Struct RetractableLastValueAccumulator 

pub struct RetractableLastValueAccumulator { /* private fields */ }

Retractable LAST_VALUE accumulator for changelog/retraction mode.

Uses BTreeMap<i64, Vec<i64>> (timestamp → values) for O(log n) insert/remove and O(1) last-value access via last_key_value().

Implementations

impl RetractableLastValueAccumulator

pub fn new() -> Self

Creates a new empty accumulator.

pub fn len(&self) -> usize

Returns the number of stored entries.

pub fn is_empty(&self) -> bool

Returns true if no entries are stored.

Trait Implementations

impl Clone for RetractableLastValueAccumulator

fn clone(&self) -> RetractableLastValueAccumulator

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RetractableLastValueAccumulator

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

Formats the value using the given formatter.

impl Default for RetractableLastValueAccumulator

fn default() -> RetractableLastValueAccumulator

Returns the “default value” for a type.

impl RetractableAccumulator for RetractableLastValueAccumulator

type Input = (i64, i64)

The input type for the aggregation.

type Output = Option<i64>

The output type produced by the aggregation.

fn add(&mut self, (timestamp, value): (i64, i64))

Adds a value to the accumulator.

fn retract(&mut self, (timestamp, value): &(i64, i64))

Retracts (un-applies) a value from the accumulator.

fn merge(&mut self, other: &Self)

Merges another accumulator into this one.

fn result(&self) -> Option<i64>

Extracts the final result from the accumulator.

fn is_empty(&self) -> bool

Returns true if the accumulator is empty (no values added).

fn supports_efficient_retraction(&self) -> bool

Returns true if this accumulator can efficiently retract.

fn reset(&mut self)

Resets the accumulator to its initial state.