WIP add benchmarks for transform invariants

tests/src/CMakeLists.txt

@@ -61,6 +61,7 @@ target_sources(
         feature/reactive_members.cpp
         feature/shared_ptr_semantics.cpp
         benchmark_signal_composing.cpp
+        benchmark_transform.cpp
         context.cpp
         detail.cpp
         event_emitter.cpp

tests/src/benchmark_transform.cpp

@@ -0,0 +1,81 @@
+//
+//         Copyright (C) 2020-2023 Krylov Yaroslav.
+//
+// Distributed under the Boost Software License, Version 1.0.
+//    (See accompanying file LICENSE_1_0.txt or copy at
+//          http://www.boost.org/LICENSE_1_0.txt)
+//
+#include <nanobench.h>
+
+#include "catch2_extra.hpp"
+#include "ureact/adaptor/observe.hpp"
+#include "ureact/adaptor/transform.hpp"
+#include "ureact/adaptor/transform2.hpp"
+#include "ureact/adaptor/transform3.hpp"
+#include "ureact/adaptor/transform4.hpp"
+#include "ureact/adaptor/transform5.hpp"
+#include "ureact/transaction.hpp"
+
+namespace
+{
+
+void perform_test( const char* name,
+    ankerl::nanobench::Bench& bench,
+    const ureact::event_source<int>& in,
+    const ureact::events<int>& out )
+{
+    int i = 0;
+    std::vector<int> result{};
+    auto obs = ureact::observe( out, std::back_inserter( result ) );
+
+    bench.run( name, [&] {
+        result.clear();
+        for( size_t j = 0; j < 100; ++j )
+            in << i;
+        {
+            ureact::transaction _{ in.get_context() };
+            for( size_t j = 0; j < 100; ++j )
+                in << i;
+        }
+        bench.doNotOptimizeAway( result );
+        ++i;
+    } );
+}
+
+#define CONCAT_IMPL( LHS, RHS ) LHS##RHS
+#define CONCAT( LHS, RHS ) CONCAT_IMPL( LHS, RHS )
+
+#define MAKE_TRANSFORM_TEST( _NAME_ )                                                              \
+    void CONCAT( test_, _NAME_ )( ankerl::nanobench::Bench & bench )                               \
+    {                                                                                              \
+        ureact::context ctx;                                                                       \
+        auto src = ureact::make_source<int>( ctx );                                                \
+        ureact::events out = src;                                                                  \
+        for( size_t i = 0; i < 100; ++i )                                                          \
+            out = ureact::_NAME_( out, std::negate<>{} );                                          \
+        perform_test( #_NAME_, bench, src, out );                                                  \
+    }
+
+MAKE_TRANSFORM_TEST( transform )
+MAKE_TRANSFORM_TEST( transform2 )
+MAKE_TRANSFORM_TEST( transform3 )
+MAKE_TRANSFORM_TEST( transform4 )
+MAKE_TRANSFORM_TEST( transform5 )
+
+} // namespace
+
+TEST_CASE( "Benchmark transform variants" )
+{
+    ankerl::nanobench::Bench bench;
+    bench.title( "Transform variants" );
+    bench.warmup( 100 );
+    bench.relative( true );
+    bench.performanceCounters( false );
+    //bench.minEpochIterations( 50 );
+
+    test_transform( bench );
+    test_transform2( bench );
+    test_transform3( bench );
+    test_transform4( bench );
+    test_transform5( bench );
+}