Rust-Heavy Performance

Use this skill when a feature can become slow or memory-heavy. Prefer implementing heavy paths in src-tauri/ and keep the frontend thin.

Core rule

• If work is CPU-heavy, row-heavy, or repeatedly recomputed, do it in Rust.
• JavaScript/React should orchestrate UI state and rendering, not run bulk processing loops.

Rust-first implementation pattern

1. Add or extend an async command in src-tauri/src/commands.rs.
2. Keep query execution and pooling logic in src-tauri/src/db.rs and related Rust modules.
3. Return a compact DTO to the frontend (already shaped for display).
4. Call it from src/data/repositories/ using existing invoke patterns.
5. Render in feature UI with virtualization for large result sets.

Memory efficiency guardrails

• Use bounded reads (LIMIT, pagination, or chunked iteration), never unbounded materialization.
• Avoid cloning large vectors/strings when references or incremental building is enough.
• Prefer streaming/chunked processing over collecting everything at once.
• Keep structs narrow for IPC responses; do not ship unused fields.
• Reuse pooled database connections; avoid ad hoc new clients per action.

Speed guardrails

• Push filtering, sorting, grouping, and aggregation down to SQL/Rust.
• Minimize Rust<->webview payload size; serialize only what UI needs now.
• Cache or memoize expensive Rust-side intermediate results only when reuse is likely and bounded.
• Use async command handlers; avoid blocking I/O in command paths.

Easy-to-implement defaults

• Start from existing command and repository patterns instead of inventing new data paths.
• Keep each command focused: one clear job, typed input, typed output.
• Introduce feature flags/options only after proving a real need.
• Keep frontend changes small: trigger command, handle loading/error, display bounded data.

Anti-patterns to avoid

• Doing large data transforms in React useMemo or useEffect.
• Returning huge raw row sets to the UI and shaping them in JavaScript.
• Recomputing heavy derived data on every render or keystroke.
• Mixing unrelated concerns into a single Rust command handler.

Review checklist

• Is the heavy work in Rust instead of JavaScript?
• Are reads and payloads explicitly bounded?
• Is memory growth controlled for worst-case input size?
• Is command/repository wiring following existing VeloxDB patterns?
• Does the UI virtualize large lists/tables and avoid unnecessary recomputation?

Source: abeni16/veloxdb — distributed by TomeVault.