pretty_print.h

/*
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * 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.
 */

#ifndef THRIFT_FATAL_PRETTY_PRINT_H_
#define THRIFT_FATAL_PRETTY_PRINT_H_ 1

#include <sstream>
#include <string>
#include <type_traits>
#include <utility>

#include <thrift/lib/cpp2/reflection/indenter.h>
#include <thrift/lib/cpp2/reflection/reflection.h>

/**
 * READ ME FIRST: this header provides pretty printers for Thrift types.
 *
 * Please refer to the top of `thrift/lib/cpp2/reflection/reflection.h` on how
 * to enable compile-time reflection for Thrift types. The present header relies
 * on it for its functionality.
 *
 * TROUBLESHOOTING:
 *  - make sure you've followed the instructions on `reflection.h` to enable
 *    generation of compile-time reflection;
 *  - make sure you've included the metadata for your Thrift types, as specified
 *    in `reflection.h`.
 *
 * @author: Marcelo Juchem <marcelo@fb.com>
 */

#include <folly/Traits.h>

#include <thrift/lib/cpp2/Thrift.h>
#include <thrift/lib/cpp2/reflection/internal/pretty_print-inl-pre.h>

namespace apache {
namespace thrift {

/**
 * Pretty-prints an object to the given output stream using Thrift's reflection
 * support.
 *
 * All Thrift types are required to be generated using the 'fatal' cpp2 flag,
 * otherwise compile-time reflection metadata won't be available.
 *
 * @author: Marcelo Juchem <marcelo@fb.com>
 */
template <typename TC, typename OutputStream, typename T>
void pretty_print(
    OutputStream&& out,
    T&& what,
    std::string indentation = "  ",
    std::string margin = std::string()) {
  using impl = apache::thrift::detail::pretty_print_impl<TC>;
  auto indenter = make_indenter(out, std::move(indentation), std::move(margin));
  impl::print(indenter, std::forward<T>(what));
}
template <typename OutputStream, typename T>
void pretty_print(
    OutputStream&& out,
    T&& what,
    std::string indentation = "  ",
    std::string margin = std::string()) {
  using TV = folly::remove_cvref_t<T>;
  using TC = type_class_of_thrift_class_enum_t<TV>;
  static_assert(!std::is_void_v<TC>);
  pretty_print<TC>(
      std::forward<OutputStream>(out),
      std::forward<T>(what),
      std::move(indentation),
      std::move(margin));
}

/**
 * Pretty-prints an object to a string using Thrift's reflection support.
 *
 * All Thrift types are required to be generated using the 'fatal' cpp2 flag,
 * otherwise compile-time reflection metadata won't be available.
 *
 * @author: Marcelo Juchem <marcelo@fb.com>
 */
template <typename TC, typename... Args>
std::string pretty_string(Args&&... args) {
  std::ostringstream out;
  pretty_print<TC>(out, std::forward<Args>(args)...);
  return out.str();
}
template <typename... Args>
std::string pretty_string(Args&&... args) {
  std::ostringstream out;
  pretty_print(out, std::forward<Args>(args)...);
  return out.str();
}

} // namespace thrift
} // namespace apache

#include <thrift/lib/cpp2/reflection/internal/pretty_print-inl-post.h>

#endif // THRIFT_FATAL_PRETTY_PRINT_H_