fix(converter): Cache same pipeline class with different options (#1152)

* Update document_converter.py

Fixing caching same class with different options by using composite key (class, options)

# TODO this will ignore if different options have been defined for the same pipeline class.

at row 292

Signed-off-by: mislavmartinic <mislav.martinic@pontistechnology.com>

* formatted script

* removed unnecessary hasattr check

* pre-commit chain run

---------

Signed-off-by: mislavmartinic <mislav.martinic@pontistechnology.com>

docling/document_converter.py

@@ -1,3 +1,4 @@
+import hashlib
 import logging
 import math
 import sys
@@ -181,7 +182,14 @@ class DocumentConverter:
             )
             for format in self.allowed_formats
         }
-        self.initialized_pipelines: Dict[Type[BasePipeline], BasePipeline] = {}
+        self.initialized_pipelines: Dict[
+            Tuple[Type[BasePipeline], str], BasePipeline
+        ] = {}
+
+    def _get_pipeline_options_hash(self, pipeline_options: PipelineOptions) -> str:
+        """Generate a hash of pipeline options to use as part of the cache key."""
+        options_str = str(pipeline_options.model_dump())
+        return hashlib.md5(options_str.encode("utf-8")).hexdigest()
 
     def initialize_pipeline(self, format: InputFormat):
         """Initialize the conversion pipeline for the selected format."""
@@ -279,31 +287,36 @@ class DocumentConverter:
                 yield item
 
     def _get_pipeline(self, doc_format: InputFormat) -> Optional[BasePipeline]:
+        """Retrieve or initialize a pipeline, reusing instances based on class and options."""
         fopt = self.format_to_options.get(doc_format)
 
-        if fopt is None:
+        if fopt is None or fopt.pipeline_options is None:
             return None
-        else:
+
         pipeline_class = fopt.pipeline_cls
         pipeline_options = fopt.pipeline_options
+        options_hash = self._get_pipeline_options_hash(pipeline_options)
 
-        if pipeline_options is None:
+        # Use a composite key to cache pipelines
-            return None
+        cache_key = (pipeline_class, options_hash)
-        # TODO this will ignore if different options have been defined for the same pipeline class.
+
-        if (
+        if cache_key not in self.initialized_pipelines:
-            pipeline_class not in self.initialized_pipelines
+            _log.info(
-            or self.initialized_pipelines[pipeline_class].pipeline_options
+                f"Initializing pipeline for {pipeline_class.__name__} with options hash {options_hash}"
-            != pipeline_options
+            )
-        ):
+            self.initialized_pipelines[cache_key] = pipeline_class(
-            self.initialized_pipelines[pipeline_class] = pipeline_class(
                 pipeline_options=pipeline_options
             )
-        return self.initialized_pipelines[pipeline_class]
+        else:
+            _log.debug(
+                f"Reusing cached pipeline for {pipeline_class.__name__} with options hash {options_hash}"
+            )
+
+        return self.initialized_pipelines[cache_key]
 
     def _process_document(
         self, in_doc: InputDocument, raises_on_error: bool
     ) -> ConversionResult:
-
         valid = (
             self.allowed_formats is not None and in_doc.format in self.allowed_formats
         )
@@ -345,7 +358,6 @@ class DocumentConverter:
         else:
             if raises_on_error:
                 raise ConversionError(f"Input document {in_doc.file} is not valid.")
-
             else:
                 # invalid doc or not of desired format
                 conv_res = ConversionResult(