Documentation ¶
Overview ¶
Package workgroups is a little helper for creating workers with the help of (sync.Errgroup) https://pkg.go.dev/golang.org/x/sync/errgroup.
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Example ¶
package main import ( "context" "fmt" "log" "os" "runtime" "github.com/go-logr/stdr" "go.xsfx.dev/workgroups" ) func main() { d, ctx := workgroups.NewDispatcher( context.Background(), stdr.New(log.New(os.Stderr, "", log.Lshortfile)), runtime.GOMAXPROCS(0), // This starts as much worker as maximal processes are allowed for go. 10, // Capacity of the queue. ) work := func(ctx context.Context) error { // Check if context already expired. // Return if its the case, else just go forward. select { case <-ctx.Done(): return fmt.Errorf("got error from context: %w", ctx.Err()) default: } // Some wannebe work... printing something. fmt.Print("hello world from work") return nil } // Starting up the workers. d.Start() // Feeding the workers some work. d.Append(workgroups.NewJob(ctx, work)) // Closing the channel for work. d.Close() // Waiting to finnish everything. if err := d.Wait(); err != nil { log.Fatal(err) } }
Output: hello world from work
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
ErrInWorker is an error that gets returned if there is a error in the work function.
Functions ¶
func Retry ¶ added in v0.4.0
Retry is a middleware for doing a retry in executing job work.
Example ¶
package main import ( "context" "errors" "fmt" "log" "os" "runtime" "time" "github.com/go-logr/stdr" "go.xsfx.dev/workgroups" ) func main() { d, ctx := workgroups.NewDispatcher( context.Background(), stdr.New(log.New(os.Stderr, "", log.Lshortfile)), runtime.GOMAXPROCS(0), // This starts as much worker as maximal processes are allowed for go. 10, // Capacity of the queue. ) // Just returning some error. So it can retry. failFunc := func() error { fmt.Print("fail ") return errors.New("fail") //nolint:goerr113 } work := func(ctx context.Context) error { // Check if context already expired. // Return if its the case, else just go forward. select { case <-ctx.Done(): return fmt.Errorf("got error from context: %w", ctx.Err()) default: } if err := failFunc(); err != nil { return err } return nil } // Starting up the workers. d.Start() ctx, cancel := context.WithTimeout(ctx, time.Second) defer cancel() // Feeding the workers some work. d.Append( workgroups.NewJob( ctx, workgroups.Retry(ctx, time.Second/2)(work), // This will retry after a half second. ), ) // Closing the channel for work. d.Close() // Waiting to finnish everything. if err := d.Wait(); err != nil { fmt.Print(err) } }
Output: fail fail error on waiting: got error from context: context deadline exceeded
Types ¶
type Dispatcher ¶
type Dispatcher struct {
// contains filtered or unexported fields
}
Dispatcher carries the job queue, the errgroup and the number of workers to start.
func NewDispatcher ¶
func NewDispatcher(ctx context.Context, log logr.Logger, numWorkers, workLength int) (*Dispatcher, context.Context)
NewDispatcher creates a new Dispatcher. It takes a context and adds it to the errgroup creation and returns it again.
func (*Dispatcher) Append ¶
func (d *Dispatcher) Append(job Job)
Append adds a job to the work queue.
func (*Dispatcher) Start ¶
func (d *Dispatcher) Start()
Start starts the configured number of workers and waits for jobs.
type Job ¶
type Job struct {
// contains filtered or unexported fields
}
Job carries a job with everything it needs. I know know that contexts shouldnt be stored in a struct. Here is an exception, because its a short living object. The context is only used as argument for the Work function. Please use the NewJob function to get around this context in struct shenanigans.