Struct StreamOutputConstraints

pub struct StreamOutputConstraints {
    pub stream_lifetime_ordinal: Option<u64>,
    pub buffer_constraints_action_required: Option<bool>,
    pub buffer_constraints: Option<StreamBufferConstraints>,
    /* private fields */
}

The stream-processor-controlled output configuration, including both StreamBufferConstraints for the output and FormatDetails for the output.

Fields

stream_lifetime_ordinal: Option<u64>

A client which always immediately re-configures output buffers on receipt of OnOutputConstraints() with buffer_constraints_action_required true can safely ignore this field.

A client is permitted to ignore an OnOutputConstraints() message even with buffer_constraints_action_required true if the client knows the server has already been told to discard the remainder of the stream with the same stream_lifetime_ordinal or if this stream_lifetime_ordinal field is set to 0. The server is required to re-send needed output config via OnOutputConstraints() with new stream_lifetime_ordinal and buffer_constraints_action_required true, if the most recent completed server-side output config isn’t what the server wants/needs yet for the new stream.

buffer_constraints_action_required: Option<bool>

When the buffer constraints are delivered, they indicate whether action is required. A false value here permits delivery of constraints which are fresher without forcing a buffer reconfiguration. If this is false, a client cannot assume that it’s safe to immediately re-configure output buffers. If this is true, the client can assume it’s safe to immediately configure output buffers once.

A client is permitted to ignore buffer constraint versions which have buffer_constraints_action_required false. The server is not permitted to change buffer_constraints_action_required from false to true for the same buffer_constraints_version_ordinal.

For each configuration, a client must use new buffers, never buffers that were previously used for anything else, and never buffers previously used for any other StreamProcessor purposes. This rule exists for multiple good reasons, relevant to both mid-stream changes, and changes on stream boundaries. A client should just use new buffers each time.

When this is true, the server has already de-refed as many low-level output buffers as the server can while still performing efficient transition to the new buffers and will de-ref the rest asap. A Sync() is not necessary to achieve non-overlap of resource usage to the extent efficiently permitted by the formats involved.

If buffer_constraints_action_required is true, the server must not deliver more output data until after output buffers have been configured (or re-configured) by the client.

buffer_constraints: Option<StreamBufferConstraints>

Trait Implementations

impl Clone for StreamOutputConstraints

fn clone(&self) -> StreamOutputConstraints

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for StreamOutputConstraints

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

Formats the value using the given formatter.

impl<D: ResourceDialect> Decode<StreamOutputConstraints, D> for StreamOutputConstraints

fn new_empty() -> Self

Creates a valid instance of Self. The specific value does not matter, since it will be overwritten by decode.

unsafe fn decode( &mut self, decoder: &mut Decoder<'_, D>, offset: usize, depth: Depth, ) -> Result<()>

Decodes an object of type T from the decoder’s buffers into self.

impl Default for StreamOutputConstraints

fn default() -> StreamOutputConstraints

Returns the “default value” for a type.

impl<D: ResourceDialect> Encode<StreamOutputConstraints, D> for &StreamOutputConstraints

unsafe fn encode( self, encoder: &mut Encoder<'_, D>, offset: usize, depth: Depth, ) -> Result<()>

Encodes the object into the encoder’s buffers. Any handles stored in the object are swapped for Handle::INVALID.

impl PartialEq for StreamOutputConstraints

fn eq(&self, other: &StreamOutputConstraints) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl TypeMarker for StreamOutputConstraints

type Owned = StreamOutputConstraints

The owned Rust type which this FIDL type decodes into.

fn inline_align(_context: Context) -> usize

Returns the minimum required alignment of the inline portion of the encoded object. It must be a (nonzero) power of two.

fn inline_size(_context: Context) -> usize

Returns the size of the inline portion of the encoded object, including padding for alignment. Must be a multiple of inline_align.

fn encode_is_copy() -> bool

Returns true if the memory layout of Self::Owned matches the FIDL wire format and encoding requires no validation. When true, we can optimize encoding arrays and vectors of Self::Owned to a single memcpy.

fn decode_is_copy() -> bool

Returns true if the memory layout of Self::Owned matches the FIDL wire format and decoding requires no validation. When true, we can optimize decoding arrays and vectors of Self::Owned to a single memcpy.

impl ValueTypeMarker for StreamOutputConstraints

type Borrowed<'a> = &'a StreamOutputConstraints

The Rust type to use for encoding. This is a particular Encode<Self> type cheaply obtainable from &Self::Owned. There are three cases:

fn borrow(value: &<Self as TypeMarker>::Owned) -> Self::Borrowed<'_>

Cheaply converts from &Self::Owned to Self::Borrowed.

impl Persistable for StreamOutputConstraints

impl StructuralPartialEq for StreamOutputConstraints