# Unofficial Upstash rate limit SDK for Rust
A rate-limiting SDK built for the Rust ecosystem that uses in-memory data storage.

## Inspiration
This rate limit SDK is inspired by the official [TypeScript rate limit SDK](https://github.com/upstash/ratelimit) created by [Upstash](https://upstash.com) team. 

## Setup

1) To setup the ratelimiter, first create a client instance of Redis that can store the request counts for a given set window:
```rust
let connection_str = std::env::var("UPSTASH_REDIS_URL").unwrap_or_else(|_| panic!("Expecting UPSTASH_REDIS_URL to be set"));
let Ok(redis) = redis::Client::open(connection_str) else {
    panic!("Failed to connect")
};
```
2) Create a client instance of the `RatelimitConfiguration` using the Redis client:

3) Use the client configuration to create a new instance of any one of the three rate-limiting algorithms:

For example: Using the fixed window algorithm to limit 10 requests in 30 seconds of the window.

```rust
let client = RatelimitConfiguration::new(redis, true, Some(String::from("my-custom-prefix")));
let ratelimit = FixedWindow::new(client, 10, "30s");
```
> In the above client configuration, using the Ephemeral cache to avoid making Redis calls if the request is already blocked and adding a custom prefix string will override the default prefix string, 

Use the `ratelimit` instance to call the limit function in any request calls to rate limit your requests:
```rust
let limit_response = state.ratelimit.limit("some-unique-identifier-like-ip", None).await;
```

## Custom rate
By default every algorithm consumes one token per request, but if you want rate-limit the requests based on the payload size or any other factor, you can do so by providing the rate value to the limit function call:

```rust
let limit_response = state.ratelimit.limit("some-unique-identifier-like-ip", Some(10)).await;
```
This will consume 10 tokens in one request.

## Examples
Check the [examples](/examples) directory

## Roadmap
- Single Region (may have latency issues)
    -
    - Fixed window algorithm ✅
    - Sliding window algorithm ✅
    - Token bucket algorithm ✅
    - Cached fixed window algorithm 🛠️
    - Analytics 🛠️
    - Forced timeout 🛠️
    - Hard reset 🛠️

- Multiple Region (no latency issues)
    -
    - Fixed window algorithm 🛠️
    - Sliding window algorithm 🛠️