vector_const_void_star &input_items,
+			gr_vector_void_star &output_items)
+{
+  gruel::scoped_lock l(d_mutex_delay);
+  assert(input_items.size() == output_items.size());
+
+  const char *iptr;
+  char *optr;
+  int cons, ret;
+
+  // No change in delay; just memcpy ins to outs
+  if(d_delta == 0) {
+    for(size_t i = 0; i < input_items.size(); i++) {
+      iptr = (const char *) input_items[i];
+      optr = (char *) output_items[i];
+      std::memcpy(optr, iptr, noutput_items*d_itemsize);
+    }
+    cons = noutput_items;
+    ret = noutput_items;
+  }
+
+  // Skip over d_delta items on the input
+  else if(d_delta < 0) {
+    int n_to_copy, n_adj;
+    int delta = -d_delta;
+    n_to_copy = std::max(0, noutput_items-delta);
+    n_adj = std::min(delta, noutput_items);
+    for(size_t i = 0; i < input_items.size(); i++) {
+      iptr = (const char *) input_items[i];
+      optr = (char *) output_items[i];
+      std::memcpy(optr, iptr+delta*d_itemsize, n_to_copy*d_itemsize);
+    }
+    cons = noutput_items;
+    ret = n_to_copy;
+    delta -= n_adj;
+    d_delta = -delta;
+  }
+
+  //produce but not consume (inserts zeros)
+  else {  // d_delta > 0
+    int n_from_input, n_padding;
+    n_from_input = std::max(0, noutput_items-d_delta);
+    n_padding = std::min(d_delta, noutput_items);
+    for(size_t i = 0; i < input_items.size(); i++) {
+      iptr = (const char *) input_items[i];
+      optr = (char *) output_items[i];
+      std::memset(optr, 0, n_padding*d_itemsize);
+      std::memcpy(optr, iptr, n_from_input*d_itemsize);
+    }
+    cons = n_from_input;
+    ret = noutput_items;
+    d_delta -= n_padding;
+  }
+
+  consume_each(cons);
+  return ret;
+}