make lm model work
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# coding=utf-8 # Copyright 2020 Huggingface
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import unittest
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import numpy as np
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# trax imports - to be deleted later
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from trax import math as trax_math
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from trax.shapes import ShapeDtype as trax_ShapeDtype
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import jax
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from trax.layers.research.efficient_attention_v2 import (
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LSHSelfAttention as TraxLSHSelfAttention,
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)
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from trax.models.reformer.reformer import DecoderBlock as TraxLSHAttentionBlock
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from trax.models.reformer.reformer import ReformerLM as TraxReformer
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from trax import layers as tl
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from transformers import ReformerAttention, ReformerLayer, ReformerConfig
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from transformers import is_torch_available # noqa: F401
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from .utils import require_torch, torch_device # noqa: F401
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if is_torch_available():
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import torch # noqa: F401
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# from transformers.modeling_reformer import ()
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PATH_TO_SAVE_WEIGHTS = "/home/patrick/hugging_face/experiments/reformer/intermediate_weights"
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class TraxUtils(object):
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""" class that will help for testing in the beginning
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should be deleted step-by-step
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README (HOW-TO-INSTALL TRAX):
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1) git clone https://github.com/patrickvonplaten/trax.git
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- I had to do one tiny change to make the imports work,
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see: https://github.com/patrickvonplaten/trax/commit/6c23e88afe7f1c57b0c38eeaa4d450e5f912590c)
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2) link your PYTHON_PATH to ~/trax/trax
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3) pip install all the missing packages HINT: the package gin is installed
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- HINT: the package gin is installed with pip install gin-config==0.1.4
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and not pip install gin.
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- The other packages can just be installed with pip install <package> form
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error message "<package> missing"
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"""
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def __init__(self, shape):
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self._shape = shape
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def convert_to_jax_array(self, np_array):
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return jax.numpy.asarray(np_array)
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def get_input_signature(self, shape=None, dtype=trax_math.numpy.float32):
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with trax_math.use_backend("jax"):
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if shape is None:
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shape = self._shape
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input_signature = trax_ShapeDtype(shape, dtype)
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return input_signature
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def get_layer(
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self,
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config,
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use_reference_code=True,
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mode="eval",
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path_to_save_weights="/home/patrick/hugging_face/experiments/reformer/intermediate_weights",
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**kwargs
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):
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with trax_math.use_backend("jax"):
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hidden_size_per_head = config.hidden_size // config.num_attention_heads
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layer = TraxLSHSelfAttention(
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n_heads=config.num_attention_heads,
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d_qk=hidden_size_per_head,
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d_v=hidden_size_per_head,
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chunk_len=config.chunk_length,
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n_chunks_before=config.num_chunks_before,
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n_chunks_after=config.num_chunks_after,
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n_hashes=config.num_hashes,
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n_buckets=config.num_buckets,
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attention_dropout=config.attention_probs_dropout_prob,
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output_dropout=config.hidden_dropout_prob,
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hash_seed=config.seed,
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causal=config.is_decoder,
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use_reference_code=use_reference_code,
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mode=mode,
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path_to_save_weights=path_to_save_weights
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)
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return layer
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def forward_layer(
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self,
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np_input_data,
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layer,
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input_signature=None,
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random_number_generator=None,
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):
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with trax_math.use_backend("jax"):
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input_data = self.convert_to_jax_array(np_input_data)
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if input_signature is None:
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input_signature = self.get_input_signature()
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weights, state = layer.init(input_signature)
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if random_number_generator is None:
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random_number_generator = layer.new_rngs(1)[0]
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output = layer(
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input_data, weights=weights, state=state, rng=random_number_generator
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)
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return output, weights, state
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def get_block(
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self,
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config,
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use_reference_code=True,
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share_qk=True,
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ff_use_sru=0,
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mode="eval",
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path_to_save_weights=PATH_TO_SAVE_WEIGHTS,
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):
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with trax_math.use_backend("jax"):
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with jax.disable_jit():
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hidden_size_per_head = config.hidden_size // config.num_attention_heads
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list_of_layers = TraxLSHAttentionBlock(
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d_model=config.d_model,
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d_ff=config.d_ff,
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d_attention_key=hidden_size_per_head,
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d_attention_value=hidden_size_per_head,
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n_heads=config.num_attention_heads,
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n_attention_chunks=config.num_attention_chunks,
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attention_type=tl.LSHSelfAttention,
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dropout=config.hidden_dropout_prob,
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share_qk=share_qk,
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ff_activation=tl.Gelu,
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ff_use_sru=ff_use_sru,
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ff_chunk_size=config.ff_chunk_size,
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mode=mode,
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causal=config.is_decoder,
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chunk_len=config.chunk_length,
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n_chunks_before=config.num_chunks_before,
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n_chunks_after=config.num_chunks_after,
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n_hashes=config.num_hashes,
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n_buckets=config.num_buckets,
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use_reference_code=use_reference_code,
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hash_seed=config.seed,
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path_to_save_weights=path_to_save_weights
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)
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block = tl.Serial(tl.ReversibleSerial([list_of_layers]))
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return block
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def forward_block(
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self,
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np_input_data,
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block,
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input_signature=None,
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random_number_generator=None,
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):
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with trax_math.use_backend("jax"):
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input_data = self.convert_to_jax_array(np_input_data)
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input_data = (input_data,) * 2
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if input_signature is None:
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input_signature = self.get_input_signature()
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input_signature = (input_signature, input_signature)
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weights, state = block.init(input_signature)
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if random_number_generator is None:
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random_number_generator = block.new_rngs(1)[0]
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output = block(
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input_data, weights=weights, state=state, rng=random_number_generator
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)
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return output, weights, state
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def get_model(
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self,
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config,
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use_reference_code=True,
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share_qk=True,
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ff_use_sru=0,
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axial_pos_shape=(),
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d_axial_pos_embs=None,
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mode="eval",
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path_to_save_weights=PATH_TO_SAVE_WEIGHTS,
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):
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with trax_math.use_backend("jax"):
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with jax.disable_jit():
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hidden_size_per_head = config.hidden_size // config.num_attention_heads
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model = TraxReformer(
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vocab_size=config.vocab_size,
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d_model=config.d_model,
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d_ff=config.d_ff,
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d_attention_key=hidden_size_per_head,
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d_attention_value=hidden_size_per_head,
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n_layers=config.num_hidden_layers,
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n_heads=config.num_attention_heads,
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dropout=config.hidden_dropout_prob,
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max_len=config.max_position_embeddings,
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n_chunks=config.num_chunks,
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n_attention_chunks=config.num_attention_chunks,
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attention_type=tl.LSHSelfAttention,
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share_qk=share_qk,
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axial_pos_shape=axial_pos_shape,
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d_axial_pos_embs=d_axial_pos_embs,
