Add test for path hashing

Author: PaulRalnikov

source/device/switch.cpp

@@ -32,10 +32,6 @@ TimeNs Switch::process() {
         return total_processing_time;
     }
     Packet packet = optional_packet.value();
-    if (packet.flow == nullptr) {
-        LOG_WARN("No flow in packet");
-        return total_processing_time;
-    }
 
     std::shared_ptr<ILink> next_link = get_link_to_destination(packet);
 

test/switch/test_switch.cpp

@@ -6,6 +6,7 @@
 
 #include "../_mocks/flow_mock.hpp"
 #include "../utils/fake_packet.hpp"
+#include "device/host.hpp"
 #include "device/switch.hpp"
 #include "host_mock.hpp"
 #include "link_mock.hpp"
@@ -164,4 +165,55 @@ TEST_F(TestSwitch, test_one_sender) { test_senders(1); }
 
 TEST_F(TestSwitch, test_multiple_senders) { test_senders(5); }
 
+TEST_F(TestSwitch, test_path_hash) {
+    // topology:
+    // sender  --- switch_1
+    //   |            |
+    //   |            |
+    // switch_2 -- receiver
+    auto sender = std::make_shared<sim::Host>("sender");
+    auto switch_1 = std::make_shared<sim::Switch>("switch_1");
+    auto switch_2 = std::make_shared<sim::Switch>("switch_2");
+    auto receiver = std::make_shared<sim::Host>("receiver");
+
+    auto link_sender_switch_1 = std::make_shared<LinkMock>(sender, switch_1);
+    switch_1->add_inlink(link_sender_switch_1);
+
+    auto link_sender_switch_2 = std::make_shared<LinkMock>(sender, switch_2);
+    switch_2->add_inlink(link_sender_switch_2);
+
+    auto link_switch_1_receiver =
+        std::make_shared<LinkMock>(switch_1, receiver);
+    switch_1->update_routing_table(receiver->get_id(), link_switch_1_receiver);
+
+    auto link_switch_2_receiver =
+        std::make_shared<LinkMock>(switch_2, receiver);
+    switch_2->update_routing_table(receiver->get_id(), link_switch_2_receiver);
+
+    sim::Packet packet_template(SizeByte(1), nullptr, sender->get_id(),
+                                receiver->get_id());
+    sim::Packet first_packet_route_1(packet_template);
+    sim::Packet second_packet_route_1(packet_template);
+    sim::Packet packet_route_2(packet_template);
+
+    link_sender_switch_1->set_ingress_packet(first_packet_route_1);
+    switch_1->process();
+    link_sender_switch_1->set_ingress_packet(second_packet_route_1);
+    switch_1->process();
+    auto arrived_packets_route_1 =
+        link_switch_1_receiver->get_arrived_packets();
+    ASSERT_EQ(arrived_packets_route_1.size(), 2);
+
+    ASSERT_EQ(arrived_packets_route_1[0].path_hash,
+              arrived_packets_route_1[1].path_hash);
+
+    link_sender_switch_2->set_ingress_packet(packet_route_2);
+    switch_2->process();
+    auto arrived_packets_route_2 =
+        link_switch_2_receiver->get_arrived_packets();
+    ASSERT_EQ(arrived_packets_route_2.size(), 1);
+    ASSERT_NE(arrived_packets_route_2[0].path_hash,
+              arrived_packets_route_1[0].path_hash);
+}
+
 }  // namespace test