zen run command (#552)

initial version -- this is primarily intended to be used for running stress tests and/or benchmarks

example usage:

`zen run -n 10 -- zenserver-test`
`zen run -n 10 -- zenserver-test --ts=core.assert` run zenserver-test 10 times (testing only the `core.assert` test suite)
`zen run --time 600 --basepath=d:\test_dir\test1 -- zenserver-test` keeps spawning new instances for 10 minutes (600 seconds)

1 files changed, 119 insertions, 0 deletions

diff --git a/src/zencore/filesystem.cpp b/src/zencore/filesystem.cpp
index b941613ec..f117001b5 100644
--- a/src/zencore/filesystem.cpp
+++ b/src/zencore/filesystem.cpp
@@ -1558,6 +1558,76 @@ RotateFiles(const std::filesystem::path& Filename, std::size_t MaxFiles)
 	return Result;
 }
 
+std::error_code
+RotateDirectories(const std::filesystem::path& DirectoryName, std::size_t MaxDirectories)
+{
+	const std::filesystem::path BasePath(DirectoryName.parent_path());
+	const std::string			Stem(DirectoryName.stem().string());
+
+	auto GetPathForIndex = [&](size_t Index) -> std::filesystem::path {
+		if (Index == 0)
+		{
+			return BasePath / Stem;
+		}
+		return BasePath / fmt::format("{}.{}", Stem, Index);
+	};
+
+	auto IsEmpty = [](const std::filesystem::path& Path, std::error_code& Ec) -> bool { return std::filesystem::is_empty(Path, Ec); };
+
+	std::error_code Result;
+	const bool		BaseIsEmpty = IsEmpty(GetPathForIndex(0), Result);
+	if (Result)
+	{
+		return Result;
+	}
+
+	if (BaseIsEmpty)
+		return Result;
+
+	for (std::size_t i = MaxDirectories; i > 0; i--)
+	{
+		const std::filesystem::path SourcePath = GetPathForIndex(i - 1);
+
+		if (std::filesystem::exists(SourcePath))
+		{
+			std::filesystem::path TargetPath = GetPathForIndex(i);
+
+			std::error_code DummyEc;
+			if (std::filesystem::exists(TargetPath, DummyEc))
+			{
+				std::filesystem::remove_all(TargetPath, DummyEc);
+			}
+			std::filesystem::rename(SourcePath, TargetPath, DummyEc);
+		}
+	}
+
+	return Result;
+}
+
+std::filesystem::path
+SearchPathForExecutable(std::string_view ExecutableName)
+{
+#if ZEN_PLATFORM_WINDOWS
+	std::wstring Executable(Utf8ToWide(ExecutableName));
+
+	DWORD Result = SearchPathW(nullptr, Executable.c_str(), L".exe", 0, nullptr, nullptr);
+
+	if (!Result)
+		return ExecutableName;
+
+	auto PathBuffer = std::make_unique_for_overwrite<WCHAR[]>(Result);
+
+	Result = SearchPathW(nullptr, Executable.c_str(), L".exe", Result, PathBuffer.get(), nullptr);
+
+	if (!Result)
+		return ExecutableName;
+
+	return PathBuffer.get();
+#else
+	return ExecutableName;
+#endif
+}
+
 //////////////////////////////////////////////////////////////////////////
 //
 // Testing related code follows...
@@ -1717,6 +1787,55 @@ TEST_CASE("PathBuilder")
 #	endif
 }
 
+TEST_CASE("RotateDirectories")
+{
+	std::filesystem::path TestBaseDir = GetRunningExecutablePath().parent_path() / ".test";
+	CleanDirectory(TestBaseDir);
+	std::filesystem::path RotateDir		= TestBaseDir / "rotate_dir" / "dir_to_rotate";
+	IoBuffer			  DummyFileData = IoBufferBuilder::MakeCloneFromMemory("blubb", 5);
+
+	auto NewDir = [&] {
+		CreateDirectories(RotateDir);
+		WriteFile(RotateDir / ".placeholder", DummyFileData);
+	};
+
+	auto DirWithSuffix = [&](int Index) -> std::filesystem::path { return RotateDir.generic_string().append(fmt::format(".{}", Index)); };
+
+	const int RotateMax = 10;
+
+	NewDir();
+	CHECK(std::filesystem::exists(RotateDir));
+	RotateDirectories(RotateDir, RotateMax);
+	CHECK(!std::filesystem::exists(RotateDir));
+	CHECK(std::filesystem::exists(DirWithSuffix(1)));
+	NewDir();
+	CHECK(std::filesystem::exists(RotateDir));
+	RotateDirectories(RotateDir, RotateMax);
+	CHECK(!std::filesystem::exists(RotateDir));
+	CHECK(std::filesystem::exists(DirWithSuffix(1)));
+	CHECK(std::filesystem::exists(DirWithSuffix(2)));
+
+	for (int i = 0; i < RotateMax; ++i)
+	{
+		NewDir();
+		std::error_code Ec		= RotateDirectories(RotateDir, 10);
+		const bool		IsError = !!Ec;
+		CHECK_EQ(IsError, false);
+	}
+
+	CHECK(!std::filesystem::exists(RotateDir));
+
+	for (int i = 0; i < RotateMax; ++i)
+	{
+		CHECK(std::filesystem::exists(DirWithSuffix(i + 1)));
+	}
+
+	for (int i = RotateMax; i < RotateMax + 5; ++i)
+	{
+		CHECK(!std::filesystem::exists(DirWithSuffix(RotateMax + i + 1)));
+	}
+}
+
 #endif
 
 }  // namespace zen