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ff_activation=tl.Gelu,
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ff_use_sru=ff_use_sru,
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ff_chunk_size=config.ff_chunk_size,
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mode=mode,
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causal=config.is_decoder,
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chunk_len=config.chunk_length,
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n_chunks_before=config.num_chunks_before,
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n_chunks_after=config.num_chunks_after,
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n_hashes=config.num_hashes,
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n_buckets=config.num_buckets,
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use_reference_code=use_reference_code,
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hash_seed=config.seed,
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path_to_save_weights=path_to_save_weights
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)
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return model
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def forward_model(
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self,
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np_input_data,
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model,
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input_signature=None,
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random_number_generator=None,
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):
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with trax_math.use_backend("jax"):
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input_data = self.convert_to_jax_array(np_input_data)
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input_data = (input_data,) * 2
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if input_signature is None:
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input_signature = self.get_input_signature(dtype=trax_math.numpy.int32)
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input_signature = (input_signature, input_signature)
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weights, state = model.init(input_signature)
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if random_number_generator is None:
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random_number_generator = model.new_rngs(1)[0]
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output = model(
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input_data, weights=weights, state=state, rng=random_number_generator
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)
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return output, weights, state
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@require_torch
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class ReformerIntegrationTests(unittest.TestCase):
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def _set_param(self, torch_layer, weight, bias=None):
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with torch.no_grad():
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assert torch_layer.weight.shape == weight.shape, "{} layer.weight does not match".format(torch.layer)
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torch_layer.weight = torch.nn.Parameter(weight)
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if bias is not None:
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assert torch_layer.bias.shape == bias.shape, "{} layer.bias does not match".format(torch.layer)
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torch_layer.bias = torch.nn.Parameter(bias)
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def _set_layer_weights_in_torch(self, weights, torch_layer, hidden_size):
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# set torch weights for 1-to-1 comparison
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np_query_key = np.asarray(weights[0])
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np_value = np.asarray(weights[1])
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np_dense = np.asarray(weights[2])
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self._set_param(torch_layer.self_attention.query_key, torch.tensor(np_query_key).transpose(1, 2).contiguous().view(-1, hidden_size))
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self._set_param(torch_layer.self_attention.value, torch.tensor(np_value).transpose(1, 2).contiguous().view(-1, hidden_size))
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self._set_param(torch_layer.output.dense, torch.tensor(np_dense).view(-1, hidden_size).contiguous().transpose(0, 1))
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def _set_block_weights_in_torch(self, weights, torch_layer, hidden_size):
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weights = weights[0]
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# layernorm 1
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layer_norm_1 = weights[0][0][0]
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layer_norm_1_weight = np.asarray(layer_norm_1[0])
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layer_norm_1_bias = np.asarray(layer_norm_1[1])
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self._set_param(torch_layer.attention.layer_norm, torch.tensor(layer_norm_1_weight), torch.tensor(layer_norm_1_bias))
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# lsh weights + output
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lsh_weights = weights[0][1]
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self._set_layer_weights_in_torch(lsh_weights, torch_layer.attention, hidden_size)
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# intermediate weighs
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intermediate_weights = weights[2][0][2][2]
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# layernorm 2
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layer_norm_2_weight = np.asarray(intermediate_weights[0][0])
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layer_norm_2_bias = np.asarray(intermediate_weights[0][1])
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self._set_param(torch_layer.feed_forward.layer_norm, torch.tensor(layer_norm_2_weight), torch.tensor(layer_norm_2_bias))
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# intermediate dense
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inter_dense_weight = np.asarray(intermediate_weights[1][0])
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inter_dense_bias = np.asarray(intermediate_weights[1][1])
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self._set_param(torch_layer.feed_forward.dense.dense, torch.tensor(inter_dense_weight).transpose(0, 1).contiguous(), torch.tensor(inter_dense_bias))
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# intermediate out
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out_dense_weight = np.asarray(intermediate_weights[4][0])
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out_dense_bias = np.asarray(intermediate_weights[4][1])
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self._set_param(torch_layer.feed_forward.output.dense, torch.tensor(out_dense_weight).transpose(0, 1).contiguous(), torch.tensor(out_dense_bias))
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def test_lsh_layer(self):
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# Remove residual connection in ReformerSelfOutput to test this layer only
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# Remove layer norm in ReformerAttention to test this layer only
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config = ReformerConfig()
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shape = (2, 7, config.hidden_size) # Batch x SeqLen x hiddenSize
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np_input = np.random.rand(*shape)
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trax_utils = TraxUtils(shape)
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trax_layer = trax_utils.get_layer(config)
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trax_output, trax_weights, trax_state = trax_utils.forward_layer(np_input, layer=trax_layer)
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hf_input = torch.tensor(np_input, dtype=torch.float)
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hf_layer = ReformerAttention(config)
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self._set_layer_weights_in_torch(trax_weights, hf_layer, config.hidden_size)
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hf_layer.eval()
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hf_attention_all_heads = hf_layer.self_attention(hf_input)[0]
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hf_output = hf_layer.output(hf_attention_all_heads, torch.zeros_like(hf_input))
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trax_torch_output = torch.tensor(np.asarray(trax_output))
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self.assertTrue(torch.allclose(hf_output, trax_torch_output, atol=1e-3))
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def test_lsh_block(self):
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config = ReformerConfig()
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shape = (2, 7, config.hidden_size) # Batch x SeqLen x ModelDimPerHead
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np_input = np.random.rand(*shape)
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trax_utils = TraxUtils(shape)
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trax_block = trax_utils.get_block(config)
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trax_output, trax_weights, trax_state = trax_utils.forward_block(np_input, block=trax_block)
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trax_torch_output_1 = torch.tensor(np.asarray(trax_output[0]))
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trax_torch_output_2 = torch.tensor(np.asarray(trax_output[1]))
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hf_input = torch.tensor(np_input, dtype=torch.float)
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hf_block = ReformerLayer(config)
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self._set_block_weights_in_torch(trax_weights, hf_block, config.hidden_size)
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hf_block.eval()
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hf_output_1, hf_output_2 = hf_block(hf_input, hf_input)[:2]
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self.assertTrue(torch.allclose(hf_output_1, trax_torch_output_1, atol=1e-3))
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self.assertTrue(torch.allclose(hf_output_2, trax_torch_output_2, atol=1e-3))
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def test_reformer_model(self):
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config = ReformerConfig()
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shape = (2, 7) # Batch x SeqLen x ModelDimPerHead
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np_input = np.random.randint(0, config.vocab_size, size=shape)
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np_zeros = np.zeros((shape[0], 1), dtype=np.int32)
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import ipdb
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ipdb.set_trace()
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torch_np_input = torch.cat([torch.tensor(np_zeros), torch.tensor(np_input[:, :-1])], dim=-1)
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trax_utils = TraxUtils(shape)
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trax_model = trax_utils.get_model(config)
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trax_output, trax_weights, trax_state = trax_utils.forward_model(np_input, model=trax_model)
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import ipdb
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ipdb.set_trace()
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@@ -1,744 +0,0 @@
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# coding=utf-8
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# Copyright 2018 The Google AI Language Team Authors and The HuggingFace Inc. team.
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# Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""PyTorch REFORMER model. """
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import logging
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import torch
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import numpy as np
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from torch import nn
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from .activations import gelu, gelu_new, swish
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from .configuration_reformer import ReformerConfig
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from .modeling_utils import PreTrainedModel
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# DELETE later
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import numpy
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logger = logging.getLogger(__name__)
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REFORMER_PRETRAINED_MODEL_ARCHIVE_MAP = {}
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# TODO: fill with pretrained model weights
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# "reformer-base-uncased": "https://s3.amazonaws.com/models.huggingface.co/reformer/reformer-base-uncased-pytorch_model.bin",
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# "reformer-large-uncased": "https://s3.amazonaws.com/models.huggingface.co/reformer/reformer-large-uncased-pytorch_model.bin",
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# "reformer-base-cased": "https://s3.amazonaws.com/models.huggingface.co/reformer/reformer-base-cased-pytorch_model.bin",
|
||||
# "reformer-large-cased": "https://s3.amazonaws.com/models.huggingface.co/reformer/reformer-large-cased-pytorch_model.bin",
|
||||
|
||||
PATH_TO_SAVE_WEIGHTS = "/home/patrick/hugging_face/experiments/reformer/intermediate_weights"
|
||||
|
||||
|
||||
def mish(x):
|
||||
return x * torch.tanh(nn.functional.softplus(x))
|
||||
|
||||
|
||||
ACT2FN = {"gelu": gelu, "relu": torch.nn.functional.relu, "swish": swish, "gelu_new": gelu_new, "mish": mish}
|
||||
ReformerLayerNorm = torch.nn.LayerNorm
|
||||
|
||||
|
||||
def create_sinusoidal_embeddings(n_pos, dim, out):
|
||||
position_enc = np.array([[pos / np.power(10000, 2 * (j // 2) / dim) for j in range(dim)] for pos in range(n_pos)])
|
||||
out[:, 0::2] = torch.FloatTensor(np.sin(position_enc[:, 0::2]))
|
||||
out[:, 1::2] = torch.FloatTensor(np.cos(position_enc[:, 1::2]))
|
||||
out.detach_()
|
||||
out.requires_grad = False
|
||||
|
||||
|
||||
class ReformerEmbeddings(nn.Module):
|
||||
"""Construct the embeddings from word, position and token_type embeddings.
