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Update insert, contains and remove methods to use Borrow trait #17

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Merged
merged 1 commit into from
Apr 23, 2025
Merged

Update insert, contains and remove methods to use Borrow trait #17

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6 changes: 3 additions & 3 deletions src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@
//! ```
//! use scalable_cuckoo_filter::ScalableCuckooFilter;
//!
//! let mut filter = ScalableCuckooFilter::new(100, 0.001);
//! let mut filter = ScalableCuckooFilter::<str>::new(100, 0.001);
//! assert!(!filter.contains("foo"));
//! filter.insert("foo");
//! assert!(filter.contains("foo"));
Expand All @@ -18,7 +18,7 @@
//! ```
//! use scalable_cuckoo_filter::ScalableCuckooFilter;
//!
//! let mut filter = ScalableCuckooFilter::new(100, 0.001);
//! let mut filter = ScalableCuckooFilter::<usize>::new(100, 0.001);
//! assert_eq!(filter.capacity(), 128);
//!
//! for i in 0..1000 {
Expand All @@ -32,7 +32,7 @@
//! ```
//! use scalable_cuckoo_filter::ScalableCuckooFilter;
//!
//! let mut filter = ScalableCuckooFilter::new(1000, 0.001);
//! let mut filter = ScalableCuckooFilter::<usize>::new(1000, 0.001);
//! for i in 0..100 {
//! filter.insert(&i);
//! }
Expand Down
58 changes: 48 additions & 10 deletions src/scalable_cuckoo_filter.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -132,6 +132,31 @@ impl Default for ScalableCuckooFilterBuilder {
use serde::{Deserialize, Serialize};

/// Scalable Cuckoo Filter.
///
/// T can be any type that implements the `Hash` trait.
/// If it contains inner references, you will need to introduce
/// two wrapper types like in this example.:
///
///
/// ```rust
/// #[derive(Hash)]
/// struct InnerTuple<'a>(&'a str, Option<&'a str>);
/// #[derive(Hash)]
/// struct MyTuple(InnerTuple<'static>);

/// impl<'a> std::borrow::Borrow<InnerTuple<'a>> for MyTuple {
/// fn borrow(&self) -> &InnerTuple<'a> {
/// &self.0
/// }
/// }
///
/// let mut filter = scalable_cuckoo_filter::ScalableCuckooFilter::<MyTuple>::new(1000, 0.05);
/// let a = "hello".to_string();
/// let q = InnerTuple(&a[..], None);
/// filter.insert(&q);

/// ```

#[derive(Debug)]
#[cfg_attr(feature = "serde_support", derive(Serialize, Deserialize))]
pub struct ScalableCuckooFilter<T: ?Sized, H = DefaultHasher, R = DefaultRng> {
Expand Down Expand Up @@ -208,7 +233,12 @@ impl<T: Hash + ?Sized, H: Hasher + Clone, R: Rng> ScalableCuckooFilter<T, H, R>
}

/// Returns `true` if this filter may contain `item`, otherwise `false`.
pub fn contains(&self, item: &T) -> bool {
//pub fn contains(&self, item: &T) -> bool {
pub fn contains<U>(&self, item: &U) -> bool
where
T: std::borrow::Borrow<U>,
U: Hash + ?Sized,
{
let item_hash = crate::hash(&self.hasher, item);
self.filters
.iter()
Expand All @@ -233,7 +263,7 @@ impl<T: Hash + ?Sized, H: Hasher + Clone, R: Rng> ScalableCuckooFilter<T, H, R>
/// ```
/// use scalable_cuckoo_filter::ScalableCuckooFilter;
///
/// let mut filter = ScalableCuckooFilter::new(1000, 0.001);
/// let mut filter = ScalableCuckooFilter::<str>::new(1000, 0.001);
/// let items = ["foo", "bar", "foo", "baz"];
///
/// for item in &items {
Expand All @@ -242,7 +272,11 @@ impl<T: Hash + ?Sized, H: Hasher + Clone, R: Rng> ScalableCuckooFilter<T, H, R>
/// }
/// }
/// ```
pub fn insert(&mut self, item: &T) {
pub fn insert<U>(&mut self, item: &U)
where
T: std::borrow::Borrow<U>,
U: Hash + ?Sized,
{
let item_hash = crate::hash(&self.hasher, item);
let last = self.filters.len() - 1;
self.filters[last].insert(&self.hasher, &mut self.rng, item_hash);
Expand All @@ -261,7 +295,11 @@ impl<T: Hash + ?Sized, H: Hasher + Clone, R: Rng> ScalableCuckooFilter<T, H, R>
/// Removes `item` from this filter.
///
/// This method returns `true` if an entry with the same fingerprint as `item` has been removed, otherwise it returns `false`.
pub fn remove(&mut self, item: &T) -> bool {
pub fn remove<U>(&mut self, item: &U) -> bool
where
T: std::borrow::Borrow<U>,
U: Hash + ?Sized,
{
let item_hash = crate::hash(&self.hasher, item);
for filter in &mut self.filters {
let removed = filter.remove(&self.hasher, item_hash);
Expand Down Expand Up @@ -309,7 +347,7 @@ mod test {

#[test]
fn it_works() {
let mut filter = ScalableCuckooFilter::new(1000, 0.001);
let mut filter = ScalableCuckooFilter::<str>::new(1000, 0.001);
assert!(filter.is_empty());
assert_eq!(filter.bits(), 14_336);

Expand Down Expand Up @@ -345,7 +383,7 @@ mod test {
}

let rng: StdRng = SeedableRng::from_seed(seed);
let mut filter = ScalableCuckooFilterBuilder::new()
let mut filter: ScalableCuckooFilter<u64, _, _> = ScalableCuckooFilterBuilder::new()
.initial_capacity(100)
.false_positive_probability(0.00001)
.rng(rng)
Expand All @@ -372,7 +410,7 @@ mod test {
.initial_capacity(100)
.false_positive_probability(0.00001)
.rng(rng)
.finish();
.finish::<usize>();

for i in 0..10_000 {
filter.insert(&i);
Expand All @@ -388,7 +426,7 @@ mod test {

#[test]
fn fingerprint_collision_remove_works() {
let mut filter = ScalableCuckooFilter::new(1000, 0.001);
let mut filter = ScalableCuckooFilter::<str>::new(1000, 0.001);
filter.insert("foo");
filter.insert("foo");
assert!(filter.contains("foo"));
Expand All @@ -402,7 +440,7 @@ mod test {

#[test]
fn shrink_to_fit_works() {
let mut filter = ScalableCuckooFilter::new(1000, 0.001);
let mut filter = ScalableCuckooFilter::<i32>::new(1000, 0.001);
for i in 0..100 {
filter.insert(&i);
}
Expand All @@ -419,7 +457,7 @@ mod test {

#[test]
fn info_params() {
let mut filter = ScalableCuckooFilter::new(10, 0.001);
let mut filter = ScalableCuckooFilter::<u64>::new(10, 0.001);

// constant values
assert_eq!(filter.max_kicks(), 512);
Expand Down