193 lines
8.0 KiB
Python
193 lines
8.0 KiB
Python
# Copyright (c) Facebook, Inc. and its affiliates.
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#
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# This source code is licensed under the MIT license found in the
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# LICENSE file in the root directory of this source tree.
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import torch
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from fairseq import utils
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from fairseq.iterative_refinement_generator import DecoderOut
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from fairseq.models import register_model, register_model_architecture
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from fairseq.models.nat import FairseqNATModel
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from fairseq.modules.transformer_sentence_encoder import init_bert_params
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import torch
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from fairseq.models.nat.nonautoregressive_transformer import NATransformerEncoder, NATransformerDecoder, NATransformerModel
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import logging
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import random
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from contextlib import contextmanager
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logger = logging.getLogger(__name__)
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@contextmanager
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def torch_seed(seed):
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state = torch.random.get_rng_state()
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state_cuda = torch.cuda.random.get_rng_state()
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torch.manual_seed(seed)
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torch.cuda.manual_seed_all(seed)
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try:
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yield
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finally:
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torch.random.set_rng_state(state)
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torch.cuda.random.set_rng_state(state_cuda)
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@register_model("block")
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class BlockNAT(FairseqNATModel):
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forward_decoder = NATransformerModel.forward_decoder
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initialize_output_tokens = NATransformerModel.initialize_output_tokens
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def __init__(self, args, encoder, decoder):
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super().__init__(args, encoder, decoder)
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@staticmethod
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def add_args(parser):
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FairseqNATModel.add_args(parser)
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parser.add_argument(
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"--src-embedding-copy",
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action="store_true",
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help="copy encoder word embeddings as the initial input of the decoder",
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)
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@classmethod
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def build_encoder(cls, args, tgt_dict, embed_tokens):
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encoder = NATransformerEncoder(args, tgt_dict, embed_tokens)
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if getattr(args, "apply_bert_init", False):
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encoder.apply(init_bert_params)
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return encoder
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@classmethod
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def build_decoder(cls, args, tgt_dict, embed_tokens):
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decoder = NATransformerDecoder(args, tgt_dict, embed_tokens)
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if getattr(args, "apply_bert_init", False):
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decoder.apply(init_bert_params)
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return decoder
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def forward(
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self, src_tokens, src_lengths, prev_output_tokens, tgt_tokens, glat=None, **kwargs
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):
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# encoding
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encoder_out = self.encoder(src_tokens, src_lengths=src_lengths, **kwargs)
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nonpad_positions = tgt_tokens.ne(self.pad)
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mask_positions = prev_output_tokens.eq(self.unk) & nonpad_positions
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mask_lens = (mask_positions).sum(1)
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l2r_positions = prev_output_tokens.ne(self.unk) & prev_output_tokens.ne(self.pad)
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l2r_lens = (l2r_positions).sum(1)
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rand_seed = random.randint(0, 19260817)
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glat_info = None
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if glat and tgt_tokens is not None:
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with torch.no_grad():
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with torch_seed(rand_seed):
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word_ins_out = self.decoder(
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normalize=False,
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prev_output_tokens=prev_output_tokens,
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encoder_out=encoder_out,
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)
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pred_tokens = word_ins_out.argmax(-1)
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same_num = ((pred_tokens == tgt_tokens) & mask_positions).sum(1)
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input_mask = torch.ones_like(nonpad_positions)
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bsz, seq_len = tgt_tokens.size()
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for li in range(bsz):
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target_num = (((mask_lens[li] - same_num[li].sum()).float()) * glat['context_p']).long()
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if target_num > 0:
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input_mask[li].scatter_(dim=0, index=(torch.randperm(mask_lens[li])[:target_num].cuda() +
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l2r_lens[li]).cuda(), value=0)
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input_mask = input_mask.eq(1)
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tgt_mask = input_mask.masked_fill(~mask_positions, False)
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glat_prev_output_tokens = prev_output_tokens.masked_fill(~input_mask, 0) + tgt_tokens.masked_fill(
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input_mask, 0)
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glat_tgt_tokens = tgt_tokens.masked_fill(~tgt_mask, self.pad)
