From 15e17c99f9df5cfd520d9c0adfdaa3e0b10599ed Mon Sep 17 00:00:00 2001 From: Sujay <89520981+SD-13@users.noreply.github.com> Date: Thu, 5 Jan 2023 00:21:54 +0530 Subject: [PATCH] Remove T5 dependency from mT5 model (#20949) make mt5 independent from t5 --- src/transformers/__init__.py | 6 +- src/transformers/models/mt5/__init__.py | 10 +- src/transformers/models/mt5/modeling_mt5.py | 1862 ++++++++++++++++++- src/transformers/utils/dummy_pt_objects.py | 7 + utils/check_repo.py | 1 + 5 files changed, 1860 insertions(+), 26 deletions(-) diff --git a/src/transformers/__init__.py b/src/transformers/__init__.py index 9763e48be5..829c0a18bd 100755 --- a/src/transformers/__init__.py +++ b/src/transformers/__init__.py @@ -1806,7 +1806,9 @@ else: "MPNetPreTrainedModel", ] ) - _import_structure["models.mt5"].extend(["MT5EncoderModel", "MT5ForConditionalGeneration", "MT5Model"]) + _import_structure["models.mt5"].extend( + ["MT5EncoderModel", "MT5ForConditionalGeneration", "MT5Model", "MT5PreTrainedModel"] + ) _import_structure["models.mvp"].extend( [ "MVP_PRETRAINED_MODEL_ARCHIVE_LIST", @@ -4922,7 +4924,7 @@ if TYPE_CHECKING: MPNetModel, MPNetPreTrainedModel, ) - from .models.mt5 import MT5EncoderModel, MT5ForConditionalGeneration, MT5Model + from .models.mt5 import MT5EncoderModel, MT5ForConditionalGeneration, MT5Model, MT5PreTrainedModel from .models.mvp import ( MVP_PRETRAINED_MODEL_ARCHIVE_LIST, MvpForCausalLM, diff --git a/src/transformers/models/mt5/__init__.py b/src/transformers/models/mt5/__init__.py index f6e717bd87..b97fbff752 100644 --- a/src/transformers/models/mt5/__init__.py +++ b/src/transformers/models/mt5/__init__.py @@ -51,7 +51,13 @@ try: except OptionalDependencyNotAvailable: pass else: - _import_structure["modeling_mt5"] = ["MT5EncoderModel", "MT5ForConditionalGeneration", "MT5Model"] + _import_structure["modeling_mt5"] = [ + "MT5EncoderModel", + "MT5ForConditionalGeneration", + "MT5Model", + "MT5PreTrainedModel", + "MT5Stack", + ] try: if not is_tf_available(): @@ -79,7 +85,7 @@ if TYPE_CHECKING: except OptionalDependencyNotAvailable: pass else: - from .modeling_mt5 import MT5EncoderModel, MT5ForConditionalGeneration, MT5Model + from .modeling_mt5 import MT5EncoderModel, MT5ForConditionalGeneration, MT5Model, MT5PreTrainedModel, MT5Stack try: if not is_tf_available(): diff --git a/src/transformers/models/mt5/modeling_mt5.py b/src/transformers/models/mt5/modeling_mt5.py index c562b01152..ec43a03fbc 100644 --- a/src/transformers/models/mt5/modeling_mt5.py +++ b/src/transformers/models/mt5/modeling_mt5.py @@ -14,29 +14,1256 @@ # limitations under the License. """ PyTorch mT5 model.""" -from ...utils import logging -from ..t5.modeling_t5 import T5EncoderModel, T5ForConditionalGeneration, T5Model +import copy +import math +import os +import warnings +from typing import Optional, Tuple, Union + +import torch +from torch import nn +from torch.nn import CrossEntropyLoss +from torch.utils.checkpoint import checkpoint + +from ...activations import ACT2FN +from ...modeling_outputs import ( + BaseModelOutput, + BaseModelOutputWithPastAndCrossAttentions, + Seq2SeqLMOutput, + Seq2SeqModelOutput, +) +from ...modeling_utils import PreTrainedModel +from ...pytorch_utils import find_pruneable_heads_and_indices, prune_linear_layer +from ...utils import ( + DUMMY_INPUTS, + DUMMY_MASK, + add_start_docstrings, + add_start_docstrings_to_model_forward, + is_torch_fx_proxy, + logging, + replace_return_docstrings, +) +from ...utils.model_parallel_utils import assert_device_map, get_device_map from .configuration_mt5 import MT5Config logger = logging.get_logger(__name__) -_CONFIG_FOR_DOC = "T5Config" -_TOKENIZER_FOR_DOC = "T5Tokenizer" +_CONFIG_FOR_DOC = "MT5Config" +_TOKENIZER_FOR_DOC = "MT5Tokenizer" +_CHECKPOINT_FOR_DOC = "mt5-small" -class MT5Model(T5Model): +PARALLELIZE_DOCSTRING = r""" + This is an experimental feature and is a subject to change at a moment's notice. + + Uses a device map to distribute attention modules of the model across several devices. If no device map is given, + it will evenly distribute blocks across all devices. + + Args: + device_map (`Dict[int, list]`, optional, defaults to None): + A dictionary that maps attention modules to devices. Note that the embedding module and LMHead are always + automatically mapped to the first device (for esoteric reasons). That means that the first device should + have fewer attention modules mapped to it than other devices. For reference, the mt5 models have the + following number of attention modules: + + - mt5-small: 6 + - mt5-base: 12 + - mt5-large: 24 + - mt5-xl: 24 + - mt5-xxl: 24 + + Example: + + ```python + # Here is an example of a device map on a machine with 4 GPUs using mt5-xl, which has a total of 24 attention modules: + model = MT5ForConditionalGeneration.from_pretrained("mt5-xl") + device_map = { + 0: [0, 1, 2], + 1: [3, 4, 5, 6, 7, 8, 9], + 2: [10, 11, 12, 13, 14, 15, 16], + 3: [17, 18, 19, 20, 21, 22, 23], + } + model.parallelize(device_map) + ``` +""" +DEPARALLELIZE_DOCSTRING = r""" + Moves the model to cpu from a model parallel state. + + Example: + + ```python + # On a 4 GPU machine with mt5-xl: + model = MT5ForConditionalGeneration.from_pretrained("Mt5-xl") + device_map = { + 0: [0, 1, 2], + 1: [3, 4, 5, 6, 7, 8, 9], + 2: [10, 11, 12, 13, 14, 15, 16], + 3: [17, 18, 19, 20, 21, 22, 23], + } + model.parallelize(device_map) # Splits the model across several devices + model.deparallelize() # Put the model back on cpu and cleans memory by calling torch.cuda.empty_cache() + ``` +""" + + +# Copied from transformers.models.t5.modeling_t5.T5LayerNorm with T5->MT5 +class MT5LayerNorm(nn.Module): + def __init__(self, hidden_size, eps=1e-6): + """ + Construct a layernorm module in the MT5 style. No bias and no subtraction of mean. + """ + super().__init__() + self.weight = nn.Parameter(torch.ones(hidden_size)) + self.variance_epsilon = eps + + def forward(self, hidden_states): + + # MT5 uses a layer_norm which only scales and doesn't shift, which is also known as Root Mean + # Square Layer Normalization https://arxiv.org/abs/1910.07467 thus varience is calculated + # w/o mean and there is no bias. Additionally we want to make sure that the accumulation for + # half-precision inputs is done in fp32 + + variance = hidden_states.to(torch.float32).pow(2).mean(-1, keepdim=True) + hidden_states = hidden_states * torch.rsqrt(variance + self.variance_epsilon) + + # convert into half-precision if necessary + if self.weight.dtype in [torch.float16, torch.bfloat16]: + hidden_states = hidden_states.to(self.weight.dtype) + + return self.weight * hidden_states + + +# Copied from transformers.models.t5.modeling_t5.T5DenseActDense with T5->MT5 +class MT5DenseActDense(nn.Module): + def __init__(self, config: MT5Config): + super().__init__() + self.wi = nn.Linear(config.d_model, config.d_ff, bias=False) + self.wo = nn.Linear(config.d_ff, config.d_model, bias=False) + self.dropout = nn.Dropout(config.dropout_rate) + self.act = ACT2FN[config.dense_act_fn] + + def forward(self, hidden_states): + hidden_states = self.wi(hidden_states) + hidden_states = self.act(hidden_states) + hidden_states = self.dropout(hidden_states) + hidden_states = self.wo(hidden_states) + return hidden_states + + +# Copied from transformers.models.t5.modeling_t5.T5DenseGatedActDense with T5->MT5 +class MT5DenseGatedActDense(nn.Module): + def __init__(self, config: MT5Config): + super().__init__() + self.wi_0 = nn.Linear(config.d_model, config.d_ff, bias=False) + self.wi_1 = nn.Linear(config.d_model, config.d_ff, bias=False) + self.wo = nn.Linear(config.d_ff, config.d_model, bias=False) + self.dropout = nn.Dropout(config.dropout_rate) + self.act = ACT2FN[config.dense_act_fn] + + def forward(self, hidden_states): + hidden_gelu = self.act(self.wi_0(hidden_states)) + hidden_linear = self.wi_1(hidden_states) + hidden_states = hidden_gelu * hidden_linear + hidden_states = self.dropout(hidden_states) + + # To make 8bit quantization work for google/flan-t5-xxl, self.wo is kept in float32. + # See https://github.com/huggingface/transformers/issues/20287 + if hidden_states.dtype != self.wo.weight.dtype: + hidden_states = hidden_states.to(self.wo.weight.dtype) + + hidden_states = self.wo(hidden_states) + return hidden_states + + +# Copied from transformers.models.t5.modeling_t5.T5LayerFF with T5->MT5 +class MT5LayerFF(nn.Module): + def __init__(self, config: MT5Config): + super().__init__() + if config.is_gated_act: + self.DenseReluDense = MT5DenseGatedActDense(config) + else: + self.DenseReluDense = MT5DenseActDense(config) + + self.layer_norm = MT5LayerNorm(config.d_model, eps=config.layer_norm_epsilon) + self.dropout = nn.Dropout(config.dropout_rate) + + def forward(self, hidden_states): + forwarded_states = self.layer_norm(hidden_states) + forwarded_states = self.DenseReluDense(forwarded_states) + hidden_states = hidden_states + self.dropout(forwarded_states) + return hidden_states + + +# Copied from transformers.models.t5.modeling_t5.T5Attention with T5->MT5 +class MT5Attention(nn.Module): + def __init__(self, config: MT5Config, has_relative_attention_bias=False): + super().