// calculate fetches the information ID associated with the given information
// sequence. In case the information sequence is not found within the underlying
// storage, a new information ID is generated and used to store the given
// information sequence. In any case the information ID is added to the given
// context.
func (c *clg) calculate(ctx spec.Context, informationSequence string) error {
informationIDKey := key.NewNetworkKey("information-sequence:%s:information-id", informationSequence)
informationID, err := c.Storage().General().Get(informationIDKey)
if storage.IsNotFound(err) {
// The given information sequence was never seen before. Thus we register it
// now with its own very unique information ID.
newID, err := c.Service().ID().New()
if err != nil {
return maskAny(err)
}
informationID = string(newID)
err = c.Storage().General().Set(informationIDKey, informationID)
if err != nil {
return maskAny(err)
}
informationSequenceKey := key.NewNetworkKey("information-id:%s:information-sequence", informationID)
err = c.Storage().General().Set(informationSequenceKey, informationSequence)
if err != nil {
return maskAny(err)
}
} else if err != nil {
return maskAny(err)
}
ctx.SetInformationID(informationID)
return nil
}
