src/build_event_streamer.h

// Copyright 2025 Google Inc. All Rights Reserved.
//
// 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 NINJA_BUILD_EVENT_STREAMER_H_
#define NINJA_BUILD_EVENT_STREAMER_H_

#include <map>
#include <string>

#include "bes_types.h"
#include "status.h"

struct OutputStream;

/// Writes Build Event Protocol messages in response
/// to build events.
class BuildEventStreamer : public Status {
 public:
  /// ninja_command: the full command used to invoke ninja
  /// config_string: text representation of ninja configuration
  /// metadata: user-defined metadata string values
  /// build_id: (optional) a build identifier string, can be empty.
  /// start_time_millis: start time of build in ms.
  /// out: output stream to write build events (unbuffered).
  BuildEventStreamer(const char* ninja_command,
                     const std::string& config_string,
                     const BuildMetadataMap& metadata,
                     const std::string& build_id, int64_t start_time_millis,
                     OutputStream* out);
  virtual ~BuildEventStreamer();

  void EdgeAddedToPlan(const Edge* edge) override;
  void EdgeRemovedFromPlan(const Edge* edge) override;
  void BuildEdgeStarted(const Edge* edge, int64_t start_time_millis) override;
  void BuildEdgeFinished(Edge* edge, int64_t start_time_millis,
                         int64_t end_time_millis, ExitStatus exit_code,
                         const std::string& output) override;
  void BuildStarted() override;
  void BuildFinished(ExitStatus exit_status) override;

  void SetExplanations(Explanations*) override;

  void InfoV(const char* msg, va_list) override;
  void WarningV(const char* msg, va_list) override;
  void ErrorV(const char* msg, va_list) override;

  // disallow copy, but allow move
  BuildEventStreamer(const BuildEventStreamer&) = delete;
  BuildEventStreamer(BuildEventStreamer&&) = default;
  BuildEventStreamer& operator=(const BuildEventStreamer&) = delete;
  BuildEventStreamer& operator=(BuildEventStreamer&&) = default;

 private:
  const char* ninja_command_;

  std::string config_string_;

  BuildMetadataMap metadata_;

  std::string build_id_;

  int64_t start_time_millis_;

  // Output stream (should be configured un-buffered)
  // Not owned, so the stream object should outlive this object.
  OutputStream* out_ = nullptr;
};

#endif // NINJA_BUILD_EVENT_STREAMER_H_