Struct Builder

pub struct Builder<const BLOCK_SIZE_BITS: usize = 512, S = CloneBuildHasher<RandomDefaultHasher>> { /* private fields */ }

A bloom filter builder.

This type can be used to construct an instance of BloomFilter via the builder pattern.

Implementations

impl<const BLOCK_SIZE_BITS: usize> Builder<BLOCK_SIZE_BITS>

pub fn seed(self, seed: &[u8; 16]) -> Self

Sets the seed for this builder. The later constructed BloomFilter will use this seed when hashing items.

Examples

use b100m_filter::BloomFilter;

let bloom = BloomFilter::builder(4).seed(&[0u8; 16]).hashes(4);

impl<const BLOCK_SIZE_BITS: usize, S: BuildHasher> Builder<BLOCK_SIZE_BITS, S>

pub fn hasher<H: BuildHasher>(self, hasher: H) -> Builder<BLOCK_SIZE_BITS, H>

Sets the hasher for this builder. The later constructed BloomFilter will use this hasher when inserting and checking items.

Examples

use b100m_filter::BloomFilter;
use ahash::RandomState;

let bloom = BloomFilter::builder(4).hasher(RandomState::default()).hashes(4);

pub fn hashes(self, num_hashes: u64) -> BloomFilter<BLOCK_SIZE_BITS, S>

“Consumes” this builder, using the provided num_hashes to return an empty BloomFilter. For performance, the actual number of hashes performed internally will be rounded to down to a power of 2, depending on BLOCK_SIZE_BITS.

Examples

use b100m_filter::BloomFilter;

let bloom = BloomFilter::builder(4).hashes(4);

pub fn expected_items( self, expected_num_items: usize, ) -> BloomFilter<BLOCK_SIZE_BITS, S>

“Consumes” this builder, using the provided expected_num_items to return an empty BloomFilter. More or less than expected_num_items may be inserted into BloomFilter, but the number of hashes per item is intially calculated to minimize false positive rate for exactly expected_num_items.

Examples

use b100m_filter::BloomFilter;

let bloom = BloomFilter::builder(4).expected_items(500);

pub fn items<I: ExactSizeIterator<Item = impl Hash>>( self, items: I, ) -> BloomFilter<BLOCK_SIZE_BITS, S>

“Consumes” this builder and constructs a BloomFilter containing all values in items. The number of hashes per item is calculated based on items.len() to minimize false positive rate.

Examples

use b100m_filter::BloomFilter;

let bloom = BloomFilter::builder(4).items([1, 2, 3].iter());

Trait Implementations

impl<const BLOCK_SIZE_BITS: usize, S: Clone> Clone for Builder<BLOCK_SIZE_BITS, S>

fn clone(&self) -> Builder<BLOCK_SIZE_BITS, S>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<const BLOCK_SIZE_BITS: usize, S: Debug> Debug for Builder<BLOCK_SIZE_BITS, S>

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

Formats the value using the given formatter.