From 18fc18431173ca48736784d30394a4dddae9cd2e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franz=20P=C3=B6schel?= <franz.poeschel@gmail.com>
Date: Tue, 11 Jun 2024 18:31:59 +0200
Subject: [PATCH] Test reading

---
 include/openPMD/IO/ADIOS/macros.hpp |  5 +++
 test/SerialIOTest.cpp               | 56 +++++++++++++++--------------
 2 files changed, 35 insertions(+), 26 deletions(-)

diff --git a/include/openPMD/IO/ADIOS/macros.hpp b/include/openPMD/IO/ADIOS/macros.hpp
index 4e5f223e44..8618573713 100644
--- a/include/openPMD/IO/ADIOS/macros.hpp
+++ b/include/openPMD/IO/ADIOS/macros.hpp
@@ -22,6 +22,11 @@
 #define openPMD_HAS_ADIOS_2_10                                                 \
     (ADIOS2_VERSION_MAJOR * 100 + ADIOS2_VERSION_MINOR >= 210)
 
+#define openPMD_HAS_ADIOS_2_10_1                                               \
+    (ADIOS2_VERSION_MAJOR * 1000 + ADIOS2_VERSION_MINOR * 10 +                 \
+         ADIOS2_VERSION_PATCH >=                                               \
+     2101)
+
 #if defined(ADIOS2_HAVE_BP5) || openPMD_HAS_ADIOS_2_10
 // ADIOS2 v2.10 no longer defines this
 #define openPMD_HAVE_ADIOS2_BP5 1
diff --git a/test/SerialIOTest.cpp b/test/SerialIOTest.cpp
index ba164885a9..65c1b7b584 100644
--- a/test/SerialIOTest.cpp
+++ b/test/SerialIOTest.cpp
@@ -4439,39 +4439,43 @@ BufferChunkSize = 2147483646 # 2^31 - 2
 
 TEST_CASE("adios2_flush_via_step")
 {
-    for (auto const suffix : {"bp4", "bp5"})
+    Series write(
+        "../samples/adios2_flush_via_step/simData_%T.bp5",
+        Access::CREATE,
+        R"(adios2.engine.parameters.FlattenSteps = "on")");
+    std::vector<float> data(10);
+    for (Iteration::IterationIndex_t i = 0; i < 5; ++i)
     {
-        Series write(
-            "../samples/adios2_flush_via_step/simData_%T." +
-                std::string(suffix),
-            Access::CREATE);
-        std::vector<float> data(10);
-        for (Iteration::IterationIndex_t i = 0; i < 5; ++i)
+        Iteration it = write.writeIterations()[i];
+        auto E_x = it.meshes["E"]["x"];
+        E_x.resetDataset({Datatype::FLOAT, {10, 10}});
+        for (Extent::value_type j = 0; j < 10; ++j)
         {
-            Iteration it = write.writeIterations()[i];
-            auto E_x = it.meshes["E"]["x"];
-            E_x.resetDataset({Datatype::FLOAT, {10, 10}});
-            for (Extent::value_type j = 0; j < 10; ++j)
-            {
-                std::iota(data.begin(), data.end(), i * 100 + j * 10);
-                E_x.storeChunk(data, {j, 0}, {1, 10});
-                write.flush(
-                    R"(adios2.engine.preferred_flush_target = "new_step")");
-            }
-            it.close();
+            std::iota(data.begin(), data.end(), i * 100 + j * 10);
+            E_x.storeChunk(data, {j, 0}, {1, 10});
+            write.flush(R"(adios2.engine.preferred_flush_target = "new_step")");
         }
+        it.close();
+    }
 
-        for (Iteration::IterationIndex_t i = 0; i < 5; ++i)
+#if openPMD_HAS_ADIOS_2_10_1
+    for (auto access : {Access::READ_RANDOM_ACCESS, Access::READ_LINEAR})
+    {
+        Series read(
+            "../samples/adios2_flush_via_step/simData_%T.bp5",
+            Access::READ_RANDOM_ACCESS);
+        std::vector<float> load_data(100);
+        data.resize(100);
+        for (auto iteration : read.readIterations())
         {
-            std::string filename = "../samples/adios2_flush_via_step/simData_" +
-                std::to_string(i) + "." + suffix;
-            adios2::ADIOS adios;
-            auto IO = adios.DeclareIO("IO");
-            auto engine = IO.Open(filename, adios2::Mode::Read);
-            REQUIRE(engine.Steps() == (suffix == std::string("bp4") ? 10 : 11));
-            engine.Close();
+            std::iota(data.begin(), data.end(), iteration.iterationIndex * 100);
+            iteration.meshes["E"]["x"].loadChunkRaw(
+                load_data.data(), {0, 0}, {10, 10});
+            iteration.close();
+            REQUIRE(load_data == data);
         }
     }
+#endif
 }
 
 TEST_CASE("adios2_engines_and_file_endings")