Raising GLOBAL_LOG_LEVEL to WARNING buys quieter output but not less work: 241 INFO call sites interpolate their payload into an f-string before the logging call gets to drop it. The heaviest is get_doc, which logs every chunk id and metadata dict in a collection, so on the full-context retrieval path that is the entire knowledge base, once per chat request.
That one line at WARNING, CPython 3.12:
| knowledge base | payload | before | after |
| -------------- | ------- | -------- | ------- |
| top-k of 3 | 1.2 kB | 3.8 us | 0.07 us |
| 500 chunks | 201 kB | 583.6 us | 0.08 us |
| 5000 chunks | 2.0 MB | 5.8 ms | 0.15 us |
The lazy form log.info('query_doc:result %s %s', result.ids, result.metadatas) hands the payload to record.getMessage(), which the InterceptHandler only reaches once a record has passed the level check. Output at INFO is byte-identical. Two sites that already built their message eagerly, one str concat and one % operator, move to the same lazy form.
When `RAG_DOCUMENT_LOADER_ENGINE` is set to `paddleocr_vl`, the dispatch branch in `Loader._get_loader` checked only the engine name and a non-empty token, so every uploaded file was handed to the PaddleOCR-VL loader regardless of its type. Text based uploads such as `.md`, `.txt` and `.csv` were base64 encoded and posted to the `/layout-parsing` endpoint tagged as PDFs, and the API rejected them with `422 Unprocessable Entity` ("PDFium: Data format error"), so those files never indexed at all.
The loader already knows which extensions it can handle: it tags images with `fileType: 1` and treats everything else as a PDF. That list is now a module level constant, and the dispatch branch gates on `['pdf'] + images`, the same way `mistral_ocr`, `datalab_marker`, `document_intelligence` and `mineru` already limit themselves. Deriving the gate from the loader's own list keeps the two in sync, so a file can never be admitted by the gate and then mislabelled as a PDF on the wire. Everything outside that set falls through to the default loader chain, so `.md` and `.txt` load as text, `.csv` through `CSVLoader`, `.docx` through `Docx2txtLoader`, and so on.
The branch also never checked `PADDLEOCR_VL_BASE_URL`. With the URL cleared, `PaddleOCRVLLoader` raised `ValueError` from its constructor and the upload failed outright instead of falling back. Both settings are now required for the branch to be taken, matching how the other engines guard their own configuration.
Fixes#24988Fixes#26759
Classic298