Struct StreamReader 

pub struct StreamReader<T> { /* private fields */ }

Represents the readable end of a Component Model stream.

Note that StreamReader instances must be disposed of using close; otherwise the in-store representation will leak and the writer end will hang indefinitely. Consider using GuardedStreamReader to ensure that disposal happens automatically.

Implementations

impl<T> StreamReader<T>

pub fn new<S>( store: S, producer: impl StreamProducer<<S as AsContext>::Data, Item = T>, ) -> StreamReader<T>

where S: AsContextMut, T: Lower + Lift + Send + Sync + 'static,

Create a new stream with the specified producer.

pub fn try_into<V>(self, store: impl AsContextMut) -> Result<V, StreamReader<T>>

where V: 'static,

Attempt to consume this object by converting it into the specified type.

This can be useful for “short-circuiting” host-to-host streams, bypassing the guest entirely. For example, if a guest task returns a host-created stream and then exits, this function may be used to retrieve the write end, after which the guest instance and store may be disposed of if no longer needed.

This will return Ok(_) if and only if the following conditions are met:

• The stream was created by the host (i.e. not by the guest).

• The StreamProducer::try_into function returns Ok(_) when given the producer provided to StreamReader::new when the stream was created, along with TypeId::of::<V>().

pub fn pipe<S>( self, store: S, consumer: impl StreamConsumer<<S as AsContext>::Data, Item = T>, )

where S: AsContextMut, T: 'static,

Set the consumer that accepts the items delivered to this stream.

pub fn close(&mut self, store: impl AsContextMut)

Close this StreamReader.

This will signal that this portion of the stream is closed causing all future writes to return immediately with “DROPPED”.

Panics

Panics if the store does not own this future. Usage of this future after calling close will also cause a panic.

pub fn close_with(&mut self, accessor: impl AsAccessor)

Convenience method around Self::close.

pub fn guard<A>(self, accessor: A) -> GuardedStreamReader<T, A>

where A: AsAccessor,

Returns a GuardedStreamReader which will auto-close this stream on drop and clean it up from the store.

Note that the accessor provided must own this future and is additionally transferred to the GuardedStreamReader return value.

pub fn try_into_stream_any( self, store: impl AsContextMut, ) -> Result<StreamAny, Error>

where T: ComponentType + 'static,

Attempts to convert this StreamReader<T> to a StreamAny.

Errors

This function will return an error if self does not belong to store.

pub fn try_from_stream_any(stream: StreamAny) -> Result<StreamReader<T>, Error>

where T: ComponentType + 'static,

Attempts to convert a StreamAny into a StreamReader<T>.

Errors

This function will fail if T doesn’t match the type of the value that stream is sending.

Trait Implementations

impl<T> Debug for StreamReader<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<T, A> From<GuardedStreamReader<T, A>> for StreamReader<T>

where A: AsAccessor,

fn from(guard: GuardedStreamReader<T, A>) -> StreamReader<T>

Converts to this type from the input type.

impl<T> ComponentType for StreamReader<T>

where T: ComponentType,

impl<T> Lift for StreamReader<T>

where T: ComponentType,

impl<T> Lower for StreamReader<T>

where T: ComponentType,