rfnoc: Adding rfnoc_graph utilities

Adding graph_utils to keep rfnoc_graph utilities to contain helper
function and commonly used algorithms for the rfnoc_graph. These
functions aren't core to the rfnoc_graph's functionality, so we'll keep
them out of its API.

2 files changed, 69 insertions, 0 deletions

diff --git a/host/include/uhd/utils/CMakeLists.txt b/host/include/uhd/utils/CMakeLists.txt
index bf367f63d..b70de86ba 100644
--- a/host/include/uhd/utils/CMakeLists.txt
+++ b/host/include/uhd/utils/CMakeLists.txt
@@ -17,6 +17,7 @@ UHD_INSTALL(FILES
     fp_compare_delta.ipp
     fp_compare_epsilon.ipp
     gain_group.hpp
+    graph_utils.hpp
     log.hpp
     log_add.hpp
     math.hpp
diff --git a/host/include/uhd/utils/graph_utils.hpp b/host/include/uhd/utils/graph_utils.hpp
new file mode 100644
index 000000000..b2c61f78f
--- /dev/null
+++ b/host/include/uhd/utils/graph_utils.hpp
@@ -0,0 +1,68 @@
+//
+// Copyright 2019 Ettus Research, a National Instruments Branch
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+//
+
+#ifndef INCLUDED_UHD_UTILS_GRAPH_UTILS_HPP
+#define INCLUDED_UHD_UTILS_GRAPH_UTILS_HPP
+
+#include <uhd/config.hpp>
+#include <uhd/rfnoc/block_id.hpp>
+#include <uhd/rfnoc/defaults.hpp>
+#include <uhd/rfnoc/graph_edge.hpp>
+#include <uhd/rfnoc_graph.hpp>
+#include <boost/none.hpp>
+#include <boost/optional.hpp>
+#include <vector>
+
+
+namespace uhd { namespace rfnoc {
+
+//! Tuple that stores a block ID, as well as an optional port number
+using block_port_def = std::tuple<std::string, boost::optional<size_t>>;
+
+// TODO: Get rid of magic strings
+/*! List of blocks that can terminate chains. Note that some blocks only terminate at
+ *  some of their ports, so we can optionally include a port number.
+ */
+static const std::vector<block_port_def> TERMINATOR_BLOCKS{
+    {NODE_ID_SEP, boost::none}, {"Radio", boost::none}, {"NullSrcSink", 0}};
+
+/*!
+ *  Get a chain of blocks that statically connect back to a terminating block. This
+ *  vector's first element is `start_block`, and the chain continues from there.
+ *
+ *  This function does not make the connections between blocks, it simply traverses the
+ *  static connections.
+ *
+ *  \param graph The rfnoc_graph that is being examined
+ *  \param start_block The block we begin to build the chain from
+ *  \param port The block port of `src_port` that the path will begin at
+ *  \param source_block Whether or not the `start_block` is a source (or a destination).
+ *                      If true, the chain will start at `start_block`'s output port. If
+ *                      false, the chain will start with `start_block`'s output port.
+ *  \return The edge list representing the data path requested
+ */
+std::vector<graph_edge_t> UHD_API get_block_chain(const rfnoc_graph::sptr graph,
+    const block_id_t start_block,
+    const size_t port,
+    const bool source_chain);
+
+
+/*! Connect desired blocks by whatever path that can be found
+ *
+ *  \param src_blk Source block's ID
+ *  \param src_port Block port where the path starts
+ *  \param dst_blk Destination block's ID
+ *  \param dst_port Block port where the path ends
+ */
+void UHD_API connect_through_blocks(rfnoc_graph::sptr graph,
+    const block_id_t src_blk,
+    const size_t src_port,
+    const block_id_t dst_blk,
+    const size_t dst_port);
+
+}} // namespace uhd::rfnoc
+
+#endif /* INCLUDED_UHD_UTILS_GRAPH_UTILS_HPP */