Implement a generic hold list for data elements associated with a generation.

2 files changed, 54 insertions, 0 deletions

diff --git a/vespalib/src/tests/util/generation_hold_list/CMakeLists.txt b/vespalib/src/tests/util/generation_hold_list/CMakeLists.txt
new file mode 100644
index 00000000000..c85b2537745
--- /dev/null
+++ b/vespalib/src/tests/util/generation_hold_list/CMakeLists.txt
@@ -0,0 +1,9 @@
+# Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+vespa_add_executable(vespalib_generation_hold_list_test_app TEST
+    SOURCES
+    generation_hold_list_test.cpp
+    DEPENDS
+    vespalib
+    GTest::GTest
+)
+vespa_add_test(NAME vespalib_generation_hold_list_test_app COMMAND vespalib_generation_hold_list_test_app)
diff --git a/vespalib/src/tests/util/generation_hold_list/generation_hold_list_test.cpp b/vespalib/src/tests/util/generation_hold_list/generation_hold_list_test.cpp
new file mode 100644
index 00000000000..0490a99f1e0
--- /dev/null
+++ b/vespalib/src/tests/util/generation_hold_list/generation_hold_list_test.cpp
@@ -0,0 +1,45 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+
+#include <vespa/vespalib/gtest/gtest.h>
+#include <vespa/vespalib/util/generation_hold_list.hpp>
+#include <vespa/vespalib/util/generationholder.h>
+
+using vespalib::GenerationHeldBase;
+using vespalib::GenerationHoldList;
+
+using MyElem = GenerationHeldBase;
+using MyHoldList = GenerationHoldList<MyElem::UP, true>;
+
+TEST(GenerationHoldListTest, holding_of_unique_ptr_elements_with_tracking_of_held_bytes)
+{
+    MyHoldList h;
+    h.insert(std::make_unique<MyElem>(3));
+    h.assign_generation(0);
+    h.insert(std::make_unique<MyElem>(5));
+    h.assign_generation(1);
+    h.insert(std::make_unique<MyElem>(7));
+    h.assign_generation(2);
+    h.insert(std::make_unique<MyElem>(11));
+    h.assign_generation(4);
+    EXPECT_EQ(3 + 5 + 7 + 11, h.get_held_bytes());
+
+    h.reclaim(0);
+    EXPECT_EQ(3 + 5 + 7 + 11, h.get_held_bytes());
+    h.reclaim(1);
+    EXPECT_EQ(5 + 7 + 11, h.get_held_bytes());
+    h.reclaim(2);
+    EXPECT_EQ(7 + 11, h.get_held_bytes());
+
+    h.insert(std::make_unique<MyElem>(13));
+    h.assign_generation(6);
+    EXPECT_EQ(7 + 11 + 13, h.get_held_bytes());
+
+    h.reclaim(6);
+    EXPECT_EQ(13, h.get_held_bytes());
+    h.reclaim(7);
+    EXPECT_EQ(0, h.get_held_bytes());
+    h.reclaim(7);
+    EXPECT_EQ(0, h.get_held_bytes());
+}
+
+GTEST_MAIN_RUN_ALL_TESTS()