markers

package
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Published: Apr 27, 2022 License: Apache-2.0, BSD-2-Clause Imports: 19 Imported by: 0

Documentation

Index

Constants

View Source
const IndexLength = marshalutil.Uint64Size

IndexLength represents the amount of bytes of a marshaled Index.

View Source
const MarkerLength = SequenceIDLength + IndexLength

MarkerLength represents the amount of bytes of a marshaled Marker.

View Source
const SequenceIDLength = marshalutil.Uint64Size

SequenceIDLength represents the amount of bytes of a marshaled SequenceID.

Variables

View Source
var DefaultManagerOptions = &ManagerOptions{
	Store:                 mapdb.NewMapDB(),
	CacheTime:             30 * time.Second,
	MaxPastMarkerDistance: 30,
}

DefaultManagerOptions defines the default options for the Manager.

Functions

func IndexComparator

func IndexComparator(a, b interface{}) int

IndexComparator is a generic comparator for Index types.

Types

type IncreaseIndexCallback

type IncreaseIndexCallback func(sequenceID SequenceID, currentHighestIndex Index) bool

IncreaseIndexCallback is the type of the callback function that is used to determine if a new Index is supposed to be assigned in a given Sequence.

type Index

type Index uint64

Index represents the ever-increasing number of the Markers in a Sequence.

func IndexFromMarshalUtil

func IndexFromMarshalUtil(marshalUtil *marshalutil.MarshalUtil) (index Index, err error)

IndexFromMarshalUtil unmarshals an Index using a MarshalUtil (for easier unmarshalling).

func (Index) Bytes

func (i Index) Bytes() (marshaledIndex []byte)

Bytes returns a marshaled version of the Index.

func (Index) String

func (i Index) String() (humanReadableIndex string)

String returns a human-readable version of the Index.

type Manager

type Manager struct {
	Options *ManagerOptions
	// contains filtered or unexported fields
}

Manager is the managing entity for the Marker related business logic. It is stateful and automatically stores its state in a KVStore.

func NewManager

func NewManager(options ...ManagerOption) (newManager *Manager)

NewManager is the constructor of the Manager that takes a KVStore to persist its state.

func (*Manager) InheritStructureDetails

func (m *Manager) InheritStructureDetails(referencedStructureDetails []*StructureDetails, increaseIndexCallback IncreaseIndexCallback) (inheritedStructureDetails *StructureDetails, newSequenceCreated bool)

InheritStructureDetails takes the StructureDetails of the referenced parents and returns new StructureDetails for the message that was just added to the DAG. It automatically creates a new Sequence and Index if necessary and returns an additional flag that indicates if a new Sequence was created. InheritStructureDetails inherits the structure details of the given parent StructureDetails.

func (*Manager) IsInPastCone

func (m *Manager) IsInPastCone(earlierStructureDetails, laterStructureDetails *StructureDetails) (isInPastCone types.TriBool)

IsInPastCone checks if the earlier node is directly or indirectly referenced by the later node in the DAG.

func (*Manager) Sequence

func (m *Manager) Sequence(sequenceID SequenceID) *objectstorage.CachedObject[*Sequence]

Sequence retrieves a Sequence from the object storage.

func (*Manager) Shutdown

func (m *Manager) Shutdown()

Shutdown shuts down the Manager and persists its state.

func (*Manager) UpdateStructureDetails

func (m *Manager) UpdateStructureDetails(structureDetailsToUpdate *StructureDetails, markerToInherit *Marker) (futureMarkersUpdated, inheritFutureMarkerFurther bool)

UpdateStructureDetails updates the StructureDetails of an existing node in the DAG by propagating new Markers of its children into its future Markers. It returns two boolean flags that indicate if the future Markers were updated and if the new Marker should be propagated further to the parents of the given node.

type ManagerOption

type ManagerOption func(options *ManagerOptions)

ManagerOption represents the return type of optional parameters that can be handed into the constructor of the Manager to configure its behavior.

