Struct OverlayView 

pub struct OverlayView { /* private fields */ }

A pinned base snapshot plus an uncommitted key overlay.

Clone is cheap for the base (Arc) and copies the overlay map; callers that only read should share one instance behind an Arc.

Implementations

impl OverlayView

pub fn new(base: Arc<ReadView>) -> Self

Wrap a pinned snapshot with an empty overlay.

pub fn with_buffer( base: Arc<ReadView>, buffer: BTreeMap<Vec<u8>, Option<Vec<u8>>>, ) -> Self

Wrap a pinned snapshot with a pre-existing overlay buffer.

pub fn base(&self) -> &Arc<ReadView>

The pinned base snapshot underneath this overlay.

pub fn buffer(&self) -> &BTreeMap<Vec<u8>, Option<Vec<u8>>>

The current overlay buffer (read-buffer-first).

pub fn commit_index(&self) -> u64

Commit index this view reads its committed base at.

pub fn cancellation(&self) -> ReadCancellation

Cancellation handle shared with the base snapshot.

pub fn put(&mut self, key: Vec<u8>, value: Vec<u8>)

Stage a write in the overlay.

pub fn delete(&mut self, key: Vec<u8>)

Stage a tombstone in the overlay.

pub fn apply_ops(&mut self, ops: &[Op])

Fold a batch of LMPG ops into the overlay. History is irrelevant to reads, so Put/Set become live values and Del/Purge tombstones.

pub fn get(&self, key: &[u8]) -> Result<Option<Vec<u8>>, StorageError>

Read one key: overlay first, then the pinned base.

Errors

Returns the underlying storage error from the base read.

pub fn range_prefix( &self, prefix: &[u8], ) -> Result<Vec<(Vec<u8>, Vec<u8>)>, StorageError>

Materialize every key/value with key starting with prefix, merging the overlay over the base (overlay wins; tombstones hide base rows).

Errors

Returns the underlying storage error from the base scan.

pub fn range_keys( &self, start: &[u8], end: &[u8], ) -> Result<Vec<Vec<u8>>, StorageError>

Materialize the keys with start <= key < end, merging the overlay over the base (overlay wins; tombstones hidden). Values are never read, so a keys-only scan does not pay for large payloads.

Errors

Returns the underlying storage error from the base scan.

pub fn range( &self, start: &[u8], end: &[u8], ) -> Result<Vec<(Vec<u8>, Vec<u8>)>, StorageError>

Materialize every key/value with start <= key < end, merging the overlay over the base. An empty end is unbounded above.

Errors

Returns the underlying storage error from the base scan.

Trait Implementations

impl Clone for OverlayView

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for OverlayView

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

Formats the value using the given formatter.