# 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.
"""isort:skip_file"""
import argparse
import importlib
import os
from argparse import Namespace
from typing import Union
import fairseq
from fairseq.dataclass import FairseqDataclass
from omegaconf import DictConfig, OmegaConf
from .composite_encoder import CompositeEncoder
from .distributed_fairseq_model import DistributedFairseqModel
from .fairseq_decoder import FairseqDecoder
from .fairseq_encoder import FairseqEncoder
from .fairseq_incremental_decoder import FairseqIncrementalDecoder
from .fairseq_model import (
BaseFairseqModel,
FairseqEncoderDecoderModel,
FairseqEncoderModel,
FairseqLanguageModel,
FairseqModel,
FairseqMultiModel,
)
MODEL_REGISTRY = {}
MODEL_DATACLASS_REGISTRY = {}
ARCH_MODEL_REGISTRY = {}
ARCH_MODEL_NAME_REGISTRY = {}
ARCH_MODEL_INV_REGISTRY = {}
ARCH_CONFIG_REGISTRY = {}
__all__ = [
"BaseFairseqModel",
"CompositeEncoder",
"DistributedFairseqModel",
"FairseqDecoder",
"FairseqEncoder",
"FairseqEncoderDecoderModel",
"FairseqEncoderModel",
"FairseqIncrementalDecoder",
"FairseqLanguageModel",
"FairseqModel",
"FairseqMultiModel",
]
def build_model(model_cfg: Union[DictConfig, Namespace], task):
if isinstance(model_cfg, DictConfig):
return ARCH_MODEL_REGISTRY[model_cfg._name].build_model(model_cfg, task)
return ARCH_MODEL_REGISTRY[model_cfg.arch].build_model(model_cfg, task)
[docs]def register_model(name, dataclass=None):
"""
New model types can be added to fairseq with the :func:`register_model`
function decorator.
For example::
@register_model('lstm')
class LSTM(FairseqEncoderDecoderModel):
(...)
.. note:: All models must implement the :class:`BaseFairseqModel` interface.
Typically you will extend :class:`FairseqEncoderDecoderModel` for
sequence-to-sequence tasks or :class:`FairseqLanguageModel` for
language modeling tasks.
Args:
name (str): the name of the model
"""
def register_model_cls(cls):
if name in MODEL_REGISTRY:
raise ValueError("Cannot register duplicate model ({})".format(name))
if not issubclass(cls, BaseFairseqModel):
raise ValueError(
"Model ({}: {}) must extend BaseFairseqModel".format(name, cls.__name__)
)
MODEL_REGISTRY[name] = cls
if dataclass is not None and not issubclass(dataclass, FairseqDataclass):
raise ValueError(
"Dataclass {} must extend FairseqDataclass".format(dataclass)
)
cls.__dataclass = dataclass
MODEL_DATACLASS_REGISTRY[name] = dataclass
return cls
return register_model_cls
[docs]def register_model_architecture(model_name, arch_name):
"""
New model architectures can be added to fairseq with the
:func:`register_model_architecture` function decorator. After registration,
model architectures can be selected with the ``--arch`` command-line
argument.
For example::
@register_model_architecture('lstm', 'lstm_luong_wmt_en_de')
def lstm_luong_wmt_en_de(args):
args.encoder_embed_dim = getattr(args, 'encoder_embed_dim', 1000)
(...)
The decorated function should take a single argument *args*, which is a
:class:`argparse.Namespace` of arguments parsed from the command-line. The
decorated function should modify these arguments in-place to match the
desired architecture.
Args:
model_name (str): the name of the Model (Model must already be
registered)
arch_name (str): the name of the model architecture (``--arch``)
"""
def arch_override_from_yaml(args, arch):
root_dir = os.path.dirname(os.path.dirname(fairseq.__file__))
yaml_path = os.path.join(root_dir, "config/model/{}.yaml".format(arch))
if not os.path.exists(yaml_path):
raise RuntimeError(f"yaml file {yaml_path} does not exist!")
arch_cfg = OmegaConf.load(yaml_path)
for k, v in arch_cfg.items():
setattr(args, k, getattr(args, k, v))
def register_model_arch_fn(fn):
if model_name not in MODEL_REGISTRY:
raise ValueError(
"Cannot register model architecture for unknown model type ({})".format(
model_name
)
)
if arch_name in ARCH_MODEL_REGISTRY:
raise ValueError(
"Cannot register duplicate model architecture ({})".format(arch_name)
)
if not callable(fn):
raise ValueError(
"Model architecture must be callable ({})".format(arch_name)
)
ARCH_MODEL_REGISTRY[arch_name] = MODEL_REGISTRY[model_name]
ARCH_MODEL_NAME_REGISTRY[arch_name] = model_name
ARCH_MODEL_INV_REGISTRY.setdefault(model_name, []).append(arch_name)
if type(fn) is type and issubclass(fn, BaseFairseqModel):
# for model classes migrated with hydra
# in this case, we are using this decorator directly on model class since
# we do not need arch overriding functions.
ARCH_CONFIG_REGISTRY[arch_name] = lambda args: arch_override_from_yaml(
args, arch=arch_name
)
else:
ARCH_CONFIG_REGISTRY[arch_name] = fn
return fn
return register_model_arch_fn
# automatically import any Python files in the models/ directory
models_dir = os.path.dirname(__file__)
for file in os.listdir(models_dir):
path = os.path.join(models_dir, file)
if (
not file.startswith("_")
and not file.startswith(".")
and (file.endswith(".py") or os.path.isdir(path))
):
model_name = file[: file.find(".py")] if file.endswith(".py") else file
module = importlib.import_module("fairseq.models." + model_name)
# extra `model_parser` for sphinx
if model_name in MODEL_REGISTRY:
parser = argparse.ArgumentParser(add_help=False)
group_archs = parser.add_argument_group("Named architectures")
group_archs.add_argument(
"--arch", choices=ARCH_MODEL_INV_REGISTRY[model_name]
)
group_args = parser.add_argument_group("Additional command-line arguments")
MODEL_REGISTRY[model_name].add_args(group_args)
globals()[model_name + "_parser"] = parser