49 lines
997 B
Go
49 lines
997 B
Go
package internet
|
|
|
|
import (
|
|
"context"
|
|
"errors"
|
|
"math/rand"
|
|
"time"
|
|
)
|
|
|
|
var (
|
|
// channel.go @ simulateAustralianInternet
|
|
CanFail = true
|
|
// 500ms ~ 3s
|
|
MinLatency = 500
|
|
MaxLatency = 3000
|
|
)
|
|
|
|
// ErrTimedOut is returned when the simulated IO decides to fail.
|
|
var ErrTimedOut = errors.New("Australian Internet unsupported.")
|
|
|
|
// SimulateAustralian simulates network latency with errors.
|
|
func SimulateAustralian() error {
|
|
return SimulateAustralianCtx(context.Background())
|
|
}
|
|
|
|
// SimulateAustralianCtx simulates network latency with errors.
|
|
func SimulateAustralianCtx(ctx context.Context) (err error) {
|
|
var ms = randClamp(MinLatency, MaxLatency)
|
|
|
|
select {
|
|
case <-time.After(time.Duration(ms) * time.Millisecond):
|
|
// noop
|
|
case <-ctx.Done():
|
|
return ctx.Err()
|
|
}
|
|
|
|
// because australia, drop packet 20% of the time if internetCanFail is
|
|
// true.
|
|
if CanFail && rand.Intn(100) < 20 {
|
|
return ErrTimedOut
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func randClamp(min, max int) int {
|
|
return rand.Intn(max-min) + min
|
|
}
|