|
||||
"""
|
||||
|
||||
def __init__(self, config):
|
||||
super().__init__()
|
||||
self.word_embeddings = nn.Embedding(config.vocab_size, config.hidden_size)
|
||||
self.position_embeddings = nn.Embedding(config.max_position_embeddings, config.hidden_size)
|
||||
if config.sinusoidal_pos_embds:
|
||||
create_sinusoidal_embeddings(
|
||||
n_pos=config.max_position_embeddings, dim=config.hidden_size, out=self.position_embeddings.weight
|
||||
)
|
||||
|
||||
self.dropout = config.hidden_dropout_prob
|
||||
|
||||
def forward(self, input_ids=None, position_ids=None, inputs_embeds=None):
|
||||
if input_ids is not None:
|
||||
input_shape = input_ids.size()
|
||||
else:
|
||||
input_shape = inputs_embeds.size()[:-1]
|
||||
|
||||
seq_length = input_shape[1]
|
||||
device = input_ids.device if input_ids is not None else inputs_embeds.device
|
||||
if position_ids is None:
|
||||
position_ids = torch.arange(seq_length, dtype=torch.long, device=device)
|
||||
position_ids = position_ids.unsqueeze(0).expand(input_shape)
|
||||
|
||||
if inputs_embeds is None:
|
||||
inputs_embeds = self.word_embeddings(input_ids)
|
||||
|
||||
position_embeddings = self.position_embeddings(position_ids)
|
||||
|
||||
# TODO: In https://github.com/google/trax/blob/d947ebc184b94bc48d7e48cc63156a047f00992e/trax/models/reformer/reformer.py#L775 there are two dropouts right after each other as
|
||||
# it is implemented here. Check if this is ok.
|
||||
|
||||
embeddings = nn.functional.dropout(inputs_embeds, self.dropout, self.training)
|
||||
embeddings = embeddings + position_embeddings
|
||||
embeddings = nn.functional.dropout(embeddings, self.dropout, self.training)
|
||||
return embeddings
|
||||
|
||||
|
||||
class LSHSelfAttention(nn.Module):
|
||||
def __init__(self, config):
|
||||
super().__init__()
|
||||
|
||||
self.num_attention_heads = config.num_attention_heads
|
||||
self.hidden_size = config.hidden_size
|
||||
self.hash_seed = config.seed
|
||||
self.num_hashes = config.num_hashes
|
||||
self.num_buckets = config.num_buckets
|
||||
self.chunk_length = config.chunk_length
|
||||
self.num_chunks_before = config.num_chunks_before
|
||||
self.num_chunks_after = config.num_chunks_after
|
||||
self.output_attentions = config.output_attentions
|
||||
self.is_decoder = config.is_decoder
|
||||
|
||||
self.attention_head_size = int(self.hidden_size / self.num_attention_heads)
|
||||
self.all_head_size = self.num_attention_heads * self.attention_head_size
|
||||
|
||||
if self.hidden_size % self.num_attention_heads != 0:
|
||||
raise ValueError(
|
||||
"The hidden size (%d) is not a multiple of the number of attention "
|
||||
"heads (%d)" % (config.hidden_size, config.num_attention_heads)
|
||||
)
|
||||
|
||||
self.query_key = nn.Linear(self.hidden_size, self.all_head_size, bias=False)
|
||||
self.value = nn.Linear(self.hidden_size, self.all_head_size, bias=False)
|
||||
|
||||
self.dropout = config.attention_probs_dropout_prob
|
||||
|
||||
def forward(
|
||||
self,
|
||||
hidden_states,
|
||||
head_mask=None,
|
||||
):
|
||||
|
||||
# get SeqLen and BatchSize
|
||||
sequence_length = hidden_states.shape[1]
|
||||
batch_size = hidden_states.shape[0]
|
||||
|
||||
mixed_query_key_vectors = self.query_key(hidden_states)
|
||||
mixed_value_vectors = self.value(hidden_states)
|
||||
|
||||
query_key_vectors = self._transpose_for_scores(mixed_query_key_vectors)
|
||||
value_vectors = self._transpose_for_scores(mixed_value_vectors)
|
||||
|
||||
assert query_key_vectors.shape[-1] == self.attention_head_size
|
||||
assert value_vectors.shape[-1] == self.attention_head_size
|
||||
|
||||
# hash query key vectors into buckets
|
||||
buckets = self._hash_vectors(query_key_vectors)
|
||||
assert int(buckets.shape[-1]) == self.num_hashes * sequence_length
|
||||
|
||||
ticker, undo_ticker = self._get_ticker_and_undo_ticker(sequence_length, buckets)
|
||||
|
||||
query_key_vectors = self._gather_by_expansion(query_key_vectors, ticker)
|
||||
value_vectors = self._gather_by_expansion(value_vectors, ticker)
|
||||
|
||||
# q_info = ticker
|
||||
|
||||
query_key_vectors = self._split_dim_by(query_key_vectors, -1, self.chunk_length)
|
||||
value_vectors = self._split_dim_by(value_vectors, -1, self.chunk_length)
|
||||
ticker = self._split_dim_by(ticker, -1, self.chunk_length)
|
||||
|
||||
# Optionally include adjacent chunks.
|
||||
if self.chunk_length is None:
|
||||
assert self.num_chunks_before == 0 and self.num_chunks_after == 0
|
||||
|
||||
key_vectors = self._len_and_dim_norm(query_key_vectors)
|
||||
|
||||
out_vectors, logits, attention_probs = self._attend(query_key_vectors, key_vectors, value_vectors, ticker, undo_ticker, head_mask)
|
||||
|
||||
if self.num_hashes > 1:
|
||||
out_vectors = self._split_dim_by(out_vectors, self.num_hashes, sequence_length)
|
||||
logits = self._split_dim_by(logits, self.num_hashes, sequence_length).unsqueeze(-1)
|
||||
|
||||
probs_vectors = torch.exp(logits - torch.logsumexp(logits, dim=2, keepdim=True))
|
||||
out_vectors = torch.sum(out_vectors * probs_vectors, dim=2)
|
||||
|
||||
assert out_vectors.shape == (batch_size, self.num_attention_heads, sequence_length, self.attention_head_size)
|
||||
|
||||
out_vectors = self._transpose_for_output(out_vectors)
|
||||
outputs = (out_vectors, attention_probs) if self.output_attentions else (out_vectors,)
|
||||
return outputs
|
||||
|
||||
def _hash_vectors(self, vectors):
|
||||
batch_size = vectors.shape[0]
|
||||
|
||||
# See https://arxiv.org/pdf/1509.02897.pdf
|
||||
# We sample a different random rotation for each round of hashing to
|
||||
# decrease the probability of hash misses.
|
||||
if isinstance(self.num_buckets, int):
|
||||
assert self.num_buckets % 2 == 0, 'There should be an even number of bucktes, but `self.num_bucktes`: {}'.format(self.num_buckets)
|
||||
rotation_size = self.num_buckets
|
||||
num_buckets = self.num_buckets
|
||||
else:
|
||||
# Factorize the hash if self.num_buckets is a list or tuple
|
||||
rotation_size, num_buckets = 0, 1
|
||||
for num_bucket in self.num_buckets:
|
||||
assert num_bucket % 2 == 0, 'The number of buckets should be even, but `num_bucket`: {}'.format(num_bucket)
|
||||
rotation_size += num_bucket
|
||||
num_buckets *= num_bucket
|
||||
|
||||
rotations_shape = (vectors.shape[-1], self.num_hashes, rotation_size // 2)
|
||||
|
||||
# TODO: delete later when integration tests are ok
|
||||
# create a random self.attention_head_size x self.num_hashes x self.num_buckets/2
|
||||
# random_rotations = torch.randn(rotations_shape, device=vectors.device)
|
||||
numpy.random.seed(self.hash_seed)
|
||||
random_rotations = torch.tensor(numpy.random.normal(size=rotations_shape), dtype=torch.float32, device=vectors.device)
|
||||
# rotated_vectors has dim:
|
||||
# Output dim: Batch_Size x Num_Attn_Heads x Num_Hashes x Seq_Len x Num_Buckets/2
|
||||
# TODO: IMPORTANT: At the moment we use the same random rotation over all batches
|
||||
# and heads -> is that bad? It seems like in original reformer a different random
|
||||
# rotation is used over heads and batches
|
||||
rotated_vectors = torch.einsum('bmtd,dhr->bmhtr', vectors, random_rotations)
|
||||
|
||||
if isinstance(self.num_buckets, int) or len(self.num_buckets) == 1:
|
||||
rotated_vectors = torch.cat([rotated_vectors, -rotated_vectors], dim=-1)
|
||||
buckets = torch.argmax(rotated_vectors, dim=-1)
|
||||
else:
