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# 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.
"""
OFA
"""
from typing import Optional
import logging
import torch
import torch.nn as nn
import torch.nn.functional as F
from fairseq import utils
from fairseq.models import register_model, register_model_architecture
from fairseq.modules.transformer_sentence_encoder import init_bert_params
from .unify_transformer import TransformerModel
logger = logging.getLogger(__name__)
@register_model("ofa")
class OFAModel(TransformerModel):
__jit_unused_properties__ = ["supported_targets"]
def __init__(self, args, encoder, decoder):
super().__init__(args, encoder, decoder)
# We follow BERT's random weight initialization
self.apply(init_bert_params)
self.classification_heads = nn.ModuleDict()
if hasattr(self.encoder, "dictionary"):
self.eos: int = self.encoder.dictionary.eos()
@staticmethod
def add_args(parser):
super(OFAModel, OFAModel).add_args(parser)
parser.add_argument(
"--pooler-dropout",
type=float,
metavar="D",
help="dropout probability in the masked_lm pooler layers",
)
parser.add_argument(
"--pooler-classifier",
type=str,
choices=['mlp', 'linear'],
help="type of pooler classifier",
)
parser.add_argument(
"--pooler-activation-fn",
choices=utils.get_available_activation_fns(),
help="activation function to use for pooler layer",
)
parser.add_argument(
"--spectral-norm-classification-head",
action="store_true",
help="Apply spectral normalization on the classification head",
)
@property
def supported_targets(self):
return {"self"}
def forward(
self,
src_tokens,
src_lengths,
prev_output_tokens,
patch_images: Optional[torch.Tensor] = None,
patch_images_2: Optional[torch.Tensor] = None,
patch_masks: Optional[torch.Tensor] = None,
code_masks: Optional[torch.Tensor] = None,
sample_patch_num: Optional[int] = None,
features_only: bool = False,
classification_head_name: Optional[str] = None,
token_embeddings: Optional[torch.Tensor] = None,
return_all_hiddens: bool = False,
alignment_layer: Optional[int] = None,
alignment_heads: Optional[int] = None,
):
if classification_head_name is not None:
features_only = True
encoder_out = self.encoder(
src_tokens,
src_lengths=src_lengths,
patch_images=patch_images,
patch_masks=patch_masks,
patch_images_2=patch_images_2,
token_embeddings=token_embeddings,
return_all_hiddens=return_all_hiddens,
sample_patch_num=sample_patch_num
)
x, extra = self.decoder(
prev_output_tokens,
code_masks=code_masks,
encoder_out=encoder_out,
features_only=features_only,
alignment_layer=alignment_layer,
alignment_heads=alignment_heads,
src_lengths=src_lengths,
return_all_hiddens=return_all_hiddens,
)
pad = self.encoder.padding_idx
if classification_head_name is not None:
prev_lengths = prev_output_tokens.ne(pad).sum(1)
gather_index = prev_lengths[:, None, None].expand(x.size(0), 1, x.size(2)) - 1
sentence_representation = x.gather(1, gather_index).squeeze()
if self.classification_heads[classification_head_name].use_two_images:
hidden_size = sentence_representation.size(1)
sentence_representation = sentence_representation.view(-1, hidden_size * 2)
for k, head in self.classification_heads.items():
# for torch script only supports iteration
if k == classification_head_name:
x = head(sentence_representation)
break
return x, extra
def register_embedding_tokens(self, ans2label_dict, src_dict, bpe):
"""Register embedding tokens"""
logger.info("Registering embedding tokens")
self.ans_tensor_list = []
for i in range(len(ans2label_dict)):
ans = src_dict[-len(ans2label_dict)+i]
ans = ans[5:-1].replace('_', ' ')
ans_tensor = src_dict.encode_line(
line=bpe.encode(' {}'.format(ans.lower())),
add_if_not_exist=False,
append_eos=False
).long()
self.ans_tensor_list.append(ans_tensor)
def register_classification_head(
self, name, num_classes=None, inner_dim=None, use_two_images=False, **kwargs
):
"""Register a classification head."""
