queue

Documentation

Overview

Package queue implements an experimental background queue for cleanup jobs. Beware: It's likely broken. We can easily close a channel which might later be written to. The current locking is but a poor workaround. A better implementation would create a queue object in main, pass it through and wait for the channel to be empty before leaving main. Will do that later.

Index

• func WithQueue(ctx context.Context, q *Queue) context.Context
• type Queue
  • func New(ctx context.Context) *Queue
  • func (q *Queue) Add(t Task) Task
  • func (q *Queue) Close(ctx context.Context) error
  • func (q *Queue) Idle(maxWait time.Duration) error
• type Queuer
  • func GetQueue(ctx context.Context) Queuer
• type Task

Functions

func WithQueue

func WithQueue(ctx context.Context, q *Queue) context.Context

WithQueue adds the given queue to the context. Add a nil queue to disable queuing in this context.

Types

type Queue

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

Queue is a serialized background processing unit.

func New

func New(ctx context.Context) *Queue

New creates a new queue.

func (*Queue) Add

func (q *Queue) Add(t Task) Task

Add enqueues a new task.

func (*Queue) Close

func (q *Queue) Close(ctx context.Context) error

Close waits for all tasks to be processed. Must only be called once on shutdown.

func (*Queue) Idle

func (q *Queue) Idle(maxWait time.Duration) error

Idle returns nil the next time the queue is empty.

type Queuer

type Queuer interface {
	Add(Task) Task
	Close(context.Context) error
	Idle(time.Duration) error
}

Queuer is a queue interface.

func GetQueue

func GetQueue(ctx context.Context) Queuer

GetQueue returns an existing queue from the context or returns a noop one.

type Task

type Task func(ctx context.Context) (context.Context, error)

Task is a background task.