Struct RateLimiter 

pub struct RateLimiter<B: CacheBackend> {
    pub cache: Arc<B>,
    pub limit: u32,
    pub ttl: Duration,
}

The RateLimiter struct for distributed, IP-based rate limiting.

Type Parameters:

• B: A type that implements the CacheBackend trait.

Fields

cache: Arc<B>

The caching backend instance (e.g., Redis, in-memory, etc.).

limit: u32

Maximum allowed requests within a TTL window.

ttl: Duration

Duration of the rate limiting window.

Implementations

impl<B: CacheBackend> RateLimiter<B>

pub fn new(cache: Arc<B>, limit: u32, ttl: Duration) -> Self

Constructs a new RateLimiter.

Arguments

• cache - A caching backend instance wrapped in Arc.
• limit - Maximum number of allowed requests in the TTL window.
• ttl - Duration for the rate limiting window.

pub fn allow(&self, ip: &str) -> bool

Checks whether a request from the given IP is allowed.

This method does the following:

1. Builds a key using the client’s IP.
2. Retrieves the current request count from the cache.
3. If under the limit, increments the count.
   • If this is the first request, sets the TTL for that key.
4. Returns true if the request is allowed, or false if the limit is exceeded.

Arguments

• ip - A string slice representing the client’s IP address.

Returns

• true if the request is allowed; false otherwise.