backend

package
v0.5.0 Latest Latest
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 Go to latest Published: Jun 28, 2024 License: Apache-2.0 Imports: 25 Imported by: 26

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Index

Constants

This section is empty.

Variables

View Source 
var (
	ErrTaskHubExists         = errors.New("task hub already exists")
	ErrTaskHubNotFound       = errors.New("task hub not found")
	ErrNotInitialized        = errors.New("backend not initialized")
	ErrWorkItemLockLost      = errors.New("lock on work-item was lost")
	ErrBackendAlreadyStarted = errors.New("backend is already started")
)
View Source 
var ErrDuplicateEvent = errors.New("duplicate event")
View Source 
var ErrNoWorkItems = errors.New("no work items were found")

Functions

func IsDurableTaskGrpcRequest added in v0.1.1 

func IsDurableTaskGrpcRequest(fullMethodName string) bool

IsDurableTaskGrpcRequest returns true if the specified gRPC method name represents an operation that is compatible with the gRPC executor.

func MarshalHistoryEvent added in v0.1.1 

func MarshalHistoryEvent(e *HistoryEvent) ([]byte, error)

MarshalHistoryEvent serializes the HistoryEvent into a protobuf byte array.

func WithOnGetWorkItemsConnectionCallback added in v0.1.1 

func WithOnGetWorkItemsConnectionCallback(callback func(context.Context) error) grpcExecutorOptions

WithOnGetWorkItemsConnectionCallback allows the caller to get a notification when an external process connects over gRPC and invokes the GetWorkItems operation. This can be useful for doing things like lazily auto-starting the task hub worker only when necessary.

func WithStreamShutdownChannel added in v0.1.2 

func WithStreamShutdownChannel(c <-chan any) grpcExecutorOptions

Types

type ActivityExecutor 

type ActivityExecutor interface {
	ExecuteActivity(context.Context, api.InstanceID, *protos.HistoryEvent) (*protos.HistoryEvent, error)
}

type ActivityWorkItem 

type ActivityWorkItem struct {
	SequenceNumber int64
	InstanceID     api.InstanceID
	NewEvent       *HistoryEvent
	Result         *HistoryEvent
	LockedBy       string
	Properties     map[string]interface{}
}

func (ActivityWorkItem) IsWorkItem added in v0.5.0 

func (wi ActivityWorkItem) IsWorkItem() bool

IsWorkItem implements core.WorkItem

func (ActivityWorkItem) String added in v0.5.0 

func (wi ActivityWorkItem) String() string

String implements core.WorkItem and fmt.Stringer

type Backend 

type Backend interface {
	// CreateTaskHub creates a new task hub for the current backend. Task hub creation must be idempotent.
	//
	// If the task hub for this backend already exists, an error of type [ErrTaskHubExists] is returned.
	CreateTaskHub(context.Context) error

	// DeleteTaskHub deletes an existing task hub configured for the current backend. It's up to the backend
	// implementation to determine how the task hub data is deleted.
	//
	// If the task hub for this backend doesn't exist, an error of type [ErrTaskHubNotFound] is returned.
	DeleteTaskHub(context.Context) error

	// Start starts any background processing done by this backend.
	Start(context.Context) error

	// Stop stops any background processing done by this backend.
	Stop(context.Context) error

	// CreateOrchestrationInstance creates a new orchestration instance with a history event that
	// wraps a ExecutionStarted event.
	CreateOrchestrationInstance(context.Context, *HistoryEvent, ...OrchestrationIdReusePolicyOptions) error

	// AddNewEvent adds a new orchestration event to the specified orchestration instance.
	AddNewOrchestrationEvent(context.Context, api.InstanceID, *HistoryEvent) error

	// GetOrchestrationWorkItem gets a pending work item from the task hub or returns [ErrNoOrchWorkItems]
	// if there are no pending work items.
	GetOrchestrationWorkItem(context.Context) (*OrchestrationWorkItem, error)

	// GetOrchestrationRuntimeState gets the runtime state of an orchestration instance.
	GetOrchestrationRuntimeState(context.Context, *OrchestrationWorkItem) (*OrchestrationRuntimeState, error)

