libminifi/include/Connection.h

/**
 * @file Connection.h
 * Connection class declaration
 *
 * 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.
 */
#ifndef LIBMINIFI_INCLUDE_CONNECTION_H_
#define LIBMINIFI_INCLUDE_CONNECTION_H_

#include <memory>
#include <set>
#include <string>
#include <vector>
#include <queue>
#include <map>
#include <mutex>
#include <atomic>
#include <algorithm>
#include "core/Core.h"
#include "core/Connectable.h"
#include "core/logging/Logger.h"
#include "core/Relationship.h"
#include "core/FlowFile.h"
#include "core/Repository.h"

namespace org {
namespace apache {
namespace nifi {
namespace minifi {
// Connection Class

class Connection : public core::Connectable, public std::enable_shared_from_this<Connection> {
 public:
  // Constructor
  /*
   * Create a new processor
   */
  explicit Connection(const std::shared_ptr<core::Repository> &flow_repository, const std::shared_ptr<core::ContentRepository> &content_repo, std::string name);
  explicit Connection(const std::shared_ptr<core::Repository> &flow_repository, const std::shared_ptr<core::ContentRepository> &content_repo, std::string name, const utils::Identifier& uuid);
  explicit Connection(const std::shared_ptr<core::Repository> &flow_repository, const std::shared_ptr<core::ContentRepository> &content_repo, std::string name, const utils::Identifier& uuid,
                      const utils::Identifier& srcUUID);
  explicit Connection(const std::shared_ptr<core::Repository> &flow_repository, const std::shared_ptr<core::ContentRepository> &content_repo, std::string name, const utils::Identifier& uuid,
                      const utils::Identifier& srcUUID, const utils::Identifier& destUUID);
  // Destructor
  virtual ~Connection() = default;

  // Set Source Processor UUID
  void setSourceUUID(const utils::Identifier& uuid) {
    src_uuid_ = uuid;
  }
  // Set Destination Processor UUID
  void setDestinationUUID(const utils::Identifier& uuid) {
    dest_uuid_ = uuid;
  }
  // Get Source Processor UUID
  utils::Identifier getSourceUUID() const {
    return src_uuid_;
  }
  // Get Destination Processor UUID
  utils::Identifier getDestinationUUID() const {
    return dest_uuid_;
  }

  // Set Connection Source Processor
  void setSource(std::shared_ptr<core::Connectable> source) {
    source_connectable_ = source;
  }
  // ! Get Connection Source Processor
  std::shared_ptr<core::Connectable> getSource() {
    return source_connectable_;
  }
  // Set Connection Destination Processor
  void setDestination(std::shared_ptr<core::Connectable> dest) {
    dest_connectable_ = dest;
  }
  // ! Get Connection Destination Processor
  std::shared_ptr<core::Connectable> getDestination() {
    return dest_connectable_;
  }

  /**
   * Deprecated function
   * Please use addRelationship.
   */
  void setRelationship(core::Relationship relationship) {
    relationships_.insert(relationship);
  }

  // Set Connection relationship
  void addRelationship(core::Relationship relationship) {
    relationships_.insert(relationship);
  }
  // ! Get Connection relationship
  const std::set<core::Relationship> &getRelationships() const {
    return relationships_;
  }
  // Set Max Queue Size
  void setMaxQueueSize(uint64_t size) {
    max_queue_size_ = size;
  }
  // Get Max Queue Size
  uint64_t getMaxQueueSize() {
    return max_queue_size_;
  }
  // Set Max Queue Data Size
  void setMaxQueueDataSize(uint64_t size) {
    max_data_queue_size_ = size;
  }
  // Get Max Queue Data Size
  uint64_t getMaxQueueDataSize() {
    return max_data_queue_size_;
  }
  // Set Flow expiration duration in millisecond
  void setFlowExpirationDuration(uint64_t duration) {
    expired_duration_ = duration;
  }
  // Get Flow expiration duration in millisecond
  uint64_t getFlowExpirationDuration() {
    return expired_duration_;
  }

  void setDropEmptyFlowFiles(bool drop) {
    drop_empty_ = drop;
  }

  bool getDropEmptyFlowFiles() const {
    return drop_empty_;
  }

  // Check whether the queue is empty
  bool isEmpty();
  // Check whether the queue is full to apply back pressure
  bool isFull();
  // Get queue size
  uint64_t getQueueSize() {
    std::lock_guard<std::mutex> lock(mutex_);
    return queue_.size();
  }
  // Get queue data size
  uint64_t getQueueDataSize() {
    return queued_data_size_;
  }

  // Put the flow file into queue
  void put(const std::shared_ptr<core::FlowFile>& flow) override;

  // Put multiple flowfiles into the queue
  void multiPut(std::vector<std::shared_ptr<core::FlowFile>>& flows);
  // Poll the flow file from queue, the expired flow file record also being returned
  std::shared_ptr<core::FlowFile> poll(std::set<std::shared_ptr<core::FlowFile>> &expiredFlowRecords);
  // Drain the flow records
  void drain(bool delete_permanently);

  void yield() override {}

  bool isWorkAvailable() override {
    return !isEmpty();
  }

  bool isRunning() override {
    return true;
  }

 protected:
  // Source Processor UUID
  utils::Identifier src_uuid_;
  // Destination Processor UUID
  utils::Identifier dest_uuid_;
  // Relationship for this connection
  std::set<core::Relationship> relationships_;
  // Source Processor (ProcessNode/Port)
  std::shared_ptr<core::Connectable> source_connectable_;
  // Destination Processor (ProcessNode/Port)
  std::shared_ptr<core::Connectable> dest_connectable_;
  // Max queue size to apply back pressure
  std::atomic<uint64_t> max_queue_size_;
  // Max queue data size to apply back pressure
  std::atomic<uint64_t> max_data_queue_size_;
  // Flow File Expiration Duration in= MilliSeconds
  std::atomic<uint64_t> expired_duration_;
  // flow file repository
  std::shared_ptr<core::Repository> flow_repository_;
  // content repository reference.
  std::shared_ptr<core::ContentRepository> content_repo_;

 private:
  bool drop_empty_;
  // Mutex for protection
  std::mutex mutex_;
  // Queued data size
  std::atomic<uint64_t> queued_data_size_;
  // Queue for the Flow File
  std::queue<std::shared_ptr<core::FlowFile>> queue_;
  // flow repository
  // Logger
  std::shared_ptr<logging::Logger> logger_;
  // Prevent default copy constructor and assignment operation
  // Only support pass by reference or pointer
  Connection(const Connection &parent);
  Connection &operator=(const Connection &parent);
};
}  // namespace minifi
}  // namespace nifi
}  // namespace apache
}  // namespace org
#endif  // LIBMINIFI_INCLUDE_CONNECTION_H_