Start to implement requests limit

src/helpers/mod.rs

@@ -15,4 +15,5 @@ pub mod movies_helper;
 pub mod survey_helper;
 pub mod comments_helper;
 pub mod notifications_helper;
-pub mod webapp_helper;
+pub mod webapp_helper;
+pub mod requests_limit_helper;

src/helpers/requests_limit_helper.rs

@@ -0,0 +1,60 @@
+//! # Requests limit helper
+//!
+//! Handle the limitation of requests, depending on threshold criterias
+
+use std::sync::{Arc, Mutex};
+
+use crate::constants::LIMIT_COUNTER_LIFETIME;
+use crate::data::error::ResultBoxError;
+use crate::utils::date_utils;
+
+/// Information about a IP address limitation
+struct IpInfo {
+    time_start: u64,
+    count: u64,
+}
+
+/// Limits cache
+type Cache = Arc<dashmap::DashMap<String, IpInfo>>;
+
+static mut LIMITS_CACHE: Option<Arc<Mutex<Cache>>> = None;
+
+/// Initialize limit cache storage
+pub fn init() {
+    let limits_cache = Arc::new(dashmap::DashMap::new());
+    let limits_cache = Some(Arc::new(Mutex::new(limits_cache)));
+
+    unsafe {
+        LIMITS_CACHE = limits_cache;
+    }
+}
+
+/// Get access to the cache. This resource must absolutely be released as quickly as possible
+fn get_cache() -> ResultBoxError<Cache> {
+    let cache: Cache;
+
+    unsafe {
+        let guard = LIMITS_CACHE.as_ref().unwrap().lock();
+        cache = guard.unwrap().clone();
+    }
+
+    Ok(cache)
+}
+
+/// Clean cached information
+pub fn clean_cache() -> ResultBoxError {
+    let time = date_utils::time();
+
+    let cache = get_cache()?;
+    let obsolete_ips: Vec<String> = cache
+        .iter()
+        .filter(|k| k.time_start + LIMIT_COUNTER_LIFETIME < time)
+        .map(|k| k.key().to_string())
+        .collect();
+
+    for obsolete_ip in obsolete_ips {
+        cache.remove(&obsolete_ip);
+    }
+
+    Ok(())
+}