feat: Configurable rate limiter max burst size (#28)

Signed-off-by: Jagoda Ślązak <[email protected]>

Author: j-g00da

src/config.rs

@@ -17,7 +17,10 @@ pub struct Config {
     pub postfix_reinject_port_incoming: u16,
     #[serde(default = "Config::default_max_message_size")]
     pub max_message_size: usize,
+    #[serde(default = "Config::default_max_user_send_per_minute")]
     pub max_user_send_per_minute: NonZeroU32,
+    #[serde(default = "Config::default_max_user_send_burst_size")]
+    pub max_user_send_burst_size: NonZeroU32,
     #[serde(default, deserialize_with = "deserialize_sequence")]
     pub passthrough_senders: Vec<String>,
     #[serde(default, deserialize_with = "deserialize_sequence")]
@@ -94,4 +97,10 @@ impl Config {
     const fn default_max_message_size() -> usize {
         31457280
     }
+    const fn default_max_user_send_per_minute() -> NonZeroU32 {
+        NonZeroU32::new(60).expect("60 != 0")
+    }
+    const fn default_max_user_send_burst_size() -> NonZeroU32 {
+        NonZeroU32::new(10).expect("10 != 0")
+    }
 }

src/outbound.rs

@@ -20,7 +20,8 @@ pub struct OutgoingBeforeQueueHandler {
 
 impl OutgoingBeforeQueueHandler {
     pub fn new(config: Config) -> Self {
-        let quota = Quota::per_minute(config.max_user_send_per_minute);
+        let quota = Quota::per_minute(config.max_user_send_per_minute)
+            .allow_burst(config.max_user_send_burst_size);
         Self {
             config: Arc::new(config),
             send_rate_limiter: RateLimiter::keyed(quota),