worker

Documentation

Index

• func Parallel(ctx context.Context, workers ...Worker) error
• type Worker
• type WorkerGroup
  • func NewWorkerGroup(ctx context.Context, workerLimit int) *WorkerGroup
  • func (wg *WorkerGroup) Start(worker Worker) error
  • func (wg *WorkerGroup) Wait() error
  • func (wg *WorkerGroup) WaitError(err error) error

Functions

func Parallel

func Parallel(ctx context.Context, workers ...Worker) error

Parallel executes a set of Workers and waits for them to finish.

Types

type Worker

type Worker func(context.Context) error

Worker is a function that WorkerGroup will run in a new goroutine.

type WorkerGroup

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

WorkerGroup is similar in principle to sync.WaitGroup but manages the Workers itself. This allows it to provide a few helpful features:

• Integration with the context library.
• Limit the number of concurrent Workers.
• Capture the errors returned by each Worker.
• Abort everything after a single Worker reports an error.

func NewWorkerGroup

func NewWorkerGroup(ctx context.Context, workerLimit int) *WorkerGroup

NewWorkerGroup creates a new group.

func (*WorkerGroup) Start

func (wg *WorkerGroup) Start(worker Worker) error

Start launches a new worker, blocking if too many workers are already running. An error indicates the group's context is closed.

func (*WorkerGroup) Wait

func (wg *WorkerGroup) Wait() error

Wait blocks until all running workers have finished. An error indicates if at least one worker returned an error or was canceled.

func (*WorkerGroup) WaitError

func (wg *WorkerGroup) WaitError(err error) error

Wait with a default error value that will be returned if no worker failed.

if err := wg.Start(worker); err != nil {
	return wg.WaitError(err)
}