# Invocation counter
[](https://github.com/oramasearch/invocation-counter/actions/workflows/ci.yml)
This data structure responses the following question: how many times a function has been called in the last X minutes?
## Installation
```text
cargo add invocation-counter
```
## Example
```rust
use invocation_counter::Counter;
fn main() {
// 4 is the group_shift_factor
// 16 is the number of buckets
let counter = Counter::<16, 4>::new(4);
let mut now = 0; // Instant::now().elapsed().as_secs();
counter.increment_by_one(now);
now += 1; // Simulate a second passing
counter.increment_by_one(now);
assert_eq!(counter.get_count_till(now), 2);
now += 2_u64.pow(4); // Simulate 16 seconds passing
counter.increment_by_one(now);
now += 1; // Simulate a second passing
counter.increment_by_one(now);
assert_eq!(counter.get_count_till(now), 4);
now += 2_u64.pow(4) * 16; // Move foward for a while...
counter.increment_by_one(now);
assert_eq!(counter.get_count_till(now), 1); // The counter should have reset
}
```