Class Topic<Value>Internal

constructor

• new Topic<Value>(fields?): Topic<Value>

• Type Parameters

  • Value

  Parameters

  • Optional fields: {
        accumulate?: boolean;
        unique?: boolean;
    }

    • Optional accumulate?: boolean

    • Optional unique?: boolean

  Returns Topic<Value>

accumulate

lc_graph_name

seen

unique

values

checkpoint

• checkpoint(): [Value[], Value[]]

• Return a string representation of the channel's current state.

  Returns [Value[], Value[]]

  Throws

  if the channel is empty (never updated yet), or doesn't support checkpoints.

fromCheckpoint

• fromCheckpoint(checkpoint?): this

• Return a new identical channel, optionally initialized from a checkpoint. Can be thought of as a "restoration" from a checkpoint which is a "snapshot" of the channel's state.

  Parameters

  • Optional checkpoint: [Value[], Value[]]

  Returns this

get

• get(): Value[]

• Return the current value of the channel.

  Returns Value[]

  Throws

  if the channel is empty (never updated yet).

update

• update(values): boolean

• Update the channel's value with the given sequence of updates. The order of the updates in the sequence is arbitrary. This method is called by Pregel for all channels at the end of each step. If there are no updates, it is called with an empty sequence.

  Raises InvalidUpdateError if the sequence of updates is invalid. Returns True if the channel was updated, False otherwise.

  Parameters

  • values: (Value | Value[])[]

  Returns boolean

  Throws

  if the sequence of updates is invalid.