Struct sled_overlay::tree::SledTreeOverlay

pub struct SledTreeOverlay { /* private fields */ }

An overlay on top of a single sled::Tree instance

Implementations

impl SledTreeOverlay

pub fn new(tree: &Tree) -> Self

Instantiate a new SledTreeOverlay on top of a given sled::Tree.

pub fn contains_key(&self, key: &[u8]) -> Result<bool, Error>

Returns true if the overlay contains a value for a specified key.

pub fn is_empty(&self) -> bool

Returns true if the overlay is empty.

pub fn last(&self) -> Result<Option<(IVec, IVec)>, Error>

Returns last value from the overlay or None if its empty, based on the Ord implementation for Vec<u8>.

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

Retrieve a value from the overlay if it exists.

pub fn insert( &mut self, key: &[u8], value: &[u8] ) -> Result<Option<IVec>, Error>

Insert a key to a new value, returning the last value if it was set.

pub fn remove(&mut self, key: &[u8]) -> Result<Option<IVec>, Error>

Delete a value, if it exists, returning the old value.

pub fn aggregate(&self) -> Option<Batch>

Aggregate all the current overlay changes into a sled::Batch ready for further operation. If there are no changes, return None.

pub fn checkpoint(&mut self)

Checkpoint current cache state so we can revert to it, if needed.

pub fn revert_to_checkpoint(&mut self)

Revert to current cache state checkpoint.

Trait Implementations

impl Clone for SledTreeOverlay

fn clone(&self) -> SledTreeOverlay

Returns a copy of the value.

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

Performs copy-assignment from source.