From e6770d0b7324f2eec92b53e2d5a80064e47e10dd Mon Sep 17 00:00:00 2001
From: Jeff Ithier <jeff@ithier.dev>
Date: Sat, 2 Nov 2024 14:25:19 +0100
Subject: [PATCH] [#500] Only copy ID from iceoryx2 into CXX one time

---
 .../cxx/include/iox2/unique_port_id.hpp       | 13 ++++--
 iceoryx2-ffi/cxx/src/unique_port_id.cpp       | 40 +++++++++----------
 2 files changed, 29 insertions(+), 24 deletions(-)

diff --git a/iceoryx2-ffi/cxx/include/iox2/unique_port_id.hpp b/iceoryx2-ffi/cxx/include/iox2/unique_port_id.hpp
index 2e9e0340..865b4156 100644
--- a/iceoryx2-ffi/cxx/include/iox2/unique_port_id.hpp
+++ b/iceoryx2-ffi/cxx/include/iox2/unique_port_id.hpp
@@ -21,6 +21,7 @@
 namespace iox2 {
 
 constexpr uint64_t UNIQUE_PORT_ID_LENGTH = 128;
+using RawIdType = std::array<uint8_t, UNIQUE_PORT_ID_LENGTH>;
 
 /// The system-wide unique id of a [`Publisher`].
 class UniquePublisherId {
@@ -31,7 +32,7 @@ class UniquePublisherId {
     auto operator=(UniquePublisherId&& rhs) noexcept -> UniquePublisherId&;
     ~UniquePublisherId();
 
-    auto bytes() -> iox::optional<std::array<uint8_t, UNIQUE_PORT_ID_LENGTH>>;
+    auto bytes() -> iox::optional<RawIdType>&;
 
   private:
     template <ServiceType, typename, typename>
@@ -44,6 +45,7 @@ class UniquePublisherId {
     void drop();
 
     iox2_unique_publisher_id_h m_handle = nullptr;
+    iox::optional<RawIdType> m_raw_id;
 };
 
 /// The system-wide unique id of a [`Subscriber`].
@@ -55,7 +57,7 @@ class UniqueSubscriberId {
     auto operator=(UniqueSubscriberId&& rhs) noexcept -> UniqueSubscriberId&;
     ~UniqueSubscriberId();
 
-    auto bytes() -> iox::optional<std::array<uint8_t, UNIQUE_PORT_ID_LENGTH>>;
+    auto bytes() -> iox::optional<RawIdType>&;
 
   private:
     template <ServiceType, typename, typename>
@@ -67,6 +69,7 @@ class UniqueSubscriberId {
     void drop();
 
     iox2_unique_subscriber_id_h m_handle = nullptr;
+    iox::optional<RawIdType> m_raw_id;
 };
 
 /// The system-wide unique id of a [`Notifier`].
@@ -78,7 +81,7 @@ class UniqueNotifierId {
     auto operator=(UniqueNotifierId&& rhs) noexcept -> UniqueNotifierId&;
     ~UniqueNotifierId();
 
-    auto bytes() -> iox::optional<std::array<uint8_t, UNIQUE_PORT_ID_LENGTH>>;
+    auto bytes() -> iox::optional<RawIdType>&;
 
   private:
     template <ServiceType>
@@ -90,6 +93,7 @@ class UniqueNotifierId {
     void drop();
 
     iox2_unique_notifier_id_h m_handle = nullptr;
+    iox::optional<RawIdType> m_raw_id;
 };
 
 /// The system-wide unique id of a [`Listener`].
@@ -101,7 +105,7 @@ class UniqueListenerId {
     auto operator=(UniqueListenerId&& rhs) noexcept -> UniqueListenerId&;
     ~UniqueListenerId();
 
