Struct fastbloom::BuilderWithBits

pub struct BuilderWithBits<const BLOCK_SIZE_BITS: usize = 512, S = DefaultHasher> { /* private fields */ }

A bloom filter builder with an immutable number of bits.

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

Examples

use fastbloom::BloomFilter;

let builder = BloomFilter::with_num_bits(1024);
let builder = BloomFilter::from_vec(vec![0; 8]);

Implementations

impl<const BLOCK_SIZE_BITS: usize> BuilderWithBits<BLOCK_SIZE_BITS>

pub fn seed(self, seed: &u128) -> Self

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

Examples

use fastbloom::BloomFilter;

let bloom = BloomFilter::with_num_bits(1024).seed(&1).hashes(4);

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

pub fn hasher<H: BuildHasher>( self, hasher: H ) -> BuilderWithBits<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 fastbloom::BloomFilter;
use ahash::RandomState;

let bloom = BloomFilter::with_num_bits(1024).hasher(RandomState::default()).hashes(4);

pub fn hashes(self, num_hashes: u32) -> BloomFilter<BLOCK_SIZE_BITS, S>

“Consumes” this builder, using the provided num_hashes to return an empty BloomFilter.

Examples

use fastbloom::BloomFilter;

let bloom = BloomFilter::with_num_bits(1024).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. The number of hashes is optimized based on expected_num_items to maximize bloom filter accuracy (minimize false positives chance on BloomFilter::contains). More or less than expected_num_items may be inserted into BloomFilter.

Examples

use fastbloom::BloomFilter;

let bloom = BloomFilter::with_num_bits(1024).expected_items(500);

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

“Consumes” this builder and constructs a BloomFilter containing all values in items. Like BuilderWithBits::expected_items, the number of hashes per item is optimized based on items.len() to maximize bloom filter accuracy (minimize false positives chance on BloomFilter::contains).

Examples

use fastbloom::BloomFilter;

let bloom = BloomFilter::with_num_bits(1024).items([1, 2, 3]);

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

pub fn block_size_64(self) -> BuilderWithBits<64, S>

Set the block size of the bloom filter to 64 bits. The underlying bit vector size will be rounded up to be a multiple of the block size.

Example

use fastbloom::BloomFilter;
let builder = BloomFilter::with_num_bits(1000).block_size_64();

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

pub fn block_size_128(self) -> BuilderWithBits<128, S>

Set the block size of the bloom filter to 128 bits. The underlying bit vector size will be rounded up to be a multiple of the block size.

Example

use fastbloom::BloomFilter;
let builder = BloomFilter::with_num_bits(1000).block_size_128();

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

pub fn block_size_256(self) -> BuilderWithBits<256, S>

Set the block size of the bloom filter to 256 bits. The underlying bit vector size will be rounded up to be a multiple of the block size.

Example

use fastbloom::BloomFilter;
let builder = BloomFilter::with_num_bits(1000).block_size_256();

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

pub fn block_size_512(self) -> BuilderWithBits<512, S>

Set the block size of the bloom filter to 512 bits. The underlying bit vector size will be rounded up to be a multiple of the block size.

Example

use fastbloom::BloomFilter;
let builder = BloomFilter::with_num_bits(1000).block_size_512();

Trait Implementations

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

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

Returns a copy 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 BuilderWithBits<BLOCK_SIZE_BITS, S>

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

Formats the value using the given formatter.

impl<const BLOCK_SIZE_BITS: usize, S: BuildHasher> PartialEq for BuilderWithBits<BLOCK_SIZE_BITS, S>

fn eq(&self, other: &Self) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<const BLOCK_SIZE_BITS: usize, S: BuildHasher> Eq for BuilderWithBits<BLOCK_SIZE_BITS, S>