Struct ValueLog 

pub struct ValueLog<BC: BlobCache, C: Compressor + Clone>(/* private fields */);

A disk-resident value log

Implementations

impl<BC: BlobCache, C: Compressor + Clone> ValueLog<BC, C>

pub fn open<P: Into<PathBuf>>(path: P, config: Config<BC, C>) -> Result<Self>

Creates or recovers a value log in the given directory.

Errors

Will return Err if an IO error occurs.

pub fn register_writer(&self, writer: SegmentWriter<C>) -> Result<()>

Registers a SegmentWriter.

Errors

Will return Err if an IO error occurs.

pub fn segment_count(&self) -> usize

Returns the amount of segments in the value log.

pub fn get(&self, vhandle: &ValueHandle) -> Result<Option<UserValue>>

Resolves a value handle.

Errors

Will return Err if an IO error occurs.

pub fn get_with_prefetch( &self, vhandle: &ValueHandle, prefetch_size: usize, ) -> Result<Option<UserValue>>

Resolves a value handle, and prefetches some values after it.

Errors

Will return Err if an IO error occurs.

pub fn get_writer(&self) -> Result<SegmentWriter<C>>

Initializes a new segment writer.

Errors

Will return Err if an IO error occurs.

pub fn drop_stale_segments(&self) -> Result<u64>

Drops stale segments.

Returns the amount of disk space (compressed data) freed.

Errors

Will return Err if an IO error occurs.

pub fn space_amp(&self) -> f32

Returns the approximate space amplification.

Returns 0.0 if there are no items.

pub fn scan_for_stats( &self, iter: impl Iterator<Item = Result<(ValueHandle, u32)>>, ) -> Result<GcReport>

Scans the given index and collects GC statistics.

Errors

Will return Err if an IO error occurs.

pub fn apply_gc_strategy<R: IndexReader, W: IndexWriter>( &self, strategy: &impl GcStrategy<BC, C>, index_reader: &R, index_writer: W, ) -> Result<u64>

Applies a GC strategy.

Errors

Will return Err if an IO error occurs.

pub fn clear(&self, prune_async: bool) -> Result<()>

Atomically removes all data from the value log.

If prune_async is set to true, the blob files will be removed from disk in a thread to avoid blocking.

Trait Implementations

impl<BC: Clone + BlobCache, C: Clone + Compressor + Clone> Clone for ValueLog<BC, C>

fn clone(&self) -> ValueLog<BC, C>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<BC: BlobCache, C: Compressor + Clone> Deref for ValueLog<BC, C>

type Target = ValueLogInner<BC, C>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.