Refactor RasterisedDocumentParser to ParserProtocol interface

- Add RasterisedDocumentParser to registry.register_defaults()
- Update parser class: remove DocumentParser inheritance, add Protocol
  class attrs/classmethods/properties, context-manager lifecycle
- Add read_file_handle_unicode_errors() to shared parsers/utils.py
- Replace inline unicode-error-handling with shared utility call

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/paperless/parsers/registry.py

@@ -195,6 +195,7 @@ class ParserRegistry:
         """
         from paperless.parsers.mail import MailDocumentParser
         from paperless.parsers.remote import RemoteDocumentParser
+        from paperless.parsers.tesseract import RasterisedDocumentParser
         from paperless.parsers.text import TextDocumentParser
         from paperless.parsers.tika import TikaDocumentParser
 
@@ -202,6 +203,7 @@ class ParserRegistry:
         self.register_builtin(RemoteDocumentParser)
         self.register_builtin(TikaDocumentParser)
         self.register_builtin(MailDocumentParser)
+        self.register_builtin(RasterisedDocumentParser)
 
     # ------------------------------------------------------------------
     # Discovery

src/paperless/parsers/tesseract.py

@@ -1,13 +1,17 @@
+from __future__ import annotations
+
+import logging
 import os
 import re
+import shutil
 import tempfile
 from pathlib import Path
 from typing import TYPE_CHECKING
+from typing import Self
 
 from django.conf import settings
 from PIL import Image
 
-from documents.parsers import DocumentParser
 from documents.parsers import ParseError
 from documents.parsers import make_thumbnail_from_pdf
 from documents.utils import maybe_override_pixel_limit
@@ -16,6 +20,28 @@ from paperless.config import OcrConfig
 from paperless.models import ArchiveFileChoices
 from paperless.models import CleanChoices
 from paperless.models import ModeChoices
+from paperless.parsers.utils import read_file_handle_unicode_errors
+from paperless.version import __full_version_str__
+
+if TYPE_CHECKING:
+    import datetime
+    from types import TracebackType
+
+    from paperless.parsers import MetadataEntry
+    from paperless.parsers import ParserContext
+
+logger = logging.getLogger("paperless.parsing.tesseract")
+
+_SUPPORTED_MIME_TYPES: dict[str, str] = {
+    "application/pdf": ".pdf",
+    "image/jpeg": ".jpg",
+    "image/png": ".png",
+    "image/tiff": ".tif",
+    "image/gif": ".gif",
+    "image/bmp": ".bmp",
+    "image/webp": ".webp",
+    "image/heic": ".heic",
+}
 
 
 class NoTextFoundException(Exception):
@@ -26,79 +52,123 @@ class RtlLanguageException(Exception):
     pass
 
 
-class RasterisedDocumentParser(DocumentParser):
+class RasterisedDocumentParser:
     """
     This parser uses Tesseract to try and get some text out of a rasterised
     image, whether it's a PDF, or other graphical format (JPEG, TIFF, etc.)
     """
 
-    logging_name = "paperless.parsing.tesseract"
+    name: str = "Paperless-ngx Tesseract OCR Parser"
+    version: str = __full_version_str__
+    author: str = "Paperless-ngx Contributors"
+    url: str = "https://github.com/paperless-ngx/paperless-ngx"
 
-    def get_settings(self) -> OcrConfig:
-        """
-        This parser uses the OCR configuration settings to parse documents
-        """
-        return OcrConfig()
+    # ------------------------------------------------------------------
+    # Class methods
+    # ------------------------------------------------------------------
 
-    def get_page_count(self, document_path, mime_type):
-        page_count = None
-        if mime_type == "application/pdf":
-            try:
-                import pikepdf
+    @classmethod
+    def supported_mime_types(cls) -> dict[str, str]:
+        return _SUPPORTED_MIME_TYPES
 
-                with pikepdf.Pdf.open(document_path) as pdf:
-                    page_count = len(pdf.pages)
-            except Exception as e:
-                self.log.warning(
-                    f"Unable to determine PDF page count {document_path}: {e}",
-                )
-        return page_count
+    @classmethod
+    def score(
+        cls,
+        mime_type: str,
+        filename: str,
+        path: Path | None = None,
+    ) -> int | None:
+        if mime_type in _SUPPORTED_MIME_TYPES:
+            return 10
+        return None
 
-    def extract_metadata(self, document_path, mime_type):
-        result = []
-        if mime_type == "application/pdf":
-            import pikepdf
+    # ------------------------------------------------------------------
+    # Properties
+    # ------------------------------------------------------------------
 
-            namespace_pattern = re.compile(r"\{(.*)\}(.*)")
+    @property
+    def can_produce_archive(self) -> bool:
+        return True
 
-            pdf = pikepdf.open(document_path)
-            meta = pdf.open_metadata()
-            for key, value in meta.items():
-                if isinstance(value, list):
-                    value = " ".join([str(e) for e in value])
-                value = str(value)
-                try:
-                    m = namespace_pattern.match(key)
-                    if m is None:  # pragma: no cover
-                        continue
-                    namespace = m.group(1)
-                    key_value = m.group(2)
-                    try:
-                        namespace.encode("utf-8")
-                        key_value.encode("utf-8")
-                    except UnicodeEncodeError as e:  # pragma: no cover
-                        self.log.debug(f"Skipping metadata key {key}: {e}")
-                        continue
-                    result.append(
-                        {
-                            "namespace": namespace,
-                            "prefix": meta.REVERSE_NS[namespace],
-                            "key": key_value,
-                            "value": value,
-                        },
-                    )
-                except Exception as e:
-                    self.log.warning(
-                        f"Error while reading metadata {key}: {value}. Error: {e}",
-                    )
-        return result
+    @property
+    def requires_pdf_rendition(self) -> bool:
+        return False
 