__init__() + self.is_decoder = config.is_decoder + self.has_relative_attention_bias = has_relative_attention_bias + self.relative_attention_num_buckets = config.relative_attention_num_buckets + self.relative_attention_max_distance = config.relative_attention_max_distance + self.d_model = config.d_model + self.key_value_proj_dim = config.d_kv + self.n_heads = config.num_heads + self.dropout = config.dropout_rate + self.inner_dim = self.n_heads * self.key_value_proj_dim + + # Mesh TensorFlow initialization to avoid scaling before softmax + self.q = nn.Linear(self.d_model, self.inner_dim, bias=False) + self.k = nn.Linear(self.d_model, self.inner_dim, bias=False) + self.v = nn.Linear(self.d_model, self.inner_dim, bias=False) + self.o = nn.Linear(self.inner_dim, self.d_model, bias=False) + + if self.has_relative_attention_bias: + self.relative_attention_bias = nn.Embedding(self.relative_attention_num_buckets, self.n_heads) + self.pruned_heads = set() + self.gradient_checkpointing = False + + def prune_heads(self, heads): + if len(heads) == 0: + return + heads, index = find_pruneable_heads_and_indices( + heads, self.n_heads, self.key_value_proj_dim, self.pruned_heads + ) + # Prune linear layers + self.q = prune_linear_layer(self.q, index) + self.k = prune_linear_layer(self.k, index) + self.v = prune_linear_layer(self.v, index) + self.o = prune_linear_layer(self.o, index, dim=1) + # Update hyper params + self.n_heads = self.n_heads - len(heads) + self.inner_dim = self.key_value_proj_dim * self.n_heads + self.pruned_heads = self.pruned_heads.union(heads) + + @staticmethod + def _relative_position_bucket(relative_position, bidirectional=True, num_buckets=32, max_distance=128): + """ + Adapted from Mesh Tensorflow: + https://github.com/tensorflow/mesh/blob/0cb87fe07da627bf0b7e60475d59f95ed6b5be3d/mesh_tensorflow/transformer/transformer_layers.py#L593 + + Translate relative position to a bucket number for relative attention. The relative position is defined as + memory_position - query_position, i.e. the distance in tokens from the attending position to the attended-to + position. If bidirectional=False, then positive relative positions are invalid. We use smaller buckets for + small absolute relative_position and larger buckets for larger absolute relative_positions. All relative + positions >=max_distance map to the same bucket. All relative positions <=-max_distance map to the same bucket. + This should allow for more graceful generalization to longer sequences than the model has been trained on + + Args: + relative_position: an int32 Tensor + bidirectional: a boolean - whether the attention is bidirectional + num_buckets: an integer + max_distance: an integer + + Returns: + a Tensor with the same shape as relative_position, containing int32 values in the range [0, num_buckets) + """ + relative_buckets = 0 + if bidirectional: + num_buckets //= 2 + relative_buckets += (relative_position > 0).to(torch.long) * num_buckets + relative_position = torch.abs(relative_position) + else: + relative_position = -torch.min(relative_position, torch.zeros_like(relative_position)) + # now relative_position is in the range [0, inf) + + # half of the buckets are for exact increments in positions + max_exact = num_buckets // 2 + is_small = relative_position < max_exact + + # The other half of the buckets are for logarithmically bigger bins in positions up to max_distance + relative_position_if_large = max_exact + ( + torch.log(relative_position.float() / max_exact) + / math.log(max_distance / max_exact) + * (num_buckets - max_exact) + ).to(torch.long) + relative_position_if_large = torch.min( + relative_position_if_large, torch.full_like(relative_position_if_large, num_buckets - 1) + ) + + relative_buckets += torch.where(is_small, relative_position, relative_position_if_large) + return relative_buckets + + def compute_bias(self, query_length, key_length, device=None): + """Compute binned relative position bias""" + if device is None: + device = self.relative_attention_bias.weight.device + context_position = torch.arange(query_length, dtype=torch.long, device=device)[:, None] + memory_position = torch.arange(key_length, dtype=torch.long, device=device)[None, :] + relative_position = memory_position - context_position # shape (query_length, key_length) + relative_position_bucket = self._relative_position_bucket( + relative_position, # shape (query_length, key_length) + bidirectional=(not self.is_decoder), + num_buckets=self.relative_attention_num_buckets, + max_distance=self.relative_attention_max_distance, + ) + values = self.relative_attention_bias(relative_position_bucket) # shape (query_length, key_length, num_heads) + values = values.permute([2, 0, 1]).unsqueeze(0) # shape (1, num_heads, query_length, key_length) + return values + + def forward( + self, + hidden_states, + mask=None, + key_value_states=None, + position_bias=None, + past_key_value=None, + layer_head_mask=None, + query_length=None, + use_cache=False, + output_attentions=False, + ): + """ + Self-attention (if key_value_states is None) or attention over source sentence (provided by key_value_states). + """ + # Input is (batch_size, seq_length, dim) + # Mask is (batch_size, key_length) (non-causal) or (batch_size, key_length, key_length) + # past_key_value[0] is (batch_size, n_heads, q_len - 1, dim_per_head) + batch_size, seq_length = hidden_states.shape[:2] + + real_seq_length = seq_length + + if past_key_value is not None: + assert ( + len(past_key_value) == 2 + ), f"past_key_value should have 2 past states: keys and values. Got { len(past_key_value)} past states" + real_seq_length += past_key_value[0].shape[2] if query_length is None else query_length + + key_length = real_seq_length if key_value_states is None else key_value_states.shape[1] + + def shape(states): + """projection""" + return states.view(batch_size, -1, self.n_heads, self.key_value_proj_dim).transpose(1, 2) + + def unshape(states): + """reshape""" + return states.transpose(1, 2).contiguous().view(batch_size, -1, self.inner_dim) + + def project(hidden_states, proj_layer, key_value_states, past_key_value): + """projects hidden states correctly to key/query states""" + if key_value_states is None: + # self-attn + # (batch_size, n_heads, seq_length, dim_per_head) + hidden_states = shape(proj_layer(hidden_states)) + elif past_key_value is None: + # cross-attn + # (batch_size, n_heads, seq_length, dim_per_head) + hidden_states = shape(proj_layer(key_value_states)) + + if past_key_value is not None: + if key_value_states is None: + # self-attn + # (batch_size, n_heads, key_length, dim_per_head) + hidden_states = torch.cat([past_key_value, hidden_states], dim=2) + elif past_key_value.shape[2] != key_value_states.shape[1]: + # checking that the `sequence_length` of the `past_key_value` is the same as + # the provided `key_value_states` to support prefix tuning + # cross-attn + # (batch_size, n_heads, seq_length, dim_per_head) + hidden_states = shape(proj_layer(key_value_states)) + else: + # cross-attn + hidden_states = past_key_value + return hidden_states + + # get query states + query_states = shape(self.q(hidden_states)) # (batch_size, n_heads, seq_length, dim_per_head) + + # get key/value states + key_states = project( + hidden_states, self.k, key_value_states, past_key_value[0] if past_key_value is not None else None + ) + value_states = project( + hidden_states, self.v, key_value_states, past_key_value[1] if past_key_value is not None else None + ) + + # compute scores + scores = torch.matmul( + query_states, key_states.transpose(3, 2) + ) # equivalent of torch.einsum("bnqd,bnkd->bnqk", query_states, key_states), compatible with onnx op>9 + + if position_bias is None: + if not self.has_relative_attention_bias: + position_bias = torch.zeros( + (1, self.n_heads, real_seq_length, key_length), device=scores.device, dtype=scores.dtype + ) + if self.gradient_checkpointing and self.training: + position_bias.requires_grad = True + else: + position_bias = self.compute_bias(real_seq_length, key_length, device=scores.device) + + # if key and values are already calculated + # we want only the last query position bias + if past_key_value is not None: + position_bias = position_bias[:, :, -hidden_states.size(1) :, :] + + if mask is not None: + position_bias = position_bias + mask # (batch_size, n_heads, seq_length, key_length) + + if self.pruned_heads: + mask = torch.ones(position_bias.shape[1]) + mask[list(self.pruned_heads)] = 0 + position_bias_masked = position_bias[:, mask.bool()] + else: + position_bias_masked = position_bias + + scores += position_bias_masked + attn_weights = nn.functional.softmax(scores.float(), dim=-1).type_as( + scores + ) # (batch_size, n_heads, seq_length, key_length) + attn_weights = nn.functional.dropout( + attn_weights, p=self.dropout, training=self.training + ) # (batch_size, n_heads, seq_length, key_length) + + # Mask heads if we want to + if layer_head_mask is not None: + attn_weights = attn_weights * layer_head_mask + + attn_output = unshape(torch.matmul(attn_weights, value_states)) # (batch_size, seq_length, dim) + attn_output = self.o(attn_output) + + present_key_value_state = (key_states, value_states) if (self.is_decoder and use_cache) else None + outputs = (attn_output,) + (present_key_value_state,) + (position_bias,) + + if output_attentions: + outputs = outputs + (attn_weights,) + return outputs + + +# Copied from transformers.models.t5.modeling_t5.T5LayerSelfAttention with T5->MT5 +class MT5LayerSelfAttention(nn.Module): + def __init__(self, config, has_relative_attention_bias=False): + super().__init__() + self.SelfAttention = MT5Attention(config, has_relative_attention_bias=has_relative_attention_bias) + self.layer_norm = MT5LayerNorm(config.d_model, eps=config.layer_norm_epsilon) + self.dropout = nn.Dropout(config.dropout_rate) + + def forward( + self, + hidden_states, + attention_mask=None, + position_bias=None, + layer_head_mask=None, + past_key_value=None, + use_cache=False, + output_attentions=False, + ): + normed_hidden_states = self.layer_norm(hidden_states) + attention_output = self.SelfAttention( + normed_hidden_states, + mask=attention_mask, + position_bias=position_bias, + layer_head_mask=layer_head_mask, + past_key_value=past_key_value, + use_cache=use_cache, + output_attentions=output_attentions, + ) + hidden_states = hidden_states + self.dropout(attention_output[0]) + outputs = (hidden_states,) + attention_output[1:] # add attentions if we output them + return outputs + + +# Copied from transformers.models.t5.modeling_t5.T5LayerCrossAttention with T5->MT5 +class MT5LayerCrossAttention(nn.Module): + def __init__(self, config): + super().