func WithCacheTime

func WithCacheTime(cacheTime time.Duration) ManagerOption

WithCacheTime is an option for the Manager that allows to specify how long objects should be cached in the object storage.

func WithMaxPastMarkerDistance

func WithMaxPastMarkerDistance(distance uint64) ManagerOption

WithMaxPastMarkerDistance is an Option for the Manager that allows to specify how many consecutive messages are allowed to not receive a new PastMaster before we create a new Sequence.

func WithStore

func WithStore(store kvstore.KVStore) ManagerOption

WithStore is an option for the Manager that allows to specify which storage layer is supposed to be used to persist data.

type ManagerOptions

type ManagerOptions struct {
	// Store is a parameter for the Manager that allows to specify which storage layer is supposed to be used to persist
	// data.
	Store kvstore.KVStore

	// CacheTime is a parameter for the Manager that allows to specify how long objects should be cached in the object
	// storage.
	CacheTime time.Duration

	// MaxPastMarkerDistance is a parameter for the Manager that allows to specify how many consecutive messages are
	// allowed to not receive a new PastMaster before we create a new Sequence.
	MaxPastMarkerDistance uint64
}

ManagerOptions is a container for all configurable parameters of the Manager.

func (*ManagerOptions) Apply

func (m *ManagerOptions) Apply(options ...ManagerOption) (managerOptions *ManagerOptions)

Apply applies the given options to the ManagerOptions object.

type Marker

type Marker struct {
	// contains filtered or unexported fields
}

Marker represents a coordinate in a Sequence that is identified by an ever-increasing Index.

func MarkerFromBytes

func MarkerFromBytes(markerBytes []byte) (marker *Marker, consumedBytes int, err error)

MarkerFromBytes unmarshals a Marker from a sequence of bytes.

func MarkerFromMarshalUtil

func MarkerFromMarshalUtil(marshalUtil *marshalutil.MarshalUtil) (marker *Marker, err error)

MarkerFromMarshalUtil unmarshals a Marker using a MarshalUtil (for easier unmarshalling).

func NewMarker

func NewMarker(sequenceID SequenceID, index Index) *Marker

NewMarker returns a new marker.

func (Marker) Bytes

func (m Marker) Bytes() (marshaledMarker []byte)

Bytes returns a marshaled version of the Marker.

func (*Marker) Index

func (m *Marker) Index() (index Index)

Index returns the coordinate of the Marker in a Sequence.

func (*Marker) SequenceID

func (m *Marker) SequenceID() (sequenceID SequenceID)

SequenceID returns the identifier of the Sequence of the Marker.

func (*Marker) String

func (m *Marker) String() (humanReadableMarker string)

String returns a human-readable version of the Marker.

type Markers

type Markers struct {
	// contains filtered or unexported fields
}

Markers represents a collection of Markers that can contain exactly one Index per SequenceID.

func FromBytes

func FromBytes(markersBytes []byte) (markers *Markers, consumedBytes int, err error)

FromBytes unmarshals a collection of Markers from a sequence of bytes.

func FromMarshalUtil

func FromMarshalUtil(marshalUtil *marshalutil.MarshalUtil) (markers *Markers, err error)

FromMarshalUtil unmarshals a collection of Markers using a MarshalUtil (for easier unmarshalling).

func NewMarkers

func NewMarkers(optionalMarkers ...*Marker) (markers *Markers)

NewMarkers creates a new collection of Markers.

func (*Markers) Bytes

func (m *Markers) Bytes() (marshalMarkers []byte)

Bytes returns the Markers in serialized byte form.

func (*Markers) Clone

func (m *Markers) Clone() (clonedMarkers *Markers)

Clone creates a deep copy of the Markers.

func (*Markers) Delete

func (m *Markers) Delete(sequenceID SequenceID) (existed bool)

Delete removes the Marker with the given SequenceID from the collection and returns a boolean flag that indicates if the element existed.

func (*Markers) Equals

func (m *Markers) Equals(other *Markers) (equals bool)

Equals is a comparator for two Markers.

func (*Markers) ForEach

func (m *Markers) ForEach(iterator func(sequenceID SequenceID, index Index) bool) (success bool)