logger.info("Registering classification head: {0}".format(name))
if name in self.classification_heads:
prev_num_classes = self.classification_heads[name].out_proj.out_features
prev_inner_dim = self.classification_heads[name].dense.out_features
if num_classes != prev_num_classes or inner_dim != prev_inner_dim:
logger.warning(
're-registering head "{}" with num_classes {} (prev: {}) '
"and inner_dim {} (prev: {})".format(
name, num_classes, prev_num_classes, inner_dim, prev_inner_dim
)
)
self.classification_heads[name] = OFAClassificationHead(
input_dim=self.args.encoder_embed_dim,
inner_dim=inner_dim or self.args.encoder_embed_dim,
num_classes=num_classes,
activation_fn=self.args.pooler_activation_fn,
pooler_dropout=self.args.pooler_dropout,
pooler_classifier=self.args.pooler_classifier,
use_two_images=use_two_images,
do_spectral_norm=getattr(
self.args, "spectral_norm_classification_head", False
),
)
def upgrade_state_dict_named(self, state_dict, name):
super().upgrade_state_dict_named(state_dict, name)
prefix = name + "." if name != "" else ""
current_head_names = (
[]
if not hasattr(self, "classification_heads")
else self.classification_heads.keys()
)
# Handle new classification heads present in the state dict.
keys_to_delete = []
for k in state_dict.keys():
if not k.startswith(prefix + "classification_heads."):
continue
head_name = k[len(prefix + "classification_heads.") :].split(".")[0]
num_classes = state_dict[
prefix + "classification_heads." + head_name + ".out_proj.weight"
].size(0)
inner_dim = state_dict[
prefix + "classification_heads." + head_name + ".dense.weight"
].size(0)
if getattr(self.args, "load_checkpoint_heads", False):
if head_name not in current_head_names:
self.register_classification_head(head_name, num_classes, inner_dim)
else:
if head_name not in current_head_names:
logger.warning(
"deleting classification head ({}) from checkpoint "
"not present in current model: {}".format(head_name, k)
)
keys_to_delete.append(k)
elif (
num_classes
!= self.classification_heads[head_name].out_proj.out_features
or inner_dim
!= self.classification_heads[head_name].dense.out_features
):
logger.warning(
"deleting classification head ({}) from checkpoint "
"with different dimensions than current model: {}".format(
head_name, k
)
)
keys_to_delete.append(k)
for k in keys_to_delete:
del state_dict[k]
def truncate_emb(key):
if key in state_dict:
state_dict[key] = state_dict[key][:-1, :]
# When finetuning on translation task, remove last row of
# embedding matrix that corresponds to mask_idx token.
loaded_dict_size = state_dict["encoder.embed_tokens.weight"].size(0)
if (
loaded_dict_size == len(self.encoder.dictionary) + 1
and "<mask>" not in self.encoder.dictionary
):
truncate_emb("encoder.embed_tokens.weight")
truncate_emb("decoder.embed_tokens.weight")
truncate_emb("encoder.output_projection.weight")
truncate_emb("decoder.output_projection.weight")
if loaded_dict_size < len(self.encoder.dictionary):
num_langids_to_add = len(self.encoder.dictionary) - loaded_dict_size
embed_dim = state_dict["encoder.embed_tokens.weight"].size(1)
new_lang_embed_to_add = torch.zeros(num_langids_to_add, embed_dim)
if getattr(self, "ans_tensor_list", None):
assert len(new_lang_embed_to_add) == len(self.ans_tensor_list)
for i, ans_tensor in enumerate(self.ans_tensor_list):
ans_embed = F.embedding(ans_tensor, state_dict["encoder.embed_tokens.weight"])
ans_embed = ans_embed.sum(0) / ans_embed.size(0)
new_lang_embed_to_add[i] = ans_embed
else:
nn.init.normal_(new_lang_embed_to_add, mean=0, std=embed_dim ** -0.5)
new_lang_embed_to_add = new_lang_embed_to_add.to(
dtype=state_dict["encoder.embed_tokens.weight"].dtype,
)
state_dict["encoder.embed_tokens.weight"] = torch.cat(
[state_dict["encoder.embed_tokens.weight"], new_lang_embed_to_add]
)
state_dict["decoder.embed_tokens.weight"] = torch.cat(
[state_dict["decoder.embed_tokens.weight"], new_lang_embed_to_add]
)
state_dict["decoder.output_projection.weight"] = torch.cat(
[state_dict["decoder.output_projection.weight"], new_lang_embed_to_add]
)
