workgroups/example_test.go
Marvin Preuss 48fac0237a fix!: closing errChan channel
it also check if context is canceld and if its so, it will not trying to
send to it work function error.

BREAKING CHANGE: it also takes now logr.Logger and stores it in the
Dispatcher
2022-05-17 13:22:18 +02:00

113 lines
2.3 KiB
Go

package workgroups_test
import (
"context"
"errors"
"fmt"
"log"
"os"
"runtime"
"time"
"github.com/go-logr/stdr"
"go.xsfx.dev/workgroups"
)
func Example() {
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
}
func ExampleRetry() {
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
}