ForEach calls the iterator for each of the contained Markers. The iteration is aborted if the iterator returns false. The method returns false if the iteration was aborted.

func (*Markers) ForEachSorted

func (m *Markers) ForEachSorted(iterator func(sequenceID SequenceID, index Index) bool) (success bool)

ForEachSorted calls the iterator for each of the contained Markers in increasing order. The iteration is aborted if the iterator returns false. The method returns false if the iteration was aborted.

func (*Markers) Get

func (m *Markers) Get(sequenceID SequenceID) (index Index, exists bool)

Get returns the Index of the Marker with the given Sequence and a flag that indicates if the Marker exists.

func (*Markers) HighestIndex

func (m *Markers) HighestIndex() (highestIndex Index)

HighestIndex returns the highest Index of all Markers in the collection.

func (*Markers) LowestIndex

func (m *Markers) LowestIndex() (lowestIndex Index)

LowestIndex returns the lowest Index of all Markers in the collection.

func (*Markers) Marker

func (m *Markers) Marker() (marker *Marker)

Marker type casts the Markers to a Marker if it contains only 1 element.

func (*Markers) Merge

func (m *Markers) Merge(markers *Markers)

Merge takes the given Markers and adds them to the collection (overwriting Markers with a lower Index if there are existing Markers with the same SequenceID).

func (*Markers) SequenceIDs

func (m *Markers) SequenceIDs() (sequenceIDs SequenceIDs)

SequenceIDs returns the SequenceIDs that are having Markers in this collection.

func (*Markers) SequenceToString

func (m *Markers) SequenceToString() (s string)

SequenceToString returns a string in the form sequenceID:index;.

func (*Markers) Set

func (m *Markers) Set(sequenceID SequenceID, index Index) (updated, added bool)

Set adds a new Marker to the collection and updates the Index of an existing entry if it is higher than a possible previously stored one. The method returns two boolean flags that indicate if an entry was updated and/or added.

func (*Markers) Size

func (m *Markers) Size() (size int)

Size returns the amount of Markers in the collection.

func (*Markers) String

func (m *Markers) String() (humanReadableMarkers string)

String returns a human-readable version of the Markers.

type ReferencedMarkers

type ReferencedMarkers struct {
	// contains filtered or unexported fields
}

ReferencedMarkers is a data structure that allows to denote which Marker of a Sequence references which other Markers of its parent Sequences in the Sequence DAG.

func NewReferencedMarkers

func NewReferencedMarkers(markers *Markers) (referencedMarkers *ReferencedMarkers)

NewReferencedMarkers is the constructor for the ReferencedMarkers.

func ReferencedMarkersFromBytes

func ReferencedMarkersFromBytes(parentReferencesBytes []byte) (referencedMarkers *ReferencedMarkers, consumedBytes int, err error)

ReferencedMarkersFromBytes unmarshals ReferencedMarkers from a sequence of bytes.

func ReferencedMarkersFromMarshalUtil

func ReferencedMarkersFromMarshalUtil(marshalUtil *marshalutil.MarshalUtil) (referencedMarkers *ReferencedMarkers, err error)

ReferencedMarkersFromMarshalUtil unmarshals ReferencedMarkers using a MarshalUtil (for easier unmarshalling).

func (*ReferencedMarkers) Add

func (r *ReferencedMarkers) Add(index Index, referencedMarkers *Markers)

Add adds new referenced Markers to the ReferencedMarkers.

func (*ReferencedMarkers) Bytes

func (r *ReferencedMarkers) Bytes() (marshaledReferencedMarkers []byte)

Bytes returns a marshaled version of the ReferencedMarkers.

func (*ReferencedMarkers) Get

func (r *ReferencedMarkers) Get(index Index) (referencedMarkers *Markers)

Get returns the Markers of parent Sequences that were referenced by the given Index.

func (*ReferencedMarkers) String

func (r *ReferencedMarkers) String() (humanReadableReferencedMarkers string)

String returns a human-readable version of the ReferencedMarkers.