|
||||
# Get the buckets for them and combine.
|
||||
buckets, cur_sum, cur_product = None, 0, 1
|
||||
for num_bucket in self.num_buckets:
|
||||
rotated_vectors = rotated_vectors[..., cur_sum:cur_sum + (num_bucket // 2)]
|
||||
cur_sum += num_bucket // 2
|
||||
rotated_vectors = torch.cat([rotated_vectors, -rotated_vectors], dim=-1)
|
||||
|
||||
if buckets is None:
|
||||
buckets = torch.argmax(rotated_vectors, dim=-1)
|
||||
else:
|
||||
buckets += cur_product * torch.argmax(rotated_vectors, dim=-1)
|
||||
|
||||
cur_product *= num_bucket
|
||||
|
||||
# buckets is now (Batch_size x Num_Attn_Heads x Num_Hashes x Seq_Len).
|
||||
# Next we add offsets so that bucket numbers from different hashing rounds don't overlap.
|
||||
offsets = torch.arange(self.num_hashes, device=vectors.device)
|
||||
offsets = torch.reshape(offsets * num_buckets, (-1, 1))
|
||||
|
||||
# repeat same values for Batch_size and Num_Attn_Heads
|
||||
offsets = offsets.repeat(batch_size, self.num_attention_heads, 1, 1)
|
||||
offset_buckets = self._merge_by_middle_dim(buckets + offsets)
|
||||
|
||||
return offset_buckets
|
||||
|
||||
def _get_ticker_and_undo_ticker(self, sequence_length, buckets):
|
||||
batch_size = buckets.shape[0]
|
||||
|
||||
# TODO: what is ticker? Is ticker something like indices?? Ask authors
|
||||
ticker = torch.arange(self.num_hashes * sequence_length, device=buckets.device)
|
||||
ticker = ticker.repeat(batch_size, self.num_attention_heads, 1)
|
||||
|
||||
buckets_and_t = sequence_length * buckets + (ticker % sequence_length)
|
||||
|
||||
# Hash-based sort
|
||||
sorted_ticker = torch.argsort(buckets_and_t, dim=-1)
|
||||
undo_sorted_ticker = torch.argsort(sorted_ticker, dim=-1)
|
||||
|
||||
sorted_ticker = (sorted_ticker % sequence_length)
|
||||
return sorted_ticker, undo_sorted_ticker
|
||||
|
||||
def _attend(self, query_vectors, key_vectors, value_vectors, ticker, undo_ticker, head_mask):
|
||||
key_vectors = self._look_adjacent(key_vectors)
|
||||
value_vectors = self._look_adjacent(value_vectors)
|
||||
|
||||
# get logits and dots
|
||||
query_key_dots = torch.matmul(query_vectors, key_vectors.transpose(-1, -2))
|
||||
|
||||
# TODO(PVP): better naming
|
||||
query_info = ticker
|
||||
key_value_info = self._look_adjacent(ticker)
|
||||
|
||||
# Causal mask
|
||||
if self.is_decoder:
|
||||
# TODO (PVP): This line can be improved in terms of memory. Mask should be inserted and does not have to be created each time layer is called
|
||||
mask = torch.lt(query_info.unsqueeze(-1), key_value_info.unsqueeze(-2)).long().to(query_info.device)
|
||||
query_key_dots = query_key_dots - mask * 1e9
|
||||
|
||||
# Self mask
|
||||
# TODO (PVP): This line can be improved in terms of memory. Mask should be inserted and does not have to be created each time layer is called
|
||||
mask = torch.eq(query_info.unsqueeze(-1), key_value_info.unsqueeze(-2)).long().to(query_info.device)
|
||||
query_key_dots = query_key_dots - mask * 1e5
|
||||
|
||||
# Note: Causal mask probably uses higher mask value (-1e9) than Self mask (-1e5) so that token is able to attend to itself when it has no other valid attention targets.
|
||||
|
||||
# Note: Self mask is used because Q and K projection weights are shared.
|
||||
# From the reformer paper (https://arxiv.org/pdf/2001.04451.pdf):
|
||||
|
||||
# " While attention to the future is not allowed, typical implementations of the
|
||||
# Transformer do allow a position to attend to itself.
|
||||
# Such behavior is undesirable in a shared-QK formulation because the dot-product
|
||||
# of a query vector with itself will almost always be greater than the dot product of a
|
||||
# query vector with a vector at another position. We therefore modify the masking
|
||||
# to forbid a token from attending to itself, except in situations
|
||||
# where a token has no other valid attention targets (e.g. the first token in a sequence) "
|
||||
|
||||
logits = torch.logsumexp(query_key_dots, dim=-1, keepdim=True)
|
||||
dots = torch.exp(query_key_dots - logits)
|
||||
|
||||
# dropout
|
||||
dots = nn.functional.dropout(dots, self.dropout, self.training)
|
||||
|
||||
# Mask heads if we want to
|
||||
if head_mask is not None:
|
||||
dots = dots * head_mask
|
||||
|
||||
# attend values
|
||||
out_vectors = torch.matmul(dots, value_vectors)
|
||||
|
||||
# merge chunk length
|
||||
logits = self._merge_by_middle_dim(logits).squeeze(-1)
|
||||
out_vectors = self._merge_by_middle_dim(out_vectors)
|
||||
|
||||
expanded_undo_sort_indices = undo_ticker.unsqueeze(-1).expand(-1, -1, -1, self.attention_head_size)
|
||||
out_vectors = torch.gather(out_vectors, 2, expanded_undo_sort_indices)
|
||||
logits = torch.gather(logits, 2, undo_ticker)
|
||||
|
||||
return out_vectors, logits, dots
|
||||
|
||||
def _look_adjacent(self, vectors):
|
||||
""" Used to implement attention between consecutive chunks.
|
||||
|
||||
Args:
|
||||
vectors: array of shape [batch_size, num_attention_heads, n_chunks, chunk_len, ...]
|
||||
Returns:
|
||||
array of shape [n_chunks, N * chunk_len, ...], where
|
||||
N = (1 + n_chunks_before + n_chunks_after).
