[#500] Expose UniquePublisherId bytes in CXX API

iceoryx2-ffi/cxx/include/iox2/unique_port_id.hpp

@@ -13,9 +13,15 @@
 #ifndef IOX2_UNIQUE_PORT_ID_HPP
 #define IOX2_UNIQUE_PORT_ID_HPP
 
+#include "iox/optional.hpp"
 #include "iox2/internal/iceoryx2.hpp"
 
+#include <array>
+
 namespace iox2 {
+
+constexpr uint64_t UNIQUE_PORT_ID_LENGTH = 128;
+
 /// The system-wide unique id of a [`Publisher`].
 class UniquePublisherId {
   public:
@@ -25,6 +31,8 @@ class UniquePublisherId {
     auto operator=(UniquePublisherId&& rhs) noexcept -> UniquePublisherId&;
     ~UniquePublisherId();
 
+    auto bytes() -> iox::optional<std::array<uint8_t, UNIQUE_PORT_ID_LENGTH>>;
+
   private:
     template <ServiceType, typename, typename>
     friend class Publisher;
@@ -38,7 +46,6 @@ class UniquePublisherId {
     iox2_unique_publisher_id_h m_handle = nullptr;
 };
 
-
 /// The system-wide unique id of a [`Subscriber`].
 class UniqueSubscriberId {
   public:

iceoryx2-ffi/cxx/src/unique_port_id.cpp

@@ -43,6 +43,15 @@ UniquePublisherId::UniquePublisherId(iox2_unique_publisher_id_h handle)
     : m_handle { handle } {
 }
 
+auto UniquePublisherId::bytes() -> iox::optional<std::array<uint8_t, UNIQUE_PORT_ID_LENGTH>> {
+    if (m_handle != nullptr) {
+        std::array<uint8_t, UNIQUE_PORT_ID_LENGTH> unique_port_id {};
+        iox2_unique_publisher_id_value(m_handle, unique_port_id.data());
+        return unique_port_id;
+    }
+    return iox::nullopt;
+};
+
 void UniquePublisherId::drop() {
     if (m_handle != nullptr) {
         iox2_unique_publisher_id_drop(m_handle);

iceoryx2-ffi/cxx/tests/src/unique_port_id_tests.cpp

@@ -17,10 +17,12 @@
 #include "iox2/publisher.hpp"
 #include "iox2/service_name.hpp"
 #include "iox2/subscriber.hpp"
+#include "iox2/unique_port_id.hpp"
 
 #include "test.hpp"
 
 #include <atomic>
+#include <gtest/gtest.h>
 
 namespace {
 using namespace iox2;
@@ -63,6 +65,13 @@ struct UniquePortIdTest : public ::testing::Test {
 
 TYPED_TEST_SUITE(UniquePortIdTest, iox2_testing::ServiceTypes);
 
+TYPED_TEST(UniquePortIdTest, unique_publisher_id_value) {
+    auto null_id = std::array<uint8_t, iox2::UNIQUE_PORT_ID_LENGTH> {};
+    auto unique_port_id = this->publisher_1.id();
+    ASSERT_TRUE(unique_port_id.bytes().has_value());
+    ASSERT_NE(unique_port_id.bytes().value(), null_id);
+}
+
 TYPED_TEST(UniquePortIdTest, unique_port_id_from_same_port_is_equal) {
     ASSERT_TRUE(this->listener_1.id() == this->listener_1.id());
     ASSERT_TRUE(this->notifier_1.id() == this->notifier_1.id());

iceoryx2-ffi/ffi/src/api/unique_publisher_id.rs

@@ -86,6 +86,24 @@ impl HandleToType for iox2_unique_publisher_id_h_ref {
 
 // BEGIN C API
 
+#[no_mangle]
+unsafe extern "C" fn iox2_unique_publisher_id_value(
+    handle: iox2_unique_publisher_id_h,
+    id_ptr: *mut u8,
+) {
+    handle.assert_non_null();
+
+    let h = &mut *handle.as_type();
+
+    if let Some(Some(id)) = (h.value.internal.as_ptr() as *const Option<UniquePublisherId>).as_ref()
+    {
+        let bytes = id.value().to_ne_bytes();
+        unsafe {
+            std::ptr::copy_nonoverlapping(bytes.as_ptr(), id_ptr, bytes.len());
+        }
+    }
+}
+
 /// This function needs to be called to destroy the unique publisher id!
 ///
 /// # Arguments

iceoryx2/src/port/port_identifiers.rs

@@ -35,6 +35,11 @@ macro_rules! generate_id {
             pub fn new() -> Self {
                 Self::default()
             }
+
+            /// Returns the underlying raw value of the ID
+            pub fn value(&self) -> u128 {
+                self.0.value()
+            }
         }
     };
 }