type ReferencingMarkers

type ReferencingMarkers struct {
	// contains filtered or unexported fields
}

ReferencingMarkers is a data structure that allows to denote which Markers of child Sequences in the Sequence DAG reference a given Marker in a Sequence.

func NewReferencingMarkers

func NewReferencingMarkers() (referencingMarkers *ReferencingMarkers)

NewReferencingMarkers is the constructor for the ReferencingMarkers.

func ReferencingMarkersFromBytes

func ReferencingMarkersFromBytes(referencingMarkersBytes []byte) (referencingMarkers *ReferencingMarkers, consumedBytes int, err error)

ReferencingMarkersFromBytes unmarshals ReferencingMarkers from a sequence of bytes.

func ReferencingMarkersFromMarshalUtil

func ReferencingMarkersFromMarshalUtil(marshalUtil *marshalutil.MarshalUtil) (referencingMarkers *ReferencingMarkers, err error)

ReferencingMarkersFromMarshalUtil unmarshals ReferencingMarkers using a MarshalUtil (for easier unmarshalling).

func (*ReferencingMarkers) Add

func (r *ReferencingMarkers) Add(index Index, referencingMarker *Marker)

Add adds a new referencing Marker to the ReferencingMarkers.

func (*ReferencingMarkers) Bytes

func (r *ReferencingMarkers) Bytes() (marshaledReferencingMarkers []byte)

Bytes returns a marshaled version of the ReferencingMarkers.

func (*ReferencingMarkers) Get

func (r *ReferencingMarkers) Get(index Index) (referencingMarkers *Markers)

Get returns the Markers of child Sequences that reference the given Index.

func (*ReferencingMarkers) String

func (r *ReferencingMarkers) String() (humanReadableReferencingMarkers string)

String returns a human-readable version of the ReferencingMarkers.

type Sequence

type Sequence struct {
	objectstorage.StorableObjectFlags
	// contains filtered or unexported fields
}

Sequence represents a set of ever-increasing Indexes that are encapsulating a certain part of the DAG.

func NewSequence

func NewSequence(id SequenceID, referencedMarkers *Markers) *Sequence

NewSequence creates a new Sequence from the given details.

func (*Sequence) AddReferencingMarker

func (s *Sequence) AddReferencingMarker(index Index, referencingMarker *Marker)

AddReferencingMarker register a Marker that referenced the given Index of this Sequence.

func (*Sequence) Bytes

func (s *Sequence) Bytes() []byte

Bytes returns a marshaled version of the Sequence.

func (*Sequence) FromBytes

func (s *Sequence) FromBytes(sequenceBytes []byte) (sequence *Sequence, err error)

FromBytes unmarshals a Sequence from a sequence of bytes.

func (*Sequence) FromMarshalUtil

func (s *Sequence) FromMarshalUtil(marshalUtil *marshalutil.MarshalUtil) (sequence *Sequence, err error)

FromMarshalUtil unmarshals a Sequence using a MarshalUtil (for easier unmarshalling).

func (*Sequence) FromObjectStorage

func (s *Sequence) FromObjectStorage(key, bytes []byte) (objectstorage.StorableObject, error)

FromObjectStorage creates a Sequence from sequences of key and bytes.

func (*Sequence) HighestIndex

func (s *Sequence) HighestIndex() Index

HighestIndex returns the Index of the latest Marker in the Sequence.

func (*Sequence) ID

func (s *Sequence) ID() SequenceID

ID returns the identifier of the Sequence.

func (*Sequence) IncreaseHighestIndex

func (s *Sequence) IncreaseHighestIndex(referencedMarkers *Markers) (index Index, increased bool)

IncreaseHighestIndex increases the highest Index of the Sequence if the referencedMarkers directly reference the Marker with the highest Index. It returns the new Index and a boolean flag that indicates if the value was increased.

func (*Sequence) LowestIndex

func (s *Sequence) LowestIndex() Index

LowestIndex returns the Index of the very first Marker in the Sequence.

