// Copyright 2021 The Abseil Authors.

//

// 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

//

//      https://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.

//

// -----------------------------------------------------------------------------

// File: cleanup.h

// -----------------------------------------------------------------------------

//

// `absl::Cleanup` implements the scope guard idiom, invoking the contained

// callback's `operator()() &&` on scope exit.

//

// Example:

//

// ```

//   absl::Status CopyGoodData(const char* source_path, const char* sink_path) {

//     FILE* source_file = fopen(source_path, "r");

//     if (source_file == nullptr) {

//       return absl::NotFoundError("No source file");  // No cleanups execute

//     }

//

//     // C++17 style cleanup using class template argument deduction

//     absl::Cleanup source_closer = [source_file] { fclose(source_file); };

//

//     FILE* sink_file = fopen(sink_path, "w");

//     if (sink_file == nullptr) {

//       return absl::NotFoundError("No sink file");  // First cleanup executes

//     }

//

//     // C++11 style cleanup using the factory function

//     auto sink_closer = absl::MakeCleanup([sink_file] { fclose(sink_file); });

//

//     Data data;

//     while (ReadData(source_file, &data)) {

//       if (!data.IsGood()) {

//         absl::Status result = absl::FailedPreconditionError("Read bad data");

//         return result;  // Both cleanups execute

//       }

//       SaveData(sink_file, &data);

//     }

//

//     return absl::OkStatus();  // Both cleanups execute

//   }

// ```

//

// Methods:

//

// `std::move(cleanup).Cancel()` will prevent the callback from executing.

//

// `std::move(cleanup).Invoke()` will execute the callback early, before

// destruction, and prevent the callback from executing in the destructor.

//

// Usage:

//

// `absl::Cleanup` is not an interface type. It is only intended to be used

// within the body of a function. It is not a value type and instead models a

// control flow construct. Check out `defer` in Golang for something similar.

#ifndef ABSL_CLEANUP_CLEANUP_H_

#define ABSL_CLEANUP_CLEANUP_H_

#include <utility>

#include "absl/base/config.h"

#include "absl/base/macros.h"

#include "absl/cleanup/internal/cleanup.h"

namespace absl {

ABSL_NAMESPACE_BEGIN

template <typename Arg, typename Callback = void()>

class ABSL_MUST_USE_RESULT Cleanup final {

  static_assert(cleanup_internal::WasDeduced<Arg>(),

                "Explicit template parameters are not supported.");

  static_assert(cleanup_internal::ReturnsVoid<Callback>(),

                "Callbacks that return values are not supported.");

 public:

  Cleanup(Callback callback) : storage_(std::move(callback)) {}  // NOLINT

log_sink_set.cc:absl::Cleanup<absl::cleanup_internal::Tag, absl::log_internal::(anonymous namespace)::GlobalLogSinkSet::LogToSinks(absl::LogEntry const&, absl::Span<absl::LogSink*>, bool)::{lambda()#1}>::Cleanup({lambda()#1})

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  Cleanup(Callback callback) : storage_(std::move(callback)) {}  // NOLINT

Unexecuted instantiation: log_sink_set.cc:absl::Cleanup<absl::cleanup_internal::Tag, absl::log_internal::(anonymous namespace)::GlobalLogSinkSet::FlushLogSinks()::{lambda()#1}>::Cleanup({lambda()#1})

  Cleanup(Cleanup&& other) = default;

  void Cancel() && {

    ABSL_HARDENING_ASSERT(storage_.IsCallbackEngaged());

    storage_.DestroyCallback();

  }

  void Invoke() && {

    ABSL_HARDENING_ASSERT(storage_.IsCallbackEngaged());

    storage_.InvokeCallback();

    storage_.DestroyCallback();

  }

  ~Cleanup() {

    if (storage_.IsCallbackEngaged()) {

      storage_.InvokeCallback();

      storage_.DestroyCallback();

    }

  }

log_sink_set.cc:absl::Cleanup<absl::cleanup_internal::Tag, absl::log_internal::(anonymous namespace)::GlobalLogSinkSet::LogToSinks(absl::LogEntry const&, absl::Span<absl::LogSink*>, bool)::{lambda()#1}>::~Cleanup()

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  ~Cleanup() {

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    if (storage_.IsCallbackEngaged()) {

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      storage_.InvokeCallback();

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      storage_.DestroyCallback();

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    }

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  }

Unexecuted instantiation: log_sink_set.cc:absl::Cleanup<absl::cleanup_internal::Tag, absl::log_internal::(anonymous namespace)::GlobalLogSinkSet::FlushLogSinks()::{lambda()#1}>::~Cleanup()

 private:

  cleanup_internal::Storage<Callback> storage_;

};

// `absl::Cleanup c = /* callback */;`

//

// C++17 type deduction API for creating an instance of `absl::Cleanup`

#if defined(ABSL_HAVE_CLASS_TEMPLATE_ARGUMENT_DEDUCTION)

template <typename Callback>

Cleanup(Callback callback) -> Cleanup<cleanup_internal::Tag, Callback>;

#endif  // defined(ABSL_HAVE_CLASS_TEMPLATE_ARGUMENT_DEDUCTION)

// `auto c = absl::MakeCleanup(/* callback */);`

//

// C++11 type deduction API for creating an instance of `absl::Cleanup`

template <typename... Args, typename Callback>

absl::Cleanup<cleanup_internal::Tag, Callback> MakeCleanup(Callback callback) {

  static_assert(cleanup_internal::WasDeduced<cleanup_internal::Tag, Args...>(),

                "Explicit template parameters are not supported.");

  static_assert(cleanup_internal::ReturnsVoid<Callback>(),

                "Callbacks that return values are not supported.");

  return {std::move(callback)};

}

log_sink_set.cc:absl::Cleanup<absl::cleanup_internal::Tag, absl::log_internal::(anonymous namespace)::GlobalLogSinkSet::LogToSinks(absl::LogEntry const&, absl::Span<absl::LogSink*>, bool)::{lambda()#1}> absl::MakeCleanup<, absl::log_internal::(anonymous namespace)::GlobalLogSinkSet::LogToSinks(absl::LogEntry const&, absl::Span<absl::LogSink*>, bool)::{lambda()#1}>(absl::cleanup_internal::Tag)

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absl::Cleanup<cleanup_internal::Tag, Callback> MakeCleanup(Callback callback) {

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  static_assert(cleanup_internal::WasDeduced<cleanup_internal::Tag, Args...>(),

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                "Explicit template parameters are not supported.");

130

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  static_assert(cleanup_internal::ReturnsVoid<Callback>(),

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                "Callbacks that return values are not supported.");

133

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  return {std::move(callback)};

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}

Unexecuted instantiation: log_sink_set.cc:absl::Cleanup<absl::cleanup_internal::Tag, absl::log_internal::(anonymous namespace)::GlobalLogSinkSet::FlushLogSinks()::{lambda()#1}> absl::MakeCleanup<, absl::log_internal::(anonymous namespace)::GlobalLogSinkSet::FlushLogSinks()::{lambda()#1}>(absl::cleanup_internal::Tag)

ABSL_NAMESPACE_END

}  // namespace absl

#endif  // ABSL_CLEANUP_CLEANUP_H_