// 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
}
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 (f *forwarder) GetNetworkPayloads(CLG systemspec.CLG, networkPayload objectspec.NetworkPayload) ([]objectspec.NetworkPayload, error) {
ctx := networkPayload.GetContext()
// Check if there are behaviour IDs known that we can use to forward the
// current network payload to.
behaviourID, ok := ctx.GetBehaviourID()
if !ok {
return nil, maskAnyf(invalidBehaviourIDError, "must not be empty")
}
behaviourIDsKey := key.NewNetworkKey("forward:configuration:behaviour-id:%s:behaviour-ids", behaviourID)
newBehaviourIDs, err := f.Storage().General().GetAllFromSet(behaviourIDsKey)
if storage.IsNotFound(err) {
// No configuration of behaviour IDs is stored. Thus we return an error.
// Eventually some other lookup is able to find sufficient network payloads.
return nil, maskAny(networkPayloadsNotFoundError)
} else if err != nil {
return nil, maskAny(err)
}
// Create a list of new network payloads.
var newNetworkPayloads []objectspec.NetworkPayload
for _, behaviourID := range newBehaviourIDs {
// Prepare a new context for the new network payload.
newCtx := ctx.Clone()
newCtx.SetBehaviourID(behaviourID)
// Create a new network payload.
newNetworkPayloadConfig := networkpayload.DefaultConfig()
newNetworkPayloadConfig.Args = networkPayload.GetArgs()
newNetworkPayloadConfig.Context = newCtx
newNetworkPayloadConfig.Destination = string(behaviourID)
newNetworkPayloadConfig.Sources = []string{networkPayload.GetDestination()}
newNetworkPayload, err := networkpayload.New(newNetworkPayloadConfig)
if err != nil {
return nil, maskAny(err)
}
newNetworkPayloads = append(newNetworkPayloads, newNetworkPayload)
}
return newNetworkPayloads, nil
}
// TODO there is nothing that reads pairs
func (c *clg) calculate(ctx spec.Context) error {
// The counter keeps track of the work already being done. We only increment
// the counter in case we were not able to do our job. As soon as some
// threshold is reached, we stop trying.
var counter int
for {
// Fetch two random features from the feature storage. This is done by
// fetching random keys. The keys itself already contain the features. Knowing
// the key structure makes it possible to simply parse the features from the
// keys 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
//
key1, err := c.Storage().Feature().GetRandom()
if err != nil {
return maskAny(err)
}
key2, err := c.Storage().Feature().GetRandom()
if err != nil {
return maskAny(err)
}
// Validate the fetched keys.
for _, k := range []string{key1, key2} {
if len(k) != 22 {
return maskAnyf(invalidFeatureKeyError, "key '%s' must have length '22'", k)
}
if !strings.HasPrefix(key1, "feature:") {
return maskAnyf(invalidFeatureKeyError, "key '%s' prefix must be 'feature:'", k)
}
if !strings.HasSuffix(key1, ":positions") {
return maskAnyf(invalidFeatureKeyError, "key '%s' suffix must be ':positions'", k)
}
}
// Combine the fetched keys to a new pair.
pair := key1[8:12] + key2[8:12]
// Write the new pair into the general storage.
pairIDKey := key.NewNetworkKey("pair:syntactic:feature:%s:pair-id", pair)
_, err = c.Storage().General().Get(pairIDKey)
if storage.IsNotFound(err) {
// The created pair was not found within the feature storage. That means
// we created a new one which we can store. Once we stored the new pair,
// we break the outer loop to be done.
newID, err := c.Service().ID().New()
if err != nil {
return maskAny(err)
}
pairID := string(newID)
err = c.Storage().General().Set(pairIDKey, pairID)
if err != nil {
return maskAny(err)
}
break
}
if counter >= 3 {
// We tried to create a new pair 3 times, but it looks like there is not
// enough data. That is why the created pair was found all the time. It
// looks like we cannot create any new pair and stop doing anything here.
break
}
counter++
}
return nil
}
func (a *activator) GetNetworkPayload(CLG systemspec.CLG, queue []objectspec.NetworkPayload) (objectspec.NetworkPayload, error) {
// Fetch the combination of successful behaviour IDs which are known to be
// useful for the activation of the requested CLG. The network payloads sent
// by the CLGs being fetched here are known to be useful because they have
// already been helpful for the execution of the current CLG tree.
behaviourID, ok := queue[0].GetContext().GetBehaviourID()
if !ok {
return nil, maskAnyf(invalidBehaviourIDError, "must not be empty")
}
behaviourIDsKey := key.NewNetworkKey("activate:configuration:behaviour-id:%s:behaviour-ids", behaviourID)
s, err := a.Storage().General().Get(behaviourIDsKey)
if storage.IsNotFound(err) {
// No successful combination of behaviour IDs is stored. Thus we return an
// error. Eventually some other lookup is able to find a sufficient network
// payload.
return nil, maskAny(networkPayloadNotFoundError)
} else if err != nil {
return nil, maskAny(err)
}
behaviourIDs := strings.Split(s, ",")
if len(behaviourIDs) == 0 {
// No activation configuration of the requested CLG is stored. Thus we
// return an error. Eventually some other lookup is able to find a
// sufficient network payload.
return nil, maskAny(networkPayloadNotFoundError)
}
// Check if there is a queued network payload for each behaviour ID we found in the
// storage. Here it is important to obtain the order of the behaviour IDs
// stored as connections. They represent the input interface of the requested
// CLG. Thus there must not be any variation applied to the lookup here,
// because we need the lookup to be reproducible.
var matches []objectspec.NetworkPayload
for _, behaviourID := range behaviourIDs {
for _, np := range queue {
// At this point there is only one source given. That is the CLG that
// forwarded the current network payload to here. If this is not the case,
// we return an error.
sources := np.GetSources()
if len(sources) != 1 {
return nil, maskAnyf(invalidSourcesError, "there must be one source")
}
if behaviourID == string(sources[0]) {
// The current behaviour ID belongs to the current network payload. We
// add the matching network payload to our list and go on to find the
// network payload belonging to the next behabiour ID.
matches = append(matches, np)
break
}
}
}
if len(behaviourIDs) != len(matches) {
// No match using the stored configuration associated with the requested CLG
// can be found. Thus we return an error. Eventually some other lookup is
// able to find a sufficient network payload.
return nil, maskAny(networkPayloadNotFoundError)
}
// The received network payloads are able to satisfy the interface of the
// requested CLG. We merge the matching network payloads together and return
// the result.
newNetworkPayload, err := mergeNetworkPayloads(matches)
if err != nil {
return nil, maskAny(err)
}
return newNetworkPayload, nil
}
