is_safetensors_compatible refactor (#2499)

* is_safetensors_compatible refactor

* files list comma

src/diffusers/pipelines/pipeline_utils.py

@@ -129,21 +129,49 @@ class AudioPipelineOutput(BaseOutput):
 
 
 def is_safetensors_compatible(filenames, variant=None) -> bool:
-    pt_filenames = set(filename for filename in filenames if filename.endswith(".bin"))
-    is_safetensors_compatible = any(file.endswith(".safetensors") for file in filenames)
-
-    for pt_filename in pt_filenames:
-        _variant = f".{variant}" if (variant is not None and variant in pt_filename) else ""
-        prefix, raw = os.path.split(pt_filename)
-        if raw == f"pytorch_model{_variant}.bin":
-            # transformers specific
-            sf_filename = os.path.join(prefix, f"model{_variant}.safetensors")
+    """
+    Checking for safetensors compatibility:
+    - By default, all models are saved with the default pytorch serialization, so we use the list of default pytorch
+      files to know which safetensors files are needed.
+    - The model is safetensors compatible only if there is a matching safetensors file for every default pytorch file.
+
+    Converting default pytorch serialized filenames to safetensors serialized filenames:
+    - For models from the diffusers library, just replace the ".bin" extension with ".safetensors"
+    - For models from the transformers library, the filename changes from "pytorch_model" to "model", and the ".bin"
+      extension is replaced with ".safetensors"
+    """
+    pt_filenames = []
+
+    sf_filenames = set()
+
+    for filename in filenames:
+        _, extension = os.path.splitext(filename)
+
+        if extension == ".bin":
+            pt_filenames.append(filename)
+        elif extension == ".safetensors":
+            sf_filenames.add(filename)
+
+    for filename in pt_filenames:
+        #  filename = 'foo/bar/baz.bam' -> path = 'foo/bar', filename = 'baz', extention = '.bam'
+        path, filename = os.path.split(filename)
+        filename, extension = os.path.splitext(filename)
+
+        if filename == "pytorch_model":
+            filename = "model"
+        elif filename == f"pytorch_model.{variant}":
+            filename = f"model.{variant}"
         else:
-            sf_filename = pt_filename[: -len(".bin")] + ".safetensors"
-        if is_safetensors_compatible and sf_filename not in filenames:
-            logger.warning(f"{sf_filename} not found")
-            is_safetensors_compatible = False
-    return is_safetensors_compatible
+            filename = filename
+
+        expected_sf_filename = os.path.join(path, filename)
+        expected_sf_filename = f"{expected_sf_filename}.safetensors"
+
+        if expected_sf_filename not in sf_filenames:
+            logger.warning(f"{expected_sf_filename} not found")
+            return False
+
+    return True
 
 
 def variant_compatible_siblings(info, variant=None) -> Union[List[os.PathLike], str]:

