Struct SledTreeOverlayStateDiff 

pub struct SledTreeOverlayStateDiff {
    pub cache: BTreeMap<IVec, (Option<IVec>, IVec)>,
    pub removed: BTreeMap<IVec, IVec>,
}

Auxilliary struct representing a SledTreeOverlayState diff log.

Fields

cache: BTreeMap<IVec, (Option<IVec>, IVec)>

Inserted data represented as a BTreeMap. The value contains both the previous key value(if it existed), along with the new one.

removed: BTreeMap<IVec, IVec>

In removed, we keep track of keys that were removed in the overlay, along with their value.

Implementations

impl SledTreeOverlayStateDiff

pub fn new(tree: &Tree, state: &SledTreeOverlayState) -> Result<Self, Error>

Instantiate a new SledTreeOverlayStateDiff, over the provided sled::Tree that is being overlayed.

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

Instantiate a new SledTreeOverlayStateDiff, over the provided sled::Tree that is being dropped. The diff will contain all existing tree keys in its cache as inserts, representing the last tree state.

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

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

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

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

pub fn inverse(&self) -> Self

Produces a SledTreeOverlayStateDiff containing the inverse changes from our own.

pub fn remove_diff(&mut self, other: &Self)

Remove provided tree overlay state changes from our own.

pub fn update_values(&mut self, other: &Self)

Update our cache key values to the ones in the provided tree overlay state changes.

Trait Implementations

impl Clone for SledTreeOverlayStateDiff

fn clone(&self) -> SledTreeOverlayStateDiff

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SledTreeOverlayStateDiff

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

Formats the value using the given formatter.

impl Default for SledTreeOverlayStateDiff

fn default() -> SledTreeOverlayStateDiff

Returns the “default value” for a type.

impl From<&SledTreeOverlayStateDiff> for SledTreeOverlayState

fn from(diff: &SledTreeOverlayStateDiff) -> Self

Converts to this type from the input type.

impl PartialEq for SledTreeOverlayStateDiff

fn eq(&self, other: &SledTreeOverlayStateDiff) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for SledTreeOverlayStateDiff