chore: import upstream snapshot with attribution

decoding/GAD/fairseq/incremental_decoding_utils.py

@@ -0,0 +1,51 @@
+# Copyright (c) Facebook, Inc. and its affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+import uuid
+from typing import Dict, Optional
+
+from torch import Tensor
+
+
+class FairseqIncrementalState(object):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.init_incremental_state()
+
+    def init_incremental_state(self):
+        self._incremental_state_id = str(uuid.uuid4())
+
+    def _get_full_incremental_state_key(self, key: str) -> str:
+        return "{}.{}".format(self._incremental_state_id, key)
+
+    def get_incremental_state(
+        self,
+        incremental_state: Optional[Dict[str, Dict[str, Optional[Tensor]]]],
+        key: str,
+    ) -> Optional[Dict[str, Optional[Tensor]]]:
+        """Helper for getting incremental state for an nn.Module."""
+        full_key = self._get_full_incremental_state_key(key)
+        if incremental_state is None or full_key not in incremental_state:
+            return None
+        return incremental_state[full_key]
+
+    def set_incremental_state(
+        self,
+        incremental_state: Optional[Dict[str, Dict[str, Optional[Tensor]]]],
+        key: str,
+        value: Dict[str, Optional[Tensor]],
+    ) -> Optional[Dict[str, Dict[str, Optional[Tensor]]]]:
+        """Helper for setting incremental state for an nn.Module."""
+        if incremental_state is not None:
+            full_key = self._get_full_incremental_state_key(key)
+            incremental_state[full_key] = value
+        return incremental_state
+
+
+def with_incremental_state(cls):
+    cls.__bases__ = (FairseqIncrementalState,) + tuple(
+        b for b in cls.__bases__ if b != FairseqIncrementalState
+    )
+    return cls