Struct MeasurementCache 

pub struct MeasurementCache { /* private fields */ }

Cache for storing measured item sizes keyed by VirtualKey.

Maintains a mapping from item keys to their actual measured dimensions. Using keys instead of indices means measured sizes follow items across reorders when a custom key extractor is used.

Implementations

impl MeasurementCache

pub fn new(initial_estimate: f64) -> Self

Creates a new empty measurement cache.

Parameters

• initial_estimate: The default size estimate used before measurements arrive.

pub fn record( &mut self, key: VirtualKey, size: f64, ) -> Result<bool, VirtualizerError>

Records a measured size for the given item key.

Updates the running average and stores the measurement. If a measurement already exists for this key, it is replaced.

Parameters

• key: The item key to record a measurement for.
• size: The measured size in pixels.

Returns

• Ok(bool): True if the measurement changed the stored value.
• Err(VirtualizerError): If the size is invalid.

Errors

• Returns MeasurementError if size is negative, NaN, or infinite.

pub fn get(&self, key: &VirtualKey) -> Option<f64>

Retrieves the measured size for a given key.

Parameters

• key: The item key to look up.

Returns

• Option<f64>: The measured size if available.

pub fn average(&self) -> f64

Returns the current average of all measured sizes.

Returns

• f64: The running average size.

pub fn count(&self) -> usize

Returns the total number of stored measurements.

Returns

• usize: The count of recorded measurements.

pub fn clear(&mut self, initial_estimate: f64)

Clears all stored measurements and resets the average.

Parameters

• initial_estimate: The new default size estimate after clearing.

pub fn remove(&mut self, key: &VirtualKey) -> Option<f64>

Removes the measurement for a specific key.

Parameters

• key: The item key whose measurement should be removed.

Returns

• Option<f64>: The removed measurement if it existed.

Trait Implementations

impl Clone for MeasurementCache

fn clone(&self) -> MeasurementCache

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MeasurementCache

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

Formats the value using the given formatter.

impl Default for MeasurementCache

fn default() -> Self

Returns a default measurement cache with a 50px estimate.