	// GetOrchestrationMetadata gets the metadata associated with the given orchestration instance ID.
	//
	// Returns [api.ErrInstanceNotFound] if the orchestration instance doesn't exist.
	GetOrchestrationMetadata(context.Context, api.InstanceID) (*api.OrchestrationMetadata, error)

	// CompleteOrchestrationWorkItem completes a work item by saving the updated runtime state to durable storage.
	//
	// Returns [ErrWorkItemLockLost] if the work-item couldn't be completed due to a lock-lost conflict (e.g., split-brain).
	CompleteOrchestrationWorkItem(context.Context, *OrchestrationWorkItem) error

	// AbandonOrchestrationWorkItem undoes any state changes and returns the work item to the work item queue.
	//
	// This is called if an internal failure happens in the processing of an orchestration work item. It is
	// not called if the orchestration work item is processed successfully (note that an orchestration that
	// completes with a failure is still considered a successfully processed work item).
	AbandonOrchestrationWorkItem(context.Context, *OrchestrationWorkItem) error

	// GetActivityWorkItem gets a pending activity work item from the task hub or returns [ErrNoWorkItems]
	// if there are no pending activity work items.
	GetActivityWorkItem(context.Context) (*ActivityWorkItem, error)

	// CompleteActivityWorkItem sends a message to the parent orchestration indicating activity completion.
	//
	// Returns [ErrWorkItemLockLost] if the work-item couldn't be completed due to a lock-lost conflict (e.g., split-brain).
	CompleteActivityWorkItem(context.Context, *ActivityWorkItem) error

	// AbandonActivityWorkItem returns the work-item back to the queue without committing any other chances.
	//
	// This is called when an internal failure occurs during activity work-item processing.
	AbandonActivityWorkItem(context.Context, *ActivityWorkItem) error

	// PurgeOrchestrationState deletes all saved state for the specified orchestration instance.
	//
	// [api.ErrInstanceNotFound] is returned if the specified orchestration instance doesn't exist.
	// [api.ErrNotCompleted] is returned if the specified orchestration instance is still running.
	PurgeOrchestrationState(context.Context, api.InstanceID) error
}

type ExecutionResults 

type ExecutionResults struct {
	Response *protos.OrchestratorResponse
	// contains filtered or unexported fields
}

type Executor 

type Executor interface {
	ExecuteOrchestrator(ctx context.Context, iid api.InstanceID, oldEvents []*protos.HistoryEvent, newEvents []*protos.HistoryEvent) (*ExecutionResults, error)
	ExecuteActivity(context.Context, api.InstanceID, *protos.HistoryEvent) (*protos.HistoryEvent, error)
	Shutdown(ctx context.Context) error
}

func NewGrpcExecutor 

func NewGrpcExecutor(be Backend, logger Logger, opts ...grpcExecutorOptions) (executor Executor, registerServerFn func(grpcServer grpc.ServiceRegistrar))

NewGrpcExecutor returns the Executor object and a method to invoke to register the gRPC server in the executor.

type HistoryEvent added in v0.1.1 

type HistoryEvent = protos.HistoryEvent

func UnmarshalHistoryEvent added in v0.1.1 

func UnmarshalHistoryEvent(bytes []byte) (*HistoryEvent, error)

UnmarshalHistoryEvent deserializes a HistoryEvent from a protobuf byte array.

type Logger added in v0.1.1 

type Logger interface {
	// Debug logs a message at level Debug.
	Debug(v ...any)
	// Debugf logs a message at level Debug.
	Debugf(format string, v ...any)
	// Info logs a message at level Info.
	Info(v ...any)
	// Infof logs a message at level Info.
	Infof(format string, v ...any)
	// Warn logs a message at level Warn.
	Warn(v ...any)
	// Warnf logs a message at level Warn.
	Warnf(format string, v ...any)
	// Error logs a message at level Error.
	Error(v ...any)
	// Errorf logs a message at level Error.
	Errorf(format string, v ...any)
}

func DefaultLogger added in v0.1.1 

func DefaultLogger() Logger

type NewTaskWorkerOptions added in v0.1.1 

type NewTaskWorkerOptions func(*WorkerOptions)

