feat(mm): add algorithm prefix to hashes

For example:
- md5:a0cd925fc063f98dbf029eee315060c3
- sha1:9e362940e5603fdc60566ea100a288ba2fe48b8c
- blake3:ce3f0c5f3c05d119f4a5dcaf209b50d3149046a0d3a9adee9fed4c83cad6b4d0

invokeai/backend/model_hash/model_hash.py

@@ -33,7 +33,7 @@ MODEL_FILE_EXTENSIONS = (".ckpt", ".safetensors", ".bin", ".pt", ".pth")
 
 class ModelHash:
     """
-    Creates a hash of a model using a specified algorithm.
+    Creates a hash of a model using a specified algorithm. The hash is prefixed by the algorithm used.
 
     Args:
         algorithm: Hashing algorithm to use. Defaults to BLAKE3.
@@ -53,15 +53,17 @@ class ModelHash:
     Usage:
         ```py
         # BLAKE3 hash
-        ModelHash().hash("path/to/some/model.safetensors")
+        ModelHash().hash("path/to/some/model.safetensors") # "blake3:ce3f0c5f3c05d119f4a5dcaf209b50d3149046a0d3a9adee9fed4c83cad6b4d0"
         # MD5
-        ModelHash("md5").hash("path/to/model/dir/")
+        ModelHash("md5").hash("path/to/model/dir/") # "md5:a0cd925fc063f98dbf029eee315060c3"
         ```
     """
 
     def __init__(
         self, algorithm: HASHING_ALGORITHMS = "blake3", file_filter: Optional[Callable[[str], bool]] = None
     ) -> None:
+        # The extra type annotation here is necessary for pyright to understand that algorithm is a Literal type
+        self.algorithm: HASHING_ALGORITHMS = algorithm
         if algorithm == "blake3":
             self._hash_file = self._blake3
         elif algorithm == "blake3_single":
@@ -90,10 +92,12 @@ class ModelHash:
         """
 
         model_path = Path(model_path)
+        # blake3_single is a single-threaded version of blake3, prefix should still be "blake3:"
+        prefix = self._get_prefix(self.algorithm)
         if model_path.is_file():
-            return self._hash_file(model_path)
+            return prefix + self._hash_file(model_path)
         elif model_path.is_dir():
-            return self._hash_dir(model_path)
+            return prefix + self._hash_dir(model_path)
         else:
             raise OSError(f"Not a valid file or directory: {model_path}")
 
@@ -117,6 +121,7 @@ class ModelHash:
         composite_hasher = blake3()
         for h in component_hashes:
             composite_hasher.update(h.encode("utf-8"))
+
         return composite_hasher.hexdigest()
 
     @staticmethod
@@ -207,3 +212,9 @@ class ModelHash:
             True if the file matches the given extensions, otherwise False
         """
         return file_path.endswith(MODEL_FILE_EXTENSIONS)
+
+    @staticmethod
+    def _get_prefix(algorithm: HASHING_ALGORITHMS) -> str:
+        """Return the prefix for the given algorithm, e.g. \"blake3:\" or \"md5:\"."""
+        # blake3_single is a single-threaded version of blake3, prefix should still be "blake3:"
+        return "blake3:" if algorithm == "blake3_single" else f"{algorithm}:"