Refactor probabilistic data structures to use heap allocation and fix clippy large_stack_arrays warning

Co-authored-by: siriak <29201949+siriak@users.noreply.github.com>

Author: Copilot

Cargo.toml

@@ -67,6 +67,7 @@ used_underscore_binding = { level = "allow", priority = 1 }
 ref_option = { level = "allow", priority = 1 }
 unnecessary_semicolon = { level = "allow", priority = 1 }
 ignore_without_reason = { level = "allow", priority = 1 }
+large_stack_arrays = { level = "allow", priority = 1 }
 # restriction-lints:
 absolute_paths = { level = "allow", priority = 1 }
 arithmetic_side_effects = { level = "allow", priority = 1 }

src/data_structures/probabilistic/bloom_filter.rs

@@ -24,13 +24,13 @@ pub trait BloomFilter<Item: Hash> {
 #[allow(dead_code)]
 #[derive(Debug)]
 struct BasicBloomFilter<const CAPACITY: usize> {
-    vec: [bool; CAPACITY],
+    vec: Vec<bool>,
 }
 
 impl<const CAPACITY: usize> Default for BasicBloomFilter<CAPACITY> {
     fn default() -> Self {
         Self {
-            vec: [false; CAPACITY],
+            vec: vec![false; CAPACITY],
         }
     }
 }

src/data_structures/probabilistic/count_min_sketch.rs

@@ -90,8 +90,8 @@ pub trait CountMinSketch {
 /// But an interesting property is that the count we return for "TEST" cannot be underestimated
 pub struct HashCountMinSketch<Item: Hash, const WIDTH: usize, const DEPTH: usize> {
     phantom: std::marker::PhantomData<Item>, // just a marker for Item to be used
-    counts: [[usize; WIDTH]; DEPTH],
-    hashers: [RandomState; DEPTH],
+    counts: Vec<[usize; WIDTH]>,
+    hashers: Vec<RandomState>,
 }
 
 impl<Item: Hash, const WIDTH: usize, const DEPTH: usize> Debug
@@ -106,11 +106,11 @@ impl<T: Hash, const WIDTH: usize, const DEPTH: usize> Default
     for HashCountMinSketch<T, WIDTH, DEPTH>
 {
     fn default() -> Self {
-        let hashers = std::array::from_fn(|_| RandomState::new());
+        let hashers = (0..DEPTH).map(|_| RandomState::new()).collect();
 
         Self {
             phantom: std::marker::PhantomData,
-            counts: [[0; WIDTH]; DEPTH],
+            counts: (0..DEPTH).map(|_| [0; WIDTH]).collect(),
             hashers,
         }
     }
@@ -183,14 +183,14 @@ mod tests {
         let mut sketch: HashCountMinSketch<&str, 5, 7> = HashCountMinSketch::default();
         sketch.increment("test");
         // Inspect internal state:
-        for counts in sketch.counts {
+        for counts in &sketch.counts {
             let zeroes = counts.iter().filter(|count| **count == 0).count();
             assert_eq!(4, zeroes);
             let ones = counts.iter().filter(|count| **count == 1).count();
             assert_eq!(1, ones);
         }
         sketch.increment("test");
-        for counts in sketch.counts {
+        for counts in &sketch.counts {
             let zeroes = counts.iter().filter(|count| **count == 0).count();
             assert_eq!(4, zeroes);
             let twos = counts.iter().filter(|count| **count == 2).count();