__init__() + self.EncDecAttention = MT5Attention(config, has_relative_attention_bias=False) + self.layer_norm = MT5LayerNorm(config.d_model, eps=config.layer_norm_epsilon) + self.dropout = nn.Dropout(config.dropout_rate) + + def forward( + self, + hidden_states, + key_value_states, + attention_mask=None, + position_bias=None, + layer_head_mask=None, + past_key_value=None, + use_cache=False, + query_length=None, + output_attentions=False, + ): + normed_hidden_states = self.layer_norm(hidden_states) + attention_output = self.EncDecAttention( + normed_hidden_states, + mask=attention_mask, + key_value_states=key_value_states, + position_bias=position_bias, + layer_head_mask=layer_head_mask, + past_key_value=past_key_value, + use_cache=use_cache, + query_length=query_length, + output_attentions=output_attentions, + ) + layer_output = hidden_states + self.dropout(attention_output[0]) + outputs = (layer_output,) + attention_output[1:] # add attentions if we output them + return outputs + + +# Copied from transformers.models.t5.modeling_t5.T5Block with T5->MT5 +class MT5Block(nn.Module): + def __init__(self, config, has_relative_attention_bias=False): + super().__init__() + self.is_decoder = config.is_decoder + self.layer = nn.ModuleList() + self.layer.append(MT5LayerSelfAttention(config, has_relative_attention_bias=has_relative_attention_bias)) + if self.is_decoder: + self.layer.append(MT5LayerCrossAttention(config)) + + self.layer.append(MT5LayerFF(config)) + + def forward( + self, + hidden_states, + attention_mask=None, + position_bias=None, + encoder_hidden_states=None, + encoder_attention_mask=None, + encoder_decoder_position_bias=None, + layer_head_mask=None, + cross_attn_layer_head_mask=None, + past_key_value=None, + use_cache=False, + output_attentions=False, + return_dict=True, + ): + + if past_key_value is not None: + if not self.is_decoder: + logger.warning("`past_key_values` is passed to the encoder. Please make sure this is intended.") + expected_num_past_key_values = 2 if encoder_hidden_states is None else 4 + + if len(past_key_value) != expected_num_past_key_values: + raise ValueError( + f"There should be {expected_num_past_key_values} past states. " + f"{'2 (past / key) for cross attention. ' if expected_num_past_key_values == 4 else ''}" + f"Got {len(past_key_value)} past key / value states" + ) + + self_attn_past_key_value = past_key_value[:2] + cross_attn_past_key_value = past_key_value[2:] + else: + self_attn_past_key_value, cross_attn_past_key_value = None, None + + self_attention_outputs = self.layer[0]( + hidden_states, + attention_mask=attention_mask, + position_bias=position_bias, + layer_head_mask=layer_head_mask, + past_key_value=self_attn_past_key_value, + use_cache=use_cache, + output_attentions=output_attentions, + ) + hidden_states, present_key_value_state = self_attention_outputs[:2] + attention_outputs = self_attention_outputs[2:] # Keep self-attention outputs and relative position weights + + # clamp inf values to enable fp16 training + if hidden_states.dtype == torch.float16 and torch.isinf(hidden_states).any(): + clamp_value = torch.finfo(hidden_states.dtype).max - 1000 + hidden_states = torch.clamp(hidden_states, min=-clamp_value, max=clamp_value) + + do_cross_attention = self.is_decoder and encoder_hidden_states is not None + if do_cross_attention: + # the actual query length is unknown for cross attention + # if using past key value states. Need to inject it here + if present_key_value_state is not None: + query_length = present_key_value_state[0].shape[2] + else: + query_length = None + + cross_attention_outputs = self.layer[1]( + hidden_states, + key_value_states=encoder_hidden_states, + attention_mask=encoder_attention_mask, + position_bias=encoder_decoder_position_bias, + layer_head_mask=cross_attn_layer_head_mask, + past_key_value=cross_attn_past_key_value, + query_length=query_length, + use_cache=use_cache, + output_attentions=output_attentions, + ) + hidden_states = cross_attention_outputs[0] + + # clamp inf values to enable fp16 training + if hidden_states.dtype == torch.float16 and torch.isinf(hidden_states).any(): + clamp_value = torch.finfo(hidden_states.dtype).max - 1000 + hidden_states = torch.clamp(hidden_states, min=-clamp_value, max=clamp_value) + + # Combine self attn and cross attn key value states + if present_key_value_state is not None: + present_key_value_state = present_key_value_state + cross_attention_outputs[1] + + # Keep cross-attention outputs and relative position weights + attention_outputs = attention_outputs + cross_attention_outputs[2:] + + # Apply Feed Forward layer + hidden_states = self.layer[-1](hidden_states) + + # clamp inf values to enable fp16 training + if hidden_states.dtype == torch.float16 and torch.isinf(hidden_states).any(): + clamp_value = torch.finfo(hidden_states.dtype).max - 1000 + hidden_states = torch.clamp(hidden_states, min=-clamp_value, max=clamp_value) + + outputs = (hidden_states,) + + if use_cache: + outputs = outputs + (present_key_value_state,) + attention_outputs + else: + outputs = outputs + attention_outputs + + return outputs # hidden-states, present_key_value_states, (self-attention position bias), (self-attention weights), (cross-attention position bias), (cross-attention weights) + + +def load_tf_weights_in_mt5(model, config, tf_checkpoint_path): + """Load tf checkpoints in a pytorch model.""" + try: + import re + + import numpy as np + import tensorflow as tf + except ImportError: + logger.error( + "Loading a TensorFlow model in PyTorch, requires TensorFlow to be installed. Please see " + "https://www.tensorflow.org/install/ for installation instructions." + ) + raise + tf_path = os.path.abspath(tf_checkpoint_path) + logger.info(f"Converting TensorFlow checkpoint from {tf_path}") + # Load weights from TF model + init_vars = tf.train.list_variables(tf_path) + names = [] + tf_weights = {} + for name, shape in init_vars: + logger.info(f"Loading TF weight {name} with shape {shape}") + array = tf.train.load_variable(tf_path, name) + names.append(name) + tf_weights[name] = array + + for txt_name in names: + name = txt_name.split("/") + # adam_v and adam_m are variables used in AdamWeightDecayOptimizer to calculated m and v + # which are not required for using pretrained model + if any( + n in ["adam_v", "adam_m", "AdamWeightDecayOptimizer", "AdamWeightDecayOptimizer_1", "global_step"] + for n in name + ): + logger.info(f"Skipping {'/'.join(name)}") + tf_weights.pop(txt_name, None) + continue + if "_slot_" in name[-1]: + logger.info(f"Skipping {'/'.join(name)}") + tf_weights.pop(txt_name, None) + continue + pointer = model + array = tf_weights[txt_name] + + for m_name in name: + if re.fullmatch(r"[A-Za-z]+_\d+", m_name): + scope_names = re.split(r"_(\d+)", m_name) + else: + scope_names = [m_name] + if scope_names[0] in ["kernel", "scale", "embedding"]: + pointer = getattr(pointer, "weight") + elif scope_names[0] == "self_attention": + pointer = getattr(pointer, "layer") + pointer = pointer[0] + elif scope_names[0] == "enc_dec_attention": + pointer = getattr(pointer, "layer") + pointer = pointer[1] + elif scope_names[0] == "dense_relu_dense": + pointer = getattr(pointer, "layer") + pointer = pointer[2] + elif scope_names[0] == "rms_norm": + if hasattr(pointer, "layer_norm"): + pointer = getattr(pointer, "layer_norm") + elif hasattr(pointer, "final_layer_norm"): + pointer = getattr(pointer, "final_layer_norm") + elif scope_names[0] == "scale": + pointer = getattr(pointer, "weight") + elif scope_names[0] == "output_bias" or scope_names[0] == "beta": + pointer = getattr(pointer, "bias") + elif scope_names[0] == "squad": + pointer = getattr(pointer, "classifier") + elif scope_names[0] == "decoder" and name[1] == "logits": + continue + elif scope_names[0] == "logits": + pointer = getattr(pointer, "lm_head") + elif scope_names[0] == "wi" and len(scope_names) > 1 and scope_names[1].isdigit(): + pointer = getattr(pointer, f"wi_{scope_names[1]}") + continue + else: + try: + pointer = getattr(pointer, scope_names[0]) + except AttributeError: + logger.info(f"Skipping {'/'.join(name)}") + continue + if len(scope_names) >= 2: + num = int(scope_names[1]) + pointer = pointer[num] + if scope_names[0] not in ["kernel", "scale", "embedding"]: + pointer = getattr(pointer, "weight") + if scope_names[0] != "embedding": + logger.info(f"Transposing numpy weight of shape {array.shape} for {name}") + array = np.transpose(array) + try: + assert ( + pointer.shape == array.shape + ), f"Pointer shape {pointer.shape} and array shape {array.shape} mismatched" + except AssertionError as e: + e.args += (pointer.shape, array.shape) + raise + logger.info(f"Initialize PyTorch weight {name}") + pointer.data = torch.from_numpy(array.astype(np.float32)) + tf_weights.pop(txt_name, None) + + logger.info(f"Weights not copied to PyTorch model: {', '.join(tf_weights.keys())}.") + return model + + +# Copied from transformers.models.t5.modeling_t5.T5PreTrainedModel with T5->MT5, t5->mt5 +class MT5PreTrainedModel(PreTrainedModel): + """ + An abstract class to handle weights initialization and a simple interface for downloading and loading pretrained + models. + """ + + config_class = MT5Config + load_tf_weights = load_tf_weights_in_mt5 + base_model_prefix = "transformer" + is_parallelizable = True + supports_gradient_checkpointing = True + _no_split_modules = ["MT5Block"] + _keep_in_fp32_modules = ["wo"] + + @property + def dummy_inputs(self): + input_ids = torch.tensor(DUMMY_INPUTS) + input_mask = torch.tensor(DUMMY_MASK) + dummy_inputs = { + "decoder_input_ids": input_ids, + "input_ids": input_ids, + "decoder_attention_mask": input_mask, + } + return dummy_inputs + + def _init_weights(self, module): + """Initialize the weights""" + factor = self.config.initializer_factor # Used for testing weights initialization + if isinstance(module, MT5LayerNorm): + module.weight.data.fill_(factor * 1.0) + elif isinstance(module, (MT5Model, MT5ForConditionalGeneration, MT5EncoderModel)): + # Mesh TensorFlow embeddings initialization + # See https://github.com/tensorflow/mesh/blob/fa19d69eafc9a482aff0b59ddd96b025c0cb207d/mesh_tensorflow/layers.py#L1624 + module.shared.weight.data.normal_(mean=0.0, std=factor * 1.0) + if hasattr(module, "lm_head") and not self.config.tie_word_embeddings: + module.lm_head.weight.data.normal_(mean=0.0, std=factor * 1.0) + elif isinstance(module, MT5DenseActDense): + # Mesh TensorFlow FF initialization + # See https://github.com/tensorflow/mesh/blob/master/mesh_tensorflow/transformer/transformer_layers.py#L56 + # and https://github.com/tensorflow/mesh/blob/fa19d69eafc9a482aff0b59ddd96b025c0cb207d/mesh_tensorflow/layers.py#L89 + module.wi.weight.data.normal_(mean=0.0, std=factor * ((self.config.d_model) ** -0.5)) + if hasattr(module.wi, "bias") and module.wi.bias is not None: + module.wi.bias.data.zero_() + module.wo.weight.data.normal_(mean=0.0, std=factor * ((self.config.d_ff) ** -0.5)) + if hasattr(module.wo, "bias") and module.wo.bias is not None: + module.wo.bias.data.zero_() + elif isinstance(module, MT5DenseGatedActDense): + module.wi_0.weight.data.normal_(mean=0.0, std=factor * ((self.config.d_model) ** -0.5)) + if hasattr(module.wi_0, "bias") and module.wi_0.bias is not None: + module.wi_0.bias.data.zero_() + module.wi_1.weight.data.normal_(mean=0.0, std=factor * ((self.config.d_model) ** -0.5)) + if hasattr(module.wi_1, "bias") and module.wi_1.bias is not None: + module.wi_1.bias.data.zero_() + module.wo.weight.data.normal_(mean=0.0, std=factor * ((self.config.d_ff) ** -0.5)) + if hasattr(module.wo, "bias") and module.wo.bias is not None: + module.wo.bias.data.zero_() + elif isinstance(module, MT5Attention): + # Mesh TensorFlow attention initialization to avoid scaling before softmax + # See https://github.com/tensorflow/mesh/blob/fa19d69eafc9a482aff0b59ddd96b025c0cb207d/mesh_tensorflow/transformer/attention.py#L136 + d_model = self.config.d_model + key_value_proj_dim = self.config.d_kv + n_heads = self.config.num_heads + module.q.weight.data.normal_(mean=0.0, std=factor * ((d_model * key_value_proj_dim) ** -0.5)) + module.k.weight.data.normal_(mean=0.0, std=factor * (d_model**-0.5)) + module.v.weight.data.normal_(mean=0.0, std=factor * (d_model**-0.5)) + module.o.weight.data.normal_(mean=0.0, std=factor * ((n_heads * key_value_proj_dim) ** -0.5)) + if module.has_relative_attention_bias: + module.relative_attention_bias.weight.data.normal_(mean=0.0, std=factor * ((d_model) ** -0.5)) + + def _set_gradient_checkpointing(self, module, value=False): + if isinstance(module, (MT5Attention, MT5Stack)): + module.gradient_checkpointing = value + + def _shift_right(self, input_ids): + decoder_start_token_id = self.config.decoder_start_token_id + pad_token_id = self.config.pad_token_id + + assert decoder_start_token_id is not None, ( + "self.model.config.decoder_start_token_id has to be defined. In MT5 it is usually set to the pad_token_id." + " See MT5 docs for more information" + ) + + # shift inputs to the right + if is_torch_fx_proxy(input_ids): + # Item assignment is not supported natively for proxies. + shifted_input_ids = torch.full(input_ids.shape[:-1] + (1,), decoder_start_token_id) + shifted_input_ids = torch.cat([shifted_input_ids, input_ids[..., :-1]], dim=-1) + else: + shifted_input_ids = input_ids.new_zeros(input_ids.shape) + shifted_input_ids[..., 1:] = input_ids[..., :-1].clone() + shifted_input_ids[..., 0] = decoder_start_token_id + + assert pad_token_id is not None, "self.model.config.pad_token_id has to be defined." + # replace possible -100 values in labels by `pad_token_id` + shifted_input_ids.masked_fill_(shifted_input_ids == -100, pad_token_id) + + return shifted_input_ids + + +# Copied from transformers.models.t5.modeling_t5.T5Stack with T5->MT5 +class MT5Stack(MT5PreTrainedModel): + def __init__(self, config, embed_tokens=None): + super().__init__(config) + + self.embed_tokens = embed_tokens + self.is_decoder = config.is_decoder + + self.block = nn.ModuleList( + [MT5Block(config, has_relative_attention_bias=bool(i == 0)) for i in range(config.num_layers)] + ) + self.final_layer_norm = MT5LayerNorm(config.d_model, eps=config.layer_norm_epsilon) + self.dropout = nn.Dropout(config.dropout_rate) + + # Initialize weights and apply final processing + self.post_init() + # Model parallel + self.model_parallel = False + self.device_map = None + self.gradient_checkpointing = False + + @add_start_docstrings(PARALLELIZE_DOCSTRING) + def parallelize(self, device_map=None): + # Check validity of device_map + self.device_map = ( + get_device_map(len(self.block), range(torch.cuda.device_count())) if device_map is None else device_map + ) + assert_device_map(self.device_map, len(self.block)) + self.model_parallel = True + self.first_device = "cpu" if "cpu" in self.device_map.keys() else "cuda:" + str(min(self.device_map.keys())) + self.last_device = "cuda:" + str(max(self.device_map.keys())) + # Load onto devices + for k, v in self.device_map.items(): + for layer in v: + cuda_device = "cuda:" + str(k) + self.block[layer] = self.block[layer].to(cuda_device) + + # Set embed_tokens to first layer + self.embed_tokens = self.embed_tokens.to(self.first_device) + # Set final layer norm to last device + self.final_layer_norm = self.final_layer_norm.to(self.last_device) + + @add_start_docstrings(PARALLELIZE_DOCSTRING) + def deparallelize(self): + self.model_parallel = False + self.device_map = None + self.first_device = "cpu" + self.last_device = "cpu" + for i in range(len(self.block)): + self.block[i] = self.block[i].to("cpu") + self.embed_tokens = self.embed_tokens.to("cpu") + self.final_layer_norm = self.final_layer_norm.to("cpu") + torch.cuda.empty_cache() + + def get_input_embeddings(self): + return self.embed_tokens + + def set_input_embeddings(self, new_embeddings): + self.embed_tokens = new_embeddings + + def forward( + self, + input_ids=None, + attention_mask=None, + encoder_hidden_states=None, + encoder_attention_mask=None, + inputs_embeds=None, + head_mask=None, + cross_attn_head_mask=None, + past_key_values=None, + use_cache=None, + output_attentions=None, + output_hidden_states=None, + return_dict=None, + ): + # Model parallel + if self.model_parallel: + torch.cuda.set_device(self.first_device) + self.embed_tokens = self.embed_tokens.to(self.first_device) + use_cache = use_cache if use_cache is not None else self.config.use_cache + output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions + output_hidden_states = ( + output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states + ) + return_dict = return_dict if return_dict is not None else self.config.use_return_dict + + if input_ids is not None and inputs_embeds is not None: + err_msg_prefix = "decoder_" if self.is_decoder else "" + raise ValueError( + f"You cannot specify both {err_msg_prefix}input_ids and {err_msg_prefix}inputs_embeds at the same time" + ) + elif input_ids is not None: + input_shape = input_ids.size() + input_ids = input_ids.view(-1, input_shape[-1]) + elif inputs_embeds is not None: + input_shape = inputs_embeds.size()[:-1] + else: + err_msg_prefix = "decoder_" if self.is_decoder else "" + raise ValueError(f"You have to specify either {err_msg_prefix}input_ids or {err_msg_prefix}inputs_embeds") + + if inputs_embeds is None: + assert self.embed_tokens is not None, "You have to initialize the model with valid token embeddings" + inputs_embeds = self.embed_tokens(input_ids) + + batch_size, seq_length = input_shape + + # required mask seq length can be calculated via length of past + mask_seq_length = past_key_values[0][0].shape[2] + seq_length if past_key_values is not None else seq_length + + if use_cache is True: + assert self.is_decoder, f"`use_cache` can only be set to `True` if {self} is used as a decoder" + + if attention_mask is None: + attention_mask = torch.ones(batch_size, mask_seq_length, device=inputs_embeds.device) + if self.is_decoder and encoder_attention_mask is None and encoder_hidden_states is not None: + encoder_seq_length = encoder_hidden_states.shape[1] + encoder_attention_mask = torch.ones( + batch_size, encoder_seq_length, device=inputs_embeds.device, dtype=torch.long + ) + + # initialize past_key_values with `None` if past does not exist + if past_key_values is None: + past_key_values = [None] * len(self.block) + + # We can provide a self-attention mask of dimensions [batch_size, from_seq_length, to_seq_length] + # ourselves in which case we just need to make it broadcastable to all heads. + extended_attention_mask = self.get_extended_attention_mask(attention_mask, input_shape) + + # If a 2D or 3D attention mask is provided for the cross-attention + # we need to make broadcastable to [batch_size, num_heads, seq_length, seq_length] + if self.is_decoder and encoder_hidden_states is not None: + encoder_batch_size, encoder_sequence_length, _ = encoder_hidden_states.size() + encoder_hidden_shape = (encoder_batch_size, encoder_sequence_length) + if encoder_attention_mask is None: + encoder_attention_mask = torch.ones(encoder_hidden_shape, device=inputs_embeds.device) + encoder_extended_attention_mask = self.invert_attention_mask(encoder_attention_mask) + else: + encoder_extended_attention_mask = None + + # Prepare head mask if needed + head_mask = self.get_head_mask(head_mask, self.config.num_layers) + cross_attn_head_mask = self.get_head_mask(cross_attn_head_mask, self.config.num_layers) + present_key_value_states = () if use_cache else None + all_hidden_states = () if output_hidden_states else None + all_attentions = () if output_attentions else None + all_cross_attentions = () if (output_attentions and self.is_decoder) else