feat: put pdfium behind threadlock

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.1.8
+
+- put `pdfium` call behind a thread lock
+
 ## 1.1.7
 
 - Update OpenCV-Python to 4.13.0.90 to squash ffmpeg vulnerability CVE-2023-6605

unstructured_inference/__version__.py

@@ -1 +1 @@
-__version__ = "1.1.7"  # pragma: no cover
+__version__ = "1.1.8"  # pragma: no cover

unstructured_inference/inference/layout.py

@@ -4,6 +4,7 @@
 import tempfile
 from functools import cached_property
 from pathlib import Path, PurePath
+from threading import Lock
 from typing import Any, BinaryIO, Collection, List, Optional, Union, cast
 
 import numpy as np
@@ -23,6 +24,8 @@
 )
 from unstructured_inference.visualize import draw_bbox
 
+_pdfium_lock = Lock()
+
 
 class DocumentLayout:
     """Class for handling documents that are saved as .pdf files. For .pdf files, a
@@ -419,46 +422,47 @@ def convert_pdf_to_image(
         raise ValueError("output_folder must be specified if path_only is true")
     if filename is None and file is None:
         raise ValueError("Either filename or file must be provided")
-    pdf = pdfium.PdfDocument(filename or file, password=password)
-    try:
-        images: dict[int, Image.Image] = {}
-        if dpi is None:
-            dpi = inference_config.PDF_RENDER_DPI
-        scale = dpi / 72.0
-        for i, page in enumerate(pdf, start=1):
-            try:
-                if first_page is not None and i < first_page:
-                    continue
-                if last_page is not None and i > last_page:
-                    break
-                bitmap = page.render(
-                    scale=scale,
-                    no_smoothtext=False,
-                    no_smoothimage=False,
-                    no_smoothpath=False,
-                    optimize_mode="print",
-                )
+    with _pdfium_lock:
+        pdf = pdfium.PdfDocument(filename or file, password=password)
+        try:
+            images: dict[int, Image.Image] = {}
+            if dpi is None:
+                dpi = inference_config.PDF_RENDER_DPI
+            scale = dpi / 72.0
+            for i, page in enumerate(pdf, start=1):
                 try:
-                    images[i] = bitmap.to_pil()
+                    if first_page is not None and i < first_page:
+                        continue
+                    if last_page is not None and i > last_page:
+                        break
+                    bitmap = page.render(
+                        scale=scale,
+                        no_smoothtext=False,
+                        no_smoothimage=False,
+                        no_smoothpath=False,
+                        optimize_mode="print",
+                    )
+                    try:
+                        images[i] = bitmap.to_pil()
+                    finally:
+                        bitmap.close()
                 finally:
-                    bitmap.close()
-            finally:
-                page.close()
-        if not output_folder:
-            return list(images.values())
-        else:
-            # Save images to output_folder
-            filenames: list[str] = []
-            assert Path(output_folder).exists()
-            assert Path(output_folder).is_dir()
-            for i, image in images.items():
-                fn: str = os.path.join(str(output_folder), f"page_{i}.png")
-                image.save(fn, format="PNG", compress_level=1, optimize=False)
-                filenames.append(fn)
-            if path_only:
-                return filenames
-            images_values: list[Image.Image] = list(images.values())
-            return images_values
-
-    finally:
-        pdf.close()
+                    page.close()
+            if not output_folder:
+                return list(images.values())
+            else:
+                # Save images to output_folder
+                filenames: list[str] = []
+                assert Path(output_folder).exists()
+                assert Path(output_folder).is_dir()
+                for i, image in images.items():
+                    fn: str = os.path.join(str(output_folder), f"page_{i}.png")
+                    image.save(fn, format="PNG", compress_level=1, optimize=False)
+                    filenames.append(fn)
+                if path_only:
+                    return filenames
+                images_values: list[Image.Image] = list(images.values())
+                return images_values
+
+        finally:
+            pdf.close()