DirectoryLoader parallel file loading

langchain/document_loaders/directory.py

@@ -3,15 +3,15 @@ import logging
 from pathlib import Path
 from typing import List, Type, Union
 
+
 from langchain.docstore.document import Document
 from langchain.document_loaders.base import BaseLoader
 from langchain.document_loaders.html_bs import BSHTMLLoader
 from langchain.document_loaders.text import TextLoader
 from langchain.document_loaders.unstructured import UnstructuredFileLoader
 
-FILE_LOADER_TYPE = Union[
-    Type[UnstructuredFileLoader], Type[TextLoader], Type[BSHTMLLoader]
-]
+FILE_LOADER_TYPE = Union[Type[UnstructuredFileLoader], Type[TextLoader],
+                         Type[BSHTMLLoader]]
 logger = logging.getLogger(__name__)
 
 
@@ -36,6 +36,7 @@ class DirectoryLoader(BaseLoader):
         loader_kwargs: Union[dict, None] = None,
         recursive: bool = False,
         show_progress: bool = False,
+        parallel: bool = False,
     ):
         """Initialize with path to directory and how to glob over it."""
         if loader_kwargs is None:
@@ -48,12 +49,28 @@ class DirectoryLoader(BaseLoader):
         self.silent_errors = silent_errors
         self.recursive = recursive
         self.show_progress = show_progress
+        self.parallel = parallel
+
+    def _load_file(self, p: Path) -> List[Document]:
+        if p.is_file():
+            if _is_visible(p.relative_to(p)) or self.load_hidden:
+                try:
+                    sub_docs = self.loader_cls(str(p),
+                                               **self.loader_kwargs).load()
+                    return sub_docs
+                except Exception as e:
+                    if self.silent_errors:
+                        logger.warning(e)
+                    else:
+                        raise e
+        return []
 
     def load(self) -> List[Document]:
         """Load documents."""
         p = Path(self.path)
         docs = []
-        items = list(p.rglob(self.glob) if self.recursive else p.glob(self.glob))
+        items = list(
+            p.rglob(self.glob) if self.recursive else p.glob(self.glob))
 
         pbar = None
         if self.show_progress:
@@ -64,27 +81,22 @@ class DirectoryLoader(BaseLoader):
             except ImportError as e:
                 logger.warning(
                     "To log the progress of DirectoryLoader you need to install tqdm, "
-                    "`pip install tqdm`"
-                )
+                    "`pip install tqdm`")
                 if self.silent_errors:
                     logger.warning(e)
                 else:
                     raise e
 
-        for i in items:
-            if i.is_file():
-                if _is_visible(i.relative_to(p)) or self.load_hidden:
-                    try:
-                        sub_docs = self.loader_cls(str(i), **self.loader_kwargs).load()
-                        docs.extend(sub_docs)
-                    except Exception as e:
-                        if self.silent_errors:
-                            logger.warning(e)
-                        else:
-                            raise e
-                    finally:
-                        if pbar:
-                            pbar.update(1)
+        if self.parallel:
+            results = process_map(self._load_file, items) # use default max_workers
+        else:
+            results = process_map(self._load_file, items, max_workers=1)
+
+        # Combine the results
+        for sub_docs in results:
+            docs.extend(sub_docs)
+            if pbar:
+                pbar.update(1)
 
         if pbar:
             pbar.close()