trainer

type Callback interface {
	//SaveModel to persist a model
	SaveModel(*pbCom.TrainTaskResult) error

	// StartTask starts a specific task of training or prediction
	StartTask(*pbCom.StartTaskRequest) error

	//StopTask to stop a training task
	// You'd better use it asynchronously to avoid deadlock
	StopTask(*pbCom.StopTaskRequest) error

	// Train to train out a model
	Train(*pb.TrainRequest) (*pb.TrainResponse, error)
}

type Evaluator interface {
	// Start starts model evaluation, segment the training set according to a certain strategy (cross validation, proportional random division),
	//  then starts the training-validation process.
	// fileRows is returned by psi.IntersectParts after sample alignment.
	Start(fileRows [][]string) error

	// Stop deletes all the leaners created by Evaluator as well as other objects
	Stop()

	// SaveModel collects the results of the training in the evaluation phase, that is, the model.
	// If the model is successfully trained,
	// it will trigger the local creation of a Model instance for validation.
	SaveModel(*pbCom.TrainTaskResult) error

	// SavePredictOut collects the prediction results in the evaluation phase.
	// If the prediction result is obtained, it will check how many prediction results have been obtained so far,
	//  and determine whether to start calculating the average scores for each metric.
	SavePredictOut(*pbCom.PredictTaskResult) error
}

type Learner interface {
	// Advance does calculation with local data and communicates with other nodes in cluster to train a model step by step
	// payload could be resolved by Learner defined by specific algorithm
	// We'd better call the method asynchronously avoid blocking the main go-routine
	Advance(payload []byte) (*pb.TrainResponse, error)
}

type LiveEvaluator interface {
	// Trigger triggers model evaluation.
	// The parameter contains two types of messages.
	// One is to set the learner for evaluation with training set and start it.
	// The other is to drive the learner to continue training. When the conditions are met(reaching pause round),
	// stop training and instantiate the model for validation.
	Trigger(*pb.LiveEvaluationTriggerMsg) error

	// Stop deletes all the leaners created by LiveEvaluator as well as other objects
	Stop()

	// SaveModel collects the results of the training in the evaluation phase,
	// that is, the model, for LiveEvaluation of Model.
	// If the model is successfully trained,
	// it will trigger the local creation of a Model instance for validation.
	SaveModel(*pbCom.TrainTaskResult) error

	// SavePredictOut collects the prediction results in the evaluation phase.
	// If the prediction result is obtained, it will start calculating metric scores,
	// then report the results to visualization system.
	SavePredictOut(*pbCom.PredictTaskResult) error
}

type RpcHandler interface {
	StepTrain(req *pb.TrainRequest, peerName string) (*pb.TrainResponse, error)

	// StepTrainWithRetry sends training message to remote mpc-node
	// retries 2 times at most
	// inteSec indicates the interval between retry requests, in seconds
	StepTrainWithRetry(req *pb.TrainRequest, peerName string, times int, inteSec int64) (*pb.TrainResponse, error)
}

type TrainResponse struct {
	Resp *pb.TrainResponse
	Err  error
}

type Trainer struct {
	// contains filtered or unexported fields
}