Struct AssociatedData 

pub struct AssociatedData { /* private fields */ }

Provides access to data associated with an item in the filter.

All data is associated by a fingerprint, meaning that collisions (false positives) will also affect the associated data - it might not be related exactly to the requested item, but just to another item that shared the same fingerprint.

This data is a copy of the data in the filter, meaning it will not be updated when filter data is changed and can be freely moved around.

Examples

use cuckoo_clock::{CuckooFilter, config::{CuckooConfiguration, LruConfig, TtlConfig}};

let filter = CuckooFilter::new_random(
    CuckooConfiguration::builder(100_000)
        .with_lru(LruConfig::default())
        .with_ttl(TtlConfig {
            ttl: 10.try_into()?,
            ttl_bits: 8.try_into()?,
        })
        .build()?
);
filter.insert("example_data");
let data = filter.get_associated_data("example_data").unwrap();

assert_eq!(data.get_stored_ttl_value()?, 10);
// `get_associated_data` also increases LRU counter - it is counted as an access
assert_eq!(data.get_lru_counter()?, 2);

Implementations

impl AssociatedData

pub fn get_fingerprint(&self) -> u32

Returns the fingerprint for this item.

Generally fingerprint is not very useful on its own, depending on the hasher used for crate::CuckooFilter.

pub fn get_lru_counter(&self) -> Result<u32, AccessError>

Returns the LRU counter for this item.

pub fn get_counter(&self) -> Result<u32, AccessError>

Returns the generic counter for this item.

pub fn get_stored_ttl_value(&self) -> Result<u32, AccessError>

Returns the stored TTL value for this item.

This is not a time to live in seconds. This is just a TTL counter, that is decremented by 1 each time crate::CuckooFilter::scan_and_update_full is called, until it reaches 0.