fixed_lag_smoother.h

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#ifndef FUSE_OPTIMIZERS_FIXED_LAG_SMOOTHER_H
#define FUSE_OPTIMIZERS_FIXED_LAG_SMOOTHER_H
 
#include <fuse_core/graph.h>
#include <fuse_core/transaction.h>
#include <fuse_optimizers/fixed_lag_smoother_params.h>
#include <fuse_optimizers/optimizer.h>
#include <fuse_optimizers/variable_stamp_index.h>
#include <ros/ros.h>
#include <std_srvs/Empty.h>
 
#include <atomic>
#include <condition_variable>
#include <functional>
#include <mutex>
#include <string>
#include <thread>
#include <vector>
 
 
namespace fuse_optimizers
{
 
class FixedLagSmoother : public Optimizer
{
public:
  FUSE_SMART_PTR_DEFINITIONS(FixedLagSmoother);
  using ParameterType = FixedLagSmootherParams;
 
  FixedLagSmoother(
    fuse_core::Graph::UniquePtr graph,
    const ros::NodeHandle& node_handle = ros::NodeHandle(),
    const ros::NodeHandle& private_node_handle = ros::NodeHandle("~"));
 
  virtual ~FixedLagSmoother();
 
protected:
  struct TransactionQueueElement
  {
    std::string sensor_name;
    fuse_core::Transaction::SharedPtr transaction;
 
    const ros::Time& stamp() const { return transaction->stamp(); }
    const ros::Time& minStamp() const { return transaction->minStamp(); }
    const ros::Time& maxStamp() const { return transaction->maxStamp(); }
  };
 
  using TransactionQueue = std::vector<TransactionQueueElement>;
 
  // Read-only after construction
  std::thread optimization_thread_;  
  ParameterType params_;  
 
  // Inherently thread-safe
  std::atomic<bool> ignited_;  
  std::atomic<bool> optimization_running_;  
  std::atomic<bool> started_;  
 
  // Guarded by pending_transactions_mutex_
  std::mutex pending_transactions_mutex_;  
  TransactionQueue pending_transactions_;  
 
  // Guarded by optimization_mutex_
  std::mutex optimization_mutex_;  
  // fuse_core::Graph* graph_ member from the base class
  ros::Time lag_expiration_;  
  fuse_core::Transaction marginal_transaction_;  
  VariableStampIndex timestamp_tracking_;  
  ceres::Solver::Summary summary_;  
 
  // Guarded by optimization_requested_mutex_
  std::mutex optimization_requested_mutex_;  
  ros::Time optimization_deadline_;  
  bool optimization_request_;  
  std::condition_variable optimization_requested_;  
 
  // Guarded by start_time_mutex_
  mutable std::mutex start_time_mutex_;  
  ros::Time start_time_;  
 
  // Ordering ROS objects with callbacks last
  ros::Timer optimize_timer_;  
  ros::ServiceServer reset_service_server_;  
  ros::ServiceServer stop_service_server_;  
  ros::ServiceServer start_service_server_;  
  ros::Publisher status_publisher_;  
 
  void autostart();
 
  void publishStatus(const bool running);
 
  void preprocessMarginalization(const fuse_core::Transaction& new_transaction);
 
  ros::Time computeLagExpirationTime() const;
 
  std::vector<fuse_core::UUID> computeVariablesToMarginalize(const ros::Time& lag_expiration);
 
  void postprocessMarginalization(const fuse_core::Transaction& marginal_transaction);
 
  void optimizationLoop();
 
  void optimizerTimerCallback(const ros::TimerEvent& event);
 
  void processQueue(fuse_core::Transaction& transaction, const ros::Time& lag_expiration);
 
  bool resetServiceCallback(std_srvs::Empty::Request&, std_srvs::Empty::Response&);
 
  bool stopServiceCallback(std_srvs::Empty::Request&, std_srvs::Empty::Response&);
 
  bool startServiceCallback(std_srvs::Empty::Request&, std_srvs::Empty::Response&);
 
  void start();
 
  void stop();
 
  ros::Time getStartTime() const
  {
    std::lock_guard<std::mutex> lock(start_time_mutex_);
    return start_time_;
  }
 
  void setStartTime(const ros::Time& start_time)
  {
    std::lock_guard<std::mutex> lock(start_time_mutex_);
    start_time_ = start_time;
  }
 
  void transactionCallback(
    const std::string& sensor_name,
    fuse_core::Transaction::SharedPtr transaction) override;
 
  void setDiagnostics(diagnostic_updater::DiagnosticStatusWrapper& status) override;
};
 
}  // namespace fuse_optimizers
 
#endif  // FUSE_OPTIMIZERS_FIXED_LAG_SMOOTHER_H