feat: Add timestamp to msgs_index7 to employ it in calc_sort_timestamp()

Tested on some random chat, the SQL query took 1.411202ms (vs 6.692714ms before) in median. Still
looks a bit slow, but already better.

src/chat.rs

@@ -1211,37 +1211,34 @@ impl ChatId {
                 )
                 .await?
         } else if received {
-            // Received messages shouldn't mingle with just sent ones and appear somewhere in the
-            // middle of the chat, so we go after the newest non fresh message.
-            //
-            // But if a received outgoing message is older than some seen message, better sort the
-            // received message purely by timestamp. We could place it just before that seen
-            // message, but anyway the user may not notice it.
+            // Received incoming messages shouldn't mingle with just sent ones and appear somewhere
+            // in the middle of the chat, so we go after the newest non fresh message. Received
+            // outgoing messages are allowed to mingle with seen messages though to avoid seen
+            // replies appearing before messages sent from another device (cases like the user
+            // sharing the account with others or bots are rare, so let them break sometimes).
             //
             // NB: Received outgoing messages may break sorting of fresh incoming ones, but this
             // shouldn't happen frequently. Seen incoming messages don't really break sorting of
             // fresh ones, they rather mean that older incoming messages are actually seen as well.
+            let states = match incoming {
+                true => "13, 16, 18, 20, 24, 26", // `> MessageState::InFresh`
+                false => "18, 20, 24, 26",        // `> MessageState::InSeen`
+            };
             context
                 .sql
                 .query_row_optional(
-                    "SELECT MAX(timestamp), MAX(IIF(state=?,timestamp_sent,0))
-                     FROM msgs
-                     WHERE chat_id=? AND hidden=0 AND state>?
-                     HAVING COUNT(*) > 0",
-                    (MessageState::InSeen, self, MessageState::InFresh),
+                    &format!(
+                        "SELECT MAX(timestamp) FROM msgs
+                        WHERE state IN ({states}) AND hidden=0 AND chat_id=?
+                        HAVING COUNT(*) > 0"
+                    ),
+                    (self,),
                     |row| {
                         let ts: i64 = row.get(0)?;
-                        let ts_sent_seen: i64 = row.get(1)?;
-                        Ok((ts, ts_sent_seen))
+                        Ok(ts)
                     },
                 )
                 .await?
-                .and_then(|(ts, ts_sent_seen)| {
-                    match incoming || ts_sent_seen <= message_timestamp {
-                        true => Some(ts),
-                        false => None,
-                    }
-                })
         } else {
             None
         };

src/message.rs

@@ -1361,7 +1361,7 @@ pub enum MessageState {
     OutDelivered = 26,
 
     /// Outgoing message read by the recipient (two checkmarks; this
-    /// requires goodwill on the receiver's side). Not used in the db for new messages.
+    /// requires goodwill on the receiver's side). API-only, not used in the db.
     OutMdnRcvd = 28,
 }
 

src/sql/migrations.rs

@@ -1328,6 +1328,18 @@ CREATE INDEX gossip_timestamp_index ON gossip_timestamp (chat_id, fingerprint);
         .await?;
     }
 
+    inc_and_check(&mut migration_version, 138)?;
+    if dbversion < migration_version {
+        // Tweak the index for `chat::calc_sort_timestamp()`.
+        sql.execute_migration(
+            "UPDATE msgs SET state=26 WHERE state=28;
+            DROP INDEX IF EXISTS msgs_index7;
+            CREATE INDEX msgs_index7 ON msgs (state, hidden, chat_id, timestamp);",
+            migration_version,
+        )
+        .await?;
+    }
+
     let new_version = sql
         .get_raw_config_int(VERSION_CFG)
         .await?

src/tests/verified_chats.rs

@@ -277,7 +277,7 @@ async fn test_old_message_5() -> Result<()> {
     .await?
     .unwrap();
 
-    assert!(msg_sent.sort_timestamp == msg_incoming.sort_timestamp);
+    assert_eq!(msg_sent.sort_timestamp, msg_incoming.sort_timestamp);
     alice
         .golden_test_chat(msg_sent.chat_id, "test_old_message_5")
         .await;

test-data/golden/test_outgoing_encrypted_msg

@@ -1,5 +1,5 @@
 Single#Chat#1001: bob@example.net [KEY bob@example.net]
 --------------------------------------------------------------------------------
-Msg#1001: info (Contact#Contact#Info): Messages are end-to-end encrypted. [NOTICED][INFO]
 Msg#1002🔒: Me (Contact#Contact#Self): Test – This is encrypted, signed, and has an Autocrypt Header without prefer-encrypt=mutual.  √
+Msg#1001: info (Contact#Contact#Info): Messages are end-to-end encrypted. [NOTICED][INFO]
 --------------------------------------------------------------------------------