writer

The push-side cursor over a WritableStream. Acquire one with gossamer/stream/writable_stream.get_writer then call write to send chunks. Release the lock via release_lock when done.

Types

Writer

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A JavaScript WritableStreamDefaultWriter — a locked writer over a WritableStream.

See WritableStreamDefaultWriter on MDN.

pub type Writer(a)

Values

abort

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pub fn abort(
  writer: Writer(a),
  reason reason: r,
) -> promise.Promise(Result(Nil, stream.StreamLifecycleError))

Aborts the stream. Returns Errored if the underlying sink’s abort callback throws or returns a rejecting promise.

close

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pub fn close(
  writer: Writer(a),
) -> promise.Promise(Result(Nil, stream.StreamLifecycleError))

Closes the stream after all writes complete. Returns Errored if the underlying sink’s close callback throws or returns a rejecting promise, or if the stream is already closing or closed.

closed

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pub fn closed(
  writer: Writer(a),
) -> promise.Promise(Result(Nil, stream.StreamLifecycleError))

Resolves when the stream closes. Returns Errored if the stream enters an errored state, or if the writer no longer holds the lock; the reason payload distinguishes the two.

desired_size

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pub fn desired_size(
  writer: Writer(a),
) -> Result(stream.DesiredSize, Nil)

The room remaining in the stream’s internal queue. Returns an error if the stream has errored or is erroring, or if the writer’s lock has been released; a closed stream reports Bounded(0).

ready

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pub fn ready(
  writer: Writer(a),
) -> promise.Promise(Result(Nil, stream.StreamLifecycleError))

Resolves when the stream is ready to accept more writes (backpressure has cleared). Returns Errored if the stream enters an errored state.

release_lock

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pub fn release_lock(writer: Writer(a)) -> Nil

Releases the writer’s lock on the stream.

write

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pub fn write(
  to writer: Writer(a),
  chunk chunk: a,
) -> promise.Promise(Result(Nil, stream.StreamLifecycleError))

Writes chunk to the stream. Returns Errored if the stream enters an errored state, or if the stream was already closed when write was called; the reason payload distinguishes the two.