func WithMaxParallelism added in v0.1.1 

func WithMaxParallelism(n int32) NewTaskWorkerOptions

type OrchestrationIdReusePolicyOptions added in v0.3.2 

type OrchestrationIdReusePolicyOptions func(*protos.OrchestrationIdReusePolicy) error

func WithOrchestrationIdReusePolicy added in v0.3.2 

func WithOrchestrationIdReusePolicy(policy *protos.OrchestrationIdReusePolicy) OrchestrationIdReusePolicyOptions

type OrchestrationRuntimeState 

type OrchestrationRuntimeState struct {
	CustomStatus *wrapperspb.StringValue
	// contains filtered or unexported fields
}

func NewOrchestrationRuntimeState 

func NewOrchestrationRuntimeState(instanceID api.InstanceID, existingHistory []*HistoryEvent) *OrchestrationRuntimeState

func (*OrchestrationRuntimeState) AddEvent 

func (s *OrchestrationRuntimeState) AddEvent(e *HistoryEvent) error

AddEvent appends a new history event to the orchestration history

func (*OrchestrationRuntimeState) ApplyActions 

func (s *OrchestrationRuntimeState) ApplyActions(actions []*protos.OrchestratorAction, currentTraceContext *protos.TraceContext) (bool, error)

ApplyActions takes a set of actions and updates its internal state, including populating the outbox.

func (*OrchestrationRuntimeState) CompletedTime 

func (s *OrchestrationRuntimeState) CompletedTime() (time.Time, error)

func (*OrchestrationRuntimeState) ContinuedAsNew 

func (s *OrchestrationRuntimeState) ContinuedAsNew() bool

func (*OrchestrationRuntimeState) CreatedTime 

func (s *OrchestrationRuntimeState) CreatedTime() (time.Time, error)

func (*OrchestrationRuntimeState) FailureDetails 

func (s *OrchestrationRuntimeState) FailureDetails() (*TaskFailureDetails, error)

func (*OrchestrationRuntimeState) Input 

func (s *OrchestrationRuntimeState) Input() (string, error)

func (*OrchestrationRuntimeState) InstanceID 

func (s *OrchestrationRuntimeState) InstanceID() api.InstanceID

func (*OrchestrationRuntimeState) IsCompleted 

func (s *OrchestrationRuntimeState) IsCompleted() bool

func (*OrchestrationRuntimeState) IsValid 

func (s *OrchestrationRuntimeState) IsValid() bool

func (*OrchestrationRuntimeState) LastUpdatedTime added in v0.1.1 

func (s *OrchestrationRuntimeState) LastUpdatedTime() (time.Time, error)

func (*OrchestrationRuntimeState) Name 

func (s *OrchestrationRuntimeState) Name() (string, error)

func (*OrchestrationRuntimeState) NewEvents 

func (s *OrchestrationRuntimeState) NewEvents() []*HistoryEvent

func (*OrchestrationRuntimeState) OldEvents 

func (s *OrchestrationRuntimeState) OldEvents() []*HistoryEvent

func (*OrchestrationRuntimeState) Output 

func (s *OrchestrationRuntimeState) Output() (string, error)

func (*OrchestrationRuntimeState) PendingMessages 

func (s *OrchestrationRuntimeState) PendingMessages() []OrchestratorMessage

func (*OrchestrationRuntimeState) PendingTasks 

func (s *OrchestrationRuntimeState) PendingTasks() []*HistoryEvent

func (*OrchestrationRuntimeState) PendingTimers 

func (s *OrchestrationRuntimeState) PendingTimers() []*HistoryEvent

func (*OrchestrationRuntimeState) RuntimeStatus 

func (s *OrchestrationRuntimeState) RuntimeStatus() protos.OrchestrationStatus

func (*OrchestrationRuntimeState) String 

func (s *OrchestrationRuntimeState) String() string

type OrchestrationWorkItem 

type OrchestrationWorkItem struct {
	InstanceID api.InstanceID
	NewEvents  []*HistoryEvent
	LockedBy   string
	RetryCount int32
	State      *OrchestrationRuntimeState
	Properties map[string]interface{}
}

