When Civitai returns 429 (Too Many Requests) during example image
downloads, the previous behavior treated all failures identically and
permanently removed the corresponding images from model metadata —
making them impossible to retry.
This commit adds:
- 429 detection + Retry-After header parsing in download_to_memory
- Exponential backoff retry (up to 3 attempts) in
download_model_images_with_tracking
- Separate tracking of rate-limited vs permanently failed URLs
- rate_limited_models progress tracking persisted to disk
- Rate-limited models are NOT added to failed_models/processed_models
so they are automatically retried on subsequent download runs
- Force mode clears failed_models when rate-limited images exist
Previously check_pending_models() only skipped models already in
processed_models, so models that had permanently failed (no CivitAI
images available, download errors) were forever reported as "pending".
This caused repeated auto-download cycles with no actual work to do.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
- Extract progress file loading to async methods to run in executor
- Refactor start_download to reduce lock time by pre-loading data before entering lock
- Improve check_pending_models efficiency with single-pass model collection and async loading
- Add type hints to get_status method
- Add tests for download task callback execution and error handling
- Add /api/example-images/check-pending endpoint to quickly check models needing downloads
- Improve DownloadManager.start_download() to return immediately without blocking
- Add _handle_download_task_done callback for proper error handling and progress saving
- Add check_pending_models() method for lightweight pre-download validation
- Update frontend ExampleImagesManager to use new check-pending endpoint
- Add comprehensive tests for new functionality
When force=true is passed via API, models in failed_models set are
re-downloaded instead of being skipped. On successful download, model is
removed from failed_models set.
This provides a manual batch repair mechanism for users when CivitAI
media server is temporarily down and causes empty folders.
Changes:
- Backend: Add force parameter to start_download(), _download_all_example_images(), _process_model()
- Backend: Skip failed_models check when force=true
- Backend: Remove model from failed_models on successful force retry
- Frontend: GlobalContextMenu now calls API with force=true directly
- Tests: Update mock to accept force parameter
- Add failed_model_timestamps to track when models fail
- Retry failed models after 24-hour cooldown period
- Skip retry if example folder already has files
- Skip retry if failure was less than 24 hours ago
- Log count of failed models with retry message
- Fix unbound snapshot variable in exception path
- Remove duplicate/unreachable directory check code
- Update string quotes to double quotes (PEP 8)
This fixes the issue where failed models were permanently skipped in
auto-download mode, even when their example folders were empty.
fix(example_images_download_manager): re-raise specific exception on download error
refactor(usage_stats): define constants locally to avoid conditional imports
test(example_images_download_manager): update exception handling in download tests
test(example_images_file_manager): differentiate between os.startfile and subprocess.Popen in tests
test(example_images_paths): ensure valid example images root with single-library mode
test(usage_stats): use string literals for metadata payload to avoid conditional imports
- Introduced a new `Downloader` class to centralize HTTP/HTTPS download management.
- Replaced direct `aiohttp` session handling with the unified downloader in `MetadataArchiveManager`, `DownloadManager`, and `ExampleImagesProcessor`.
- Added support for resumable downloads, progress tracking, and error handling in the new downloader.
- Updated methods to utilize the downloader's capabilities for downloading files and images, improving code maintainability and readability.
