zeek/auxil/out_ptr/tests/source/custom_unique_deleter_test.cpp

// Copyright ⓒ 2018-2021 ThePhD.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
//  See https://github.com/ThePhD/out_ptr/blob/master/docs/out_ptr.adoc for documentation.

#include <ztd/out_ptr/out_ptr.hpp>

#include <catch2/catch.hpp>

#include <atomic>
#include <mutex>
#include <thread>
#include <array>
#include <fstream>
#include <cstdio>
#include <cstddef>

#ifdef _WIN32

#include <io.h>
#include <fcntl.h>

#else

#include <unistd.h>
#include <assert.h>

int fopen_s(FILE** f, const char* name, const char* mode) {
	int ret = 0;
	assert(f);
	*f = fopen(name, mode);
	/* Can't be sure about 1-to-1 mapping of errno and MS' errno_t */
	if (!*f)
		ret = errno;
	return ret;
}

#endif // Windows

struct fd {
	int handle;

	fd()
	: fd(nullptr) {
	}
	fd(std::nullptr_t)
	: handle(static_cast<intptr_t>(-1)) {
	}
	fd(int h)
	: handle(h) {
	}
	fd(FILE* f)
#ifdef _WIN32
	: handle(f ? _fileno(f) : static_cast<intptr_t>(-1)){
#else
	: handle(f ? fileno(f) : static_cast<intptr_t>(-1)) {
#endif // Windows
	}

	  operator FILE*() const {
		if (!*this)
			return nullptr;
#ifdef _WIN32
		return _fdopen(handle, "r+b");
#else
		return fdopen(handle, "r+b");
#endif // Windows
	}

	explicit operator bool() const {
		return *this != nullptr;
	}

	bool operator==(std::nullptr_t) const {
		return handle == -1;
	}

	bool operator!=(std::nullptr_t) const {
		return handle != -1;
	}

	bool operator==(const fd& fd) const {
		return handle == fd.handle;
	}

	bool operator!=(const fd& fd) const {
		return handle == fd.handle;
	}
};

struct fd_deleter {
	using pointer = fd;

	void operator()(fd des) const {
		if (des.handle != -1) {
#ifdef _WIN32
			_close(des.handle);
#else
			close(des.handle);
#endif // Windows
		}
	}
};

template <typename Name, typename Data>
void write_file_attempt(Name&& filename, Data&& data) {
	bool success = false;
	for (std::size_t i = 0; i < 20; ++i) {
		try {
			std::ofstream file(std::forward<Name>(filename), std::ios::out);
			file.exceptions(std::ios_base::badbit | std::ios_base::failbit);
			file << std::forward<Data>(data) << std::endl;
			file.close();
		}
		catch (const std::exception&) {
			std::this_thread::sleep_for(std::chrono::milliseconds(10));
			continue;
		}
		success = true;
		break;
	}
	if (!success) {
		throw std::runtime_error("cannot open file or write out");
	}
}

struct write_file_attempt_object {
	template <typename... Args>
	void operator()(Args&&... args) {
		write_file_attempt(std::forward<Args>(args)...);
	}
};

TEST_CASE("out_ptr/fd_with_custom_pointer", "out_ptr type works with smart pointers that specialize their ::pointer type and provide custom semantics") {
	struct fd {
		int handle;

		fd()
		: fd(nullptr) {
		}
		fd(std::nullptr_t)
		: handle(static_cast<intptr_t>(-1)) {
		}
		fd(FILE* f)
#ifdef _WIN32
		: handle(f ? _fileno(f) : static_cast<intptr_t>(-1)){
#else
		: handle(f ? fileno(f) : static_cast<intptr_t>(-1)) {
#endif // Windows
		}

		  operator FILE*() const {
			if (!*this)
				return nullptr;
#ifdef _WIN32
			return _fdopen(handle, "rb");
#else
			return fdopen(handle, "rb");
#endif // Windows
		}

		explicit operator bool() const {
			return *this != nullptr;
		}

		bool operator==(std::nullptr_t) const {
			return handle == -1;
		}

		bool operator!=(std::nullptr_t) const {
			return handle != -1;
		}

		bool operator==(const fd& fd) const {
			return handle == fd.handle;
		}

		bool operator!=(const fd& fd) const {
			return handle != fd.handle;
		}

		bool operator==(int fdhandle) const {
			return handle == fdhandle;
		}

		bool operator!=(int fdhandle) const {
			return handle != fdhandle;
		}
	};

	struct fd_deleter {
		using pointer = fd;

		void operator()(fd des) const {
			if (des.handle != -1) {
#ifdef _WIN32
				fclose(des);
				//_close(des.handle);
#else
				close(des.handle);
#endif // Windows
			}
		}
	};

	SECTION("without_file") {
		std::unique_ptr<int, fd_deleter> my_unique_fd;
		auto err = fopen_s(ztd::out_ptr::out_ptr<FILE*>(my_unique_fd), "nonexistent.blah.io", "rb");
		REQUIRE(err != 0);
		REQUIRE(my_unique_fd.get() == nullptr);
	}
}