Struct Bloom

pub struct Bloom<T: ?Sized> { /* private fields */ }

Bloom filter structure

Implementations

impl<T: ?Sized> Bloom<T>

pub fn new_with_seed( bitmap_size: usize, items_count: usize, seed: &[u8; 32], ) -> Result<Self, &'static str>

Create a new bloom filter structure. bitmap_size is the size in bytes (not bits) that will be allocated in memory items_count is an estimation of the maximum number of items to store. seed is a random value used to generate the hash functions.

pub fn new(bitmap_size: usize, items_count: usize) -> Result<Self, &'static str>

Create a new bloom filter structure. bitmap_size is the size in bytes (not bits) that will be allocated in memory items_count is an estimation of the maximum number of items to store.

pub fn new_for_fp_rate( items_count: usize, fp_p: f64, ) -> Result<Self, &'static str>

Create a new bloom filter structure. items_count is an estimation of the maximum number of items to store. fp_p is the wanted rate of false positives, in ]0.0, 1.0[

pub fn new_for_fp_rate_with_seed( items_count: usize, fp_p: f64, seed: &[u8; 32], ) -> Result<Self, &'static str>

Create a new bloom filter structure. items_count is an estimation of the maximum number of items to store. fp_p is the wanted rate of false positives, in ]0.0, 1.0[

pub fn compute_bitmap_size(items_count: usize, fp_p: f64) -> usize

Compute a recommended bitmap size for items_count items and a fp_p rate of false positives. fp_p obviously has to be within the ]0.0, 1.0[ range.

pub fn len(&self) -> u64

Return the number of bits in the filter.

pub fn set(&mut self, item: &T)

where T: Hash,

Record the presence of an item.

pub fn check(&self, item: &T) -> bool

where T: Hash,

Check if an item is present in the set. There can be false positives, but no false negatives.

pub fn check_and_set(&mut self, item: &T) -> bool

where T: Hash,

Record the presence of an item in the set, and return the previous state of this item.

pub fn as_slice(&self) -> &[u8]

View the bloom filter as an opaque slice of bytes. This can be used to save the bloom filter to a file.

pub fn from_slice(bytes: &[u8]) -> Result<Self, &'static str>

Create a bloom filter from a slice of bytes, previously generated with as_slice.

pub fn to_bytes(&self) -> Vec<u8>

Serialize the bloom filter to an opaque byte vector.

pub fn into_bytes(self) -> Vec<u8>

Transform the bloom filter into a byte vector.

pub fn from_bytes(bytes: Vec<u8>) -> Result<Self, &'static str>

Transform a byte vector into a bloom filter.

pub fn number_of_hash_functions(&self) -> u32

Return the number of hash functions used for check and set

pub fn clear(&mut self)

Clear all of the bits in the filter, removing all keys from the set

pub fn fill(&mut self)

Set all of the bits in the filter, making it appear like every key is in the set

pub fn is_empty(&self) -> bool

Test if there are no elements in the set

pub fn seed(&self) -> [u8; 32]

Return the seed used to generate the hash functions

Trait Implementations

impl<T: Clone + ?Sized> Clone for Bloom<T>

fn clone(&self) -> Bloom<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: ?Sized> Debug for Bloom<T>

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

Formats the value using the given formatter.