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</pre><pre class="rust"><code><span class="doccomment">//! Rate limiter using a fixed window counter for arbitrary keys, backed by Redis for Actix Web.</span>
<span class="doccomment">//!</span>
<span class="doccomment">//! ```toml</span>
<span class="doccomment">//! [dependencies]</span>
<span class="doccomment">//! actix-web = "4"</span>
<span class="attribute">#![<span class="ident">doc</span> <span class="op">=</span> <span class="macro">concat!</span>(<span class="string">"actix-limitation = \""</span>, <span class="macro">env!</span>(<span class="string">"CARGO_PKG_VERSION_MAJOR"</span>), <span class="string">"."</span>, <span class="macro">env!</span>(<span class="string">"CARGO_PKG_VERSION_MINOR"</span>),<span class="string">"\""</span>)]</span>
<span class="doccomment">//! ```</span>
<span class="doccomment">//!</span>
<span class="doccomment">//! ```no_run</span>
<span class="doccomment">//! use std::time::Duration;</span>
<span class="doccomment">//! use actix_web::{get, web, App, HttpServer, Responder};</span>
<span class="doccomment">//! use actix_limitation::{Limiter, RateLimiter};</span>
<span class="doccomment">//!</span>
<span class="doccomment">//! #[get("/{id}/{name}")]</span>
<span class="doccomment">//! async fn index(info: web::Path<(u32, String)>) -> impl Responder {</span>
<span class="doccomment">//! format!("Hello {}! id:{}", info.1, info.0)</span>
<span class="doccomment">//! }</span>
<span class="doccomment">//!</span>
<span class="doccomment">//! #[actix_web::main]</span>
<span class="doccomment">//! async fn main() -> std::io::Result<()> {</span>
<span class="doccomment">//! let limiter = web::Data::new(</span>
<span class="doccomment">//! Limiter::builder("redis://127.0.0.1")</span>
<span class="doccomment">//! .cookie_name("session-id".to_owned())</span>
<span class="doccomment">//! .session_key("rate-api-id".to_owned())</span>
<span class="doccomment">//! .limit(5000)</span>
<span class="doccomment">//! .period(Duration::from_secs(3600)) // 60 minutes</span>
<span class="doccomment">//! .build()</span>
<span class="doccomment">//! .unwrap(),</span>
<span class="doccomment">//! );</span>
<span class="doccomment">//!</span>
<span class="doccomment">//! HttpServer::new(move || {</span>
<span class="doccomment">//! App::new()</span>
<span class="doccomment">//! .wrap(RateLimiter)</span>
<span class="doccomment">//! .app_data(limiter.clone())</span>
<span class="doccomment">//! .service(index)</span>
<span class="doccomment">//! })</span>
<span class="doccomment">//! .bind(("127.0.0.1", 8080))?</span>
<span class="doccomment">//! .run()</span>
<span class="doccomment">//! .await</span>
<span class="doccomment">//! }</span>
<span class="doccomment">//! ```</span>
<span class="attribute">#![<span class="ident">forbid</span>(<span class="ident">unsafe_code</span>)]</span>
<span class="attribute">#![<span class="ident">deny</span>(<span class="ident">rust_2018_idioms</span>, <span class="ident">nonstandard_style</span>)]</span>
<span class="attribute">#![<span class="ident">warn</span>(<span class="ident">future_incompatible</span>, <span class="ident">missing_docs</span>, <span class="ident">missing_debug_implementations</span>)]</span>
<span class="attribute">#![<span class="ident">doc</span>(<span class="ident">html_logo_url</span> <span class="op">=</span> <span class="string">"https://actix.rs/img/logo.png"</span>)]</span>
<span class="attribute">#![<span class="ident">doc</span>(<span class="ident">html_favicon_url</span> <span class="op">=</span> <span class="string">"https://actix.rs/favicon.ico"</span>)]</span>
<span class="kw">use</span> <span class="ident">std</span>::{<span class="ident">borrow::Cow</span>, <span class="ident">time::Duration</span>};
<span class="kw">use</span> <span class="ident">redis::Client</span>;
<span class="kw">mod</span> <span class="ident">builder</span>;
<span class="kw">mod</span> <span class="ident">errors</span>;
<span class="kw">mod</span> <span class="ident">middleware</span>;
<span class="kw">mod</span> <span class="ident">status</span>;
<span class="kw">pub</span> <span class="kw">use</span> <span class="ident"><span class="self">self</span>::builder::Builder</span>;
<span class="kw">pub</span> <span class="kw">use</span> <span class="ident"><span class="self">self</span>::errors::Error</span>;
<span class="kw">pub</span> <span class="kw">use</span> <span class="ident"><span class="self">self</span>::middleware::RateLimiter</span>;
<span class="kw">pub</span> <span class="kw">use</span> <span class="ident"><span class="self">self</span>::status::Status</span>;
<span class="doccomment">/// Default request limit.</span>
<span class="kw">pub</span> <span class="kw">const</span> <span class="ident">DEFAULT_REQUEST_LIMIT</span>: <span class="ident">usize</span> <span class="op">=</span> <span class="number">5000</span>;