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prev_output_tokens, tgt_tokens = glat_prev_output_tokens, glat_tgt_tokens
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glat_info = {
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"glat_accu": (same_num.sum() / mask_lens.sum()).item(),
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"glat_context_p": glat['context_p'],
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}
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with torch_seed(rand_seed):
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word_ins_out = self.decoder(
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normalize=False,
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prev_output_tokens=prev_output_tokens,
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encoder_out=encoder_out,
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)
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ret = {
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"word_ins": {
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"out": word_ins_out,
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"tgt": tgt_tokens,
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"mask": tgt_tokens.ne(self.pad),
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"ls": self.args.label_smoothing,
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"nll_loss": True,
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}
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}
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if glat_info is not None:
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ret.update(glat_info)
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return ret
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@register_model_architecture(
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"block", "block_6e6d512"
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)
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def base_architecture(args):
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args.encoder_embed_path = getattr(args, "encoder_embed_path", None)
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args.encoder_embed_dim = getattr(args, "encoder_embed_dim", 512)
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args.encoder_ffn_embed_dim = getattr(args, "encoder_ffn_embed_dim", 2048)
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args.encoder_layers = getattr(args, "encoder_layers", 6)
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args.encoder_attention_heads = getattr(args, "encoder_attention_heads", 8)
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args.encoder_normalize_before = getattr(args, "encoder_normalize_before", False)
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args.encoder_learned_pos = getattr(args, "encoder_learned_pos", False)
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args.decoder_embed_path = getattr(args, "decoder_embed_path", None)
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args.decoder_embed_dim = getattr(args, "decoder_embed_dim", args.encoder_embed_dim)
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args.decoder_ffn_embed_dim = getattr(
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args, "decoder_ffn_embed_dim", args.encoder_ffn_embed_dim
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)
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args.decoder_layers = getattr(args, "decoder_layers", 6)
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args.decoder_attention_heads = getattr(args, "decoder_attention_heads", 8)
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args.decoder_normalize_before = getattr(args, "decoder_normalize_before", False)
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args.decoder_learned_pos = getattr(args, "decoder_learned_pos", False)
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args.attention_dropout = getattr(args, "attention_dropout", 0.0)
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args.activation_dropout = getattr(args, "activation_dropout", 0.0)
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args.activation_fn = getattr(args, "activation_fn", "relu")
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args.dropout = getattr(args, "dropout", 0.1)
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args.adaptive_softmax_cutoff = getattr(args, "adaptive_softmax_cutoff", None)
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args.adaptive_softmax_dropout = getattr(args, "adaptive_softmax_dropout", 0)
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args.share_decoder_input_output_embed = getattr(
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args, "share_decoder_input_output_embed", False
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)
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args.share_all_embeddings = getattr(args, "share_all_embeddings", False)
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args.no_token_positional_embeddings = getattr(
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args, "no_token_positional_embeddings", False
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)
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args.adaptive_input = getattr(args, "adaptive_input", False)
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args.apply_bert_init = getattr(args, "apply_bert_init", False)
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args.decoder_output_dim = getattr(
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args, "decoder_output_dim", args.decoder_embed_dim
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)
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args.decoder_input_dim = getattr(args, "decoder_input_dim", args.decoder_embed_dim)
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# --- special arguments ---
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args.src_embedding_copy = getattr(args, "src_embedding_copy", False)
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@register_model_architecture(
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"block", "block"
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)
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def block_architecture(args):
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args.encoder_layers = getattr(args, "encoder_layers", 6)
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args.encoder_embed_dim = getattr(args, "encoder_embed_dim", 512)
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args.encoder_ffn_embed_dim = getattr(args, "encoder_ffn_embed_dim", args.encoder_embed_dim*4)
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args.encoder_attention_heads = getattr(args, "encoder_attention_heads", args.encoder_embed_dim//64)
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args.decoder_layers = getattr(args, "decoder_layers", 6)
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args.decoder_embed_dim = getattr(args, "decoder_embed_dim", 512)
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args.decoder_ffn_embed_dim = getattr(args, "decoder_ffn_embed_dim", args.decoder_embed_dim*4)
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args.decoder_attention_heads = getattr(args, "decoder_attention_heads", args.decoder_embed_dim//64)
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base_architecture(args)
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@register_model_architecture(
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"block", "block_base"
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)
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def base_architecture2(args):
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base_architecture(args)
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