|
||||
"""
|
||||
if self.num_chunks_before == 0 and self.num_chunks_after == 0:
|
||||
return vectors
|
||||
|
||||
slices = []
|
||||
for i in range(-self.num_chunks_before, self.num_chunks_after + 1):
|
||||
if i == 0:
|
||||
slices.append(vectors)
|
||||
else:
|
||||
slices.append(torch.cat([vectors[:, :, i:, ...], vectors[:, :, :i, ...]], dim=2))
|
||||
return torch.cat(slices, dim=3)
|
||||
|
||||
def _len_and_dim_norm(self, vectors):
|
||||
vectors = self._len_norm(vectors)
|
||||
vectors = vectors / torch.sqrt(torch.tensor(self.attention_head_size, device=vectors.device, dtype=torch.float32))
|
||||
return vectors
|
||||
|
||||
def _len_norm(self, x, epsilon=1e-6):
|
||||
variance = torch.mean(x**2, -1, keepdim=True)
|
||||
norm_x = x / torch.sqrt(variance + epsilon)
|
||||
return norm_x
|
||||
|
||||
def _gather_by_expansion(self, vectors, idxs):
|
||||
expanded_idxs = idxs.unsqueeze(-1).expand(-1, -1, -1, self.attention_head_size)
|
||||
vectors = vectors.repeat(1, 1, self.num_hashes, 1)
|
||||
return torch.gather(vectors, 2, expanded_idxs)
|
||||
|
||||
def _transpose_for_scores(self, x):
|
||||
new_x_shape = x.size()[:-1] + (self.num_attention_heads, self.attention_head_size)
|
||||
x = x.view(*new_x_shape)
|
||||
return x.transpose(2, 1)
|
||||
|
||||
def _transpose_for_output(self, x):
|
||||
x = x.permute(0, 2, 1, 3)
|
||||
return torch.reshape(x, (x.size()[0], -1, self.num_attention_heads * self.attention_head_size))
|
||||
|
||||
def _split_dim_by(self, vectors, dim_factor_1, dim_factor_2):
|
||||
batch_size = vectors.shape[0]
|
||||
split_dim_shape = (batch_size, self.num_attention_heads, dim_factor_1, dim_factor_2)
|
||||
|
||||
if len(vectors.shape) == 4:
|
||||
return torch.reshape(vectors, split_dim_shape + (self.attention_head_size,))
|
||||
elif len(vectors.shape) == 3:
|
||||
return torch.reshape(vectors, split_dim_shape)
|
||||
else:
|
||||
raise ValueError("Input vector rank should be one of [3, 4], but is: {}".format(len(vectors.shape)))
|
||||
|
||||
def _merge_by_middle_dim(self, vectors):
|
||||
batch_size = vectors.shape[0]
|
||||
new_dim_shape = (batch_size, self.num_attention_heads, -1)
|
||||
|
||||
if len(vectors.shape) == 5:
|
||||
return torch.reshape(vectors, new_dim_shape + (vectors.shape[-1],))
|
||||
elif len(vectors.shape) == 4:
|
||||
return torch.reshape(vectors, new_dim_shape)
|
||||
else:
|
||||
raise ValueError("Input vector rank should be one of [4, 5], but is: {}".format(len(vectors.shape)))
|
||||
|
||||
|
||||
class ReformerSelfOutput(nn.Module):
|
||||
def __init__(self, config):
|
||||
super().__init__()
|
||||
self.dense = nn.Linear(config.hidden_size, config.hidden_size, bias=False)
|
||||
self.dropout = config.hidden_dropout_prob
|
||||
|
||||
def forward(self, hidden_states, input_tensor):
|
||||
hidden_states = self.dense(hidden_states)
|
||||
hidden_states = nn.functional.dropout(hidden_states, self.dropout, self.training)
|
||||
# residual connection
|
||||
output = (hidden_states + input_tensor)
|
||||
return output
|
||||
|
||||
|
||||
class ReformerAttention(nn.Module):
|
||||
def __init__(self, config):
|
||||
super().__init__()
|
||||
self.layer_norm = ReformerLayerNorm(config.hidden_size, eps=config.layer_norm_eps)
|
||||
self.self_attention = LSHSelfAttention(config)
|
||||
self.output = ReformerSelfOutput(config)
|
||||
|
||||
def forward(
|
||||
self,
|
||||
hidden_states,
|
||||
prev_attention_output,
|
||||
head_mask=None,
|
||||
):
|
||||
norm_hidden_states = self.layer_norm(hidden_states)
|
||||
self_attention_outputs = self.self_attention(
|
||||
norm_hidden_states, head_mask
|
||||
)
|
||||
|
||||
# Implementation of RevNet (see Fig. 6 in https://towardsdatascience.com/illustrating-the-reformer-393575ac6ba0)
|
||||
# X_1 = prev_attention_output; X_2 = hidden_states
|
||||
attention_output = self.output(self_attention_outputs[0], prev_attention_output)
|
||||
outputs = (attention_output,) + self_attention_outputs[1:] # add attentions if we output them
|
||||
return outputs
|
||||
|
||||
|
||||
class ReformerFeedForwardDense(nn.Module):
|
||||
def __init__(self, config):
|
||||
super().__init__()
|
||||
self.dense = nn.Linear(config.hidden_size, config.intermediate_size)
|
||||
self.dropout = config.hidden_dropout_prob
|
||||
if isinstance(config.hidden_act, str):
|
||||
self.act_fn = ACT2FN[config.hidden_act]
|
||||
else:
|
||||
self.act_fn = config.hidden_act
|
||||
|
||||
def forward(self, hidden_states):
|
||||
hidden_states = self.dense(hidden_states)
|
||||
hidden_states = nn.functional.dropout(hidden_states, self.dropout, self.training)
|
||||
hidden_states = self.act_fn(hidden_states)
|
||||
return hidden_states
|
||||
|
||||
|
||||
class ReformerFeedForwardOutput(nn.Module):
|
||||
def __init__(self, config):
|
||||
super().__init__()
|
||||
self.dense = nn.Linear(config.intermediate_size, config.hidden_size)
|
||||
self.dropout = config.hidden_dropout_prob
|
||||
|
||||
def forward(self, hidden_states, input_tensor):
|
||||
hidden_states = self.dense(hidden_states)
|
||||
hidden_states = nn.functional.dropout(hidden_states, self.dropout, self.training)
|
||||
output = (hidden_states + input_tensor)
|
||||
return output
|
||||
|
||||
|
||||
class ReformerFeedForward(nn.Module):
|
||||
def __init__(self, config):
|
||||
super().__init__()
|
||||
self.layer_norm = ReformerLayerNorm(config.hidden_size, eps=config.layer_norm_eps)
|
||||
self.dense = ReformerFeedForwardDense(config)
|
||||
self.output = ReformerFeedForwardOutput(config)
|
||||
|
||||
def forward(self, attention_output, prev_attention_output):
|
||||
norm_attention_output = self.layer_norm(attention_output)
|
||||
dense_output = self.dense(norm_attention_output)
|
||||
output = self.output(dense_output, prev_attention_output)
|
||||
return output
|
||||
|
||||
|
||||
class ReformerLayer(nn.Module):
|
||||
def __init__(self, config):
|
||||
super().__init__()
|
||||
self.attention = ReformerAttention(config)
|
||||
self.feed_forward = ReformerFeedForward(config)
|
||||
|
||||
def forward(
|
||||
self,
|
||||
prev_attention_output,
|
||||
hidden_states,
|
||||
head_mask=None,
|
||||
):
|
||||
|
||||
# Implementation of RevNet (see Fig. 6 in https://towardsdatascience.com/illustrating-the-reformer-393575ac6ba0)
|
||||
# X_1 = prev_attention_output; X_2 = hidden_states
|
||||
# Y_1 = attention_output; Y_2 = output
|
||||
attention_outputs = self.attention(hidden_states, prev_attention_output, head_mask)
|
||||
attention_output = attention_outputs[0]
|
||||
output = self.feed_forward(attention_output, hidden_states)
|
||||
|
||||
outputs = (attention_output, output) + attention_outputs[1:]
|
||||
|
||||
return outputs
|
||||
|
||||
|
||||
class ReformerEncoder(nn.Module):
|
||||
def __init__(self, config):
|
||||
super().__init__()
|
||||
self.output_attentions = config.output_attentions
|
||||
self.output_hidden_states = config.output_hidden_states
|
||||
self.layer = nn.ModuleList([ReformerLayer(config) for _ in range(config.num_hidden_layers)])
|
||||
# Reformer is using Rev Nets, thus last layer outputs are concatenated and
|
||||
# Layer Norm is done over 2 * hidden_size
|
||||
self.layer_norm = ReformerLayerNorm(2 * config.hidden_size, eps=config.layer_norm_eps)
|
||||
self.dropout = config.hidden_dropout_prob
|
||||
|
||||
def forward(
|
||||
self,
|
||||
hidden_states,
|
||||
head_mask=None,
|
||||
):
|
||||
all_hidden_states = ()
|
||||
all_attentions = ()
|
||||
attention_output = hidden_states
|
||||
|
||||
for i, layer_module in enumerate(self.layer):
|
||||
if self.output_hidden_states:
|
||||
all_hidden_states = all_hidden_states + (attention_output, hidden_states)
|
||||
|
||||
layer_outputs = layer_module(attention_output, hidden_states, head_mask[i])
|
||||
attention_output, hidden_states = layer_outputs[:2]
|
||||
|
||||
if self.output_attentions:
|
||||
all_attentions = all_attentions + (layer_outputs[2],)
|
||||
|
||||
# Add last layer
|
||||
if self.output_hidden_states:
|
||||
all_hidden_states = all_hidden_states + (attention_output, hidden_states)
|
||||
|
||||
trax_2_layer_output_1 = np.load(PATH_TO_SAVE_WEIGHTS + '/encoder_output_1.npy')
|
||||
trax_2_layer_output_2 = np.load(PATH_TO_SAVE_WEIGHTS + '/encoder_output_2.npy')
|
||||
|
||||
import ipdb
|
||||
ipdb.set_trace()
|
||||
|
||||
# Concatenate 2 RevNet outputs
|
||||
hidden_states = torch.cat([attention_output, hidden_states], dim=-1)
|
||||
|
||||
# Apply layer norm to concatenated hidden states
|
||||
hidden_states = self.layer_norm(hidden_states)
|
||||
|
||||
# Apply dropout
|
||||
hidden_states = nn.functional.dropout(hidden_states, self.dropout, self.training)
|
||||
|
||||
outputs = (hidden_states,)
|
||||
if self.output_hidden_states:
|
||||
outputs = outputs + (all_hidden_states,)
|
||||
if self.output_attentions:
|
||||
outputs = outputs + (all_attentions,)
|
||||
return outputs # last-layer hidden state, (all hidden states), (all attentions)
|
||||
|
||||
|
||||
class ReformerPreTrainedModel(PreTrainedModel):
|
||||
""" An abstract class to handle weights initialization and
|
||||
a simple interface for downloading and loading pretrained models.
