Struct CollapsingLowestDenseStore 

pub struct CollapsingLowestDenseStore { /* private fields */ }

A dense store that collapses lowest-indexed bins when capacity is exceeded.

This store maintains a maximum number of bins. When adding a new index would exceed this limit, the lowest-indexed bins are collapsed (merged into the next lowest bin), sacrificing accuracy for lower quantiles to preserve accuracy for higher quantiles.

Use this store when:

• You need bounded memory usage
• Higher quantiles (e.g., p95, p99) are more important than lower quantiles
• You’re tracking latencies or other metrics where the tail matters most

Implementations

impl CollapsingLowestDenseStore

pub fn new(max_num_bins: usize) -> Self

Creates an empty CollapsingLowestDenseStore with the given maximum number of bins.

pub fn is_collapsed(&self) -> bool

Returns true if this store has collapsed bins.

If true, accuracy guarantees may not hold for lower quantiles.

Trait Implementations

impl Clone for CollapsingLowestDenseStore

fn clone(&self) -> CollapsingLowestDenseStore

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CollapsingLowestDenseStore

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

Formats the value using the given formatter.

impl Default for CollapsingLowestDenseStore

fn default() -> Self

Creates a collapsing lowest dense store with a default of 2048 bins.

impl PartialEq for CollapsingLowestDenseStore

fn eq(&self, other: &CollapsingLowestDenseStore) -> 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 Store for CollapsingLowestDenseStore

fn add(&mut self, index: i32, count: u64)

Adds a count to the bin at the given index.

fn total_count(&self) -> u64

Returns the total count across all bins.

fn min_index(&self) -> Option<i32>

Returns the minimum index with a non-zero count, or None if empty.

fn max_index(&self) -> Option<i32>

Returns the maximum index with a non-zero count, or None if empty.

fn key_at_rank(&self, rank: u64) -> Option<i32>

Returns the index of the bin containing the given rank.

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

Merges another store into this one.

fn is_empty(&self) -> bool

Returns true if the store is empty.

fn clear(&mut self)

Clears all bins from the store.

fn merge_from_proto( &mut self, proto: &ProtoStore, ) -> Result<(), ProtoConversionError>

Populates this store from a protobuf Store.

fn to_proto(&self) -> ProtoStore

Converts this store to a protobuf Store.

impl Eq for CollapsingLowestDenseStore

impl StructuralPartialEq for CollapsingLowestDenseStore