func (item *Item) Ship(user string, qty uint64, timestamp string) (*Shipment, bool, error) {
// Create a reproducible ID based on input data (hence the timestamp)
hash := services.MakeHash(user, item.Name, qty, timestamp)
shipment := item.catalog.MakeShipment(hash)
if err := shipment.lock.Lock(); err != nil {
return nil, false, fmt.Errorf("Failed to lock shipment: %v", err)
}
defer shipment.unlock()
existed, err := shipment.LoadExisting()
if err != nil {
return nil, false, err
}
if !existed {
shipment.User = user
shipment.Item = item.Name
shipment.Quantity = qty
shipment.Status = catalogApi.ShipmentCreated
if err = shipment.Save(); err != nil {
return nil, false, err
}
}
return shipment, existed, nil
}
func (payments *Payments) NewPayment(username string, value float64, timestamp string) (*Payment, bool, error) {
// Create a reproducible ID based on input data (hence the timestamp)
hash := services.MakeHash(username, value, timestamp)
// Try to fetch an existing payment
payment := payments.MakePayment(hash)
existed, err := payment.LoadExisting(true, false)
if err != nil {
return nil, false, err
}
defer payment.unlock()
// Create the payment, if it did not exist
if !existed {
payment.User = username
payment.Value = value
payment.TransactionId = ""
payment.setStatus(PaymentCreated)
if err = payment.Save(); err != nil {
return nil, false, err
}
}
// Now try to create the remote transaction
if err = payment.advance(PaymentPending); err != nil {
return nil, false, err
} else {
return payment, existed, nil
}
}
func (shop *Shop) noteFreshOrder(username string, item string, qty uint64) error {
hash := services.MakeHash(username, item, qty)
resp := shop.redis.Cmd("set", fresh_orders_key+hash, shop.redisLockValue, "ex", fresh_order_timeout_sec, "nx")
if err := resp.Err(); err != nil {
return err
}
if str, _ := resp.Str(); resp.HasResult() && str == "OK" {
return nil
} else {
// The same order has been submitted within fresh_order_timeout
return fmt.Errorf("Order rejected: duplicate order suspected")
}
}