Class Projection<T>

constructor

• new Projection<T>(actorID: number, trustedSequence?: unknown): Projection<T>

  Prepares to sequence a projection, optionally hydrating from a trusted sequence stored by the application.

  Type Parameters

  • T

  Parameters

  • actorID: number

    Actor identifier used in acknowledgements.

  • OptionaltrustedSequence: unknown

    Optional trusted Sequence in Structural Order; string Footage is split into UTF-16 code units.

  Returns Projection<T>

  Throws

  SequencerError if native initialization fails.

ReadonlyactorID

apply

• apply(gossip: unknown): readonly [Change<T>, Gossip<T> | undefined] | undefined

  Applies gossiped Insertions and Acknowledgements.

  Parameters

  • gossip: unknown

    Batch of Insertion and Acknowledgement tuples.

  Returns readonly [Change<T>, Gossip<T> | undefined] | undefined

  Visible changes and optional acknowledgement Gossip, or undefined for invalid input. Earlier entries may already have been applied.

  Throws

  SequencerError with code PROJECTION_DESTROYED after destruction.

destroy

• destroy(): void

  Destroys the Projection. Repeated calls have no effect.

  Returns void

insert

• insert(values: T[], at: number): Gossip<T>

  Inserts values at a Projection position.

  Parameters

  • values: T[]

    Nonempty array of values to insert.

  • at: number

    Insertion position in 0..length(), inclusive.

  Returns Gossip<T>

  Gossip describing the insertion.

  Throws

  SequencerError with code PROJECTION_DESTROYED after destruction.

length

• length(): number

  Returns the length, A.K.A. amount of entries of this projection.

  Returns number

  Current Projection length.

  Throws

  SequencerError with code PROJECTION_DESTROYED after destruction.

merge

• merge(
      sequence: unknown,
  ): readonly [Change<T>, Gossip<T> | undefined] | undefined

  Applies relevant acknowledgements and nonduplicate insertions from a replica of the sequence.

  Parameters

  • sequence: unknown

    Sequence to merge.

  Returns readonly [Change<T>, Gossip<T> | undefined] | undefined

  Visible changes and optional acknowledgement Gossip, or undefined if the Sequence has an invalid runtime shape.

  Throws

  SequencerError with code PROJECTION_DESTROYED after destruction.

remove

• remove(startAt?: number, endWith?: number): Gossip<T>

  Removes an inclusive range of Projection positions.

  Parameters

  • OptionalstartAt: number

    First position to remove; defaults to 0.

  • OptionalendWith: number

    Last position to remove; defaults to length() - 1.

  Returns Gossip<T>

  Reducing Insertions and their acknowledgement as Gossip.

  Throws

  SequencerError if destroyed or the native runtime reports an operation failure.

replace

• replace(withValues: T[], startAt?: number, endWith?: number): Gossip<T>

  Replaces an inclusive range of Projection positions.

  Parameters

  • withValues: T[]

    Replacement values; an empty array only removes the range.

  • OptionalstartAt: number

    First position to replace; defaults to 0.

  • OptionalendWith: number

    Last position to replace; defaults to length() - 1.

  Returns Gossip<T>

  Removal and insertion Gossip, in that order.

  Throws

  SequencerError if destroyed or the native runtime reports an operation failure.

retire

• retire(actorID: number): void

  Retires an Actor from future compaction requirements.

  Parameters

  • actorID: number

    Actor whose Acknowledgements are no longer required for compaction.

  Returns void

  Remarks

  The application is responsible for deciding which Actors are retired and for propagating that decision to the relevant replicas.

  Throws

  SequencerError if destroyed or the native runtime reports an operation failure.

sequence

• sequence<StringEncoded extends boolean = false>(
      stringEncode?: StringEncoded,
  ): readonly [
      U32List,
      StringEncoded extends true ? string : readonly (T | undefined)[],
  ]

  Sequences state into a compact serializable format.

  Type Parameters

  • StringEncoded extends boolean = false

  Parameters

  • OptionalstringEncode: StringEncoded

    Whether to concatenate Footage into a string; each text Frame must be one UTF-16 code unit. Defaults to false.

  Returns readonly [
      U32List,
      StringEncoded extends true ? string : readonly (T | undefined)[],
  ]

  A Sequence with acknowledged removals compacted in the exported state.

  Remarks

  Register active Actors before removal. Equal complete Session frontiers permit masks and deleted Footage to be omitted from the retained checkpoint. Compaction may translate retained anchors without rewriting this instance.

  Throws

  SequencerError if destroyed or the native runtime reports an operation failure.

  Throws

  SequencerError with code STRING_ENCODING_FAILED if Footage concatenation fails.

value

• value(at: number): T | undefined

  Returns the value at a Projection position.

  Parameters

  • at: number

    Valid visible position in 0..length() - 1.

  Returns T | undefined

  The corresponding Footage value.

  Throws

  SequencerError with code PROJECTION_DESTROYED after destruction.

values

• values(startAt?: number, endWith?: number): T[]

  Returns values from an inclusive range of Projection positions.

  Parameters

  • OptionalstartAt: number

    First included position; defaults to 0.

  • OptionalendWith: number

    Last included position; defaults to length() - 1.

  Returns T[]

  A new array of values, or an empty array for an empty range.

  Throws

  SequencerError if destroyed or the native runtime reports an operation failure.