Struct RamDiskLayer

pub struct RamDiskLayer { /* private fields */ }

A disk layer backed entirely by RAM.

Implementations

impl RamDiskLayer

pub fn new(size: u64) -> Result<Self, Error>

Makes a new RAM disk layer of size bytes.

Trait Implementations

impl Debug for RamDiskLayer

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

Formats the value using the given formatter.

impl Inspect for RamDiskLayer

fn inspect(&self, req: Request<'_>)

Inspects the object.

impl LayerIo for RamDiskLayer

fn layer_type(&self) -> &str

Returns the layer type name as a string.

fn sector_count(&self) -> u64

Returns the current sector count.

fn sector_size(&self) -> u32

Returns the logical sector size of the backing store.

fn is_logically_read_only(&self) -> bool

Returns true if the layer is logically read only.

fn disk_id(&self) -> Option<[u8; 16]>

Optionally returns a 16-byte identifier for the disk, if there is a natural one for this backing store.

fn physical_sector_size(&self) -> u32

Returns the physical sector size of the backing store.

fn is_fua_respected(&self) -> bool

Returns true if the fua parameter to [LayerIo::write] is respected by the backing store by ensuring that the IO is immediately committed to disk.

async fn read( &self, buffers: &RequestBuffers<'_>, sector: u64, marker: SectorMarker<'_>, ) -> Result<(), DiskError>

Reads sectors from the layer.

async fn write( &self, buffers: &RequestBuffers<'_>, sector: u64, _fua: bool, ) -> Result<(), DiskError>

Writes sectors to the layer.

fn write_no_overwrite(&self) -> Option<impl WriteNoOverwrite>

Optionally returns a write-no-overwrite implementation.

async fn sync_cache(&self) -> Result<(), DiskError>

Issues an asynchronous flush operation to the disk.

async fn wait_resize(&self, sector_count: u64) -> u64

Waits for the disk sector size to be different than the specified value.

async fn unmap( &self, sector_offset: u64, sector_count: u64, _block_level_only: bool, next_is_zero: bool, ) -> Result<(), DiskError>

Unmap sectors from the layer.

fn unmap_behavior(&self) -> UnmapBehavior

Returns the behavior of the unmap operation.

fn optimal_unmap_sectors(&self) -> u32

Returns the optimal granularity for unmaps, in sectors.

impl WriteNoOverwrite for RamDiskLayer

async fn write_no_overwrite( &self, buffers: &RequestBuffers<'_>, sector: u64, ) -> Result<(), DiskError>

Write to the layer without overwriting existing data. Existing sectors must be preserved.