feat: Add max prev events config option, allowing adjusting limit for prev_events fetching

src/config/mod.rs

@@ -40,6 +40,8 @@ pub struct Config {
     pub max_request_size: u32,
     #[serde(default = "default_max_concurrent_requests")]
     pub max_concurrent_requests: u16,
+    #[serde(default = "default_max_fetch_prev_events")]
+    pub max_fetch_prev_events: u16,
     #[serde(default = "false_fn")]
     pub allow_registration: bool,
     #[serde(default = "true_fn")]
@@ -249,6 +251,10 @@ fn default_max_concurrent_requests() -> u16 {
     100
 }
 
+fn default_max_fetch_prev_events() -> u16 {
+    100_u16
+}
+
 fn default_log() -> String {
     "warn,state_res=warn,_=off,sled=off".to_owned()
 }

src/service/globals/mod.rs

@@ -222,6 +222,10 @@ impl Service {
         self.config.max_request_size
     }
 
+    pub fn max_fetch_prev_events(&self) -> u16 {
+        self.config.max_fetch_prev_events
+    }
+
     pub fn allow_registration(&self) -> bool {
         self.config.allow_registration
     }

src/service/rooms/event_handler/mod.rs

@@ -1226,7 +1226,7 @@ impl Service {
                 .await
                 .pop()
             {
-                if amount > 100 {
+                if amount > services().globals.max_fetch_prev_events() {
                     // Max limit reached
                     warn!("Max prev event limit reached!");
                     graph.insert(prev_event_id.clone(), HashSet::new());