# Copy any newly-added classification heads into the state dict
# with their current weights.
if hasattr(self, "classification_heads"):
cur_state = self.classification_heads.state_dict()
for k, v in cur_state.items():
if prefix + "classification_heads." + k not in state_dict:
logger.info("Overwriting " + prefix + "classification_heads." + k)
state_dict[prefix + "classification_heads." + k] = v
class OFAClassificationHead(nn.Module):
"""Head for sentence-level classification tasks."""
def __init__(
self,
input_dim,
inner_dim,
num_classes,
activation_fn,
pooler_dropout,
pooler_classifier,
use_two_images=False,
do_spectral_norm=False,
):
super().__init__()
self.pooler_classifier = pooler_classifier
self.use_two_images = use_two_images
input_dim = input_dim * 2 if use_two_images else input_dim
if pooler_classifier == "mlp":
self.dense = nn.Linear(input_dim, inner_dim)
self.activation_fn = utils.get_activation_fn(activation_fn)
self.dropout = nn.Dropout(p=pooler_dropout)
self.out_proj = nn.Linear(inner_dim, num_classes)
elif pooler_classifier == "linear":
self.dropout = nn.Dropout(p=pooler_dropout)
self.out_proj = nn.Linear(input_dim, num_classes)
else:
raise NotImplementedError
if do_spectral_norm:
self.out_proj = torch.nn.utils.spectral_norm(self.out_proj)
def forward(self, features, **kwargs):
if self.pooler_classifier == 'mlp':
x = features
x = self.dropout(x)
x = self.dense(x)
x = self.activation_fn(x)
x = self.dropout(x)
x = self.out_proj(x)
elif self.pooler_classifier == 'linear':
x = features
x = self.dropout(x)
x = self.out_proj(x)
else:
raise NotImplementedError
return x
@register_model_architecture("ofa", "ofa_large")
def ofa_large_architecture(args):
args.encoder_embed_path = getattr(args, "encoder_embed_path", None)
args.encoder_embed_dim = getattr(args, "encoder_embed_dim", 1024)
args.encoder_ffn_embed_dim = getattr(args, "encoder_ffn_embed_dim", 4 * 1024)
args.encoder_layers = getattr(args, "encoder_layers", 12)
args.encoder_attention_heads = getattr(args, "encoder_attention_heads", 16)
args.encoder_normalize_before = getattr(args, "encoder_normalize_before", True)
args.encoder_learned_pos = getattr(args, "encoder_learned_pos", True)
args.decoder_embed_path = getattr(args, "decoder_embed_path", None)
args.decoder_embed_dim = getattr(args, "decoder_embed_dim", args.encoder_embed_dim)
args.decoder_ffn_embed_dim = getattr(
args, "decoder_ffn_embed_dim", args.encoder_ffn_embed_dim
)
args.decoder_layers = getattr(args, "decoder_layers", 12)
args.decoder_attention_heads = getattr(args, "decoder_attention_heads", 16)
args.decoder_normalize_before = getattr(args, "decoder_normalize_before", True)
args.decoder_learned_pos = getattr(args, "decoder_learned_pos", True)
args.attention_dropout = getattr(args, "attention_dropout", 0.0)
args.relu_dropout = getattr(args, "relu_dropout", 0.0)
args.dropout = getattr(args, "dropout", 0.0)
args.max_target_positions = getattr(args, "max_target_positions", 1024)
args.max_source_positions = getattr(args, "max_source_positions", 1024)
args.adaptive_softmax_cutoff = getattr(args, "adaptive_softmax_cutoff", None)
args.adaptive_softmax_dropout = getattr(args, "adaptive_softmax_dropout", 0)
args.share_decoder_input_output_embed = getattr(
