Struct BloomFilter 

pub struct BloomFilter<T: AsRef<[u8]>> {
    pub bits: Vec<u8>,
    /* private fields */
}

Defines a bloom filter for items of a given type provided a capacity and a desired false positive rate.

Fields

bits: Vec<u8>

Implementations

impl<T: AsRef<[u8]>> BloomFilter<T>

pub fn new(capacity: u32, desired_fp_rate: f32) -> BloomFilter<T>

Creates a new bloom filter using the package’s default hasher with a specified capacity and desired false positive rate. In order to customize the bloom filter further, such as using a custom hash function, use the BloomBuilder struct instead.

Example

use flowerbloom::BloomFilter;
let capacity = 1000;
let desired_fp_rate = 0.01;
let mut bf = BloomFilter::new(capacity, desired_fp_rate);

bf.insert("hello");
bf.insert("world");

if !bf.has("nyan") {
    println!("definitely not in the bloom filter");
}

pub fn insert(&mut self, elem: T)

Insert an element into the bloom filter

Example

use flowerbloom::BloomFilter;
let capacity = 1000;
let desired_fp_rate = 0.01;
let mut bf = BloomFilter::new(capacity, desired_fp_rate);

bf.insert("foo");
bf.insert("bar");
bf.insert("baz");

pub fn has(&self, elem: T) -> bool

Checks if the bloom filter contains a specified element. The bloom filter can produce false positives from this function at the rate specified upon the struct’s creation. It will never produce false negatives, however.

Example

use flowerbloom::{BloomBuilder, BloomFilter};

/// Initialize a bloom filter with a default hasher over strings.
let capacity: u32 = 50;
let desired_fp_rate: f32 = 0.03;
let mut bf: BloomFilter<&str> = BloomBuilder::new(capacity, desired_fp_rate)
                .build();

bf.insert("foo");
bf.insert("bar");
bf.insert("baz");

if !bf.has("nyan") {
    println!("definitely not in the bloom filter");
}

pub fn clear(&mut self)

Clear all set bits of the bloom filter, setting them back to zero.

Trait Implementations

impl<T: AsRef<[u8]>> Display for BloomFilter<T>

Displays the bloom filter as a lowercase hex string.

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

Formats the value using the given formatter.

impl<T: AsRef<[u8]>> FromIterator<T> for BloomFilter<T>

Converts an iterator into a bloom filter with a default hasher and sensible false positive rate of 0.03.

Example

use flowerbloom::{BloomFilter};

let items = vec!["foo", "bar", "baz"];
let bf: BloomFilter<&str> = items.into_iter().collect();
let _ = bf.has("nyan");

fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self

Creates a value from an iterator.