Struct IndexedChunkMap 

pub struct IndexedChunkMap { /* private fields */ }

An implementation of ChunkMap to support chunk state tracking by using a bitmap file.

The IndexedChunkMap is an implementation of ChunkMap which uses a bitmap file and atomic bitmap operations to track readiness state. It creates or opens a file with the name $blob_id.chunk_map to record whether a chunk has been cached by the blob cache, and atomic bitmap operations are used to manipulate the state bit. The bitmap file will be persisted to disk.

This approach can be used to share chunk ready state between multiple nydusd instances. For example: the bitmap file layout is [0b00000000, 0b00000000], when blobcache calls set_ready(3), the layout should be changed to [0b00010000, 0b00000000].

Implementations

impl IndexedChunkMap

pub fn new(blob_path: &str, chunk_count: u32, persist: bool) -> Result<Self>

Create a new instance of IndexedChunkMap.

Trait Implementations

impl ChunkIndexGetter for IndexedChunkMap

type Index = u32

Type of index needed by ChunkMap.

fn get_index(chunk: &dyn BlobChunkInfo) -> Self::Index

Get the chunk’s id/key for state tracking.

impl ChunkMap for IndexedChunkMap

fn is_ready(&self, chunk: &dyn BlobChunkInfo) -> Result<bool>

Check whether the chunk is ready for use.

fn set_ready_and_clear_pending(&self, chunk: &dyn BlobChunkInfo) -> Result<()>

Set the chunk to ready for use and clear the pending state.

fn is_persist(&self) -> bool

Check whether the implementation supports state persistence.

fn as_range_map(&self) -> Option<&dyn RangeMap<I = u32>>

Convert the objet to an RangeMap object.

fn is_pending(&self, _chunk: &dyn BlobChunkInfo) -> Result<bool>

Check whether the chunk is pending for downloading.

fn is_ready_or_pending(&self, chunk: &dyn BlobChunkInfo) -> Result<bool>

Check whether a chunk is ready for use or pending for downloading.

fn check_ready_and_mark_pending( &self, _chunk: &dyn BlobChunkInfo, ) -> StorageResult<bool>

Check whether the chunk is ready for use, and mark it as pending if not ready yet.

fn clear_pending(&self, _chunk: &dyn BlobChunkInfo)

Clear the pending state of the chunk.

impl RangeMap for IndexedChunkMap

type I = u32

fn is_range_all_ready(&self) -> bool

Check whether all chunks or data managed by the RangeMap object are ready.

fn is_range_ready(&self, start_index: u32, count: u32) -> Result<bool>

Check whether all chunks or data in the range are ready for use.

fn check_range_ready_and_mark_pending( &self, start_index: u32, count: u32, ) -> Result<Option<Vec<u32>>>

Check whether all chunks or data in the range [start, start + count) are ready.

fn set_range_ready_and_clear_pending( &self, start_index: u32, count: u32, ) -> Result<()>

Mark all chunks or data in the range as ready for use.

fn clear_range_pending(&self, _start: Self::I, _count: Self::I)

Clear the pending state for all chunks or data in the range.

fn wait_for_range_ready(&self, _start: Self::I, _count: Self::I) -> Result<bool>

Wait for all chunks or data in the range to be ready until timeout.