Struct StagingRing 

pub struct StagingRing<B = Buffer> { /* private fields */ }

The slots, their capacities and fences: one frame’s staging memory at a time, reused once the GPU is done with it.

Generic over the buffer type for the reason the module header gives; the engine uses the default StagingRing<wgpu::Buffer>.

Implementations

impl<B> StagingRing<B>

pub fn new() -> Self

An empty ring of STAGING_SLOTS slots of at most MAX_SLOT_BYTES each. No buffer exists until the first frame.

pub fn with_limits(max_slots: usize, max_slot_bytes: u64) -> Self

An empty ring with its slot count and per-slot ceiling stated.

pub fn stats(&self) -> StagingStats

What this ring has done so far.

pub fn slot_count(&self) -> usize

How many slots exist.

pub fn slot(&self, index: usize) -> Option<(u64, SlotState)>

Slot index’s capacity and state, if it exists.

impl<B: Clone> StagingRing<B>

pub fn acquire<A>(&mut self, allocator: &A, bytes: u64) -> Option<SlotLease<B>>

where A: StagingAllocator<Buffer = B>,

Hands out a slot holding at least bytes, or None when the frame needs more than a slot may hold or every slot is still in flight.

In order of preference: a ready slot already large enough (no allocation), a ready slot too small or an abandoned/failed one replaced at slot_capacity(bytes), a new slot while the ring has fewer than its limit. A slot in flight is never handed out.

impl StagingRing<Buffer>

pub fn begin(&mut self, device: &Device, bytes: u64) -> Option<StagingFrame>

Opens one frame’s staging: a mapped slot of at least bytes, or None when the caller should fall back to queue writes this frame (see Self::acquire).

When every slot is still in flight the device is polled once, without waiting, so a slot whose submission has already finished is re-mapped rather than skipped.

Trait Implementations

impl<B: Debug> Debug for StagingRing<B>

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

Formats the value using the given formatter.

impl<B> Default for StagingRing<B>

fn default() -> Self

Returns the “default value” for a type.