Struct CountMinSketch 

pub struct CountMinSketch { /* private fields */ }

Count-Min Sketch for space-efficient frequency estimation.

Uses multiple hash functions to estimate item frequencies with bounded error. Space usage is O(width * depth) regardless of stream size.

Implementations

impl CountMinSketch

pub fn new(width: usize, depth: usize) -> Self

Create a new sketch with given width and depth.

• width: Number of counters per row (larger = more accurate)
• depth: Number of hash functions (larger = lower error probability)

Typical values: width=1000, depth=5 for ~1% error with 99% confidence.

pub fn with_seed(width: usize, depth: usize, seed: u64) -> Self

Create a sketch with a specific seed for reproducibility.

pub fn add(&mut self, item: &str)

Add an item to the sketch.

pub fn add_count(&mut self, item: &str, count: u64)

Add an item with a specific count.

pub fn estimate(&self, item: &str) -> u64

Estimate the frequency of an item.

Returns the minimum count across all hash functions, which is guaranteed to be >= true count (never underestimates).

pub fn total_count(&self) -> u64

Get the total count of all items added.

pub fn merge(&mut self, other: &Self) -> Result<(), &'static str>

Merge another sketch into this one (both must have same dimensions).

Trait Implementations

impl Clone for CountMinSketch

fn clone(&self) -> CountMinSketch

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CountMinSketch

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for CountMinSketch

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for CountMinSketch

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.