MQL5-Google-Onedrive/.jules/bolt.md
google-labs-jules[bot] f154cfa341 Bolt: Optimize repo validation scanning
Replaced `pathlib.Path.rglob("*")` with `os.walk(topdown=True)` in `scripts/ci_validate_repo.py` to prune large directories like `.git` and `node_modules` in-place. This avoids unnecessary traversal and syscalls, improving CI validation performance.

Also:
- Fixed indentation logic in file scanning loop.
- Renamed inner loop variable to avoid shadowing.
- Documented learning in `.jules/bolt.md`.
2026-02-25 05:45:03 +00:00

3 KiB

Bolt's Journal

This journal is for CRITICAL, non-routine performance learnings ONLY.

  • Codebase-specific bottlenecks
  • Failed optimizations (and why)
  • Surprising performance patterns
  • Rejected changes with valuable lessons

2024-07-25 - MQL5 Native Functions vs. Scripted Loops

Learning: My assumption that a manual MQL5 loop over a pre-cached array would be faster than built-in functions like iHighest() and iLowest() was incorrect. The code review pointed out that MQL5's native, built-in functions are implemented in highly optimized C++ and are significantly faster than loops executed in the MQL5 scripting layer. The original comment stating this was correct. Action: Always prefer using MQL5's built-in, native functions for calculations like finding highs/lows over manual loops, even if the data is already in a local array. The performance gain from the native implementation outweighs the overhead of the function call.

2026-01-23 - Python File System Checks

Learning: Checking for file existence (os.path.exists) before getting metadata (os.path.getmtime) introduces a redundant syscall. os.stat() provides both pieces of information in a single syscall and uses the EAFP (Easier to Ask for Forgiveness than Permission) pattern, which is more Pythonic and slightly faster, especially in high-frequency loops or handlers. Action: Use os.stat() when both existence and metadata are needed, wrapping it in a try...except OSError block.

2026-01-26 - yfinance Bulk Download

Learning: yfinance Ticker.history in a loop is significantly slower than yf.download with a list of tickers due to sequential HTTP requests. yf.download with group_by='ticker' provides a consistent MultiIndex structure even for single tickers, simplifying bulk processing. Action: Always prefer yf.download(tickers) over iterating yf.Ticker(t) when fetching data for multiple symbols.

2026-02-09 - Git Command Performance

Learning: git for-each-ref is a powerful tool for batch data retrieval, but without filtering, it processes all refs, including thousands of stale merged branches in older repositories. Calculating ahead-behind counts for these stale branches is O(N) where N is total branches, which can be significantly slower than O(M) where M is active branches. Action: Always filter git for-each-ref with --no-merged (or --merged depending on use case) when only interested in a subset of branches, especially when expensive formatting options like ahead-behind are used.

2026-02-12 - Python Recursive File Scanning

Learning: pathlib.Path.rglob("*") exhaustively traverses all subdirectories (including huge ones like .git, node_modules) before yielding paths, making post-filtering inefficient O(N). os.walk(topdown=True) allows pruning entire directory trees in-place by modifying dirs, reducing complexity to O(Relevant Files) and skipping thousands of syscalls. Action: Prefer os.walk with in-place dirs pruning over rglob + filtering when scanning repositories with large ignored directories.