func (*Sequence) ObjectStorageKey

func (s *Sequence) ObjectStorageKey() []byte

ObjectStorageKey returns the key that is used to store the object in the database. It is required to match the StorableObject interface.

func (*Sequence) ObjectStorageValue

func (s *Sequence) ObjectStorageValue() []byte

ObjectStorageValue marshals the Sequence into a sequence of bytes. The ID is not serialized here as it is only used as a key in the object storage.

func (*Sequence) ReferencedMarkers

func (s *Sequence) ReferencedMarkers(index Index) *Markers

ReferencedMarkers returns a collection of Markers that were referenced by the given Index.

func (*Sequence) ReferencingMarkers

func (s *Sequence) ReferencingMarkers(index Index) *Markers

ReferencingMarkers returns a collection of Markers that reference the given Index.

func (*Sequence) String

func (s *Sequence) String() string

String returns a human-readable version of the Sequence.

func (*Sequence) TryExtend

func (s *Sequence) TryExtend(referencedPastMarkers *Markers, increaseIndexCallback IncreaseIndexCallback) (index Index, remainingReferencedPastMarkers *Markers, extended bool)

TryExtend tries to extend the Sequence with a new Index by checking if the referenced PastMarkers contain the last assigned Index of the Sequence. It returns the new Index, the remaining Markers pointing to other Sequences and a boolean flag that indicating if a new Index was assigned.

type SequenceID

type SequenceID uint64

SequenceID is the type of the identifier of a Sequence.

func SequenceIDFromBytes

func SequenceIDFromBytes(sequenceIDBytes []byte) (sequenceID SequenceID, consumedBytes int, err error)

SequenceIDFromBytes unmarshals a SequenceID from a sequence of bytes.

func SequenceIDFromMarshalUtil

func SequenceIDFromMarshalUtil(marshalUtil *marshalutil.MarshalUtil) (sequenceID SequenceID, err error)

SequenceIDFromMarshalUtil unmarshals a SequenceIDs using a MarshalUtil (for easier unmarshalling).

func (SequenceID) Bytes

func (a SequenceID) Bytes() (marshaledSequenceID []byte)

Bytes returns a marshaled version of the SequenceID.

func (SequenceID) String

func (a SequenceID) String() (humanReadableSequenceID string)

String returns a human-readable version of the SequenceID.

type SequenceIDs

type SequenceIDs map[SequenceID]types.Empty

SequenceIDs represents a collection of SequenceIDs.

func NewSequenceIDs

func NewSequenceIDs(sequenceIDs ...SequenceID) (result SequenceIDs)

NewSequenceIDs creates a new collection of SequenceIDs.

func (SequenceIDs) Bytes

func (s SequenceIDs) Bytes() (marshaledSequenceIDs []byte)

Bytes returns a marshaled version of the SequenceIDs.

func (SequenceIDs) String

func (s SequenceIDs) String() (humanReadableSequenceIDs string)

String returns a human-readable version of the SequenceIDs.

type StructureDetails

type StructureDetails struct {
	Rank          uint64
	PastMarkerGap uint64
	IsPastMarker  bool
	PastMarkers   *Markers
	FutureMarkers *Markers
	// contains filtered or unexported fields
}

StructureDetails represents a container for the complete Marker related information of a node in a DAG that are used to interact with the public API of this package.

func StructureDetailsFromMarshalUtil

func StructureDetailsFromMarshalUtil(marshalUtil *marshalutil.MarshalUtil) (structureDetails *StructureDetails, err error)

StructureDetailsFromMarshalUtil unmarshals a StructureDetails using a MarshalUtil (for easier unmarshalling).

func (*StructureDetails) Bytes

func (m *StructureDetails) Bytes() (marshaledStructureDetails []byte)

Bytes returns a marshaled version of the StructureDetails.

func (*StructureDetails) Clone

func (m *StructureDetails) Clone() (clone *StructureDetails)

Clone creates a deep copy of the StructureDetails.

func (*StructureDetails) String

func (m *StructureDetails) String() (humanReadableStructureDetails string)

String returns a human-readable version of the StructureDetails.

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