Struct ElementState

pub struct ElementState {
    pub type_specific: Option<TypeSpecificElementState>,
    pub enabled: Option<bool>,
    pub latency: Option<Latency>,
    pub vendor_specific_data: Option<Vec<u8>>,
    pub started: Option<bool>,
    pub bypassed: Option<bool>,
    pub turn_on_delay: Option<i64>,
    pub turn_off_delay: Option<i64>,
    pub processing_delay: Option<i64>,
    /* private fields */
}

The current state of an element, as returned from the driver. Note that this table contains fields that are not present in SettableElementState, since they cannot be set by clients.

Fields

type_specific: Option<TypeSpecificElementState>

If included, type-specific state parameters for the processing element.

If this processing element is disabled and its type-specific state is provided, then the type-specific state is only informational (e.g. the state of a stopped element, if it were to be re-started without also providing additional superceding state information).

Optional.

enabled: Option<bool>

Process element enable/disable state. By default processing elements are enabled. If the corresponding Element returned can_disable equals to false, then this field can’t be set to false. If enabled is not included, then state must be included if and only if the processing element is currently enabled.

Optional.

Deprecation

Use bypassed instead.

latency: Option<Latency>

If included, how much latency is added to the pipeline if this processing element is enabled. This field must not be present in a SetElementState state since the latency can’t be set by a client, it can only provided by the server in a WatchElementState reply.

Optional.

vendor_specific_data: Option<Vec<u8>>

If included, an opaque object of octets for exchanging vendor specific information.

Optional.

started: Option<bool>

The started/stopped state for this processing element. If true, the hardware associated with the element is started. If false, stopped.

By default processing elements are started.

A stopped processing element does not provide its abstracted functionality. Specifically, no audio data flows through a stopped element.

Required.

bypassed: Option<bool>

The bypassed state for this processing element. If true, the hardware associated with the element is bypassed. If false, not bypassed.

By default processing elements are not bypassed. If the corresponding Element returned can_bypass equals to false, then this field can’t be set to true.

A bypassed element does not affect the flow of audio through the topology.

Optional.

turn_on_delay: Option<i64>

If included, the driver’s best estimate of the amount of time it takes the element’s hardware to enter a fully operational mode after started has changed from false to true. Hardware may require some duration to get into a fully operational mode after a change in power state, for example.

If this delay is not taken into account, then the initial frames of an audio stream may be lost while an audio element is powering up. If not included, turn_on_delay is unknown.

Optional.

turn_off_delay: Option<i64>

If included, the driver’s best estimate of the amount of time it takes the element’s hardware to enter a fully disabled mode after started has changed from true to false. Hardware may require some duration to get into a fully stopped state after a change in power state, for example.

If this delay is not taken into account, more frames will be emitted/captured than a client may realize, specifically when elements are powering down. If not included, turn_off_delay is unknown.

Optional.

processing_delay: Option<i64>

If included, the driver’s best estimate (as currently configured, including bypassed) of the delay added by this processing element.

This value must be taken into account by clients when determining the requirements for minimum lead time (during playback) and minimum capture delay (during capture).

For an element of type RING_BUFFER, this delay should not include the inherent delay added by the temporary buffering needed to copy data in and out of a ring buffer, which is contained in the RingBufferProperties field driver_transfer_bytes.

Optional.

Trait Implementations

impl Clone for ElementState

fn clone(&self) -> ElementState

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ElementState

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

Formats the value using the given formatter.

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

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 ElementState

fn default() -> ElementState

Returns the “default value” for a type.

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

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 ElementState

fn eq(&self, other: &ElementState) -> 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 ElementState

type Owned = ElementState

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 ElementState

type Borrowed<'a> = &'a ElementState

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 ElementState

impl StructuralPartialEq for ElementState