tests/pipelines/test_pipeline_utils.py

+import unittest
+
+from diffusers.pipelines.pipeline_utils import is_safetensors_compatible
+
+
+class IsSafetensorsCompatibleTests(unittest.TestCase):
+    def test_all_is_compatible(self):
+        filenames = [
+            "safety_checker/pytorch_model.bin",
+            "safety_checker/model.safetensors",
+            "vae/diffusion_pytorch_model.bin",
+            "vae/diffusion_pytorch_model.safetensors",
+            "text_encoder/pytorch_model.bin",
+            "text_encoder/model.safetensors",
+            "unet/diffusion_pytorch_model.bin",
+            "unet/diffusion_pytorch_model.safetensors",
+        ]
+        self.assertTrue(is_safetensors_compatible(filenames))
+
+    def test_diffusers_model_is_compatible(self):
+        filenames = [
+            "unet/diffusion_pytorch_model.bin",
+            "unet/diffusion_pytorch_model.safetensors",
+        ]
+        self.assertTrue(is_safetensors_compatible(filenames))
+
+    def test_diffusers_model_is_not_compatible(self):
+        filenames = [
+            "safety_checker/pytorch_model.bin",
+            "safety_checker/model.safetensors",
+            "vae/diffusion_pytorch_model.bin",
+            "vae/diffusion_pytorch_model.safetensors",
+            "text_encoder/pytorch_model.bin",
+            "text_encoder/model.safetensors",
+            "unet/diffusion_pytorch_model.bin",
+            # Removed: 'unet/diffusion_pytorch_model.safetensors',
+        ]
+        self.assertFalse(is_safetensors_compatible(filenames))
+
+    def test_transformer_model_is_compatible(self):
+        filenames = [
+            "text_encoder/pytorch_model.bin",
+            "text_encoder/model.safetensors",
+        ]
+        self.assertTrue(is_safetensors_compatible(filenames))
+
+    def test_transformer_model_is_not_compatible(self):
+        filenames = [
+            "safety_checker/pytorch_model.bin",
+            "safety_checker/model.safetensors",
+            "vae/diffusion_pytorch_model.bin",
+            "vae/diffusion_pytorch_model.safetensors",
+            "text_encoder/pytorch_model.bin",
+            # Removed: 'text_encoder/model.safetensors',
+            "unet/diffusion_pytorch_model.bin",
+            "unet/diffusion_pytorch_model.safetensors",
+        ]
+        self.assertFalse(is_safetensors_compatible(filenames))
+
+    def test_all_is_compatible_variant(self):
+        filenames = [
+            "safety_checker/pytorch_model.fp16.bin",
+            "safety_checker/model.fp16.safetensors",
+            "vae/diffusion_pytorch_model.fp16.bin",
+            "vae/diffusion_pytorch_model.fp16.safetensors",
+            "text_encoder/pytorch_model.fp16.bin",
+            "text_encoder/model.fp16.safetensors",
+            "unet/diffusion_pytorch_model.fp16.bin",
+            "unet/diffusion_pytorch_model.fp16.safetensors",
+        ]
+        variant = "fp16"
+        self.assertTrue(is_safetensors_compatible(filenames, variant=variant))
+
+    def test_diffusers_model_is_compatible_variant(self):
+        filenames = [
+            "unet/diffusion_pytorch_model.fp16.bin",
+            "unet/diffusion_pytorch_model.fp16.safetensors",
+        ]
+        variant = "fp16"
+        self.assertTrue(is_safetensors_compatible(filenames, variant=variant))
+
+    def test_diffusers_model_is_compatible_variant_partial(self):
+        # pass variant but use the non-variant filenames
+        filenames = [
+            "unet/diffusion_pytorch_model.bin",
+            "unet/diffusion_pytorch_model.safetensors",
+        ]
+        variant = "fp16"
+        self.assertTrue(is_safetensors_compatible(filenames, variant=variant))
+
+    def test_diffusers_model_is_not_compatible_variant(self):
+        filenames = [
+            "safety_checker/pytorch_model.fp16.bin",
+            "safety_checker/model.fp16.safetensors",
+            "vae/diffusion_pytorch_model.fp16.bin",
+            "vae/diffusion_pytorch_model.fp16.safetensors",
+            "text_encoder/pytorch_model.fp16.bin",
+            "text_encoder/model.fp16.safetensors",
+            "unet/diffusion_pytorch_model.fp16.bin",
+            # Removed: 'unet/diffusion_pytorch_model.fp16.safetensors',
+        ]
+        variant = "fp16"
+        self.assertFalse(is_safetensors_compatible(filenames, variant=variant))
+
+    def test_transformer_model_is_compatible_variant(self):
+        filenames = [
+            "text_encoder/pytorch_model.fp16.bin",
+            "text_encoder/model.fp16.safetensors",
+        ]
+        variant = "fp16"
+        self.assertTrue(is_safetensors_compatible(filenames, variant=variant))
+
+    def test_transformer_model_is_compatible_variant_partial(self):
+        # pass variant but use the non-variant filenames
+        filenames = [
+            "text_encoder/pytorch_model.bin",
+            "text_encoder/model.safetensors",
+        ]
+        variant = "fp16"
+        self.assertTrue(is_safetensors_compatible(filenames, variant=variant))
+
+    def test_transformer_model_is_not_compatible_variant(self):
+        filenames = [
+            "safety_checker/pytorch_model.fp16.bin",
+            "safety_checker/model.fp16.safetensors",
+            "vae/diffusion_pytorch_model.fp16.bin",
+            "vae/diffusion_pytorch_model.fp16.safetensors",
+            "text_encoder/pytorch_model.fp16.bin",
+            # 'text_encoder/model.fp16.safetensors',
+            "unet/diffusion_pytorch_model.fp16.bin",
+            "unet/diffusion_pytorch_model.fp16.safetensors",
+        ]
+        variant = "fp16"
+        self.assertFalse(is_safetensors_compatible(filenames, variant=variant))