Bolt/sqlite query performance 11696236825373191407

.jules/bolt.md

@@ -20,3 +20,6 @@
 ## 2024-08-01 - Bytecode Disassembler String Allocation Optimization
 **Learning:** Formatting directly into a string buffer inside a tight loop with `write!(buffer, ...)` avoids unnecessary string heap allocations compared to `buffer.push_str(&format!(...))`.
 **Action:** Always prefer formatting directly into the target String buffer when concatenating strings in loops in performance-sensitive paths like debuggers or disassemblers.
+## 2024-05-24 - Optimize rusqlite extraction in query_map
+**Learning:** When mapping `rusqlite` query results to dynamic types like `IndexMap<String, RuntimeValue>` in `techscript_stdlib`, use `row.get_ref_unwrap(i)` to map the underlying `rusqlite::types::ValueRef` directly to the corresponding `RuntimeValue` (e.g., `Int`, `Float`, `Str`), avoiding the overhead and type issues of coercing all numeric and null columns to `String`s.
+**Action:** When extracting data from rusqlite database rows, inspect the `ValueRef` directly with `get_ref` or `get_ref_unwrap` instead of eagerly copying out a target Rust type like `String`, significantly reducing allocations and retaining correct native types for numeric and null data.

stdlib/src/sqlite.rs

@@ -185,7 +185,7 @@ impl StdlibRegistry {
                                 .query_map(rusqlite::params_from_iter(params), |row| {
                                     let mut map = IndexMap::with_capacity(col_count);
                                     for i in 0..col_count {
-                                        let val = row.get_ref(i)?;
+                                        let val = row.get_ref_unwrap(i);
                                         let rt_val = match val {
                                             rusqlite::types::ValueRef::Null => RuntimeValue::Null,
                                             rusqlite::types::ValueRef::Integer(v) => {
@@ -194,11 +194,9 @@ impl StdlibRegistry {
                                             rusqlite::types::ValueRef::Real(v) => {
                                                 RuntimeValue::Float(v)
                                             }
-                                            rusqlite::types::ValueRef::Text(v) => {
-                                                RuntimeValue::Str(
-                                                    String::from_utf8_lossy(v).into_owned(),
-                                                )
-                                            }
+                                            rusqlite::types::ValueRef::Text(v) => RuntimeValue::Str(
+                                                std::str::from_utf8(v).unwrap_or_default().to_string(),
+                                            ),
                                             rusqlite::types::ValueRef::Blob(v) => {
                                                 RuntimeValue::Str(
                                                     String::from_utf8_lossy(v).into_owned(),