<span class="doccomment">/// Default period (in seconds).</span>
<span class="kw">pub</span> <span class="kw">const</span> <span class="ident">DEFAULT_PERIOD_SECS</span>: <span class="ident">u64</span> <span class="op">=</span> <span class="number">3600</span>;
<span class="doccomment">/// Default cookie name.</span>
<span class="kw">pub</span> <span class="kw">const</span> <span class="ident">DEFAULT_COOKIE_NAME</span>: <span class="kw-2">&</span><span class="ident">str</span> <span class="op">=</span> <span class="string">"sid"</span>;
<span class="doccomment">/// Default session key.</span>
<span class="kw">pub</span> <span class="kw">const</span> <span class="ident">DEFAULT_SESSION_KEY</span>: <span class="kw-2">&</span><span class="ident">str</span> <span class="op">=</span> <span class="string">"rate-api-id"</span>;
<span class="doccomment">/// Rate limiter.</span>
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>, <span class="ident">Clone</span>)]</span>
<span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">Limiter</span> {
<span class="ident">client</span>: <span class="ident">Client</span>,
<span class="ident">limit</span>: <span class="ident">usize</span>,
<span class="ident">period</span>: <span class="ident">Duration</span>,
<span class="ident">cookie_name</span>: <span class="ident">Cow</span><span class="op"><</span><span class="lifetime">'static</span>, <span class="ident">str</span><span class="op">></span>,
<span class="ident">session_key</span>: <span class="ident">Cow</span><span class="op"><</span><span class="lifetime">'static</span>, <span class="ident">str</span><span class="op">></span>,
}
<span class="kw">impl</span> <span class="ident">Limiter</span> {
<span class="doccomment">/// Construct rate limiter builder with defaults.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// See [`redis-rs` docs](https://docs.rs/redis/0.21/redis/#connection-parameters) on connection</span>
<span class="doccomment">/// parameters for how to set the Redis URL.</span>
<span class="attribute">#[<span class="ident">must_use</span>]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">builder</span>(<span class="ident">redis_url</span>: <span class="kw">impl</span> <span class="ident">Into</span><span class="op"><</span><span class="ident">String</span><span class="op">></span>) -> <span class="ident">Builder</span> {
<span class="ident">Builder</span> {
<span class="ident">redis_url</span>: <span class="ident">redis_url</span>.<span class="ident">into</span>(),
<span class="ident">limit</span>: <span class="ident">DEFAULT_REQUEST_LIMIT</span>,
<span class="ident">period</span>: <span class="ident">Duration::from_secs</span>(<span class="ident">DEFAULT_PERIOD_SECS</span>),
<span class="ident">cookie_name</span>: <span class="ident">Cow::Borrowed</span>(<span class="ident">DEFAULT_COOKIE_NAME</span>),
<span class="ident">session_key</span>: <span class="ident">Cow::Borrowed</span>(<span class="ident">DEFAULT_SESSION_KEY</span>),
}
}
<span class="doccomment">/// Consumes one rate limit unit, returning the status.</span>
<span class="kw">pub</span> <span class="kw">async</span> <span class="kw">fn</span> <span class="ident">count</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">key</span>: <span class="kw">impl</span> <span class="ident">Into</span><span class="op"><</span><span class="ident">String</span><span class="op">></span>) -> <span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">Status</span>, <span class="ident">Error</span><span class="op">></span> {
<span class="kw">let</span> (<span class="ident">count</span>, <span class="ident">reset</span>) <span class="op">=</span> <span class="self">self</span>.<span class="ident">track</span>(<span class="ident">key</span>).<span class="kw">await</span><span class="question-mark">?</span>;
<span class="kw">let</span> <span class="ident">status</span> <span class="op">=</span> <span class="ident">Status::new</span>(<span class="ident">count</span>, <span class="self">self</span>.<span class="ident">limit</span>, <span class="ident">reset</span>);
<span class="kw">if</span> <span class="ident">count</span> <span class="op">></span> <span class="self">self</span>.<span class="ident">limit</span> {
<span class="prelude-val">Err</span>(<span class="ident">Error::LimitExceeded</span>(<span class="ident">status</span>))
} <span class="kw">else</span> {
<span class="prelude-val">Ok</span>(<span class="ident">status</span>)
}
}
<span class="doccomment">/// Tracks the given key in a period and returns the count and TTL for the key in seconds.</span>
