Struct devices::virtio::descriptor_utils::DescriptorChainRegions

struct DescriptorChainRegions {
    regions: SmallVec<[MemRegion; 2]>,
    current_region_index: usize,
    current_region_offset: usize,
    bytes_consumed: usize,
}

Fields

regions: SmallVec<[MemRegion; 2]>

current_region_index: usize

current_region_offset: usize

bytes_consumed: usize

Implementations

impl DescriptorChainRegions

fn new(regions: SmallVec<[MemRegion; 2]>) -> Self

fn available_bytes(&self) -> usize

fn bytes_consumed(&self) -> usize

fn get_remaining_regions(&self) -> MemRegionIter<'_>

Returns all the remaining buffers in the DescriptorChain. Calling this function does not consume any bytes from the DescriptorChain. Instead callers should use the consume method to advance the DescriptorChain. Multiple calls to get with no intervening calls to consume will return the same data.

fn get_remaining_regions_with_count(&self, count: usize) -> MemRegionIter<'_>

Like get_remaining_regions but guarantees that the combined length of all the returned iovecs is not greater than count. The combined length of the returned iovecs may be less than count but will always be greater than 0 as long as there is still space left in the DescriptorChain.

fn get_remaining<'mem>( &self, mem: &'mem GuestMemory, ) -> SmallVec<[VolatileSlice<'mem>; 16]>

Returns all the remaining buffers in the DescriptorChain as VolatileSlices of the given GuestMemory. Calling this function does not consume any bytes from the DescriptorChain. Instead callers should use the consume method to advance the DescriptorChain. Multiple calls to get with no intervening calls to consume will return the same data.

fn get_remaining_with_count<'mem>( &self, mem: &'mem GuestMemory, count: usize, ) -> SmallVec<[VolatileSlice<'mem>; 16]>

Like ‘get_remaining_regions_with_count’ except convert the offsets to volatile slices in the ‘GuestMemory’ given by ‘mem’.

fn consume(&mut self, count: usize)

Consumes count bytes from the DescriptorChain. If count is larger than self.available_bytes() then all remaining bytes in the DescriptorChain will be consumed.

fn split_at(&mut self, offset: usize) -> DescriptorChainRegions