First commit

pkgs/xformers/components/feedforward/__init__.py

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+# Copyright (c) Facebook, Inc. and its affiliates. All rights reserved.
+#
+# This source code is licensed under the BSD license found in the
+# LICENSE file in the root directory of this source tree.
+
+
+from pathlib import Path
+from typing import Any, Callable, Dict, Set, Union
+
+from xformers.utils import (
+    generate_matching_config,
+    get_registry_decorator,
+    import_all_modules,
+)
+
+from .base import Feedforward, FeedforwardConfig  # noqa
+
+# CREDITS: Classy Vision registry mechanism
+
+FEEDFORWARD_REGISTRY: Dict[str, Any] = {}
+FEEDFORWARD_CLASS_NAMES: Set[str] = set()
+
+
+def build_feedforward(config: Union[Dict[str, Any], FeedforwardConfig]):
+    """Builds a feedforward from a config.
+
+    This assumes a 'name' key in the config which is used to determine what
+    attention class to instantiate. For instance, a config `{"name": "my_feedforward",
+    "foo": "bar"}` will find a class that was registered as "my_feedforward"
+    (see :func:`register_feedforward`) and call .from_config on it."""
+
+    if not isinstance(config, FeedforwardConfig):
+        config_instance = generate_matching_config(
+            config, FEEDFORWARD_REGISTRY[config["name"]].config
+        )
+    else:
+        config_instance = config
+
+    return FEEDFORWARD_REGISTRY[config_instance.name].constructor.from_config(
+        config_instance
+    )
+
+
+"""Registers a Feedforward subclass.
+
+    This decorator allows xFormers to instantiate a subclass of Feedforward
+    from a configuration file, even if the class itself is not part of the
+    xFormers framework. To use it, apply this decorator to a Feedforward
+    subclass, like this:
+
+    .. code-block:: python
+
+        @dataclass
+        class MyConfig:
+            ...
+
+        @register_feedforward('my_ff', MyConfig)
+        class MyFeedforward(Feedforward):
+            ...
+
+    To instantiate a feedforward from a configuration file, see :func:`build_feedforward`."""
+register_feedforward: Callable[
+    [str, Any], Callable[[Any], Any]
+] = get_registry_decorator(
+    FEEDFORWARD_REGISTRY, FEEDFORWARD_CLASS_NAMES, Feedforward, FeedforwardConfig
+)
+
+try:
+    from .fused_mlp import FusedMLP  # noqa
+
+    _fused_mlp_available = True
+except ImportError:
+    _fused_mlp_available = False
+from .mlp import MLP  # noqa
+
+__all__ = [
+    "MLP",
+    "Feedforward",
+    "build_feedforward",
+    "register_feedforward",
+]
+
+if _fused_mlp_available:
+    __all__ += ["FusedMLP"]
+
+# automatically import any Python files in the directory
+import_all_modules(str(Path(__file__).parent), "xformers.components.feedforward")