Package google.golang.org/appengine/taskqueue (v1.6.8)
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Package taskqueue provides a client for App Engine's taskqueue service. Using this service, applications may perform work outside a user's request.
A Task may be constructed manually; alternatively, since the most common taskqueue operation is to add a single POST task, NewPOSTTask makes it easy.
t:=taskqueue.NewPOSTTask("/worker",url.Values{ "key":{key}, }) taskqueue.Add(c,t,"")//addttothedefaultqueue
Variables
ErrTaskAlreadyAdded
var(
//ErrTaskAlreadyAddedistheerrorreturnedbyAddandAddMultiwhenataskhasalreadybeenaddedwithaparticularname.
ErrTaskAlreadyAdded=errors .New ("taskqueue: task has already been added")
)Functions
func Delete
Delete deletes a task from a named queue.
func DeleteMulti
DeleteMulti deletes multiple tasks from a named queue. If a given task could not be deleted, an appengine.MultiError is returned. Each task is deleted independently; one may fail to delete while the others are successfully deleted.
func ModifyLease
ModifyLease modifies the lease of a task. Used to request more processing time, or to abandon processing. leaseTime is in seconds and must not be negative.
func Purge
Purge removes all tasks from a queue.
QueueStatistics
typeQueueStatisticsstruct{
Tasksint // may be an approximation
OldestETAtime .Time // zero if there are no pending tasks
Executed1Minuteint // tasks executed in the last minute
InFlightint // tasks executing now
EnforcedRatefloat64 // requests per second
}QueueStatistics represents statistics about a single task queue.
func QueueStats
funcQueueStats(ccontext .Context ,queueNames[]string )([]QueueStatistics ,error )QueueStats retrieves statistics about queues.
RequestHeaders
typeRequestHeadersstruct{
QueueNamestring
TaskNamestring
TaskRetryCountint64
TaskExecutionCountint64
TaskETAtime .Time
TaskPreviousResponseint
TaskRetryReasonstring
FailFastbool
}RequestHeaders are the special HTTP request headers available to push task HTTP request handlers. These headers are set internally by App Engine. See https://cloud.google.com/appengine/docs/standard/go/taskqueue/push/creating-handlers#reading_request_headers for a description of the fields.
func ParseRequestHeaders
funcParseRequestHeaders(hhttp .Header )*RequestHeaders ParseRequestHeaders parses the special HTTP request headers available to push task request handlers. This function silently ignores values of the wrong format.
RetryOptions
typeRetryOptionsstruct{
// 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.
RetryLimitint32
// 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.
AgeLimittime .Duration
// Minimum time between successive tries (only for push tasks).
MinBackofftime .Duration
// Maximum time between successive tries (only for push tasks).
MaxBackofftime .Duration
// Maximum number of times to double the interval between successive tries before the intervals increase linearly (only for push tasks).
MaxDoublingsint32
// 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.
ApplyZeroMaxDoublingsbool
}RetryOptions let you control whether to retry a task and the backoff intervals between tries.
Task
typeTaskstruct{
// Path is the worker URL for the task.
// If unset, it will default to /_ah/queue/A Task represents a task to be executed.
func Add
Add adds the task to a named queue. An empty queue name means that the default queue will be used. Add returns an equivalent Task with defaults filled in, including setting the task's Name field to the chosen name if the original was empty.
func AddMulti
AddMulti adds multiple tasks to a named queue. An empty queue name means that the default queue will be used. AddMulti returns a slice of equivalent tasks with defaults filled in, including setting each task's Name field to the chosen name if the original was empty. If a given task is badly formed or could not be added, an appengine.MultiError is returned.
func Lease
Lease leases tasks from a queue. leaseTime is in seconds. The number of tasks fetched will be at most maxTasks.
func LeaseByTag
funcLeaseByTag(ccontext .Context ,maxTasksint ,queueNamestring ,leaseTimeint ,tagstring )([]*Task ,error )LeaseByTag leases tasks from a queue, grouped by tag. If tag is empty, then the returned tasks are grouped by the tag of the task with earliest ETA. leaseTime is in seconds. The number of tasks fetched will be at most maxTasks.
func NewPOSTTask
NewPOSTTask creates a Task that will POST to a path with the given form data.