delegate namespace conversion to DC

Summary: `populate_dataclass` is very basic in how it populates the dataclass. We might want more specific behaviour for some config dataclasses (like the hierarchical behaviour in TransformerConfig, see rest of stack). This diff move the populate logic to a `from_namespace` method in `FairseqDataclass` so that the a specific Dataclass can reimplement it.

Reviewed By: myleott

Differential Revision: D29521388

fbshipit-source-id: f3a6dc80e4ddfc9563c6e85c37c563173f193f4d

fairseq/dataclass/configs.py

@@ -79,6 +79,22 @@ def _get_argparse_alias(self, attribute_name: str) -> Any:
     def _get_choices(self, attribute_name: str) -> Any:
         return self._get_meta(attribute_name, "choices")
 
+    @classmethod
+    def from_namespace(cls, args):
+        if isinstance(args, cls):
+            return args
+        else:
+            config = cls()
+            for k in config.__dataclass_fields__.keys():
+                if k.startswith("_"):
+                    # private member, skip
+                    continue
+                if hasattr(args, k):
+                    setattr(config, k, getattr(args, k))
+
+            return config
+
+
 
 @dataclass
 class CommonConfig(FairseqDataclass):

fairseq/dataclass/utils.py

@@ -419,20 +419,6 @@ def convert_namespace_to_omegaconf(args: Namespace) -> DictConfig:
     return cfg
 
 
-def populate_dataclass(
-    dataclass: FairseqDataclass,
-    args: Namespace,
-) -> FairseqDataclass:
-    for k in dataclass.__dataclass_fields__.keys():
-        if k.startswith("_"):
-            # private member, skip
-            continue
-        if hasattr(args, k):
-            setattr(dataclass, k, getattr(args, k))
-
-    return dataclass
-
-
 def overwrite_args_by_name(cfg: DictConfig, overrides: Dict[str, any]):
     # this will be deprecated when we get rid of argparse and model_overrides logic
 

fairseq/models/__init__.py

@@ -10,7 +10,7 @@
 from contextlib import ExitStack
 
 from fairseq.dataclass import FairseqDataclass
-from fairseq.dataclass.utils import merge_with_parent, populate_dataclass
+from fairseq.dataclass.utils import merge_with_parent
 from hydra.core.config_store import ConfigStore
 from omegaconf import open_dict, OmegaConf
 
@@ -84,7 +84,7 @@ def build_model(cfg: FairseqDataclass, task):
         dc = MODEL_DATACLASS_REGISTRY[model_type]
 
         if isinstance(cfg, argparse.Namespace):
-            cfg = populate_dataclass(dc(), cfg)
+            cfg = dc.from_namespace(cfg)
         else:
             cfg = merge_with_parent(dc(), cfg)
     else:

fairseq/registry.py

@@ -7,7 +7,7 @@
 
 from typing import Union
 from fairseq.dataclass import FairseqDataclass
-from fairseq.dataclass.utils import populate_dataclass, merge_with_parent
+from fairseq.dataclass.utils import merge_with_parent
 from hydra.core.config_store import ConfigStore
 from omegaconf import DictConfig
 
@@ -45,7 +45,7 @@ def build_x(cfg: Union[DictConfig, str, Namespace], *extra_args, **extra_kwargs)
         else:
             choice = getattr(cfg, registry_name, None)
             if choice in DATACLASS_REGISTRY:
-                cfg = populate_dataclass(DATACLASS_REGISTRY[choice](), cfg)
+                cfg = DATACLASS_REGISTRY[choice].from_namespace(cfg)
 
         if choice is None:
             if required:

fairseq/tasks/__init__.py

@@ -9,7 +9,7 @@
 import os
 
 from fairseq.dataclass import FairseqDataclass
-from fairseq.dataclass.utils import merge_with_parent, populate_dataclass
+from fairseq.dataclass.utils import merge_with_parent
 from hydra.core.config_store import ConfigStore
 
 from .fairseq_task import FairseqTask, LegacyFairseqTask  # noqa
@@ -30,7 +30,7 @@ def setup_task(cfg: FairseqDataclass, **kwargs):
         task = TASK_REGISTRY[task_name]
         if task_name in TASK_DATACLASS_REGISTRY:
             dc = TASK_DATACLASS_REGISTRY[task_name]
-            cfg = populate_dataclass(dc(), cfg)
+            cfg = dc.from_namespace(cfg)
     else:
         task_name = getattr(cfg, "_name", None)