Class: Restate::DurableFuture

Inherits:
Object
  • Object
show all
Defined in:
lib/restate/durable_future.rb,
sig/restate.rbs

Overview

A durable future wrapping a VM handle. Lazily resolves on first await and caches the result. Returned by ctx.run and ctx.sleep.

Direct Known Subclasses

DurableCallFuture

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(ctx, handle, serde: nil) ⇒ DurableFuture

Returns a new instance of DurableFuture.

Parameters:

  • ctx (Object)
  • handle (Integer)
  • serde: (Object) (defaults to: nil) 


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# File 'lib/restate/durable_future.rb', line 10

def initialize(ctx, handle, serde: nil)
  @ctx = ctx
  @handle = handle
  @serde = serde
  @resolved = false
  @value = nil
end

Instance Attribute Details

#handle ⇒ Integer (readonly)

Returns the value of attribute handle.

Returns:

  • (Integer) 


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# File 'lib/restate/durable_future.rb', line 8

def handle
  @handle
end

Instance Method Details

#await ⇒ Object

Block until the result is available and return it. Caches across calls, including failures — a second await on a failed future re-raises the same TerminalError rather than re-fetching from the VM (the notification is single-shot).

Returns:

  • (Object) —

    the deserialized result

Raises:

  • (@error) 


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# File 'lib/restate/durable_future.rb', line 24

def await
  resolve! unless @resolved
  raise @error if @error

  @value
end

#completed? ⇒ Boolean

Check whether the future has completed (non-blocking).

Returns:

  • (Boolean) 


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# File 'lib/restate/durable_future.rb', line 34

def completed?
  @resolved || @ctx.completed?(@handle)
end

#or_timeout(duration) ⇒ Object

Race self against Restate.sleep(duration). Returns the value if the future wins; raises TimeoutError otherwise. Does not cancel the underlying work (matches TS/Java SDKs); on a Restate::DurableCallFuture, call #cancel in the rescue if you want the remote invocation stopped.

Parameters:

  • duration (Numeric)

Returns:

  • (Object)

Raises:



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# File 'lib/restate/durable_future.rb', line 43

def or_timeout(duration)
  sleep_future = Restate.sleep(duration)
  Restate.wait_any(self, sleep_future)
  return await if completed?

  raise TimeoutError
end

#resolve! ⇒ void

This method returns an undefined value.



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# File 'lib/restate/durable_future.rb', line 53

def resolve!
  raw = @ctx.resolve_handle(@handle)
  @value = @serde ? @serde.deserialize(raw) : raw
rescue TerminalError => e
  @error = e
ensure
  @resolved = true
end