work on generic packet handler (got rx working)

1 files changed, 161 insertions, 0 deletions

diff --git a/host/lib/transport/vrt_packet_handler.hpp b/host/lib/transport/vrt_packet_handler.hpp
new file mode 100644
index 000000000..a6161ef55
--- /dev/null
+++ b/host/lib/transport/vrt_packet_handler.hpp
@@ -0,0 +1,161 @@
+//
+// Copyright 2010 Ettus Research LLC
+//
+// This program 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 of the License, or
+// (at your option) any later version.
+//
+// This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+#ifndef INCLUDED_LIBUHD_TRANSPORT_VRT_PACKET_HANDLER_HPP
+#define INCLUDED_LIBUHD_TRANSPORT_VRT_PACKET_HANDLER_HPP
+
+#include <uhd/types/io_type.hpp>
+#include <uhd/types/otw_type.hpp>
+#include <uhd/types/metadata.hpp>
+#include <uhd/transport/vrt.hpp>
+#include <uhd/transport/convert_types.hpp>
+#include <uhd/transport/zero_copy.hpp>
+#include <boost/asio/buffer.hpp>
+#include <boost/function.hpp>
+#include <iostream>
+
+namespace vrt_packet_handler{
+
+/***********************************************************************
+ * vrt packet handler for recv
+ **********************************************************************/
+    struct recv_state{
+        //init the expected seq number
+        size_t next_packet_seq;
+
+        //state variables to handle fragments
+        uhd::transport::managed_recv_buffer::sptr managed_buff;
+        boost::asio::const_buffer copy_buff;
+        size_t fragment_offset_in_samps;
+
+        recv_state(void){
+            //first expected seq is zero
+            next_packet_seq = 0;
+
+            //initially empty copy buffer
+            copy_buff = boost::asio::buffer("", 0);
+        }
+    };
+
+    typedef boost::function<void(uhd::transport::managed_recv_buffer::sptr)> recv_cb_t;
+
+    static inline void recv_cb_nop(uhd::transport::managed_recv_buffer::sptr){
+        /* NOP */
+    }
+
+    static inline size_t recv(
+        recv_state &state,
+        const boost::asio::mutable_buffer &buff,
+        uhd::rx_metadata_t &metadata,
+        const uhd::io_type_t &io_type,
+        const uhd::otw_type_t &otw_type,
+        double tick_rate,
+        uhd::transport::zero_copy_if::sptr zc_iface,
+        size_t vrt_header_offset_words32 = 0,
+        const recv_cb_t& recv_cb = &recv_cb_nop
+    ){
+        ////////////////////////////////////////////////////////////////
+        // Perform the recv
+        ////////////////////////////////////////////////////////////////
+        {
+            //perform a receive if no rx data is waiting to be copied
+            if (boost::asio::buffer_size(state.copy_buff) == 0){
+                state.fragment_offset_in_samps = 0;
+                state.managed_buff = zc_iface->get_recv_buff();
+                recv_cb(state.managed_buff);
+            }
+            //otherwise flag the metadata to show that is is a fragment
+            else{
+                metadata = uhd::rx_metadata_t();
+                goto vrt_recv_copy_convert;
+            }
+        }
+
+        ////////////////////////////////////////////////////////////////
+        // Unpack the vrt header
+        ////////////////////////////////////////////////////////////////
+        {
+            size_t num_packet_words32 = state.managed_buff->size()/sizeof(boost::uint32_t);
+            if (num_packet_words32 <= vrt_header_offset_words32){
+                state.copy_buff = boost::asio::buffer("", 0);
+                goto vrt_recv_copy_convert; //must exit here after setting the buffer
+            }
+            const boost::uint32_t *vrt_hdr = state.managed_buff->cast<const boost::uint32_t *>() + vrt_header_offset_words32;
+            size_t num_header_words32_out, num_payload_words32_out, packet_count_out;
+            uhd::transport::vrt::unpack(
+                metadata,                //output
+                vrt_hdr,                 //input
+                num_header_words32_out,  //output
+                num_payload_words32_out, //output
+                num_packet_words32,      //input
+                packet_count_out,        //output
+                tick_rate
+            );
+
+            //handle the packet count / sequence number
+            if (packet_count_out != state.next_packet_seq){
+                std::cerr << "S" << (packet_count_out - state.next_packet_seq)%16;
+            }
+            state.next_packet_seq = (packet_count_out+1)%16;
+
+            //setup the buffer to point to the data
+            state.copy_buff = boost::asio::buffer(
+                vrt_hdr + num_header_words32_out,
+                num_payload_words32_out*sizeof(boost::uint32_t)
+            );
+        }
+
+        ////////////////////////////////////////////////////////////////
+        // Perform copy-convert into buffer
+        ////////////////////////////////////////////////////////////////
+        vrt_recv_copy_convert:{
+            size_t bytes_per_item = (otw_type.width * 2) / 8;
+
+            //extract the number of samples available to copy
+            //and a pointer into the usrp2 received items memory
+            size_t bytes_available = boost::asio::buffer_size(state.copy_buff);
+            size_t num_samps = std::min(
+                boost::asio::buffer_size(buff)/io_type.size,
+                bytes_available/bytes_per_item
+            );
+
+            //setup the fragment flags and offset
+            metadata.more_fragments = boost::asio::buffer_size(buff)/io_type.size < num_samps;
+            metadata.fragment_offset = state.fragment_offset_in_samps;
+            state.fragment_offset_in_samps += num_samps; //set for next time
+
+            //copy-convert the samples from the recv buffer
+            uhd::transport::convert_otw_type_to_io_type(
+                boost::asio::buffer_cast<const void*>(state.copy_buff), otw_type,
+                boost::asio::buffer_cast<void*>(buff), io_type,
+                num_samps
+            );
+
+            //update the rx copy buffer to reflect the bytes copied
+            size_t bytes_copied = num_samps*bytes_per_item;
+            state.copy_buff = boost::asio::buffer(
+                boost::asio::buffer_cast<const boost::uint8_t*>(state.copy_buff) + bytes_copied,
+                bytes_available - bytes_copied
+            );
+
+            return num_samps;
+        }
+    }
+
+} //namespace vrt_packet_handler
+
+#endif /* INCLUDED_LIBUHD_TRANSPORT_VRT_PACKET_HANDLER_HPP */