Switch to using get_system_time_in_ns() function everywhere. (backport #354)

rmw_zenoh_cpp/src/detail/rmw_client_data.cpp

@@ -17,7 +17,6 @@
 #include <fastcdr/FastBuffer.h>
 
 #include <array>
-#include <chrono>
 #include <cinttypes>
 #include <limits>
 #include <memory>
@@ -413,10 +412,8 @@ rmw_ret_t ClientData::send_request(
         return;
       }
 
-      std::chrono::time_point<std::chrono::system_clock> now = std::chrono::system_clock::now();
-
       sub_data->add_new_reply(
-        std::make_unique<rmw_zenoh_cpp::ZenohReply>(reply, now.time_since_epoch().count()));
+        std::make_unique<rmw_zenoh_cpp::ZenohReply>(reply, get_system_time_in_ns()));
     },
     zenoh::closures::none,
     std::move(opts),

rmw_zenoh_cpp/src/detail/rmw_service_data.cpp

@@ -161,10 +161,7 @@ std::shared_ptr<ServiceData> ServiceData::make(
         return;
       }
 
-      std::chrono::nanoseconds::rep received_timestamp =
-      std::chrono::system_clock::now().time_since_epoch().count();
-
-      sub_data->add_new_query(std::make_unique<ZenohQuery>(query, received_timestamp));
+      sub_data->add_new_query(std::make_unique<ZenohQuery>(query, get_system_time_in_ns()));
     },
     zenoh::closures::none,
     std::move(qable_options),

rmw_zenoh_cpp/src/detail/rmw_subscription_data.cpp

@@ -16,7 +16,6 @@
 
 #include <fastcdr/FastBuffer.h>
 
-#include <chrono>
 #include <cinttypes>
 #include <limits>
 #include <memory>
@@ -225,7 +224,7 @@ bool SubscriptionData::init()
         sub_data->add_new_message(
           std::make_unique<SubscriptionData::Message>(
             sample.get_payload(),
-            std::chrono::system_clock::now().time_since_epoch().count(),
+            get_system_time_in_ns(),
             std::move(attachment_data)),
           std::string(sample.get_keyexpr().as_string_view()));
       },
@@ -308,7 +307,7 @@ bool SubscriptionData::init()
         sub_data->add_new_message(
           std::make_unique<SubscriptionData::Message>(
             sample.get_payload(),
-            std::chrono::system_clock::now().time_since_epoch().count(),
+            get_system_time_in_ns(),
             std::move(attachment_data)),
           std::string(sample.get_keyexpr().as_string_view()));
       },

rmw_zenoh_cpp/src/detail/zenoh_utils.cpp

@@ -83,6 +83,13 @@ std::chrono::nanoseconds::rep ZenohReply::get_received_timestamp() const
   return received_timestamp_;
 }
 
+int64_t get_system_time_in_ns()
+{
+  auto now = std::chrono::system_clock::now().time_since_epoch();
+  return std::chrono::duration_cast<std::chrono::nanoseconds>(now).count();
+}
+
+///=============================================================================
 Payload::Payload(const zenoh::Bytes & bytes)
 {
   // NOTE(fuzzypixelz): `zenoh::Bytes` is an list of reference-couted buffers. When the list of

rmw_zenoh_cpp/src/detail/zenoh_utils.hpp

@@ -69,6 +69,8 @@ class ZenohQuery final
   std::chrono::nanoseconds::rep received_timestamp_;
 };
 
+int64_t get_system_time_in_ns();
+
 class Payload
 {
 public: