extensions/script/python/PyProcessSession.h

/**
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

#pragma once

#include <utility>
#include <memory>
#include <vector>

#include "pybind11/embed.h"
#include "core/ProcessSession.h"
#include "../ScriptFlowFile.h"
#include "PyInputStream.h"
#include "PyOutputStream.h"

#if defined(__GNUC__) || defined(__GNUG__)
#pragma GCC visibility push(hidden)
#endif

namespace org::apache::nifi::minifi::python {

namespace py = pybind11;

class PyProcessSession {
 public:
  explicit PyProcessSession(std::shared_ptr<core::ProcessSession> session);

  std::shared_ptr<script::ScriptFlowFile> get();
  std::shared_ptr<script::ScriptFlowFile> create();
  std::shared_ptr<script::ScriptFlowFile> create(const std::shared_ptr<script::ScriptFlowFile>& flow_file);
  void transfer(const std::shared_ptr<script::ScriptFlowFile>& flow_file, const core::Relationship& relationship);
  void read(const std::shared_ptr<script::ScriptFlowFile>& flow_file, py::object input_stream_callback);
  void write(const std::shared_ptr<script::ScriptFlowFile>& flow_file, py::object output_stream_callback);
  void remove(const std::shared_ptr<script::ScriptFlowFile>& flow_file);

  /**
   * Sometimes we want to release shared pointers to core resources when
   * we know they are no longer in need. This method is for those times.
   *
   * For example, we do not want to hold on to shared pointers to FlowFiles
   * after an onTrigger call, because doing so can be very expensive in terms
   * of repository resources.
   */
  void releaseCoreResources();

 private:
  std::vector<std::shared_ptr<script::ScriptFlowFile>> flow_files_;
  std::shared_ptr<core::ProcessSession> session_;
};

}  // namespace org::apache::nifi::minifi::python

#if defined(__GNUC__) || defined(__GNUG__)
#pragma GCC visibility pop
#endif