|
||||
"""
|
||||
|
||||
config_class = ReformerConfig
|
||||
pretrained_model_archive_map = REFORMER_PRETRAINED_MODEL_ARCHIVE_MAP
|
||||
base_model_prefix = "reformer"
|
||||
|
||||
def _init_weights(self, module):
|
||||
""" Initialize the weights """
|
||||
if isinstance(module, (nn.Linear, nn.Embedding)):
|
||||
# Slightly different from the TF version which uses truncated_normal for initialization
|
||||
# cf https://github.com/pytorch/pytorch/pull/5617
|
||||
module.weight.data.normal_(mean=0.0, std=self.config.initializer_range)
|
||||
elif isinstance(module, ReformerLayerNorm):
|
||||
module.bias.data.zero_()
|
||||
module.weight.data.fill_(1.0)
|
||||
if isinstance(module, nn.Linear) and module.bias is not None:
|
||||
module.bias.data.zero_()
|
||||
|
||||
|
||||
class ReformerModel(ReformerPreTrainedModel):
|
||||
"""
|
||||
|
||||
The model can behave as an encoder (with only self-attention) as well
|
||||
as a decoder, in which case a layer of cross-attention is added between
|
||||
the self-attention layers, following the architecture described in `Attention is all you need`_ by Ashish Vaswani,
|
||||
Noam Shazeer, Niki Parmar, Jakob Uszkoreit, Llion Jones, Aidan N. Gomez, Lukasz Kaiser and Illia Polosukhin.
|
||||
|
||||
To behave as an decoder the model needs to be initialized with the
|
||||
:obj:`is_decoder` argument of the configuration set to :obj:`True`; an
|
||||
:obj:`encoder_hidden_states` is expected as an input to the forward pass.
|
||||
|
||||
.. _`Attention is all you need`:
|
||||
https://arxiv.org/abs/1706.03762
|
||||
|
||||
"""
|
||||
|
||||
def __init__(self, config):
|
||||
super().__init__(config)
|
||||
self.config = config
|
||||
|
||||
self.embeddings = ReformerEmbeddings(config)
|
||||
self.encoder = ReformerEncoder(config)
|
||||
|
||||
self.init_weights()
|
||||
|
||||
def get_input_embeddings(self):
|
||||
return self.embeddings.word_embeddings
|
||||
|
||||
def set_input_embeddings(self, value):
|
||||
self.embeddings.word_embeddings = value
|
||||
|
||||
def _prune_heads(self, heads_to_prune):
|
||||
""" Prunes heads of the model.
|
||||
heads_to_prune: dict of {layer_num: list of heads to prune in this layer}
|
||||
See base class PreTrainedModel
|
||||
"""
|
||||
for layer, heads in heads_to_prune.items():
|
||||
self.encoder.layer[layer].attention.prune_heads(heads)
|
||||
|
||||
def forward(
|
||||
self,
|
||||
input_ids=None,
|
||||
attention_mask=None,
|
||||
position_ids=None,
|
||||
head_mask=None,
|
||||
inputs_embeds=None,
|
||||
):
|
||||
r"""
|
||||
Return:
|
||||
:obj:`tuple(torch.FloatTensor)` comprising various elements depending on the configuration (:class:`~transformers.BertConfig`) and inputs:
|
||||
last_hidden_state (:obj:`torch.FloatTensor` of shape :obj:`(batch_size, sequence_length, hidden_size)`):
|
||||
Sequence of hidden-states at the output of the last layer of the model.
|
||||
hidden_states (:obj:`tuple(torch.FloatTensor)`, `optional`, returned when ``config.output_hidden_states=True``):
|
||||
Tuple of :obj:`torch.FloatTensor` (one for the output of the embeddings + one for the output of each layer)
|
||||
of shape :obj:`(batch_size, sequence_length, hidden_size)`.
|
||||
|
||||
Hidden-states of the model at the output of each layer plus the initial embedding outputs.
|
||||
attentions (:obj:`tuple(torch.FloatTensor)`, `optional`, returned when ``config.output_attentions=True``):
|
||||
Tuple of :obj:`torch.FloatTensor` (one for each layer) of shape
|
||||
:obj:`(batch_size, num_heads, sequence_length, sequence_length)`.
|
||||
|
||||
Attentions weights after the attention softmax, used to compute the weighted average in the self-attention
|
||||
heads.
|
||||
|
||||
Examples::
|
||||
|
||||
"""
|
||||
|
||||
if input_ids is not None and inputs_embeds is not None:
|
||||
raise ValueError("You cannot specify both input_ids and inputs_embeds at the same time")
|
||||
elif input_ids is not None:
|
||||
input_shape = input_ids.size() # noqa: F841
|
||||
elif inputs_embeds is not None:
|
||||
input_shape = inputs_embeds.size()[:-1] # noqa: F841
|
||||
else:
|
||||
raise ValueError("You have to specify either input_ids or inputs_embeds")
|
||||
|
||||
device = input_ids.device if input_ids is not None else inputs_embeds.device # noqa: F841
|
||||
|
||||
# Prepare head mask if needed
|
||||
# 1.0 in head_mask indicate we keep the head
|
||||
# attention_probs has shape bsz x n_heads x N x N
|
||||
# input head_mask has shape [num_heads] or [num_hidden_layers x num_heads]
|
||||
# and head_mask is converted to shape [num_hidden_layers x batch x num_heads x seq_length x seq_length]
|
||||
if head_mask is not None:
|
||||
if head_mask.dim() == 1:
|
||||
head_mask = head_mask.unsqueeze(0).unsqueeze(0).unsqueeze(-1).unsqueeze(-1)
|
||||
head_mask = head_mask.expand(self.config.num_hidden_layers, -1, -1, -1, -1)
|
||||
elif head_mask.dim() == 2:
|
||||
head_mask = (
|
||||
head_mask.unsqueeze(1).unsqueeze(-1).unsqueeze(-1)
|
||||
) # We can specify head_mask for each layer
|
||||
head_mask = head_mask.to(
|
||||
dtype=next(self.parameters()).dtype
|
||||
) # switch to fload if need + fp16 compatibility
|
||||
else:
|
||||
head_mask = [None] * self.config.num_hidden_layers
|
||||
|
||||
embedding_output = self.embeddings(
|
||||
input_ids=input_ids, position_ids=position_ids, inputs_embeds=inputs_embeds
|
||||
)
|
||||
|
||||
encoder_outputs = self.encoder(
|
||||
embedding_output,
|
||||
head_mask=head_mask,
|
||||
)
|
||||
sequence_output = encoder_outputs[0]
|
||||
|
||||
# add hidden_states and attentions if they are here
|
||||
outputs = (sequence_output,) + encoder_outputs[1:]
|
||||
return outputs # sequence_output, pooled_output, (hidden_states), (attentions)
|
||||
|
||||
|
||||
class ReformerWithLMHead(ReformerPreTrainedModel):
|
||||
def __init__(self, config):
|
||||
super().__init__(config)
|
||||
|
||||
self.reformer = ReformerModel(config)
|
||||
self.lm_head = ReformerOnlyLMHead(config)
|
||||
|
||||
self.init_weights()
|
||||
|
||||
def get_output_embeddings(self):
|
||||
return self.lm_head.predictions.decoder
|
||||
|
||||
@add_start_docstrings_to_callable(BERT_INPUTS_DOCSTRING)
|
||||
def forward(
|
||||
self,
|
||||
input_ids=None,
|
||||
position_ids=None,
|
||||
head_mask=None,
|
||||
inputs_embeds=None,
|
||||
lm_labels=None,
|
||||
):
|
||||
outputs = self.reformer(
|
||||
input_ids,
|
||||
attention_mask=attention_mask,
|
||||
token_type_ids=token_type_ids,
|
||||
position_ids=position_ids,
|
||||
head_mask=head_mask,
|
||||
inputs_embeds=inputs_embeds,
|
||||
encoder_hidden_states=encoder_hidden_states,
|
||||
encoder_attention_mask=encoder_attention_mask,
|
||||
)
|
||||
|
||||
sequence_output = outputs[0]
|
||||
prediction_scores = self.cls(sequence_output)
|
||||
|
||||
outputs = (prediction_scores,) + outputs[2:] # Add hidden states and attention if they are here