func (*OrchestrationWorkItem) GetAbandonDelay 

func (wi *OrchestrationWorkItem) GetAbandonDelay() time.Duration

func (OrchestrationWorkItem) IsWorkItem added in v0.5.0 

func (wi OrchestrationWorkItem) IsWorkItem() bool

IsWorkItem implements core.WorkItem

func (OrchestrationWorkItem) String added in v0.5.0 

func (wi OrchestrationWorkItem) String() string

String implements core.WorkItem and fmt.Stringer

type OrchestratorExecutor 

type OrchestratorExecutor interface {
	ExecuteOrchestrator(
		ctx context.Context,
		iid api.InstanceID,
		oldEvents []*protos.HistoryEvent,
		newEvents []*protos.HistoryEvent) (*ExecutionResults, error)
}

type OrchestratorMessage 

type OrchestratorMessage struct {
	HistoryEvent     *HistoryEvent
	TargetInstanceID string
}

type TaskFailureDetails added in v0.1.1 

type TaskFailureDetails = protos.TaskFailureDetails

type TaskHubClient added in v0.1.1 

type TaskHubClient interface {
	ScheduleNewOrchestration(ctx context.Context, orchestrator interface{}, opts ...api.NewOrchestrationOptions) (api.InstanceID, error)
	FetchOrchestrationMetadata(ctx context.Context, id api.InstanceID) (*api.OrchestrationMetadata, error)
	WaitForOrchestrationStart(ctx context.Context, id api.InstanceID) (*api.OrchestrationMetadata, error)
	WaitForOrchestrationCompletion(ctx context.Context, id api.InstanceID) (*api.OrchestrationMetadata, error)
	TerminateOrchestration(ctx context.Context, id api.InstanceID, opts ...api.TerminateOptions) error
	RaiseEvent(ctx context.Context, id api.InstanceID, eventName string, opts ...api.RaiseEventOptions) error
	SuspendOrchestration(ctx context.Context, id api.InstanceID, reason string) error
	ResumeOrchestration(ctx context.Context, id api.InstanceID, reason string) error
	PurgeOrchestrationState(ctx context.Context, id api.InstanceID, opts ...api.PurgeOptions) error
}

func NewTaskHubClient added in v0.1.1 

func NewTaskHubClient(be Backend) TaskHubClient

type TaskHubWorker 

type TaskHubWorker interface {
	// Start starts the backend and the configured internal workers.
	Start(context.Context) error

	// Shutdown stops the backend and all internal workers.
	Shutdown(context.Context) error
}

func NewTaskHubWorker 

func NewTaskHubWorker(be Backend, orchestrationWorker TaskWorker, activityWorker TaskWorker, logger Logger) TaskHubWorker

type TaskProcessor 

type TaskProcessor interface {
	Name() string
	FetchWorkItem(context.Context) (WorkItem, error)
	ProcessWorkItem(context.Context, WorkItem) error
	AbandonWorkItem(context.Context, WorkItem) error
	CompleteWorkItem(context.Context, WorkItem) error
}

type TaskWorker 

type TaskWorker interface {
	// Start starts background polling for the activity work items.
	Start(context.Context)

	// ProcessNext attempts to fetch and process a work item. This method returns
	// true if a work item was found and processing started; false otherwise. An
	// error is returned if the context is cancelled.
	ProcessNext(context.Context) (bool, error)

	// StopAndDrain stops the worker and waits for all outstanding work items to finish.
	StopAndDrain()
}

func NewActivityTaskWorker 

func NewActivityTaskWorker(be Backend, executor ActivityExecutor, logger Logger, opts ...NewTaskWorkerOptions) TaskWorker

func NewOrchestrationWorker 

func NewOrchestrationWorker(be Backend, executor OrchestratorExecutor, logger Logger, opts ...NewTaskWorkerOptions) TaskWorker

func NewTaskWorker 

func NewTaskWorker(p TaskProcessor, logger Logger, opts ...NewTaskWorkerOptions) TaskWorker

type WorkItem 

type WorkItem interface {
	fmt.Stringer
	IsWorkItem() bool
}

type WorkerOptions added in v0.1.1 

type WorkerOptions struct {
	MaxParallelWorkItems int32
}

func NewWorkerOptions added in v0.1.1 

func NewWorkerOptions() *WorkerOptions

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