Example #1
0
// Serve starts the go-horizon system, binding it to a socket, setting up
// the shutdown signals and starting the appropriate db-streaming pumps.
func (a *App) Serve() {

	a.web.router.Compile()
	http.Handle("/", a.web.router)

	listenStr := fmt.Sprintf(":%d", a.config.Port)
	listener := bind.Socket(listenStr)
	log.Infof(a.ctx, "Starting horizon on %s", listener.Addr())

	graceful.HandleSignals()
	bind.Ready()
	graceful.PreHook(func() {
		log.Info(a.ctx, "received signal, gracefully stopping")
		a.Cancel()
	})
	graceful.PostHook(func() {
		log.Info(a.ctx, "stopped")
	})

	if a.config.Autopump {
		sse.SetPump(a.ctx, sse.AutoPump)
	} else {
		sse.SetPump(a.ctx, db.NewLedgerClosePump(a.ctx, a.historyDb))
	}

	err := graceful.Serve(listener, http.DefaultServeMux)

	if err != nil {
		log.Panic(a.ctx, err)
	}

	graceful.Wait()
}
Example #2
0
// NewLedgerClosePump starts a background proc that continually watches the
// history database provided.  The watch is stopped after the provided context
// is cancelled.
//
// Every second, the proc spawned by calling this func will check to see
// if a new ledger has been imported (by ruby-horizon as of 2015-04-30, but
// should eventually end up being in this project).  If a new ledger is seen
// the the channel returned by this function emits
func NewLedgerClosePump(ctx context.Context, db *sql.DB) <-chan time.Time {
	result := make(chan time.Time)

	go func() {
		var lastSeenLedger int32
		for {
			select {
			case <-time.After(1 * time.Second):
				var latestLedger int32
				row := db.QueryRow("SELECT MAX(sequence) FROM history_ledgers")
				err := row.Scan(&latestLedger)

				if err != nil {
					log.Warn(ctx, "Failed to check latest ledger", err)
					break
				}

				if latestLedger > lastSeenLedger {
					log.Debugf(ctx, "saw new ledger: %d, prev: %d", latestLedger, lastSeenLedger)
					lastSeenLedger = latestLedger
					result <- time.Now()
				}

			case <-ctx.Done():
				log.Info(ctx, "canceling ledger pump")
				return
			}
		}
	}()

	return result
}