Class ChannelMap<T>

constructor

• new ChannelMap<T>(name: string, codec: Codec<T>): ChannelMap<T>

  Creates a ChannelMap definition.

  Type Parameters

  • T

  Parameters

  • name: string

    Non-empty name without /, unique within the Flow.

  • codec: Codec<T>

    Element codec shared by every instance.

  Returns ChannelMap<T>

Readonlycodec

Readonlyname

atLeast

• atLeast(instance: string, count: number, conditionId?: string): Condition

  Creates an instance condition requiring at least count values.

  Parameters

  • instance: string

    The map instance. Slash is prohibited because it is a reserved character.

  • count: number

    Inclusive non-negative lower bound.

  • OptionalconditionId: string

    Optional stable condition identifier.

  Returns Condition

  A condition without an upper bound.

atMost

• atMost(instance: string, count: number, conditionId?: string): Condition

  Creates a non-blocking instance condition consuming up to count queued values. When its surrounding Wait completes, it consumes values queued then; an empty queue yields none.

  Parameters

  • instance: string

    The map instance. Slash is prohibited because it is a reserved character.

  • count: number

    Inclusive non-negative upper bound.

  • OptionalconditionId: string

    Optional stable condition identifier.

  Returns Condition

  A condition without a positive lower bound.

delete

• delete(context: Context, instance: string, messageId: string): void

  Stages best-effort deletion of one pending message from a ChannelMap instance.

  Parameters

  • context: Context

    Current Step, timeout-handler, or RPC Context.

  • instance: string

    The ChannelMap instance. Slash is prohibited because it is a reserved character.

  • messageId: string

    Non-empty server-assigned message ID.

  Returns void

findPendingMessage

• findPendingMessage(
      context: Context,
      instance: string,
      messageId: string,
  ): ChannelMessage<T> | undefined

  Finds one instance message in the loaded pending snapshot.

  Parameters

  • context: Context

    Current Step, timeout-handler, or RPC Context.

  • instance: string

    Logical ChannelMap instance.

  • messageId: string

    Server-assigned message ID.

  Returns ChannelMessage<T> | undefined

  The matching message, or undefined when absent from the snapshot.

forN

• forN(instance: string, count: number, conditionId?: string): Condition

  Creates an instance condition consuming exactly count values.

  Parameters

  • instance: string

    The map instance. Slash is prohibited because it is a reserved character.

  • count: number

    Required non-negative count.

  • OptionalconditionId: string

    Optional stable condition identifier.

  Returns Condition

  A condition with equal bounds.

forOne

• forOne(instance: string, conditionId?: string): Condition

  Creates an instance condition consuming exactly one value.

  Parameters

  • instance: string

    The map instance. Slash is prohibited because it is a reserved character.

  • OptionalconditionId: string

    Optional stable condition identifier.

  Returns Condition

  An exact-one instance condition.

getAllInstanceKeys

• getAllInstanceKeys(context: Context): readonly string[]

  Returns decoded non-empty instance keys in ascending order.

  Parameters

  • context: Context

    Current Step, timeout-handler, or RPC Context.

  Returns readonly string[]

  Keys including publications buffered by the current handler.

getMapSize

• getMapSize(context: Context): number

  Returns the number of non-empty instances visible to the current handler.

  Parameters

  • context: Context

    Current Step, timeout-handler, or RPC Context.

  Returns number

  The number of keys after including publications buffered by this handler.

loadMessages

• loadMessages(instance: string): ChannelMapLoad

  Selects one instance's pending messages for a handler snapshot.

  Parameters

  • instance: string

    Non-empty logical instance key. The SDK escapes it for the protocol.

  Returns ChannelMapLoad

  An exact instance load for RPC, Step, or timeout-handler options.

pendingMessages

• pendingMessages(
      context: Context,
      instance: string,
  ): readonly ChannelMessage<T>[]

  Returns one loaded instance snapshot in FIFO order.

  Parameters

  • context: Context

    Current Step, timeout-handler, or RPC Context.

  • instance: string

    Logical ChannelMap instance.

  Returns readonly ChannelMessage<T>[]

  Immutable pending message IDs and decoded values.

  Throws

  ChannelMessagesNotLoadedError when this handler did not load the instance's messages.

publish

• publish(context: Context, instance: string, value: T): void

  Stages one value for a ChannelMap instance.

  Parameters

  • context: Context

    Current Step or RPC Context.

  • instance: string

    The map instance. Slash is prohibited because it is a reserved character.

  • value: T

    Typed value to append.

  Returns void

range

• range(
      instance: string,
      atLeast?: number,
      atMost?: number,
      conditionId?: string,
  ): Condition

  Creates a bounded condition for one ChannelMap instance. Dex waits only for atLeast, then consumes currently queued values up to atMost. Omitting atLeast makes the condition complete immediately.

  Parameters

  • instance: string

    The map instance. Slash is prohibited because it is a reserved character.

  • OptionalatLeast: number

    Optional inclusive lower bound.

  • OptionalatMost: number

    Optional inclusive upper bound.

  • OptionalconditionId: string

    Optional stable condition identifier.

  Returns Condition

  A validated instance condition.

results

• results(context: Context, instance: string): readonly T[]

  Returns values selected for one instance by the satisfied condition.

  Parameters

  • context: Context

    Current Step Context.

  • instance: string

    The map instance. Slash is prohibited because it is a reserved character.

  Returns readonly T[]

  Ordered values for this Step execution.

size

• size(context: Context, instance: string): number

  Returns one instance's queued value count.

  Parameters

  • context: Context

    Current Step or RPC Context.

  • instance: string

    The map instance. Slash is prohibited because it is a reserved character.

  Returns number

  Non-negative queued value count.