func (c *clg) calculate(ctx spec.Context) (string, error) {
behaviourID, ok := ctx.GetBehaviourID()
if !ok {
return "", maskAnyf(invalidBehaviourIDError, "must not be empty")
}
behaviourIDKey := key.NewNetworkKey("behaviour-id:%s:separator", behaviourID)
separator, err := c.Storage().General().Get(behaviourIDKey)
if storage.IsNotFound(err) {
randomKey, err := c.Storage().Feature().GetRandom()
if err != nil {
return "", maskAny(err)
}
// Make sure the fetched feature is valid based on its key structure. The
// key itself already contains the feature. Knowing the key structure makes
// it possible to simply parse the feature from the key fetched from the
// feature storage. These features are stored by the split-features CLG.
// Changes in the key structure there must be aligned with implementation
// details here. The current key structure looks as follows.
//
// feature:%s:positions
//
if len(randomKey) != 22 {
return "", maskAnyf(invalidFeatureKeyError, "key '%s' must have length '22'", randomKey)
}
if !strings.HasPrefix(randomKey, "feature:") {
return "", maskAnyf(invalidFeatureKeyError, "key '%s' prefix must be 'feature:'", randomKey)
}
if !strings.HasSuffix(randomKey, ":positions") {
return "", maskAnyf(invalidFeatureKeyError, "key '%s' suffix must be ':positions'", randomKey)
}
// Create a new separator from the fetched random feature. Note that a
// feature is considered 4 characters long and the random factory takes a
// max parameter, which is exlusive.
feature := randomKey[8:12]
featureIndex, err := c.Service().Random().CreateMax(5)
if err != nil {
return "", maskAny(err)
}
separator = string(feature[featureIndex])
// Store the newly created separator using the CLGs own behaviour ID. In case
// this CLG is asked again to return its separator, it will lookup its
// separator in the general storage.
err = c.Storage().General().Set(behaviourIDKey, separator)
if err != nil {
return "", maskAny(err)
}
} else if err != nil {
return "", maskAny(err)
}
return separator, nil
}
func (c *clg) forwardNetworkPayload(ctx spec.Context, informationSequence string) error {
// Find the original information sequence using the information ID from the
// context.
informationID, ok := ctx.GetInformationID()
if !ok {
return maskAnyf(invalidInformationIDError, "must not be empty")
}
informationSequenceKey := key.NewNetworkKey("information-id:%s:information-sequence", informationID)
informationSequence, err := c.Storage().General().Get(informationSequenceKey)
if err != nil {
return maskAny(err)
}
// Find the first behaviour ID using the CLG tree ID from the context. The
// behaviour ID we are looking up here is the ID of the initial input CLG.
clgTreeID, ok := ctx.GetCLGTreeID()
if !ok {
return maskAnyf(invalidCLGTreeIDError, "must not be empty")
}
firstBehaviourIDKey := key.NewNetworkKey("clg-tree-id:%s:first-behaviour-id", clgTreeID)
inputBehaviourID, err := c.Storage().General().Get(firstBehaviourIDKey)
if err != nil {
return maskAny(err)
}
// Lookup the behaviour ID of the current output CLG. Below we are using this
// to set the source of the new network payload accordingly.
outputBehaviourID, ok := ctx.GetBehaviourID()
if !ok {
return maskAnyf(invalidBehaviourIDError, "must not be empty")
}
// Create a new contect using the given context and adapt the new context with
// the information of the current scope.
newCtx := ctx.Clone()
newCtx.SetBehaviourID(inputBehaviourID)
newCtx.SetCLGName("input")
newCtx.SetCLGTreeID(clgTreeID)
// We do not need to set the expectation because it never changes.
// We do not need to set the session ID because it never changes.
// Create a new network payload.
newNetworkPayloadConfig := networkpayload.DefaultConfig()
newNetworkPayloadConfig.Args = []reflect.Value{reflect.ValueOf(informationSequence)}
newNetworkPayloadConfig.Context = newCtx
newNetworkPayloadConfig.Destination = string(inputBehaviourID)
newNetworkPayloadConfig.Sources = []string{string(outputBehaviourID)}
newNetworkPayload, err := networkpayload.New(newNetworkPayloadConfig)
if err != nil {
return maskAny(err)
}
// Write the transformed network payload to the queue.
networkPayloadKey := key.NewNetworkKey("events:network-payload")
b, err := json.Marshal(newNetworkPayload)
if err != nil {
return maskAny(err)
}
err = c.Storage().General().PushToList(networkPayloadKey, string(b))
if err != nil {
return maskAny(err)
}
return nil
}
