queue

Documentation

Index

• Variables
• type FilterFn
• type InfoT
  • func (t *InfoT) String() string
• type Queue
  • func New(ctx context.Context) Queue
  • func WithTaskStore(ctx context.Context, q Queue, s store.Store) Queue

Variables

var (
	// ErrCancel indicates the task was canceled.
	ErrCancel = errors.New("queue: task canceled")

	// ErrNotFound indicates the task was not found in the queue.
	ErrNotFound = errors.New("queue: task not found")
)

Types

type FilterFn

type FilterFn func(*model.Task) bool

Filter filters tasks in the queue. If the Filter returns false, the Task is skipped and not returned to the subscriber.

type InfoT

type InfoT struct {
	Pending       []*model.Task `json:"pending"`
	WaitingOnDeps []*model.Task `json:"waiting_on_deps"`
	Running       []*model.Task `json:"running"`
	Stats         struct {
		Workers       int `json:"worker_count"`
		Pending       int `json:"pending_count"`
		WaitingOnDeps int `json:"waiting_on_deps_count"`
		Running       int `json:"running_count"`
	} `json:"stats"`
	Paused bool `json:"paused"`

} //	@name InfoT

InfoT provides runtime information.

func (*InfoT) String

func (t *InfoT) String() string

type Queue

type Queue interface {
	// Push pushes a task to the tail of this queue.
	Push(c context.Context, task *model.Task) error

	// PushAtOnce pushes multiple tasks to the tail of this queue.
	PushAtOnce(c context.Context, tasks []*model.Task) error

	// Poll retrieves and removes a task head of this queue.
	Poll(c context.Context, agentID int64, f FilterFn) (*model.Task, error)

	// Extend extends the deadline for a task.
	Extend(c context.Context, id string) error

	// Done signals the task is complete.
	Done(c context.Context, id string, exitStatus model.StatusValue) error

	// Error signals the task is done with an error.
	Error(c context.Context, id string, err error) error

	// ErrorAtOnce signals multiple done are complete with an error.
	ErrorAtOnce(c context.Context, ids []string, err error) error

	// Evict removes a pending task from the queue.
	Evict(c context.Context, id string) error

	// EvictAtOnce removes multiple pending tasks from the queue.
	EvictAtOnce(c context.Context, ids []string) error

	// Wait waits until the task is complete.
	Wait(c context.Context, id string) error

	// Info returns internal queue information.
	Info(c context.Context) InfoT

	// Pause stops the queue from handing out new work items in Poll
	Pause()

	// Resume starts the queue again.
	Resume()

	// KickAgentWorkers kicks all workers for a given agent.
	KickAgentWorkers(agentID int64)
}

Queue defines a task queue for scheduling tasks among a pool of workers.

func New

func New(ctx context.Context) Queue

New returns a new fifo queue.

func WithTaskStore

func WithTaskStore(ctx context.Context, q Queue, s store.Store) Queue

WithTaskStore returns a queue that is backed by the TaskStore. This ensures the task Queue can be restored when the system starts.