status-go/services/wallet/transmitter.go

65 lines
1.3 KiB
Go

package wallet
import (
"errors"
"sync"
"github.com/ethereum/go-ethereum/event"
"github.com/ethereum/go-ethereum/log"
"github.com/status-im/status-go/signal"
)
type publisher interface {
Subscribe(interface{}) event.Subscription
}
// SignalsTransmitter transmits received events as wallet signals.
type SignalsTransmitter struct {
publisher
wg sync.WaitGroup
quit chan struct{}
}
// Start runs loop in background.
func (tmr *SignalsTransmitter) Start() error {
if tmr.quit != nil {
return errors.New("already running")
}
tmr.quit = make(chan struct{})
events := make(chan Event, 10)
sub := tmr.publisher.Subscribe(events)
tmr.wg.Add(1)
go func() {
defer tmr.wg.Done()
for {
select {
case <-tmr.quit:
sub.Unsubscribe()
return
case err := <-sub.Err():
// technically event.Feed cannot send an error to subscription.Err channel.
// the only time we will get an event is when that channel is closed.
if err != nil {
log.Error("wallet signals transmitter failed with", "error", err)
}
return
case event := <-events:
signal.SendWalletEvent(event)
}
}
}()
return nil
}
// Stop stops the loop and waits till it exits.
func (tmr *SignalsTransmitter) Stop() {
if tmr.quit == nil {
return
}
close(tmr.quit)
tmr.wg.Wait()
tmr.quit = nil
}