tweaking visible messages limits

spacetimedb/src/reducers.rs

@@ -414,8 +414,9 @@ pub fn subscribe_to_channel(ctx: &ReducerContext, channel_id: u64) {
         .channel_id()
         .find(channel_id);
     let current_max = hwm.map(|h| h.last_seq_id).unwrap_or(0);
-    let earliest = if current_max > 99 {
-        current_max - 99
+    let limit = get_recent_message_limit(&ctx.db);
+    let earliest = if current_max >= limit {
+        current_max - (limit - 1)
     } else {
         1
     };
@@ -1041,8 +1042,9 @@ pub fn create_thread_with_message(
         ctx.db.recent_message().id().update(parent_rm);
     }
 
-    if seq_id > 100 {
-        let old_seq_id = seq_id - 100;
+    let limit = get_recent_message_limit(&ctx.db);
+    if seq_id > limit {
+        let old_seq_id = seq_id - limit;
         let to_delete: Vec<_> = ctx
             .db
             .recent_message()
@@ -1146,8 +1148,9 @@ pub fn send_message(
         }
     }
 
-    if seq_id > 100 {
-        let old_seq_id = seq_id - 100;
+    let limit = get_recent_message_limit(&ctx.db);
+    if seq_id > limit {
+        let old_seq_id = seq_id - limit;
         let to_delete: Vec<_> = ctx
             .db
             .recent_message()

spacetimedb/src/utils.rs

@@ -28,6 +28,14 @@ pub fn validate_message_length(db: &Local, text: &str) -> Result<(), String> {
     Ok(())
 }
 
+pub fn get_recent_message_limit(db: &Local) -> u64 {
+    db.system_configuration()
+        .key()
+        .find("recent_message_limit".to_string())
+        .and_then(|c| c.value.parse::<u64>().ok())
+        .unwrap_or(50)
+}
+
 pub fn get_next_seq_id(db: &Local, channel_id: u64) -> u64 {
     let hwm = db.channel_high_water_mark().channel_id().find(channel_id);
     let next_seq_id = hwm.as_ref().map(|h| h.last_seq_id + 1).unwrap_or(1);