add permanent ban support (to handle unresolvable torrent errors / todo)

src/ban.rs

@@ -8,7 +8,7 @@ pub struct Item {
 }
 
 pub struct Ban {
-    index: HashMap<Id20, DateTime<Local>>,
+    index: HashMap<Id20, Option<DateTime<Local>>>,
     timeout: Duration,
 }
 
@@ -20,7 +20,7 @@ impl Ban {
         }
     }
 
-    pub fn get(&self, key: &Id20) -> Option<&DateTime<Local>> {
+    pub fn get(&self, key: &Id20) -> Option<&Option<DateTime<Local>>> {
         self.index.get(key)
     }
 
@@ -31,8 +31,10 @@ impl Ban {
     /// * return removed `Item` details
     pub fn update(&mut self, time: DateTime<Local>) -> Vec<Item> {
         let mut b = Vec::with_capacity(self.index.len());
-        self.index.retain(|i, &mut expires| {
-            if time > expires {
+        self.index.retain(|i, &mut e| {
+            if let Some(expires) = e
+                && time > expires
+            {
                 b.push(Item {
                     expires,
                     info_hash: i.as_string(),
@@ -45,13 +47,23 @@ impl Ban {
         b
     }
 
-    /// * return expiration time
-    pub fn add(&mut self, key: Id20) -> DateTime<Local> {
-        let t = self
-            .index
-            .values()
-            .max()
-            .map_or(Local::now(), |t| *t + self.timeout);
+    /// Add torrent to the ban list
+    ///
+    /// If the `is_permanent` option is `true` - ban permanently,
+    /// or **automatically** count optimal ban time based on the current index max time and timeout offset value.
+    ///
+    /// * return expiration time or `None` if the ban is permanent
+    pub fn add(&mut self, key: Id20, is_permanent: bool) -> Option<DateTime<Local>> {
+        let t = if is_permanent {
+            None
+        } else {
+            Some(
+                self.index
+                    .values()
+                    .max()
+                    .map_or(Local::now(), |t| t.unwrap_or(Local::now()) + self.timeout),
+            )
+        };
         assert!(self.index.insert(key, t).is_none());
         t
     }