taskqueue

type AnonymousQueueData map[string][]*Task

type Interface interface {
	// NewTask simply creates a new Task object with the Path field populated.
	// The path parameter may be blank, if you want to use the default task path
	// ("/_ah/queue/<queuename>").
	NewTask(path string) *Task

	Add(task *Task, queueName string) error
	Delete(task *Task, queueName string) error

	AddMulti(tasks []*Task, queueName string) error
	DeleteMulti(tasks []*Task, queueName string) error

	Purge(queueName string) error

	Stats(queueNames ...string) ([]Statistics, error)

	Testable() Testable

	Raw() RawInterface
}

type QueueData map[string]map[string]*Task

type RawCB func(error)

type RawFactory func(c context.Context, wantTxn bool) RawInterface

type RawFilter func(context.Context, RawInterface) RawInterface

type RawInterface interface {
	// AddMulti adds multiple tasks to the given queue, calling cb for each item.
	//
	// The task passed to the callback function will have all the default values
	// filled in, and will have the Name field populated, if the input task was
	// anonymous (e.g. the Name field was blank).
	AddMulti(tasks []*Task, queueName string, cb RawTaskCB) error
	DeleteMulti(tasks []*Task, queueName string, cb RawCB) error

	Purge(queueName string) error

	Stats(queueNames []string, cb RawStatsCB) error

	Testable() Testable
}

type RawStatsCB func(*Statistics, error)

type RawTaskCB func(*Task, error)

type RetryOptions struct {
	// Number of tries/leases after which the task fails permanently and is deleted.
	// If AgeLimit is also set, both limits must be exceeded for the task to fail permanently.
	RetryLimit int32

	// Maximum time allowed since the task's first try before the task fails permanently and is deleted (only for push tasks).
	// If RetryLimit is also set, both limits must be exceeded for the task to fail permanently.
	AgeLimit time.Duration

	// Minimum time between successive tries (only for push tasks).
	MinBackoff time.Duration

	// Maximum time between successive tries (only for push tasks).
	MaxBackoff time.Duration

	// Maximum number of times to double the interval between successive tries before the intervals increase linearly (only for push tasks).
	MaxDoublings int32

	// If MaxDoublings is zero, set ApplyZeroMaxDoublings to true to override the default non-zero value.
	// Otherwise a zero MaxDoublings is ignored and the default is used.
	ApplyZeroMaxDoublings bool
}

type Statistics struct {
	Tasks     int       // may be an approximation
	OldestETA time.Time // zero if there are no pending tasks

	Executed1Minute int     // tasks executed in the last minute
	InFlight        int     // tasks executing now
	EnforcedRate    float64 // requests per second
}

type Task struct {
	// Path is the worker URL for the task.
	// If unset, it will default to /_ah/queue/<queue_name>.
	Path string

	// Payload is the data for the task.
	// This will be delivered as the HTTP request body.
	// It is only used when Method is POST, PUT or PULL.
	// url.Values' Encode method may be used to generate this for POST requests.
	Payload []byte

	// Additional HTTP headers to pass at the task's execution time.
	// To schedule the task to be run with an alternate app version
	// or backend, set the "Host" header.
	Header http.Header

	// Method is the HTTP method for the task ("GET", "POST", etc.),
	// or "PULL" if this is task is destined for a pull-based queue.
	// If empty, this defaults to "POST".
	Method string

	// A name for the task.
	// If empty, a name will be chosen.
	Name string

	// Delay specifies the duration the task queue service must wait
	// before executing the task.
	// Either Delay or ETA may be set, but not both.
	Delay time.Duration

	// ETA specifies the earliest time a task may be executed (push queues)
	// or leased (pull queues).
	// Either Delay or ETA may be set, but not both.
	ETA time.Time

	// The number of times the task has been dispatched or leased.
	RetryCount int32

	// Tag for the task. Only used when Method is PULL.
	Tag string

	// Retry options for this task. May be nil.
	RetryOptions *RetryOptions
}

type Testable interface {
	CreateQueue(queueName string)
	GetScheduledTasks() QueueData
	GetTombstonedTasks() QueueData
	GetTransactionTasks() AnonymousQueueData
	ResetTasks()
}