None + position_bias = None + encoder_decoder_position_bias = None + + hidden_states = self.dropout(inputs_embeds) + + for i, (layer_module, past_key_value) in enumerate(zip(self.block, past_key_values)): + layer_head_mask = head_mask[i] + cross_attn_layer_head_mask = cross_attn_head_mask[i] + # Model parallel + if self.model_parallel: + torch.cuda.set_device(hidden_states.device) + # Ensure that attention_mask is always on the same device as hidden_states + if attention_mask is not None: + attention_mask = attention_mask.to(hidden_states.device) + if position_bias is not None: + position_bias = position_bias.to(hidden_states.device) + if encoder_hidden_states is not None: + encoder_hidden_states = encoder_hidden_states.to(hidden_states.device) + if encoder_extended_attention_mask is not None: + encoder_extended_attention_mask = encoder_extended_attention_mask.to(hidden_states.device) + if encoder_decoder_position_bias is not None: + encoder_decoder_position_bias = encoder_decoder_position_bias.to(hidden_states.device) + if layer_head_mask is not None: + layer_head_mask = layer_head_mask.to(hidden_states.device) + if cross_attn_layer_head_mask is not None: + cross_attn_layer_head_mask = cross_attn_layer_head_mask.to(hidden_states.device) + if output_hidden_states: + all_hidden_states = all_hidden_states + (hidden_states,) + + if self.gradient_checkpointing and self.training: + if use_cache: + logger.warning( + "`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`..." + ) + use_cache = False + + def create_custom_forward(module): + def custom_forward(*inputs): + return tuple(module(*inputs, use_cache, output_attentions)) + + return custom_forward + + layer_outputs = checkpoint( + create_custom_forward(layer_module), + hidden_states, + extended_attention_mask, + position_bias, + encoder_hidden_states, + encoder_extended_attention_mask, + encoder_decoder_position_bias, + layer_head_mask, + cross_attn_layer_head_mask, + None, # past_key_value is always None with gradient checkpointing + ) + else: + layer_outputs = layer_module( + hidden_states, + attention_mask=extended_attention_mask, + position_bias=position_bias, + encoder_hidden_states=encoder_hidden_states, + encoder_attention_mask=encoder_extended_attention_mask, + encoder_decoder_position_bias=encoder_decoder_position_bias, + layer_head_mask=layer_head_mask, + cross_attn_layer_head_mask=cross_attn_layer_head_mask, + past_key_value=past_key_value, + use_cache=use_cache, + output_attentions=output_attentions, + ) + + # layer_outputs is a tuple with: + # hidden-states, key-value-states, (self-attention position bias), (self-attention weights), (cross-attention position bias), (cross-attention weights) + if use_cache is False: + layer_outputs = layer_outputs[:1] + (None,) + layer_outputs[1:] + + hidden_states, present_key_value_state = layer_outputs[:2] + + # We share the position biases between the layers - the first layer store them + # layer_outputs = hidden-states, key-value-states (self-attention position bias), (self-attention weights), + # (cross-attention position bias), (cross-attention weights) + position_bias = layer_outputs[2] + if self.is_decoder and encoder_hidden_states is not None: + encoder_decoder_position_bias = layer_outputs[4 if output_attentions else 3] + # append next layer key value states + if use_cache: + present_key_value_states = present_key_value_states + (present_key_value_state,) + + if output_attentions: + all_attentions = all_attentions + (layer_outputs[3],) + if self.is_decoder: + all_cross_attentions = all_cross_attentions + (layer_outputs[5],) + + # Model Parallel: If it's the last layer for that device, put things on the next device + if self.model_parallel: + for k, v in self.device_map.items(): + if i == v[-1] and "cuda:" + str(k) != self.last_device: + hidden_states = hidden_states.to("cuda:" + str(k + 1)) + + hidden_states = self.final_layer_norm(hidden_states) + hidden_states = self.dropout(hidden_states) + + # Add last layer + if output_hidden_states: + all_hidden_states = all_hidden_states + (hidden_states,) + + if not return_dict: + return tuple( + v + for v in [ + hidden_states, + present_key_value_states, + all_hidden_states, + all_attentions, + all_cross_attentions, + ] + if v is not None + ) + return BaseModelOutputWithPastAndCrossAttentions( + last_hidden_state=hidden_states, + past_key_values=present_key_value_states, + hidden_states=all_hidden_states, + attentions=all_attentions, + cross_attentions=all_cross_attentions, + ) + + +MT5_START_DOCSTRING = r""" + + The MT5 model was proposed in [Exploring the Limits of Transfer Learning with a Unified Text-to-Text + Transformer](https://arxiv.org/abs/1910.10683) by Colin Raffel, Noam Shazeer, Adam Roberts, Katherine Lee, Sharan + Narang, Michael Matena, Yanqi Zhou, Wei Li, Peter J. Liu. It's an encoder decoder transformer pre-trained in a + text-to-text denoising generative setting. + + This model inherits from [`PreTrainedModel`]. Check the superclass documentation for the generic methods the + library implements for all its model (such as downloading or saving, resizing the input embeddings, pruning heads + etc.) + + This model is also a PyTorch [torch.nn.Module](https://pytorch.org/docs/stable/nn.html#torch.nn.Module) subclass. + Use it as a regular PyTorch Module and refer to the PyTorch documentation for all matter related to general usage + and behavior. + + Parameters: + config ([`MT5Config`]): Model configuration class with all the parameters of the model. + Initializing with a config file does not load the weights associated with the model, only the + configuration. Check out the [`~PreTrainedModel.from_pretrained`] method to load the model weights. +""" + +MT5_INPUTS_DOCSTRING = r""" + Args: + input_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`): + Indices of input sequence tokens in the vocabulary. MT5 is a model with relative position embeddings so you + should be able to pad the inputs on both the right and the left. + + Indices can be obtained using [`MT5Tokenizer`]. See [`PreTrainedTokenizer.encode`] and + [`PreTrainedTokenizer.__call__`] for detail. + + [What are input IDs?](../glossary#input-ids) + + To know more on how to prepare `input_ids` for pretraining take a look a [MT5 Training](./mt5#training). + attention_mask (`torch.FloatTensor` of shape `(batch_size, sequence_length)`, *optional*): + Mask to avoid performing attention on padding token indices. Mask values selected in `[0, 1]`: + + - 1 for tokens that are **not masked**, + - 0 for tokens that are **masked**. + + [What are attention masks?](../glossary#attention-mask) + decoder_input_ids (`torch.LongTensor` of shape `(batch_size, target_sequence_length)`, *optional*): + Indices of decoder input sequence tokens in the vocabulary. + + Indices can be obtained using [`MT5Tokenizer`]. See [`PreTrainedTokenizer.encode`] and + [`PreTrainedTokenizer.__call__`] for details. + + [What are decoder input IDs?](../glossary#decoder-input-ids) + + MT5 uses the `pad_token_id` as the starting token for `decoder_input_ids` generation. If `past_key_values` + is used, optionally only the last `decoder_input_ids` have to be input (see `past_key_values`). + + To know more on how to prepare `decoder_input_ids` for pretraining take a look at [MT5 + Training](./mt5#training). + decoder_attention_mask (`torch.BoolTensor` of shape `(batch_size, target_sequence_length)`, *optional*): + Default behavior: generate a tensor that ignores pad tokens in `decoder_input_ids`. Causal mask will also + be used by default. + head_mask (`torch.FloatTensor` of shape `(num_heads,)` or `(num_layers, num_heads)`, *optional*): + Mask to nullify selected heads of the self-attention modules in the encoder. Mask values selected in `[0, + 1]`: + + - 1 indicates the head is **not masked**, + - 0 indicates the head is **masked**. + + decoder_head_mask (`torch.FloatTensor` of shape `(num_heads,)` or `(num_layers, num_heads)`, *optional*): + Mask to nullify selected heads of the self-attention modules in the decoder. Mask values selected in `[0, + 1]`: + + - 1 indicates the head is **not masked**, + - 0 indicates the head is **masked**. + + cross_attn_head_mask (`torch.Tensor` of shape `(num_heads,)` or `(num_layers, num_heads)`, *optional*): + Mask to nullify selected heads of the cross-attention modules in the decoder. Mask values selected in + `[0, 1]`: + + - 1 indicates the head is **not masked**, + - 0 indicates the head is **masked**. + + encoder_outputs (`tuple(tuple(torch.FloatTensor)`, *optional*): + Tuple consists of (`last_hidden_state`, `optional`: *hidden_states*, `optional`: *attentions*) + `last_hidden_state` of shape `(batch_size, sequence_length, hidden_size)` is a sequence of hidden states at + the output of the last layer of the encoder. Used in the cross-attention of the decoder. + past_key_values (`tuple(tuple(torch.FloatTensor))` of length `config.n_layers` with each tuple having 4 tensors of shape `(batch_size, num_heads, sequence_length - 1, embed_size_per_head)`): + Contains precomputed key and value hidden states of the attention blocks. Can be used to speed up decoding. + + If `past_key_values` are used, the user can optionally input only the last `decoder_input_ids` (those that + don't have their past key value states given to this model) of shape `(batch_size, 1)` instead of all + `decoder_input_ids` of shape `(batch_size, sequence_length)`. + inputs_embeds (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`, *optional*): + Optionally, instead of passing `input_ids` you can choose to directly pass an embedded representation. This + is useful if you want more control over how to convert `input_ids` indices into associated vectors than the + model's internal embedding lookup matrix. + decoder_inputs_embeds (`torch.FloatTensor` of shape `(batch_size, target_sequence_length, hidden_size)`, *optional*): + Optionally, instead of passing `decoder_input_ids` you can choose to directly pass an embedded + representation. If `past_key_values` is used, optionally only the last `decoder_inputs_embeds` have to be + input (see `past_key_values`). This is useful if you want more control over how to convert + `decoder_input_ids` indices into associated vectors than the model's internal embedding lookup matrix. + + If `decoder_input_ids` and `decoder_inputs_embeds` are both unset, `decoder_inputs_embeds` takes the value + of `inputs_embeds`. + + use_cache (`bool`, *optional*): + If set to `True`, `past_key_values` key value states are returned and can be used to speed up decoding (see + `past_key_values`). + + output_attentions (`bool`, *optional*): + Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned + tensors for more detail. + output_hidden_states (`bool`, *optional*): + Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors for + more detail. + return_dict (`bool`, *optional*): + Whether or not to return a [`~utils.ModelOutput`] instead of a plain tuple. +""" + +MT5_ENCODER_INPUTS_DOCSTRING = r""" + Args: + input_ids (`torch.LongTensor` of shape `(batch_size, sequence_length)`): + Indices of input sequence tokens in the vocabulary. MT5 is a model with relative position embeddings so you + should be able to pad the inputs on both the right and the left. + + Indices can be obtained using [`MT5Tokenizer`]. See [`PreTrainedTokenizer.encode`] and + [`PreTrainedTokenizer.__call__`] for detail. + + To know more on how to prepare `input_ids` for pretraining take a look a [MT5 Training](./mt5#training). + attention_mask (`torch.FloatTensor` of shape `(batch_size, sequence_length)`, *optional*): + Mask to avoid performing attention on padding token indices. Mask values selected in `[0, 1]`: + + - 1 for tokens that are **not masked**, + - 0 for tokens that are **masked**. + + [What are attention masks?](../glossary#attention-mask) + head_mask (`torch.FloatTensor` of shape `(num_heads,)` or `(num_layers, num_heads)`, *optional*): + Mask to nullify selected heads of the self-attention modules. Mask values selected in `[0, 1]`: + + - 1 indicates the head is **not masked**, + - 0 indicates the head is **masked**. + + inputs_embeds (`torch.FloatTensor` of shape `(batch_size, sequence_length, hidden_size)`, *optional*): + Optionally, instead of passing `input_ids` you can choose to directly pass an embedded representation. This + is useful if you want more control over how to convert `input_ids` indices into associated vectors than the + model's internal embedding lookup matrix. + output_attentions (`bool`, *optional*): + Whether or not to return the attentions tensors of all attention layers. See `attentions` under returned + tensors for more detail. + output_hidden_states (`bool`, *optional*): + Whether or not to return the hidden states of all layers. See `hidden_states` under returned tensors for + more detail. + return_dict (`bool`, *optional*): + Whether or not to return a [`~utils.ModelOutput`] instead of a plain tuple. +""" + +# Warning message for FutureWarning: head_mask was separated into two input args - head_mask, decoder_head_mask +__HEAD_MASK_WARNING_MSG = """ +The input argument `head_mask` was split into two arguments `head_mask` and `decoder_head_mask`. Currently, +`decoder_head_mask` is set to copy `head_mask`, but this feature is deprecated and will be removed in future versions. +If you do not want to use any `decoder_head_mask` now, please set `decoder_head_mask = torch.ones(num_layers, +num_heads)`. +""" + + +@add_start_docstrings( + "The bare MT5 Model transformer outputting raw hidden-states without any specific head on top.", + MT5_START_DOCSTRING, +) +class MT5Model(MT5PreTrainedModel): r""" - This class overrides [`T5Model`]. Please check the superclass for the appropriate documentation alongside usage - examples. - Examples: ```python - >>> from transformers import MT5Model, T5Tokenizer + >>> from transformers import MT5Model, MT5Tokenizer >>> model = MT5Model.from_pretrained("google/mt5-small") - >>> tokenizer = T5Tokenizer.from_pretrained("google/mt5-small") + >>> tokenizer = MT5Tokenizer.from_pretrained("google/mt5-small") >>> article = "UN Offizier sagt, dass weiter verhandelt werden muss in Syrien." >>> summary = "Weiter Verhandlung in Syrien." >>> inputs = tokenizer(article, return_tensors="pt") @@ -56,20 +1283,211 @@ class MT5Model(T5Model): r"encoder.embed_tokens.weight", r"decoder.embed_tokens.weight", ] + _keys_to_ignore_on_load_unexpected = [ + r"decoder.block.0.layer.1.EncDecAttention.relative_attention_bias.weight", + ] + + # Copied from transformers.models.t5.modeling_t5.T5Model.__init__ with T5->MT5 + def __init__(self, config: MT5Config): + super().__init__(config) + self.shared = nn.Embedding(config.vocab_size, config.d_model) + + encoder_config = copy.deepcopy(config) + encoder_config.is_decoder = False + encoder_config.use_cache = False + encoder_config.is_encoder_decoder = False + self.encoder = MT5Stack(encoder_config, self.shared) + + decoder_config = copy.deepcopy(config) + decoder_config.is_decoder = True + decoder_config.is_encoder_decoder = False + decoder_config.num_layers = config.num_decoder_layers + self.decoder = MT5Stack(decoder_config, self.shared) + + # Initialize weights and apply final processing + self.post_init() + + # Model parallel + self.model_parallel = False + self.device_map = None + + @add_start_docstrings(PARALLELIZE_DOCSTRING) + # Copied from transformers.models.t5.modeling_t5.T5Model.parallelize + def parallelize(self, device_map=None): + self.device_map = ( + get_device_map(len(self.encoder.block), range(torch.cuda.device_count())) + if device_map is None + else device_map + ) + assert_device_map(self.device_map, len(self.encoder.block)) + self.encoder.parallelize(self.device_map) + self.decoder.parallelize(self.device_map) + self.model_parallel = True + + @add_start_docstrings(DEPARALLELIZE_DOCSTRING) + # Copied from transformers.models.t5.modeling_t5.T5Model.deparallelize + def deparallelize(self): + self.encoder.deparallelize() + self.decoder.deparallelize() + self.encoder = self.encoder.to("cpu") + self.decoder = self.decoder.to("cpu") + self.model_parallel = False + self.device_map = None + torch.cuda.empty_cache() + + # Copied from transformers.models.t5.modeling_t5.T5Model.get_input_embeddings + def get_input_embeddings(self): + return self.shared + + # Copied from transformers.models.t5.modeling_t5.T5Model.set_input_embeddings + def set_input_embeddings(self, new_embeddings): + self.shared = new_embeddings + self.encoder.set_input_embeddings(new_embeddings) + self.decoder.set_input_embeddings(new_embeddings) + + # Copied from transformers.models.t5.modeling_t5.T5Model.get_encoder + def get_encoder(self): + return self.encoder + + # Copied from transformers.models.t5.modeling_t5.T5Model.get_decoder + def get_decoder(self): + return self.decoder + + # Copied from transformers.models.t5.modeling_t5.T5Model._prune_heads + 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) + + @add_start_docstrings_to_model_forward(MT5_INPUTS_DOCSTRING) + @replace_return_docstrings(output_type=Seq2SeqModelOutput, config_class=_CONFIG_FOR_DOC) + # Copied from transformers.models.t5.modeling_t5.T5Model.forward with T5->MT5, t5->mt5 + def forward( + self, + input_ids: Optional[torch.LongTensor] = None, + attention_mask: Optional[torch.FloatTensor] = None, + decoder_input_ids: Optional[torch.LongTensor] = None, + decoder_attention_mask: Optional[torch.BoolTensor] = None, + head_mask: Optional[torch.FloatTensor] = None, + decoder_head_mask: Optional[torch.FloatTensor] = None, + cross_attn_head_mask: Optional[torch.Tensor] = None, + encoder_outputs: Optional[Tuple[Tuple[torch.FloatTensor]]] = None, + past_key_values: Optional[Tuple[Tuple[torch.FloatTensor]]] = None, + inputs_embeds: Optional[torch.Tensor] = None, + decoder_inputs_embeds: Optional[torch.Tensor] = None, + use_cache: Optional[bool] = None, + output_attentions: Optional[bool] = None, + output_hidden_states: Optional[bool] = None, + return_dict: Optional[bool] = None, + ) -> Union[Tuple[torch.FloatTensor], Seq2SeqModelOutput]: + r""" + Returns: + + Example: + + ```python + >>> from transformers import MT5Tokenizer, MT5Model + + >>> tokenizer = MT5Tokenizer.from_pretrained("mt5-small") + >>> model = MT5Model.from_pretrained("mt5-small") + + >>> input_ids = tokenizer( + ... "Studies have been shown that owning a dog is good for you", return_tensors="pt" + ... ).input_ids # Batch size 1 + >>> decoder_input_ids = tokenizer("Studies show that", return_tensors="pt").input_ids # Batch size 1 + + >>> # preprocess: Prepend decoder_input_ids with start token which is pad token for MT5Model. + >>> # This is not needed for torch's MT5ForConditionalGeneration as it does this internally using labels arg. + >>> decoder_input_ids = model._shift_right(decoder_input_ids) + + >>> # forward pass + >>> outputs = model(input_ids=input_ids, decoder_input_ids=decoder_input_ids) + >>> last_hidden_states = outputs.last_hidden_state + ```""" + use_cache = use_cache if use_cache is not None else self.config.use_cache + return_dict = return_dict if return_dict is not None else self.config.use_return_dict + + # FutureWarning: head_mask was separated into two input args - head_mask, decoder_head_mask + if head_mask is not None and decoder_head_mask is None: + if self.config.num_layers == self.config.num_decoder_layers: + warnings.warn(__HEAD_MASK_WARNING_MSG, FutureWarning) + decoder_head_mask = head_mask + + # Encode if needed (training, first prediction pass) + if encoder_outputs is None: + encoder_outputs = self.encoder( + input_ids=input_ids, + attention_mask=attention_mask, + inputs_embeds=inputs_embeds, + head_mask=head_mask, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + ) + elif return_dict and not isinstance(encoder_outputs, BaseModelOutput): + encoder_outputs = BaseModelOutput( + last_hidden_state=encoder_outputs[0], + hidden_states=encoder_outputs[1] if len(encoder_outputs) > 1 else None, + attentions=encoder_outputs[2] if len(encoder_outputs) > 2 else None, + ) + + hidden_states = encoder_outputs[0] + + # Set device for model parallelism + if self.model_parallel: + torch.cuda.set_device(self.decoder.first_device) + hidden_states = hidden_states.to(self.decoder.first_device) + if decoder_input_ids is not None: + decoder_input_ids = decoder_input_ids.to(self.decoder.first_device) + if attention_mask is not None: + attention_mask = attention_mask.to(self.decoder.first_device) + if decoder_attention_mask is not None: + decoder_attention_mask = decoder_attention_mask.to(self.decoder.first_device) + + # Decode + decoder_outputs = self.decoder( + input_ids=decoder_input_ids, + attention_mask=decoder_attention_mask, + inputs_embeds=decoder_inputs_embeds, + past_key_values=past_key_values, + encoder_hidden_states=hidden_states, + encoder_attention_mask=attention_mask, + head_mask=decoder_head_mask, + cross_attn_head_mask=cross_attn_head_mask, + use_cache=use_cache, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + ) + + if not return_dict: + return decoder_outputs + encoder_outputs + + return Seq2SeqModelOutput( + last_hidden_state=decoder_outputs.last_hidden_state, + past_key_values=decoder_outputs.past_key_values, + decoder_hidden_states=decoder_outputs.hidden_states, + decoder_attentions=decoder_outputs.attentions, + cross_attentions=decoder_outputs.cross_attentions, + encoder_last_hidden_state=encoder_outputs.last_hidden_state, + encoder_hidden_states=encoder_outputs.hidden_states, + encoder_attentions=encoder_outputs.attentions, + ) -class MT5ForConditionalGeneration(T5ForConditionalGeneration): +@add_start_docstrings("""MT5 Model with a `language modeling` head on top.""", MT5_START_DOCSTRING) +class MT5ForConditionalGeneration(MT5PreTrainedModel): r""" - This class overrides [`T5ForConditionalGeneration`]. Please check the superclass for the appropriate documentation - alongside usage examples. - Examples: ```python - >>> from transformers import MT5ForConditionalGeneration, T5Tokenizer + >>> from transformers import MT5ForConditionalGeneration, MT5Tokenizer >>> model = MT5ForConditionalGeneration.from_pretrained("google/mt5-small") - >>> tokenizer = T5Tokenizer.from_pretrained("google/mt5-small") + >>> tokenizer = MT5Tokenizer.from_pretrained("google/mt5-small") >>> article = "UN Offizier sagt, dass weiter verhandelt werden muss in Syrien." >>> summary = "Weiter Verhandlung in Syrien." >>> inputs = tokenizer(article, text_target=summary, return_tensors="pt") @@ -86,20 +1504,316 @@ class MT5ForConditionalGeneration(T5ForConditionalGeneration): _keys_to_ignore_on_save = [ r"encoder.embed_tokens.weight", ] + _keys_to_ignore_on_load_unexpected = [ + r"decoder.block.0.layer.1.EncDecAttention.relative_attention_bias.weight", + ] + + # Copied from transformers.models.t5.modeling_t5.T5ForConditionalGeneration.__init__ with T5->MT5 + def __init__(self, config: MT5Config): + super().__init__(config) + self.model_dim = config.d_model + + self.shared = nn.Embedding(config.vocab_size, config.d_model) + + encoder_config = copy.deepcopy(config) + encoder_config.is_decoder = False + encoder_config.use_cache = False + encoder_config.is_encoder_decoder = False + self.encoder = MT5Stack(encoder_config, self.shared) + + decoder_config = copy.deepcopy(config) + decoder_config.is_decoder = True + decoder_config.is_encoder_decoder = False + decoder_config.num_layers = config.num_decoder_layers + self.decoder = MT5Stack(decoder_config, self.shared) + + self.lm_head = nn.Linear(config.d_model, config.vocab_size, bias=False) + + # Initialize weights and apply final processing + self.post_init() + + # Model parallel + self.model_parallel = False + self.device_map = None + + @add_start_docstrings(PARALLELIZE_DOCSTRING) + # Copied from transformers.models.t5.modeling_t5.T5ForConditionalGeneration.parallelize + def parallelize(self, device_map=None): + self.device_map = ( + get_device_map(len(self.encoder.block), range(torch.cuda.device_count())) + if device_map is None + else device_map + ) + assert_device_map(self.device_map, len(self.encoder.block)) + self.encoder.parallelize(self.device_map) + self.decoder.parallelize(self.device_map) + self.lm_head = self.lm_head.to(self.decoder.first_device) + self.model_parallel = True + + @add_start_docstrings(DEPARALLELIZE_DOCSTRING) + # Copied from transformers.models.t5.modeling_t5.T5ForConditionalGeneration.deparallelize + def deparallelize(self): + self.encoder.deparallelize() + self.decoder.deparallelize() + self.encoder = self.encoder.to("cpu") + self.decoder = self.decoder.to("cpu") + self.lm_head = self.lm_head.to("cpu") + self.model_parallel = False + self.device_map = None + torch.cuda.empty_cache() + + # Copied from transformers.models.t5.modeling_t5.T5ForConditionalGeneration.get_input_embeddings + def get_input_embeddings(self): + return self.shared + + # Copied from transformers.models.t5.modeling_t5.T5ForConditionalGeneration.set_input_embeddings + def set_input_embeddings(self, new_embeddings): + self.shared = new_embeddings + self.encoder.set_input_embeddings(new_embeddings) + self.decoder.set_input_embeddings(new_embeddings) + + # Copied from transformers.models.t5.modeling_t5.T5ForConditionalGeneration.set_output_embeddings + def set_output_embeddings(self, new_embeddings): + self.lm_head = new_embeddings + + # Copied from transformers.models.t5.modeling_t5.T5ForConditionalGeneration.get_output_embeddings + def get_output_embeddings(self): + return self.lm_head + + # Copied from transformers.models.t5.modeling_t5.T5ForConditionalGeneration.get_encoder + def get_encoder(self): + return self.encoder + + # Copied from transformers.models.t5.modeling_t5.T5ForConditionalGeneration.get_decoder + def get_decoder(self): + return self.decoder + + @add_start_docstrings_to_model_forward(MT5_INPUTS_DOCSTRING) + @replace_return_docstrings(output_type=Seq2SeqLMOutput, config_class=_CONFIG_FOR_DOC) + # Copied from transformers.models.t5.modeling_t5.T5ForConditionalGeneration.forward with T5->MT5, t5->mt5 + def forward( + self, + input_ids: Optional[torch.LongTensor] = None, + attention_mask: Optional[torch.FloatTensor] = None, + decoder_input_ids: Optional[torch.LongTensor] = None, + decoder_attention_mask: Optional[torch.BoolTensor] = None, + head_mask: Optional[torch.FloatTensor] = None, + decoder_head_mask: Optional[torch.FloatTensor] = None, + cross_attn_head_mask: Optional[torch.Tensor] = None, + encoder_outputs: Optional[Tuple[Tuple[torch.Tensor]]] = None, + past_key_values: Optional[Tuple[Tuple[torch.Tensor]]] = None, + inputs_embeds: Optional[torch.FloatTensor] = None, + decoder_inputs_embeds: Optional[torch.FloatTensor] = None, + labels: Optional[torch.LongTensor] = None, + use_cache: Optional[bool] = None, + output_attentions: Optional[bool] = None, + output_hidden_states: Optional[bool] = None, + return_dict: Optional[bool] = None, + ) -> Union[Tuple[torch.FloatTensor], Seq2SeqLMOutput]: + r""" + labels (`torch.LongTensor` of shape `(batch_size,)`, *optional*): + Labels for computing the sequence classification/regression loss. Indices should be in `[-100, 0, ..., + config.vocab_size - 1]`. All labels set to `-100` are ignored (masked), the loss is only computed for + labels in `[0, ..., config.vocab_size]` + + Returns: + + Examples: + + ```python + >>> from transformers import MT5Tokenizer, MT5ForConditionalGeneration + + >>> tokenizer = MT5Tokenizer.from_pretrained("mt5-small") + >>> model = MT5ForConditionalGeneration.from_pretrained("mt5-small") + + >>> # training + >>> input_ids = tokenizer("The walks in park", return_tensors="pt").input_ids + >>> labels = tokenizer(" cute dog the ", return_tensors="pt").input_ids + >>> outputs = model(input_ids=input_ids, labels=labels) + >>> loss = outputs.loss + >>> logits = outputs.logits + + >>> # inference + >>> input_ids = tokenizer( + ... "summarize: studies have shown that owning a dog is good for you", return_tensors="pt" + ... ).input_ids # Batch size 1 + >>> outputs = model.generate(input_ids) + >>> print(tokenizer.decode(outputs[0], skip_special_tokens=True)) + >>> # studies have shown that owning a dog is good for you. + ```""" + use_cache = use_cache if use_cache is not None else self.config.use_cache + return_dict = return_dict if return_dict is not None else self.config.use_return_dict + + # FutureWarning: head_mask was separated into two input args - head_mask, decoder_head_mask + if head_mask is not None and decoder_head_mask is None: + if self.config.num_layers == self.config.num_decoder_layers: + warnings.warn(__HEAD_MASK_WARNING_MSG, FutureWarning) + decoder_head_mask = head_mask + + # Encode if needed (training, first prediction pass) + if encoder_outputs is None: + # Convert encoder inputs in embeddings if needed + encoder_outputs = self.encoder( + input_ids=input_ids, + attention_mask=attention_mask, + inputs_embeds=inputs_embeds, + head_mask=head_mask, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + ) + elif return_dict and not isinstance(encoder_outputs, BaseModelOutput): + encoder_outputs = BaseModelOutput( + last_hidden_state=encoder_outputs[0], + hidden_states=encoder_outputs[1] if len(encoder_outputs) > 1 else None, + attentions=encoder_outputs[2] if len(encoder_outputs) > 2 else None, + ) + + hidden_states = encoder_outputs[0] + + if self.model_parallel: + torch.cuda.set_device(self.decoder.first_device) + + if labels is not None and decoder_input_ids is None and decoder_inputs_embeds is None: + # get decoder inputs from shifting lm labels to the right + decoder_input_ids = self._shift_right(labels) + + # Set device for model parallelism + if