|
||||
|
||||
# Although this may seem awkward, BertForMaskedLM supports two scenarios:
|
||||
# 1. If a tensor that contains the indices of masked labels is provided,
|
||||
# the cross-entropy is the MLM cross-entropy that measures the likelihood
|
||||
# of predictions for masked words.
|
||||
# 2. If `lm_labels` is provided we are in a causal scenario where we
|
||||
# try to predict the next token for each input in the decoder.
|
||||
if masked_lm_labels is not None:
|
||||
loss_fct = CrossEntropyLoss() # -100 index = padding token
|
||||
masked_lm_loss = loss_fct(prediction_scores.view(-1, self.config.vocab_size), masked_lm_labels.view(-1))
|
||||
outputs = (masked_lm_loss,) + outputs
|
||||
|
||||
if lm_labels is not None:
|
||||
# we are doing next-token prediction; shift prediction scores and input ids by one
|
||||
prediction_scores = prediction_scores[:, :-1, :].contiguous()
|
||||
lm_labels = lm_labels[:, 1:].contiguous()
|
||||
loss_fct = CrossEntropyLoss()
|
||||
ltr_lm_loss = loss_fct(prediction_scores.view(-1, self.config.vocab_size), lm_labels.view(-1))
|
||||
outputs = (ltr_lm_loss,) + outputs
|
||||
|
||||
return outputs # (masked_lm_loss), (ltr_lm_loss), prediction_scores, (hidden_states), (attentions)
|
||||
+141
-14
@@ -24,9 +24,10 @@ from trax.layers.research.efficient_attention_v2 import (
|
||||
LSHSelfAttention as TraxLSHSelfAttention,
|
||||
)
|
||||
from trax.models.reformer.reformer import DecoderBlock as TraxLSHAttentionBlock
|
||||
from trax.models.reformer.reformer import ReformerLM as TraxReformer
|
||||
from trax import layers as tl
|
||||
|
||||
from transformers import ReformerAttention, ReformerLayer, ReformerConfig
|
||||
from transformers import ReformerAttention, ReformerLayer, ReformerConfig, ReformerModelWithLMHead
|
||||
|
||||
|
||||
from transformers import is_torch_available # noqa: F401
|
||||
@@ -64,11 +65,11 @@ class TraxUtils(object):
|
||||
def convert_to_jax_array(self, np_array):
|
||||
return jax.numpy.asarray(np_array)
|
||||
|
||||
def get_input_signature(self, shape=None):
|
||||
def get_input_signature(self, shape=None, dtype=trax_math.numpy.float32):
|
||||
with trax_math.use_backend("jax"):
|
||||
if shape is None:
|
||||
shape = self._shape
|
||||
input_signature = trax_ShapeDtype(shape)
|
||||
input_signature = trax_ShapeDtype(shape, dtype)
|
||||
return input_signature
|
||||
|
||||
def get_layer(
|
||||
@@ -163,9 +164,9 @@ class TraxUtils(object):
|
||||
hash_seed=config.seed,
|
||||
path_to_save_weights=path_to_save_weights
|
||||
)
|
||||
layer = tl.Serial(tl.ReversibleSerial([list_of_layers]))
|
||||
block = tl.Serial(tl.ReversibleSerial([list_of_layers]))
|
||||
|
||||
return layer
|
||||
return block
|
||||
|
||||
def forward_block(
|
||||
self,
|
||||
@@ -193,6 +194,79 @@ class TraxUtils(object):
|
||||
|
||||
return output, weights, state
|
||||
|
||||
def get_model(
|
||||
self,
|
||||
config,
|
||||
use_reference_code=True,
|
||||
share_qk=True,
|
||||
ff_use_sru=0,
|
||||
axial_pos_shape=(),
|
||||
d_axial_pos_embs=None,
|
||||
mode="eval",
|
||||
path_to_save_weights=PATH_TO_SAVE_WEIGHTS,
|
||||
):
|
||||
with trax_math.use_backend("jax"):
|
||||
with jax.disable_jit():
|
||||
hidden_size_per_head = config.hidden_size // config.num_attention_heads
|
||||
model = TraxReformer(
|
||||
vocab_size=config.vocab_size,
|
||||
d_model=config.d_model,
|
||||
d_ff=config.d_ff,
|
||||
d_attention_key=hidden_size_per_head,
|
||||
d_attention_value=hidden_size_per_head,
|
||||
n_layers=config.num_hidden_layers,
|
||||
n_heads=config.num_attention_heads,
|
||||
dropout=config.hidden_dropout_prob,
|
||||
max_len=config.max_position_embeddings,
|
||||
n_chunks=config.num_chunks,
|
||||
n_attention_chunks=config.num_attention_chunks,
|
||||
attention_type=tl.LSHSelfAttention,
|
||||
share_qk=share_qk,
|
||||
axial_pos_shape=axial_pos_shape,
|
||||
d_axial_pos_embs=d_axial_pos_embs,
|
||||
ff_activation=tl.Gelu,
|
||||
ff_use_sru=ff_use_sru,
|
||||
ff_chunk_size=config.ff_chunk_size,
|
||||
mode=mode,
|
||||
causal=config.is_decoder,
|
||||
chunk_len=config.chunk_length,
|
||||
n_chunks_before=config.num_chunks_before,
|
||||
n_chunks_after=config.num_chunks_after,
|
||||
n_hashes=config.num_hashes,
|
||||
n_buckets=config.num_buckets,
|
||||
use_reference_code=use_reference_code,
|
||||
hash_seed=config.seed,
|
||||
path_to_save_weights=path_to_save_weights
|
||||
)
|
||||
|
||||
return model
|
||||
|
||||
def forward_model(
|
||||
self,
|
||||
np_input_data,
|
||||
model,
|
||||
input_signature=None,
|
||||
random_number_generator=None,
|
||||
):
|
||||
with trax_math.use_backend("jax"):
|
||||
input_data = self.convert_to_jax_array(np_input_data)
|
||||
input_data = (input_data,) * 2
|
||||
|
||||
if input_signature is None:
|
||||
input_signature = self.get_input_signature(dtype=trax_math.numpy.int32)
|
||||
input_signature = (input_signature, input_signature)
|
||||
|
||||
weights, state = model.init(input_signature)
|
||||
|
||||
if random_number_generator is None:
|
||||
random_number_generator = model.new_rngs(1)[0]
|
||||
|
||||
output = model(
|
||||
input_data, weights=weights, state=state, rng=random_number_generator
|
||||
)
|
||||
|
||||
return output, weights, state
|
||||
|
||||
|
||||
@require_torch
|
||||
class ReformerIntegrationTests(unittest.TestCase):
|
||||
@@ -215,18 +289,17 @@ class ReformerIntegrationTests(unittest.TestCase):
|
||||
self._set_param(torch_layer.self_attention.value, torch.tensor(np_value).transpose(1, 2).contiguous().view(-1, hidden_size))
|
||||
self._set_param(torch_layer.output.dense, torch.tensor(np_dense).view(-1, hidden_size).contiguous().transpose(0, 1))
|
||||
|
||||
def _set_block_weights_in_torch(self, weights, torch_layer, hidden_size):
|
||||
weights = weights[0]
|
||||
