[TASK-383] Error Handling fix CPP, for pointer returning methods

bindings/cpp/src/connection.cpp

@@ -47,15 +47,13 @@ Connection& Connection::operator=(Connection&& other) noexcept {
 }
 
 Result Connection::Create(const Configuration& config, Connection& out) {
-    try {
-        auto ffi_config = utils::to_ffi_config(config);
-        out.conn_ = ffi::new_connection(ffi_config);
-        return utils::make_ok();
-    } catch (const rust::Error& e) {
-        return utils::make_client_error(e.what());
-    } catch (const std::exception& e) {
-        return utils::make_client_error(e.what());
+    auto ffi_config = utils::to_ffi_config(config);
+    auto ffi_result = ffi::new_connection(ffi_config);
+    auto result = utils::from_ffi_result(ffi_result.result);
+    if (result.Ok()) {
+        out.conn_ = utils::ptr_from_ffi<ffi::Connection>(ffi_result);
     }
+    return result;
 }
 
 bool Connection::Available() const { return conn_ != nullptr; }
@@ -65,30 +63,26 @@ Result Connection::GetAdmin(Admin& out) {
         return utils::make_client_error("Connection not available");
     }
 
-    try {
-        out.admin_ = conn_->get_admin();
-        return utils::make_ok();
-    } catch (const rust::Error& e) {
-        return utils::make_client_error(e.what());
-    } catch (const std::exception& e) {
-        return utils::make_client_error(e.what());
+    auto ffi_result = conn_->get_admin();
+    auto result = utils::from_ffi_result(ffi_result.result);
+    if (result.Ok()) {
+        out.admin_ = utils::ptr_from_ffi<ffi::Admin>(ffi_result);
     }
+    return result;
 }
 
 Result Connection::GetTable(const TablePath& table_path, Table& out) {
     if (!Available()) {
         return utils::make_client_error("Connection not available");
     }
 
-    try {
-        auto ffi_path = utils::to_ffi_table_path(table_path);
-        out.table_ = conn_->get_table(ffi_path);
-        return utils::make_ok();
-    } catch (const rust::Error& e) {
-        return utils::make_client_error(e.what());
-    } catch (const std::exception& e) {
-        return utils::make_client_error(e.what());
+    auto ffi_path = utils::to_ffi_table_path(table_path);
+    auto ffi_result = conn_->get_table(ffi_path);
+    auto result = utils::from_ffi_result(ffi_result.result);
+    if (result.Ok()) {
+        out.table_ = utils::ptr_from_ffi<ffi::Table>(ffi_result);
     }
+    return result;
 }
 
 }  // namespace fluss

bindings/cpp/src/ffi_converter.hpp

@@ -19,6 +19,8 @@
 
 #pragma once
 
+#include <cassert>
+
 #include "fluss.hpp"
 #include "lib.rs.h"
 
@@ -37,6 +39,12 @@ inline Result from_ffi_result(const ffi::FfiResult& ffi_result) {
     return Result{ffi_result.error_code, std::string(ffi_result.error_message)};
 }
 
+template <typename T>
+inline T* ptr_from_ffi(const ffi::FfiPtrResult& r) {
+    assert(r.ptr != 0 && "ptr_from_ffi: null pointer in FfiPtrResult");
+    return reinterpret_cast<T*>(r.ptr);
+}
+
 inline ffi::FfiTablePath to_ffi_table_path(const TablePath& path) {
     ffi::FfiTablePath ffi_path;
     ffi_path.database_name = rust::String(path.database_name);