feat: implement batch queries for improved list performance

Co-authored-by: aider (openai/andrew.openrouter.qwen.qwen3-coder) <aider@aider.chat>

src/db.rs

@@ -443,3 +443,66 @@ pub fn get_item_meta_value(conn: &Connection, item: &Item, name: String) -> Resu
         None => Ok(None),
     }
 }
+
+pub fn get_tags_for_items(conn: &Connection, item_ids: &[i64]) -> Result<std::collections::HashMap<i64, Vec<Tag>>> {
+    debug!("DB: Getting tags for items: {:?}", item_ids);
+    
+    if item_ids.is_empty() {
+        return Ok(std::collections::HashMap::new());
+    }
+    
+    // Create placeholders for the IN clause
+    let placeholders: Vec<String> = item_ids.iter().map(|_| "?".to_string()).collect();
+    let placeholders_str = placeholders.join(",");
+    
+    let sql = format!("SELECT id, name FROM tags WHERE id IN ({}) ORDER BY id ASC, name ASC", placeholders_str);
+    
+    let mut statement = conn
+        .prepare_cached(&sql)
+        .context("Problem preparing SQL statement")?;
+    
+    let mut rows = statement.query(rusqlite::params_from_iter(item_ids))?;
+    
+    let mut tags_map: std::collections::HashMap<i64, Vec<Tag>> = std::collections::HashMap::new();
+    
+    while let Some(row) = rows.next()? {
+        let id: i64 = row.get(0)?;
+        let name: String = row.get(1)?;
+        
+        tags_map.entry(id).or_insert_with(Vec::new).push(Tag { id, name });
+    }
+    
+    Ok(tags_map)
+}
+
+pub fn get_meta_for_items(conn: &Connection, item_ids: &[i64]) -> Result<std::collections::HashMap<i64, std::collections::HashMap<String, String>>> {
+    debug!("DB: Getting meta for items: {:?}", item_ids);
+    
+    if item_ids.is_empty() {
+        return Ok(std::collections::HashMap::new());
+    }
+    
+    // Create placeholders for the IN clause
+    let placeholders: Vec<String> = item_ids.iter().map(|_| "?".to_string()).collect();
+    let placeholders_str = placeholders.join(",");
+    
+    let sql = format!("SELECT id, name, value FROM metas WHERE id IN ({}) ORDER BY id ASC, name ASC", placeholders_str);
+    
+    let mut statement = conn
+        .prepare_cached(&sql)
+        .context("Problem preparing SQL statement")?;
+    
+    let mut rows = statement.query(rusqlite::params_from_iter(item_ids))?;
+    
+    let mut meta_map: std::collections::HashMap<i64, std::collections::HashMap<String, String>> = std::collections::HashMap::new();
+    
+    while let Some(row) = rows.next()? {
+        let id: i64 = row.get(0)?;
+        let name: String = row.get(1)?;
+        let value: String = row.get(2)?;
+        
+        meta_map.entry(id).or_insert_with(std::collections::HashMap::new).insert(name, value);
+    }
+    
+    Ok(meta_map)
+}

src/modes/list.rs

@@ -38,31 +38,23 @@ pub fn mode_list(
 
     debug!("MAIN: Items: {:?}", items);
 
+    // Collect all item IDs for batch queries
+    let item_ids: Vec<i64> = items.iter().map(|item| item.id.unwrap()).collect();
+    
+    // Fetch all tags for all items in a single query
+    let all_tags = crate::db::get_tags_for_items(conn, &item_ids)?;
     let mut tags_by_item: std::collections::HashMap<i64, Vec<String>> =
         std::collections::HashMap::new();
-    let mut meta_by_item: std::collections::HashMap<
-        i64,
-        std::collections::HashMap<String, String>,
-    > = std::collections::HashMap::new();
     
-    for item in items.iter() {
+    // Convert Tag structs to just names
-        let item_id = item.id.unwrap();
+    for (item_id, tags) in all_tags {
-
+        let tag_names: Vec<String> = tags.into_iter().map(|tag| tag.name).collect();
-        let item_tags: Vec<String> = crate::db::get_item_tags(conn, item)?
+        tags_by_item.insert(item_id, tag_names);
-            .into_iter()
-            .map(|x| x.name)
-            .collect();
-        tags_by_item.insert(item_id, item_tags);
-
-        let mut item_meta: std::collections::HashMap<String, String> =
-            std::collections::HashMap::new();
-
-        for meta in crate::db::get_item_meta(conn, item)? {
-            item_meta.insert(meta.name.clone(), meta.value);
-        }
-        meta_by_item.insert(item_id, item_meta);
     }
     
+    // Fetch all metadata for all items in a single query
+    let meta_by_item = crate::db::get_meta_for_items(conn, &item_ids)?;
+
     let mut table = Table::new();
     table.set_format(*prettytable::format::consts::FORMAT_CLEAN);