args, "share_decoder_input_output_embed", True
)
args.share_all_embeddings = getattr(args, "share_all_embeddings", True)
args.decoder_output_dim = getattr(
args, "decoder_output_dim", args.decoder_embed_dim
)
args.decoder_input_dim = getattr(args, "decoder_input_dim", args.decoder_embed_dim)
args.no_scale_embedding = getattr(args, "no_scale_embedding", True)
args.layernorm_embedding = getattr(args, "layernorm_embedding", True)
args.activation_fn = getattr(args, "activation_fn", "gelu")
args.pooler_activation_fn = getattr(args, "pooler_activation_fn", "tanh")
args.pooler_dropout = getattr(args, "pooler_dropout", 0.0)
args.pooler_classifier = getattr(args, "pooler_classifier", "mlp")
args.resnet_drop_path_rate = getattr(args, "resnet_drop_path_rate", 0.0)
args.encoder_drop_path_rate = getattr(args, "encoder_drop_path_rate", 0.0)
args.decoder_drop_path_rate = getattr(args, "decoder_drop_path_rate", 0.0)
args.resnet_type = getattr(args, "resnet_type", "resnet152")
args.token_bucket_size = getattr(args, "token_bucket_size", 256)
args.image_bucket_size = getattr(args, "image_bucket_size", 42)
args.freeze_encoder_embedding = getattr(args, "freeze_encoder_embedding", False)
args.freeze_decoder_embedding = getattr(args, "freeze_decoder_embedding", False)
args.add_type_embedding = getattr(args, "add_type_embedding", True)
args.attn_scale_factor = getattr(args, "attn_scale_factor", 2)
args.code_image_size = getattr(args, "code_image_size", 128)
args.patch_layernorm_embedding = getattr(args, "patch_layernorm_embedding", True)
args.code_layernorm_embedding = getattr(args, "code_layernorm_embedding", True)
args.entangle_position_embedding = getattr(args, "entangle_position_embedding", False)
args.disable_entangle = getattr(args, "disable_entangle", False)
args.sync_bn = getattr(args, "sync_bn", False)
args.scale_attn = getattr(args, "scale_attn", False)
args.scale_fc = getattr(args, "scale_fc", False)
args.scale_heads = getattr(args, "scale_heads", False)
args.scale_resids = getattr(args, "scale_resids", False)
@register_model_architecture("ofa", "ofa_base")
def ofa_base_architecture(args):
args.encoder_embed_dim = getattr(args, "encoder_embed_dim", 768)
args.encoder_ffn_embed_dim = getattr(args, "encoder_ffn_embed_dim", 4 * 768)
args.encoder_layers = getattr(args, "encoder_layers", 6)
args.encoder_attention_heads = getattr(args, "encoder_attention_heads", 12)
args.decoder_layers = getattr(args, "decoder_layers", 6)
args.decoder_attention_heads = getattr(args, "decoder_attention_heads", 12)
args.resnet_type = getattr(args, "resnet_type", "resnet101")
ofa_large_architecture(args)
@register_model_architecture("ofa", "ofa_huge")
def ofa_huge_architecture(args):
args.encoder_embed_dim = getattr(args, "encoder_embed_dim", 1280)
args.encoder_ffn_embed_dim = getattr(args, "encoder_ffn_embed_dim", 4 * 1280)
args.encoder_layers = getattr(args, "encoder_layers", 24)
args.encoder_attention_heads = getattr(args, "encoder_attention_heads", 16)
args.decoder_layers = getattr(args, "decoder_layers", 12)
args.decoder_attention_heads = getattr(args, "decoder_attention_heads", 16)
args.resnet_type = getattr(args, "resnet_type", "resnet152")
ofa_large_architecture(args)