## Summary
This PR is the direct successor to the previous `docx` lazy-loading
implementation. It addresses the technical debt intentionally left out
in the last PR by fully migrating the `qa` and `manual` parsing
strategies to the new lazy-loading model.
Additionally, this PR comprehensively refactors the underlying `docx`
parsing pipeline to eliminate significant code redundancy and introduces
robust fallback mechanisms to handle completely corrupted image streams
safely.
## What's Changed
* **Centralized Abstraction (`docx_parser.py`)**: Moved the
`get_picture` extraction logic up to the `RAGFlowDocxParser` base class.
Previously, `naive`, `qa`, and `manual` parsers maintained separate,
redundant copies of this method. All downstream strategies now natively
gather raw blobs and return `LazyDocxImage` objects automatically.
* **Robust Corrupted Image Fallback (`docx_parser.py`)**: Handled edge
cases where `python-docx` encounters critically malformed magic headers.
Implemented an explicit `try-except` structure that safely intercepts
`UnrecognizedImageError` (and similar exceptions) and seamlessly falls
back to retrieving the raw binary via `getattr(related_part, "blob",
None)`, preventing parser crashes on damaged documents.
* **Legacy Code & Redundancy Purge**:
* Removed the duplicate `get_picture` methods from `naive.py`, `qa.py`,
and `manual.py`.
* Removed the standalone, immediate-decoding `concat_img` method in
`manual.py`. It has been completely replaced by the globally unified,
lazy-loading-compatible `rag.nlp.concat_img`.
* Cleaned up unused legacy imports (e.g., `PIL.Image`, docx exception
packages) across all updated strategy files.
## Scope
To keep this PR focused, I have restricted these changes strictly to the
unification of `docx` extraction logic and the lazy-load migration of
`qa` and `manual`.
## Validation & Testing
I've tested this to ensure no regressions and validated the fallback
logic:
* **Output Consistency**: Compared identical `.docx` inputs using `qa`
and `manual` strategies before and after this branch: chunk counts,
extracted text, table HTML, and attached images match perfectly.
* **Memory Footprint Drop**: Confirmed a noticeable drop in peak memory
usage when processing image-dense documents through the `qa` and
`manual` pipelines, bringing them up to parity with the `naive`
strategy's performance gains.
## Breaking Changes
* None.
**Summary**
This PR tackles a significant memory bottleneck when processing
image-heavy Word documents. Previously, our pipeline eagerly decoded
DOCX images into `PIL.Image` objects, which caused high peak memory
usage. To solve this, I've introduced a **lazy-loading approach**:
images are now stored as raw blobs and only decoded exactly when and
where they are consumed.
This successfully reduces the memory footprint while keeping the parsing
output completely identical to before.
**What's Changed**
Instead of a dry file-by-file list, here is the logical breakdown of the
updates:
* **The Core Abstraction (`lazy_image.py`)**: Introduced `LazyDocxImage`
along with helper APIs to handle lazy decoding, image-type checks, and
NumPy compatibility. It also supports `.close()` and detached PIL access
to ensure safe lifecycle management and prevent memory leaks.
* **Pipeline Integration (`naive.py`, `figure_parser.py`, etc.)**:
Updated the general DOCX picture extraction to return these new lazy
images. Downstream consumers (like the figure/VLM flow and base64
encoding paths) now decode images right at the use site using detached
PIL instances, avoiding shared-instance side effects.
* **Compatibility Hooks (`operators.py`, `book.py`, etc.)**: Added
necessary compatibility conversions so these lazy images flow smoothly
through existing merging, filtering, and presentation steps without
breaking.
**Scope & What is Intentionally Left Out**
To keep this PR focused, I have restricted these changes strictly to the
**general Word pipeline** and its downstream consumers.
The `QA` and `manual` Word parsing pipelines are explicitly **not
modified** in this PR. They can be safely migrated to this new lazy-load
model in a subsequent, standalone PR.
**Design Considerations**
I briefly considered adding image compression during processing, but
decided against it to avoid any potential quality degradation in the
derived outputs. I also held off on a massive pipeline re-architecture
to avoid overly invasive changes right now.
**Validation & Testing**
I've tested this to ensure no regressions:
* Compared identical DOCX inputs before and after this branch: chunk
counts, extracted text, table HTML, and image descriptions match
perfectly.
* **Confirmed a noticeable drop in peak memory usage when processing
image-dense documents.** For a 30MB Word document containing 243 1080p
screenshots, memory consumption is reduced by approximately 1.5GB.
**Breaking Changes**
None.
