# broomfilter
[](https://github.com/ae2rs/broomfilter/actions/workflows/ci.yml)
[](https://crates.io/crates/broomfilter)
[](https://docs.rs/broomfilter)
[](https://www.rust-lang.org)
[](LICENSE)
[](https://crates.io/crates/broomfilter)
A (pretty fast) bloom filter implementation in Rust.
---
## 🤔 What is this?
A bloom filter is a probabilistic data structure that can tell you:
- ❌ **"Definitely not in the set"** — 100% accurate
- 🤷 **"Probably in the set"** — maybe, who knows
Think of it as that friend who says "I'm *pretty sure* I locked the door."
You can trust them when they say they didn't, but when they say they did... you might want to go check.
### 🧹 Theory of broom sweeping (simplified)
```
item ──→ [ hash hash hash ] ──→ flip bits in the array
🧹💨
query ──→ [ hash hash hash ] ──→ check bits
├── all set? → "probably yes" 🤷
└── any unset? → "definitely no" ❌
```
---
## 💡 Why does this exist?
Because I wanted to learn how a bloom filter actually worked instead of just reciting the definition in tech interviews.
Turns out its super fun to optimize!
---
## 🚀 Usage
```rust
use broomfilter::Filter;
// Create a filter with 2^14 bits, optimized for 10,000 items
let mut filter = Filter::new(14, 10_000).unwrap();
// Insert some things 🧹
filter.insert("hello");
filter.insert("world");
// Check for things
assert!(filter.contains("hello")); // true — probably 🤷
assert!(!filter.contains("goodbye")); // false — definitely ❌
```
---
## 🏗️ Status
> ⚠️ **Work in progress** — handle with care (or don't, I'm a dev, not a cop)
It works, it has benchmarks, it *probably* won't break. But then again,
the whole point of a bloom filter is that you can never be 100% sure about anything.
| Insert items | ✅ Swept in |
| Check membership | ✅ Probably |
| False positives | ✅ It's a feature |
| False negatives | 🚫 Impossible (finally, some certainty) |
| Delete items | 🧹 Nope, the broom only sweeps one way |
---
## 📜 License
MIT — do whatever you want with it, just don't blame me when it breaks.