self.model_parallel: + torch.cuda.set_device(self.decoder.first_device) + hidden_states = hidden_states.to(self.decoder.first_device) + if decoder_input_ids is not None: + decoder_input_ids = decoder_input_ids.to(self.decoder.first_device) + if attention_mask is not None: + attention_mask = attention_mask.to(self.decoder.first_device) + if decoder_attention_mask is not None: + decoder_attention_mask = decoder_attention_mask.to(self.decoder.first_device) + + # Decode + decoder_outputs = self.decoder( + input_ids=decoder_input_ids, + attention_mask=decoder_attention_mask, + inputs_embeds=decoder_inputs_embeds, + past_key_values=past_key_values, + encoder_hidden_states=hidden_states, + encoder_attention_mask=attention_mask, + head_mask=decoder_head_mask, + cross_attn_head_mask=cross_attn_head_mask, + use_cache=use_cache, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + ) + + sequence_output = decoder_outputs[0] + + # Set device for model parallelism + if self.model_parallel: + torch.cuda.set_device(self.encoder.first_device) + self.lm_head = self.lm_head.to(self.encoder.first_device) + sequence_output = sequence_output.to(self.lm_head.weight.device) + + if self.config.tie_word_embeddings: + # Rescale output before projecting on vocab + # See https://github.com/tensorflow/mesh/blob/fa19d69eafc9a482aff0b59ddd96b025c0cb207d/mesh_tensorflow/transformer/transformer.py#L586 + sequence_output = sequence_output * (self.model_dim**-0.5) + + lm_logits = self.lm_head(sequence_output) + + loss = None + if labels is not None: + loss_fct = CrossEntropyLoss(ignore_index=-100) + loss = loss_fct(lm_logits.view(-1, lm_logits.size(-1)), labels.view(-1)) + # TODO(thom): Add z_loss https://github.com/tensorflow/mesh/blob/fa19d69eafc9a482aff0b59ddd96b025c0cb207d/mesh_tensorflow/layers.py#L666 + + if not return_dict: + output = (lm_logits,) + decoder_outputs[1:] + encoder_outputs + return ((loss,) + output) if loss is not None else output + + return Seq2SeqLMOutput( + loss=loss, + logits=lm_logits, + past_key_values=decoder_outputs.past_key_values, + decoder_hidden_states=decoder_outputs.hidden_states, + decoder_attentions=decoder_outputs.attentions, + cross_attentions=decoder_outputs.cross_attentions, + encoder_last_hidden_state=encoder_outputs.last_hidden_state, + encoder_hidden_states=encoder_outputs.hidden_states, + encoder_attentions=encoder_outputs.attentions, + ) + + # Copied from transformers.models.t5.modeling_t5.T5ForConditionalGeneration.prepare_inputs_for_generation + def prepare_inputs_for_generation( + self, + input_ids, + past=None, + attention_mask=None, + head_mask=None, + decoder_head_mask=None, + cross_attn_head_mask=None, + use_cache=None, + encoder_outputs=None, + **kwargs + ): + + # cut decoder_input_ids if past is used + if past is not None: + input_ids = input_ids[:, -1:] + + return { + "decoder_input_ids": input_ids, + "past_key_values": past, + "encoder_outputs": encoder_outputs, + "attention_mask": attention_mask, + "head_mask": head_mask, + "decoder_head_mask": decoder_head_mask, + "cross_attn_head_mask": cross_attn_head_mask, + "use_cache": use_cache, + } + + # Copied from transformers.models.t5.modeling_t5.T5ForConditionalGeneration.prepare_decoder_input_ids_from_labels + def prepare_decoder_input_ids_from_labels(self, labels: torch.Tensor): + return self._shift_right(labels) + + # Copied from transformers.models.t5.modeling_t5.T5ForConditionalGeneration._reorder_cache + def _reorder_cache(self, past, beam_idx): + # if decoder past is not included in output + # speedy decoding is disabled and no need to reorder + if past is None: + logger.warning("You might want to consider setting `use_cache=True` to speed up decoding") + return past + + reordered_decoder_past = () + for layer_past_states in past: + # get the correct batch idx from layer past batch dim + # batch dim of `past` is at 2nd position + reordered_layer_past_states = () + for layer_past_state in layer_past_states: + # need to set correct `past` for each of the four key / value states + reordered_layer_past_states = reordered_layer_past_states + ( + layer_past_state.index_select(0, beam_idx.to(layer_past_state.device)), + ) + + assert reordered_layer_past_states[0].shape == layer_past_states[0].shape + assert len(reordered_layer_past_states) == len(layer_past_states) + + reordered_decoder_past = reordered_decoder_past + (reordered_layer_past_states,) + return reordered_decoder_past -class MT5EncoderModel(T5EncoderModel): +@add_start_docstrings( + "The bare MT5 Model transformer outputting encoder's raw hidden-states without any specific head on top.", + MT5_START_DOCSTRING, +) +class MT5EncoderModel(MT5PreTrainedModel): r""" - This class overrides [`T5EncoderModel`]. Please check the superclass for the appropriate documentation alongside - usage examples. - Examples: ```python - >>> from transformers import MT5EncoderModel, T5Tokenizer + >>> from transformers import MT5EncoderModel, MT5Tokenizer >>> model = MT5EncoderModel.from_pretrained("google/mt5-small") - >>> tokenizer = T5Tokenizer.from_pretrained("google/mt5-small") + >>> tokenizer = MT5Tokenizer.from_pretrained("google/mt5-small") >>> article = "UN Offizier sagt, dass weiter verhandelt werden muss in Syrien." >>> input_ids = tokenizer(article, return_tensors="pt").input_ids >>> outputs = model(input_ids) @@ -114,3 +1828,107 @@ class MT5EncoderModel(T5EncoderModel): _keys_to_ignore_on_save = [ r"encoder.embed_tokens.weight", ] + _keys_to_ignore_on_load_missing = [r"encoder.embed_tokens.weight"] + + # Copied from transformers.models.t5.modeling_t5.T5EncoderModel.__init__ with T5->MT5 + def __init__(self, config: MT5Config): + super().__init__(config) + self.shared = nn.Embedding(config.vocab_size, config.d_model) + + encoder_config = copy.deepcopy(config) + encoder_config.use_cache = False + encoder_config.is_encoder_decoder = False + self.encoder = MT5Stack(encoder_config, self.shared) + + # Initialize weights and apply final processing + self.post_init() + + # Model parallel + self.model_parallel = False + self.device_map = None + + @add_start_docstrings(PARALLELIZE_DOCSTRING) + # Copied from transformers.models.t5.modeling_t5.T5EncoderModel.parallelize + def parallelize(self, device_map=None): + self.device_map = ( + get_device_map(len(self.encoder.block), range(torch.cuda.device_count())) + if device_map is None + else device_map + ) + assert_device_map(self.device_map, len(self.encoder.block)) + self.encoder.parallelize(self.device_map) + self.model_parallel = True + + @add_start_docstrings(DEPARALLELIZE_DOCSTRING) + # Copied from transformers.models.t5.modeling_t5.T5EncoderModel.deparallelize + def deparallelize(self): + self.encoder.deparallelize() + self.encoder = self.encoder.to("cpu") + self.model_parallel = False + self.device_map = None + torch.cuda.empty_cache() + + # Copied from transformers.models.t5.modeling_t5.T5EncoderModel.get_input_embeddings + def get_input_embeddings(self): + return self.shared + + # Copied from transformers.models.t5.modeling_t5.T5EncoderModel.set_input_embeddings + def set_input_embeddings(self, new_embeddings): + self.shared = new_embeddings + self.encoder.set_input_embeddings(new_embeddings) + + # Copied from transformers.models.t5.modeling_t5.T5EncoderModel.get_encoder + def get_encoder(self): + return self.encoder + + # Copied from transformers.models.t5.modeling_t5.T5EncoderModel._prune_heads + 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.block[layer].layer[0].SelfAttention.prune_heads(heads) + + @add_start_docstrings_to_model_forward(MT5_ENCODER_INPUTS_DOCSTRING) + @replace_return_docstrings(output_type=BaseModelOutput, config_class=_CONFIG_FOR_DOC) + # Copied from transformers.models.t5.modeling_t5.T5EncoderModel.forward with T5->MT5, t5->mt5 + def forward( + self, + input_ids: Optional[torch.LongTensor] = None, + attention_mask: Optional[torch.FloatTensor] = None, + head_mask: Optional[torch.FloatTensor] = None, + inputs_embeds: Optional[torch.FloatTensor] = None, + output_attentions: Optional[bool] = None, + output_hidden_states: Optional[bool] = None, + return_dict: Optional[bool] = None, + ) -> Union[Tuple[torch.FloatTensor], BaseModelOutput]: + r""" + Returns: + + Example: + + ```python + >>> from transformers import MT5Tokenizer, MT5EncoderModel + + >>> tokenizer = MT5Tokenizer.from_pretrained("mt5-small") + >>> model = MT5EncoderModel.from_pretrained("mt5-small") + >>> input_ids = tokenizer( + ... "Studies have been shown that owning a dog is good for you", return_tensors="pt" + ... ).input_ids # Batch size 1 + >>> outputs = model(input_ids=input_ids) + >>> last_hidden_states = outputs.last_hidden_state + ```""" + return_dict = return_dict if return_dict is not None else self.config.use_return_dict + + encoder_outputs = self.encoder( + input_ids=input_ids, + attention_mask=attention_mask, + inputs_embeds=inputs_embeds, + head_mask=head_mask, + output_attentions=output_attentions, + output_hidden_states=output_hidden_states, + return_dict=return_dict, + ) + + return encoder_outputs diff --git a/src/transformers/utils/dummy_pt_objects.py b/src/transformers/utils/dummy_pt_objects.py index 5f32e1991d..b3dc278739 100644 --- a/src/transformers/utils/dummy_pt_objects.py +++ b/src/transformers/utils/dummy_pt_objects.py @@ -4003,6 +4003,13 @@ class MT5Model(metaclass=DummyObject): requires_backends(self, ["torch"]) +class MT5PreTrainedModel(metaclass=DummyObject): + _backends = ["torch"] + + def __init__(self, *args, **kwargs): + requires_backends(self, ["torch"]) + + MVP_PRETRAINED_MODEL_ARCHIVE_LIST = None diff --git a/utils/check_repo.py b/utils/check_repo.py index dfec3f5ce7..fc687ba464 100755 --- a/utils/check_repo.py +++ b/utils/check_repo.py @@ -40,6 +40,7 @@ PRIVATE_MODELS = [ "LongT5Stack", "RealmBertModel", "T5Stack", + "MT5Stack", "SwitchTransformersStack", "TFDPRSpanPredictor", "MaskFormerSwinModel",