refactoring(sql): recreate config table with UNIQUE constraint

Author: link2xt

src/sql.rs

@@ -572,22 +572,13 @@ impl Sql {
     pub async fn set_raw_config(&self, key: &str, value: Option<&str>) -> Result<()> {
         let mut lock = self.config_cache.write().await;
         if let Some(value) = value {
-            let exists = self
-                .exists("SELECT COUNT(*) FROM config WHERE keyname=?;", (key,))
-                .await?;
-
-            if exists {
-                self.execute("UPDATE config SET value=? WHERE keyname=?;", (value, key))
-                    .await?;
-            } else {
-                self.execute(
-                    "INSERT INTO config (keyname, value) VALUES (?, ?);",
-                    (key, value),
-                )
-                .await?;
-            }
+            self.execute(
+                "INSERT OR REPLACE INTO config (keyname, value) VALUES (?, ?)",
+                (key, value),
+            )
+            .await?;
         } else {
-            self.execute("DELETE FROM config WHERE keyname=?;", (key,))
+            self.execute("DELETE FROM config WHERE keyname=?", (key,))
                 .await?;
         }
         lock.insert(key.to_string(), value.map(|s| s.to_string()));
@@ -608,7 +599,7 @@ impl Sql {
 
         let mut lock = self.config_cache.write().await;
         let value = self
-            .query_get_value("SELECT value FROM config WHERE keyname=?;", (key,))
+            .query_get_value("SELECT value FROM config WHERE keyname=?", (key,))
             .await
             .context(format!("failed to fetch raw config: {key}"))?;
         lock.insert(key.to_string(), value.clone());

src/sql/migrations.rs

@@ -785,6 +785,27 @@ CREATE INDEX msgs_status_updates_index2 ON msgs_status_updates (uid);
         .await?;
     }
 
+    if dbversion < 106 {
+        // Recreate `config` table with UNIQUE constraint on `keyname`.
+        sql.execute_migration(
+            r#"
+CREATE TABLE new_config (
+  id INTEGER PRIMARY KEY,
+  keyname TEXT UNIQUE,
+  value TEXT NOT NULL
+);
+INSERT OR IGNORE INTO new_config SELECT
+  id, keyname, value
+FROM config;
+DROP TABLE config;
+ALTER TABLE new_config RENAME TO config;
+CREATE INDEX config_index1 ON config (keyname);
+"#,
+            106,
+        )
+        .await?;
+    }
+
     let new_version = sql
         .get_raw_config_int(VERSION_CFG)
         .await?