-    def get_thumbnail(self, document_path, mime_type, file_name=None):
-        return make_thumbnail_from_pdf(
-            self.archive_path or document_path,
-            self.tempdir,
-            self.logging_group,
+    # ------------------------------------------------------------------
+    # Lifecycle
+    # ------------------------------------------------------------------
+
+    def __init__(self, logging_group: object = None) -> None:
+        settings.SCRATCH_DIR.mkdir(parents=True, exist_ok=True)
+        self.tempdir = Path(
+            tempfile.mkdtemp(prefix="paperless-", dir=settings.SCRATCH_DIR),
         )
+        self.settings = OcrConfig()
+        self.archive_path: Path | None = None
+        self.text: str | None = None
+        self.date: datetime.datetime | None = None
+        self.log = logger
+
+    def __enter__(self) -> Self:
+        return self
+
+    def __exit__(
+        self,
+        exc_type: type[BaseException] | None,
+        exc_val: BaseException | None,
+        exc_tb: TracebackType | None,
+    ) -> None:
+        logger.debug("Cleaning up temporary directory %s", self.tempdir)
+        shutil.rmtree(self.tempdir, ignore_errors=True)
+
+    # ------------------------------------------------------------------
+    # Core parsing interface
+    # ------------------------------------------------------------------
+
+    def configure(self, context: ParserContext) -> None:
+        pass
+
+    # ------------------------------------------------------------------
+    # Result accessors
+    # ------------------------------------------------------------------
+
+    def get_text(self) -> str | None:
+        return self.text
+
+    def get_date(self) -> datetime.datetime | None:
+        return self.date
+
+    def get_archive_path(self) -> Path | None:
+        return self.archive_path
+
+    # ------------------------------------------------------------------
+    # Thumbnail, page count, and metadata
+    # ------------------------------------------------------------------
+
+    def get_thumbnail(self, document_path: Path, mime_type: str) -> Path:
+        return make_thumbnail_from_pdf(
+            self.archive_path or Path(document_path),
+            self.tempdir,
+        )
+
+    def get_page_count(self, document_path: Path, mime_type: str) -> int | None:
+        if mime_type == "application/pdf":
+            from paperless.parsers.utils import get_page_count_for_pdf
+
+            return get_page_count_for_pdf(Path(document_path), log=self.log)
+        return None
+
+    def extract_metadata(
+        self,
+        document_path: Path,
+        mime_type: str,
+    ) -> list[MetadataEntry]:
+        if mime_type != "application/pdf":
+            return []
+
+        from paperless.parsers.utils import extract_pdf_metadata
+
+        return extract_pdf_metadata(Path(document_path), log=self.log)
 
     def is_image(self, mime_type) -> bool:
         return mime_type in [
@@ -163,7 +233,7 @@ class RasterisedDocumentParser(DocumentParser):
             and sidecar_file.is_file()
             and self.settings.mode != "redo"
         ):
-            text = self.read_file_handle_unicode_errors(sidecar_file)
+            text = read_file_handle_unicode_errors(sidecar_file)
 
             if "[OCR skipped on page" not in text:
                 # This happens when there's already text in the input file.
@@ -196,7 +266,7 @@ class RasterisedDocumentParser(DocumentParser):
                     ],
                     logger=self.log,
                 )
-                text = self.read_file_handle_unicode_errors(Path(tmp.name))
+                text = read_file_handle_unicode_errors(Path(tmp.name))
 
             return post_process_text(text)
 
@@ -218,8 +288,6 @@ class RasterisedDocumentParser(DocumentParser):
         *,
         safe_fallback=False,
     ):
-        if TYPE_CHECKING:
-            assert isinstance(self.settings, OcrConfig)
         ocrmypdf_args = {
             "input_file_or_options": input_file,
             "output_file": output_file,
@@ -330,7 +398,13 @@ class RasterisedDocumentParser(DocumentParser):
 
         return ocrmypdf_args
 
-    def parse(self, document_path: Path, mime_type, file_name=None) -> None:
+    def parse(
+        self,
+        document_path: Path,
+        mime_type: str,
+        *,
+        produce_archive: bool = True,
+    ) -> None:
         # This forces tesseract to use one core per page.
         os.environ["OMP_THREAD_LIMIT"] = "1"
         VALID_TEXT_LENGTH = 50

src/paperless/parsers/utils.py

@@ -20,6 +20,34 @@ if TYPE_CHECKING:
 logger = logging.getLogger("paperless.parsers.utils")
 
 
+def read_file_handle_unicode_errors(
+    filepath: Path,
+    log: logging.Logger | None = None,
+) -> str:
+    """Read a file as UTF-8 text, replacing invalid bytes rather than raising.
+
+    Parameters
+    ----------
+    filepath:
+        Absolute path to the file to read.
+    log:
+        Logger to use for warnings.  Falls back to the module-level logger
+        when omitted.
+
+    Returns
+    -------
+    str
+        File content as a string, with any invalid UTF-8 sequences replaced
+        by the Unicode replacement character.
+    """
+    _log = log or logger
+    try:
+        return filepath.read_text(encoding="utf-8")
+    except UnicodeDecodeError as e:
+        _log.warning("Unicode error during text reading, continuing: %s", e)
+        return filepath.read_bytes().decode("utf-8", errors="replace")
+
+
 def get_page_count_for_pdf(
     document_path: Path,
     log: logging.Logger | None = None,