<span class="kw">async</span> <span class="kw">fn</span> <span class="ident">track</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">key</span>: <span class="kw">impl</span> <span class="ident">Into</span><span class="op"><</span><span class="ident">String</span><span class="op">></span>) -> <span class="prelude-ty">Result</span><span class="op"><</span>(<span class="ident">usize</span>, <span class="ident">usize</span>), <span class="ident">Error</span><span class="op">></span> {
<span class="kw">let</span> <span class="ident">key</span> <span class="op">=</span> <span class="ident">key</span>.<span class="ident">into</span>();
<span class="kw">let</span> <span class="ident">expires</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">period</span>.<span class="ident">as_secs</span>();
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">connection</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">client</span>.<span class="ident">get_tokio_connection</span>().<span class="kw">await</span><span class="question-mark">?</span>;
<span class="comment">// The seed of this approach is outlined Atul R in a blog post about rate limiting using</span>
<span class="comment">// NodeJS and Redis. For more details, see https://blog.atulr.com/rate-limiter</span>
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">pipe</span> <span class="op">=</span> <span class="ident">redis::pipe</span>();
<span class="ident">pipe</span>.<span class="ident">atomic</span>()
.<span class="ident">cmd</span>(<span class="string">"SET"</span>) <span class="comment">// Set key and value</span>
.<span class="ident">arg</span>(<span class="kw-2">&</span><span class="ident">key</span>)
.<span class="ident">arg</span>(<span class="number">0</span>)
.<span class="ident">arg</span>(<span class="string">"EX"</span>) <span class="comment">// Set the specified expire time, in seconds.</span>
.<span class="ident">arg</span>(<span class="ident">expires</span>)
.<span class="ident">arg</span>(<span class="string">"NX"</span>) <span class="comment">// Only set the key if it does not already exist.</span>
.<span class="ident">ignore</span>() <span class="comment">// --- ignore returned value of SET command ---</span>
.<span class="ident">cmd</span>(<span class="string">"INCR"</span>) <span class="comment">// Increment key</span>
.<span class="ident">arg</span>(<span class="kw-2">&</span><span class="ident">key</span>)
.<span class="ident">cmd</span>(<span class="string">"TTL"</span>) <span class="comment">// Return time-to-live of key</span>
.<span class="ident">arg</span>(<span class="kw-2">&</span><span class="ident">key</span>);
<span class="kw">let</span> (<span class="ident">count</span>, <span class="ident">ttl</span>) <span class="op">=</span> <span class="ident">pipe</span>.<span class="ident">query_async</span>(<span class="kw-2">&mut</span> <span class="ident">connection</span>).<span class="kw">await</span><span class="question-mark">?</span>;
<span class="kw">let</span> <span class="ident">reset</span> <span class="op">=</span> <span class="ident">Status::epoch_utc_plus</span>(<span class="ident">Duration::from_secs</span>(<span class="ident">ttl</span>))<span class="question-mark">?</span>;
<span class="prelude-val">Ok</span>((<span class="ident">count</span>, <span class="ident">reset</span>))
}
}
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">test</span>)]</span>
<span class="kw">mod</span> <span class="ident">tests</span> {
<span class="kw">use</span> <span class="kw">super</span>::<span class="kw-2">*</span>;
<span class="attribute">#[<span class="ident">test</span>]</span>
<span class="kw">fn</span> <span class="ident">test_create_limiter</span>() {
<span class="kw">let</span> <span class="ident">builder</span> <span class="op">=</span> <span class="ident">Limiter::builder</span>(<span class="string">"redis://127.0.0.1:6379/1"</span>);
<span class="kw">let</span> <span class="ident">limiter</span> <span class="op">=</span> <span class="ident">builder</span>.<span class="ident">build</span>();
<span class="macro">assert!</span>(<span class="ident">limiter</span>.<span class="ident">is_ok</span>());
<span class="kw">let</span> <span class="ident">limiter</span> <span class="op">=</span> <span class="ident">limiter</span>.<span class="ident">unwrap</span>();
<span class="macro">assert_eq!</span>(<span class="ident">limiter</span>.<span class="ident">limit</span>, <span class="number">5000</span>);
<span class="macro">assert_eq!</span>(<span class="ident">limiter</span>.<span class="ident">period</span>, <span class="ident">Duration::from_secs</span>(<span class="number">3600</span>));
<span class="macro">assert_eq!</span>(<span class="ident">limiter</span>.<span class="ident">cookie_name</span>, <span class="ident">DEFAULT_COOKIE_NAME</span>);
<span class="macro">assert_eq!</span>(<span class="ident">limiter</span>.<span class="ident">session_key</span>, <span class="ident">DEFAULT_SESSION_KEY</span>);
}
}
</code></pre></div>
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