Conversation
Replaces the O(N) iterative read of file content for size validation with an O(1) `seek(0, 2)` and `tell()` operation. This eliminates significant blocking time (e.g., ~1s for 50MB) on the event loop during file uploads. - Modified `validate_file_size` in `backend/src/api/conversions.py` - Confirmed speedup via reproduction script (42000x faster for 50MB) - Verified upload functionality with `test_chunked_upload_validation.py` Co-authored-by: anchapin <6326294+anchapin@users.noreply.github.com>
|
👋 Jules, reporting for duty! I'm here to lend a hand with this pull request. When you start a review, I'll add a 👀 emoji to each comment to let you know I've read it. I'll focus on feedback directed at me and will do my best to stay out of conversations between you and other bots or reviewers to keep the noise down. I'll push a commit with your requested changes shortly after. Please note there might be a delay between these steps, but rest assured I'm on the job! For more direct control, you can switch me to Reactive Mode. When this mode is on, I will only act on comments where you specifically mention me with New to Jules? Learn more at jules.google/docs. For security, I will only act on instructions from the user who triggered this task. |
![sourcery-ai[bot]](https://avatars.githubusercontent.com/in/48477?s=60&v=4){kind=small}
There was a problem hiding this comment.
Pull request overview
This PR improves backend upload performance by optimizing file size validation in the conversions API to avoid reading through the entire uploaded file content.
Changes:
- Replaced O(N) size calculation by iterating
UploadFile.filewith an O(1)seek(..., end)+tell()approach. - Ensured the file pointer is reset back to the start after measuring size.
- Added a Bolt learning entry documenting the performance pitfall and the preferred approach.
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
backend/src/api/conversions.py |
Switches file size validation to seek/tell to avoid synchronous iteration over file contents. |
.jules/bolt.md |
Documents the “don’t read files to compute size in async code” learning and recommended pattern. |
1 participant
This PR optimizes the
validate_file_sizefunction inbackend/src/api/conversions.py.Previously, the function iterated over the entire
UploadFilecontent to calculate its size, which is an O(N) operation that blocks the asyncio event loop becauseSpooledTemporaryFileiteration is synchronous. This caused significant latency (e.g., ~1s blocking for a 50MB file) and would degrade server performance under concurrent load.The optimization replaces the iteration with
file.file.seek(0, 2)(seek to end) andfile.file.tell()(get position), which is an O(1) operation. It then correctly resets the file pointer to 0.Performance Impact:
Verification:
UploadFilebehavior.backend/src/tests/integration/test_chunked_upload_validation.pypasses, ensuring no regressions in upload handling.PR created automatically by Jules for task 4003961969538228830 started by @anchapin