Struct value_log::ValueLog

pub struct ValueLog(/* private fields */);

A disk-resident value log

Implementations

impl ValueLog

pub fn open<P: Into<PathBuf>>(path: P, config: Config) -> 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<W: IndexWriter>( &self, writer: SegmentWriter<W>, ) -> Result<()>

Registers writer

Errors

Will return Err if an IO error occurs.

pub fn segment_count(&self) -> usize

Returns segment count

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

Resolves a value handle

Errors

Will return Err if an IO error occurs.

pub fn get_writer<W: IndexWriter>( &self, index_writer: W, ) -> Result<SegmentWriter<W>>

Initializes a new segment writer

Errors

Will return Err if an IO error occurs.

pub fn select_segments_for_space_amp_reduction( &self, space_amp_target: f32, ) -> Vec<u64>

Tries to find a least-effort-selection of segments to merge to reach a certain space amplification.

pub fn find_segments_with_stale_threshold(&self, threshold: f32) -> Vec<u64>

Finds segment IDs that have reached a stale threshold.

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

Drops stale segments.

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<()>

Scans the given index and collecting GC statistics.

Errors

Will return Err if an IO error occurs.

pub fn rollover<R: IndexReader, W: IndexWriter>( &self, ids: &[u64], index_reader: &R, index_writer: W, ) -> Result<()>

Rewrites some segments into new segment(s), blocking the caller until the operation is completely done.

Errors

Will return Err if an IO error occurs.

Trait Implementations

impl Clone for ValueLog

fn clone(&self) -> ValueLog

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Deref for ValueLog

type Target = ValueLogInner

The resulting type after dereferencing.

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

Dereferences the value.