Allow max shard size to be specified when saving pipeline (#9440)

allow max shard size to be specified when saving pipeline

src/diffusers/pipelines/pipeline_utils.py

@@ -189,6 +189,7 @@ class DiffusionPipeline(ConfigMixin, PushToHubMixin):
         save_directory: Union[str, os.PathLike],
         safe_serialization: bool = True,
         variant: Optional[str] = None,
+        max_shard_size: Union[int, str] = "10GB",
         push_to_hub: bool = False,
         **kwargs,
     ):
@@ -204,6 +205,13 @@ class DiffusionPipeline(ConfigMixin, PushToHubMixin):
                 Whether to save the model using `safetensors` or the traditional PyTorch way with `pickle`.
             variant (`str`, *optional*):
                 If specified, weights are saved in the format `pytorch_model.<variant>.bin`.
+            max_shard_size (`int` or `str`, defaults to `"10GB"`):
+                The maximum size for a checkpoint before being sharded. Checkpoints shard will then be each of size
+                lower than this size. If expressed as a string, needs to be digits followed by a unit (like `"5GB"`).
+                If expressed as an integer, the unit is bytes. Note that this limit will be decreased after a certain
+                period of time (starting from Oct 2024) to allow users to upgrade to the latest version of `diffusers`.
+                This is to establish a common default size for this argument across different libraries in the Hugging
+                Face ecosystem (`transformers`, and `accelerate`, for example).
             push_to_hub (`bool`, *optional*, defaults to `False`):
                 Whether or not to push your model to the Hugging Face model hub after saving it. You can specify the
                 repository you want to push to with `repo_id` (will default to the name of `save_directory` in your
@@ -278,12 +286,15 @@ class DiffusionPipeline(ConfigMixin, PushToHubMixin):
             save_method_signature = inspect.signature(save_method)
             save_method_accept_safe = "safe_serialization" in save_method_signature.parameters
             save_method_accept_variant = "variant" in save_method_signature.parameters
+            save_method_accept_max_shard_size = "max_shard_size" in save_method_signature.parameters
 
             save_kwargs = {}
             if save_method_accept_safe:
                 save_kwargs["safe_serialization"] = safe_serialization
             if save_method_accept_variant:
                 save_kwargs["variant"] = variant
+            if save_method_accept_max_shard_size:
+                save_kwargs["max_shard_size"] = max_shard_size
 
             save_method(os.path.join(save_directory, pipeline_component_name), **save_kwargs)