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mcp-nextcloud/nextcloud_mcp_server/document_processors/base.py
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Chris CoutinhoandClaude Opus 4.8 b779627fa6 fix(observability): address third review round
Remaining items from the PR #831 Claude review:

- processor span symmetry: add "vector_sync.total_chars" to the sparse
  embedding span (already on the dense span) and drop the redundant
  "embedding.batch_size" attribute from both spans — it always equalled
  vector_sync.chunk_count and would mislead once batching is split.
- metrics: document the deliberate "throughput counts only on full success"
  contract in record_document_parse (partial extractions flagged
  success=False are counted as a parse-error but never inflate
  pages/chars/bytes throughput).
- config: extract _detect_base_provider() -> (family, model) as the single
  source of truth for the provider-detection priority chain, shared by
  get_embedding_model_name() and get_embedding_provider_family(). Preserves
  the intentional gateway asymmetry (only the family method short-circuits).
- base.py: Optional[...] -> PEP 604 `... | None`; drop now-unused import.

Behavior unchanged (get_embedding_* outputs covered by test_config.py).

Refs Deck #175, PR #831.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-03 02:01:28 +02:00

139 lines
4.3 KiB
Python

"""Abstract base class for document processing plugins."""
from abc import ABC, abstractmethod
from collections.abc import Awaitable, Callable
from typing import Any
from pydantic import BaseModel
class ProcessingResult(BaseModel):
"""Standardized result from any document processor."""
text: str
"""Extracted text content"""
metadata: dict[str, Any]
"""Processor-specific metadata"""
processor: str
"""Name of processor that handled this (e.g., 'unstructured', 'tesseract')"""
success: bool = True
"""Whether processing succeeded"""
error: str | None = None
"""Error message if processing failed"""
class DocumentProcessor(ABC):
"""Abstract base class for document processing plugins.
Document processors extract text from various file formats (PDF, DOCX, images, etc.).
Each processor implements this interface and can be registered with the ProcessorRegistry.
Example:
class MyProcessor(DocumentProcessor):
@property
def name(self) -> str:
return "my_processor"
@property
def supported_mime_types(self) -> set[str]:
return {"application/pdf", "image/jpeg"}
async def process(self, content: bytes, content_type: str, **kwargs) -> ProcessingResult:
# Extract text from content
return ProcessingResult(text="...", metadata={}, processor=self.name)
async def health_check(self) -> bool:
return True
"""
@property
@abstractmethod
def name(self) -> str:
"""Unique identifier for this processor (e.g., 'unstructured', 'tesseract')."""
pass
@property
def tier(self) -> str:
"""Extraction tier this processor belongs to (escalation ladder).
Used as the ``tier`` label/attribute in observability so that adding new
extraction tiers later (docling, OCR, LLM) is purely additive. Vocabulary
(cheapest first): ``fast`` -> ``structured`` -> ``ocr`` -> ``llm``.
Defaults to ``"fast"``; override in processors that belong to a higher
tier.
"""
return "fast"
@property
@abstractmethod
def supported_mime_types(self) -> set[str]:
"""Set of MIME types this processor can handle.
Examples: {"application/pdf", "image/jpeg", "image/png"}
"""
pass
@abstractmethod
async def process(
self,
content: bytes,
content_type: str,
filename: str | None = None,
options: dict[str, Any] | None = None,
progress_callback: Callable[[float, float | None, str | None], Awaitable[None]]
| None = None,
) -> ProcessingResult:
"""Process a document and extract text.
Args:
content: Document bytes
content_type: MIME type of the document
filename: Optional filename for format detection
options: Processor-specific options (e.g., OCR language, strategy)
progress_callback: Optional async callback for progress updates.
Called as: await progress_callback(progress, total, message)
- progress: Current progress value (monotonically increasing)
- total: Optional total value (None if unknown)
- message: Optional human-readable status message
Returns:
ProcessingResult with extracted text and metadata
Raises:
ProcessorError: If processing fails
"""
pass
@abstractmethod
async def health_check(self) -> bool:
"""Check if processor is available and healthy.
Returns:
True if processor is ready to use, False otherwise
"""
pass
def supports(self, content_type: str) -> bool:
"""Check if this processor supports the given MIME type.
Args:
content_type: MIME type (may include parameters like "application/pdf; charset=utf-8")
Returns:
True if this processor can handle the type
"""
# Strip parameters from content type
base_type = content_type.split(";")[0].strip().lower()
return base_type in self.supported_mime_types
class ProcessorError(Exception):
"""Raised when document processing fails."""
pass