def _set_block_weights_in_torch(self, weights, torch_block, hidden_size):
|
||||
|
||||
# layernorm 1
|
||||
layer_norm_1 = weights[0][0][0]
|
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layer_norm_1_weight = np.asarray(layer_norm_1[0])
|
||||
layer_norm_1_bias = np.asarray(layer_norm_1[1])
|
||||
self._set_param(torch_layer.attention.layer_norm, torch.tensor(layer_norm_1_weight), torch.tensor(layer_norm_1_bias))
|
||||
self._set_param(torch_block.attention.layer_norm, torch.tensor(layer_norm_1_weight), torch.tensor(layer_norm_1_bias))
|
||||
|
||||
# lsh weights + output
|
||||
lsh_weights = weights[0][1]
|
||||
self._set_layer_weights_in_torch(lsh_weights, torch_layer.attention, hidden_size)
|
||||
self._set_layer_weights_in_torch(lsh_weights, torch_block.attention, hidden_size)
|
||||
|
||||
# intermediate weighs
|
||||
intermediate_weights = weights[2][0][2][2]
|
||||
@@ -234,17 +307,51 @@ class ReformerIntegrationTests(unittest.TestCase):
|
||||
# layernorm 2
|
||||
layer_norm_2_weight = np.asarray(intermediate_weights[0][0])
|
||||
layer_norm_2_bias = np.asarray(intermediate_weights[0][1])
|
||||
self._set_param(torch_layer.feed_forward.layer_norm, torch.tensor(layer_norm_2_weight), torch.tensor(layer_norm_2_bias))
|
||||
self._set_param(torch_block.feed_forward.layer_norm, torch.tensor(layer_norm_2_weight), torch.tensor(layer_norm_2_bias))
|
||||
|
||||
# intermediate dense
|
||||
inter_dense_weight = np.asarray(intermediate_weights[1][0])
|
||||
inter_dense_bias = np.asarray(intermediate_weights[1][1])
|
||||
self._set_param(torch_layer.feed_forward.dense.dense, torch.tensor(inter_dense_weight).transpose(0, 1).contiguous(), torch.tensor(inter_dense_bias))
|
||||
self._set_param(torch_block.feed_forward.dense.dense, torch.tensor(inter_dense_weight).transpose(0, 1).contiguous(), torch.tensor(inter_dense_bias))
|
||||
|
||||
# intermediate out
|
||||
out_dense_weight = np.asarray(intermediate_weights[4][0])
|
||||
out_dense_bias = np.asarray(intermediate_weights[4][1])
|
||||
self._set_param(torch_layer.feed_forward.output.dense, torch.tensor(out_dense_weight).transpose(0, 1).contiguous(), torch.tensor(out_dense_bias))
|
||||
self._set_param(torch_block.feed_forward.output.dense, torch.tensor(out_dense_weight).transpose(0, 1).contiguous(), torch.tensor(out_dense_bias))
|
||||
|
||||
def _set_model_weights_in_torch(self, weights, torch_model, hidden_size):
|
||||
|
||||
# reformer model
|
||||
torch_model_reformer = torch_model.reformer
|
||||
|
||||
# word embeds
|
||||
word_embeddings = np.asarray(weights[1])
|
||||
self._set_param(torch_model_reformer.embeddings.word_embeddings, torch.tensor(word_embeddings))
|
||||
|
||||
# pos embeds
|
||||
pos_embeddings = np.asarray(weights[3])
|
||||
self._set_param(torch_model_reformer.embeddings.position_embeddings, torch.tensor(pos_embeddings[0]))
|
||||
|
||||
trax_layer_weights = weights[5]
|
||||
assert len(torch_model_reformer.encoder.layer) * 4 + 1 == len(trax_layer_weights), "HF and trax model do not have the same number of layers"
|
||||
for layer_idx, layer in enumerate(torch_model_reformer.encoder.layer):
|
||||
block_weights = trax_layer_weights[4 * layer_idx: 4 * (layer_idx + 1)]
|
||||
self._set_block_weights_in_torch(block_weights, layer, hidden_size)
|
||||
|
||||
# output weights
|
||||
out_weights = weights[6]
|
||||
|
||||
# output layer norm
|
||||
layer_norm_out_weight = np.asarray(out_weights[0][0])
|
||||
layer_norm_out_bias = np.asarray(out_weights[0][1])
|
||||
self._set_param(torch_model_reformer.encoder.layer_norm, torch.tensor(layer_norm_out_weight), torch.tensor(layer_norm_out_bias))
|
||||
|
||||
# output embeddings
|
||||
output_embed_weights = np.asarray(out_weights[2][0])
|
||||
output_embed_bias = np.asarray(out_weights[2][1])
|
||||
self._set_param(torch_model.lm_head.decoder, torch.tensor(output_embed_weights).transpose(0, 1).contiguous(), torch.tensor(output_embed_bias))
|
||||
|
||||
pass
|
||||
|
||||
def test_lsh_layer(self):
|
||||
# Remove residual connection in ReformerSelfOutput to test this layer only
|
||||
@@ -282,7 +389,7 @@ class ReformerIntegrationTests(unittest.TestCase):
|
||||
|
||||
hf_input = torch.tensor(np_input, dtype=torch.float)
|
||||
hf_block = ReformerLayer(config)
|
||||
self._set_block_weights_in_torch(trax_weights, hf_block, config.hidden_size)
|
||||
self._set_block_weights_in_torch(trax_weights[0], hf_block, config.hidden_size)
|
||||
hf_block.eval()
|
||||
|
||||
hf_output_1, hf_output_2 = hf_block(hf_input, hf_input)[:2]
|
||||
@@ -290,4 +397,24 @@ class ReformerIntegrationTests(unittest.TestCase):
|
||||
self.assertTrue(torch.allclose(hf_output_1, trax_torch_output_1, atol=1e-3))
|
||||
self.assertTrue(torch.allclose(hf_output_2, trax_torch_output_2, atol=1e-3))
|
||||
|
||||
pass
|
||||
def test_reformer_lm_model(self):
|
||||
config = ReformerConfig()
|
||||
|
||||
shape = (2, 7) # Batch x SeqLen x ModelDimPerHead
|
||||
np_input = np.random.randint(0, config.vocab_size, size=shape)
|
||||
np_zeros = np.zeros((shape[0], 1), dtype=np.int)
|
||||
|
||||
trax_utils = TraxUtils(shape)
|
||||
trax_model = trax_utils.get_model(config)
|
||||
trax_output, trax_weights, trax_state = trax_utils.forward_model(np_input, model=trax_model)
|
||||
trax_torch_output = torch.tensor(np.asarray(trax_output[0]))
|
||||
|
||||
hf_input = torch.cat([torch.tensor(np_zeros), torch.tensor(np_input[:, :-1])], dim=-1)
|
||||
hf_model = ReformerModelWithLMHead(config)
|
||||
self._set_model_weights_in_torch(trax_weights, hf_model, config.hidden_size)
|
||||
hf_model.eval()
|
||||
|
||||
hf_output = hf_model(hf_input)
|
||||
log_softmax_output = torch.nn.functional.log_softmax(hf_output[0], dim=-1)
|
||||
|
||||
self.assertTrue(torch.allclose(log_softmax_output, trax_torch_output, atol=1e-3))
|
||||
Reference in new issue
Block a user