-    auto bytes() -> iox::optional<std::array<uint8_t, UNIQUE_PORT_ID_LENGTH>>;
+    auto bytes() -> iox::optional<RawIdType>&;
 
   private:
     template <ServiceType>
@@ -113,6 +117,7 @@ class UniqueListenerId {
     void drop();
 
     iox2_unique_listener_id_h m_handle = nullptr;
+    iox::optional<RawIdType> m_raw_id;
 };
 
 auto operator==(const UniquePublisherId& lhs, const UniquePublisherId& rhs) -> bool;
diff --git a/iceoryx2-ffi/cxx/src/unique_port_id.cpp b/iceoryx2-ffi/cxx/src/unique_port_id.cpp
index 13a76c68..4055f53f 100644
--- a/iceoryx2-ffi/cxx/src/unique_port_id.cpp
+++ b/iceoryx2-ffi/cxx/src/unique_port_id.cpp
@@ -43,13 +43,13 @@ 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> bytes {};
+auto UniquePublisherId::bytes() -> iox::optional<RawIdType>& {
+    if (!m_raw_id.has_value() && m_handle != nullptr) {
+        RawIdType bytes {};
         iox2_unique_publisher_id_value(m_handle, bytes.data());
-        return bytes;
+        m_raw_id.emplace(std::move(bytes));
     }
-    return iox::nullopt;
+    return m_raw_id;
 };
 
 void UniquePublisherId::drop() {
@@ -90,13 +90,13 @@ UniqueSubscriberId::UniqueSubscriberId(iox2_unique_subscriber_id_h handle)
     : m_handle { handle } {
 }
 
-auto UniqueSubscriberId::bytes() -> iox::optional<std::array<uint8_t, UNIQUE_PORT_ID_LENGTH>> {
-    if (m_handle != nullptr) {
-        std::array<uint8_t, UNIQUE_PORT_ID_LENGTH> bytes {};
+auto UniqueSubscriberId::bytes() -> iox::optional<RawIdType>& {
+    if (!m_raw_id.has_value() && m_handle != nullptr) {
+        RawIdType bytes {};
         iox2_unique_subscriber_id_value(m_handle, bytes.data());
-        return bytes;
+        m_raw_id.emplace(std::move(bytes));
     }
-    return iox::nullopt;
+    return m_raw_id;
 };
 
 void UniqueSubscriberId::drop() {
@@ -136,13 +136,13 @@ UniqueNotifierId::UniqueNotifierId(iox2_unique_notifier_id_h handle)
     : m_handle { handle } {
 }
 
-auto UniqueNotifierId::bytes() -> iox::optional<std::array<uint8_t, UNIQUE_PORT_ID_LENGTH>> {
-    if (m_handle != nullptr) {
-        std::array<uint8_t, UNIQUE_PORT_ID_LENGTH> bytes {};
+auto UniqueNotifierId::bytes() -> iox::optional<RawIdType>& {
+    if (!m_raw_id.has_value() && m_handle != nullptr) {
+        RawIdType bytes {};
         iox2_unique_notifier_id_value(m_handle, bytes.data());
-        return bytes;
+        m_raw_id.emplace(std::move(bytes));
     }
-    return iox::nullopt;
+    return m_raw_id;
 };
 
 void UniqueNotifierId::drop() {
@@ -182,13 +182,13 @@ UniqueListenerId::UniqueListenerId(iox2_unique_listener_id_h handle)
     : m_handle { handle } {
 }
 
-auto UniqueListenerId::bytes() -> iox::optional<std::array<uint8_t, UNIQUE_PORT_ID_LENGTH>> {
-    if (m_handle != nullptr) {
-        std::array<uint8_t, UNIQUE_PORT_ID_LENGTH> bytes {};
+auto UniqueListenerId::bytes() -> iox::optional<RawIdType>& {
+    if (!m_raw_id.has_value() && m_handle != nullptr) {
+        RawIdType bytes {};
         iox2_unique_listener_id_value(m_handle, bytes.data());
-        return bytes;
+        m_raw_id.emplace(std::move(bytes));
     }
-    return iox::nullopt;
+    return m_raw_id;
 };
 
 void UniqueListenerId::drop() {