#!/usr/bin/env python # coding=utf-8 # Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved. import math import torch import torch.utils.checkpoint from torch import nn from torch.nn import CrossEntropyLoss, MSELoss, BCEWithLogitsLoss from transformers.activations import ACT2FN from transformers.modeling_utils import Conv1D, PreTrainedModel from transformers.utils import logging from .config_codesage import CodeSageConfig from transformers.modeling_outputs import BaseModelOutputWithPooling, SequenceClassifierOutput logger = logging.get_logger(__name__) CODESAGE_PRETRAINED_MODEL_ARCHIVE_LIST = [ "codesage/codesage-small", "codesage/codesage-base", "codesage/codesage-large", # See all CodeSage models at https://huggingface.co./models?filter=codesage ] class CodeSageAttention(nn.Module): def __init__(self, config): super().__init__() self.hidden_size = config.hidden_size self.num_heads = config.num_attention_heads self.head_dim = config.hidden_size // self.num_heads if self.head_dim * self.num_heads != config.hidden_size: raise ValueError( f"`hidden_size` must be divisible by num_heads " f"(got `hidden_size`: {config.hidden_size} and `num_heads`: {self.num_heads})." ) self.c_attn = Conv1D(3 * self.hidden_size, self.hidden_size) self.c_proj = Conv1D(self.hidden_size, self.hidden_size) self.attention_dropout = nn.Dropout(config.attention_dropout_prob) self.residual_dropout = nn.Dropout(config.residual_dropout_prob) def attn(self, query, key, value, attention_mask=None, head_mask=None): attn_weights = torch.matmul(query, key.transpose(-1, -2)) attn_weights = attn_weights / math.sqrt(self.head_dim) if attention_mask is not None: attn_weights = attn_weights + attention_mask attn_weights = nn.Softmax(dim=-1)(attn_weights) attn_weights = self.attention_dropout(attn_weights) if head_mask is not None: attn_weights = attn_weights * head_mask attn_output = torch.matmul(attn_weights, value) return attn_output, attn_weights def split_heads(self, tensor, num_heads, attn_head_size): """ Splits hidden_size dim into attn_head_size and num_heads """ new_shape = tensor.size()[:-1] + (num_heads, attn_head_size) tensor = tensor.view(*new_shape) return tensor.permute(0, 2, 1, 3) # (batch, head, seq_length, head_features) def merge_heads(self, tensor, num_heads, attn_head_size): """ Merges attn_head_size dim and num_attn_heads dim into hidden_size """ tensor = tensor.permute(0, 2, 1, 3).contiguous() new_shape = tensor.size()[:-2] + (num_heads * attn_head_size,) return tensor.view(new_shape) def forward( self, hidden_states, attention_mask=None, head_mask=None, output_attentions=False, ): query, key, value = self.c_attn(hidden_states).split(self.hidden_size, dim=2) query = self.split_heads(query, self.num_heads, self.head_dim) key = self.split_heads(key, self.num_heads, self.head_dim) value = self.split_heads(value, self.num_heads, self.head_dim) attn_output, attn_weights = self.attn(query, key, value, attention_mask, head_mask) attn_output = self.merge_heads(attn_output, self.num_heads, self.head_dim) attn_output = self.c_proj(attn_output) attn_output = self.residual_dropout(attn_output) outputs = (attn_output, attn_weights) if output_attentions else (attn_output,) return outputs # a, present, (attentions) class CodeSageMLP(nn.Module): def __init__(self, intermediate_size, config): super().__init__() self.c_fc = Conv1D(intermediate_size, config.hidden_size) self.act = ACT2FN[config.activation_function] self.c_proj = Conv1D(config.hidden_size, intermediate_size) self.dropout = nn.Dropout(config.residual_dropout_prob) def forward(self, hidden_states): hidden_states = self.c_fc(hidden_states) hidden_states = self.act(hidden_states) hidden_states = self.c_proj(hidden_states) hidden_states = self.dropout(hidden_states) return hidden_states class CodeSageBlock(nn.Module): def __init__(self, config): super().__init__() hidden_size = config.hidden_size inner_dim = config.intermediate_size if config.intermediate_size is not None else 4 * hidden_size self.ln_1 = nn.LayerNorm(hidden_size, eps=config.layer_norm_epsilon) self.attn = CodeSageAttention(config) self.ln_2 = nn.LayerNorm(hidden_size, eps=config.layer_norm_epsilon) self.mlp = CodeSageMLP(inner_dim, config) def forward( self, hidden_states, attention_mask=None, head_mask=None, output_attentions=False, ): residual = hidden_states hidden_states = self.ln_1(hidden_states) attn_outputs = self.attn( hidden_states, attention_mask=attention_mask, head_mask=head_mask, output_attentions=output_attentions ) attn_output = attn_outputs[0] # output_attn: a, present, (attentions) outputs = attn_outputs[1:] hidden_states = attn_output + residual residual = hidden_states hidden_states = self.ln_2(hidden_states) feed_forward_hidden_states = self.mlp(hidden_states) hidden_states = residual + feed_forward_hidden_states outputs = (hidden_states,) + outputs[1:] return outputs # hidden_states, present, (attentions) class CodeSagePreTrainedModel(PreTrainedModel): config_class = CodeSageConfig def _init_weights(self, module): """Initialize the weights.""" if isinstance(module, (nn.Linear, Conv1D)): module.weight.data.normal_(mean=0.0, std=self.config.initializer_range) if module.bias is not None: module.bias.data.zero_() elif isinstance(module, nn.Embedding): module.weight.data.normal_(mean=0.0, std=self.config.initializer_range) if module.padding_idx is not None: module.weight.data[module.padding_idx].zero_() elif isinstance(module, nn.LayerNorm): module.bias.data.zero_() module.weight.data.fill_(1.0) class CodeSageModel(CodeSagePreTrainedModel): def __init__(self, config): super().__init__(config) self.wte = nn.Embedding(config.vocab_size, config.hidden_size) self.wpe = nn.Embedding(config.max_position_embeddings, config.hidden_size) self.drop = nn.Dropout(config.embedding_dropout_prob) self.h = nn.ModuleList([CodeSageBlock(config) for _ in range(config.num_hidden_layers)]) self.ln_f = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_epsilon) self.init_weights() def get_input_embeddings(self): return self.wte def set_input_embeddings(self, new_embeddings: torch.Tensor): self.wte = new_embeddings def forward( self, input_ids=None, attention_mask=None, position_ids=None, head_mask=None, inputs_embeds=None, output_attentions=None, output_hidden_states=None, return_dict=None ): 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: raise ValueError("You cannot specify both input_ids and inputs_embeds at the same time") if input_ids is not None: input_shape = input_ids.size() elif inputs_embeds is not None: input_shape = inputs_embeds.size()[:-1] 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 if position_ids is None: position_ids = torch.arange(input_shape[-1], dtype=torch.long, device=device) position_ids = position_ids.unsqueeze(0).view(-1, input_shape[-1]) else: position_ids = position_ids.view(-1, input_shape[-1]) extended_attention_mask = None if attention_mask is not None: assert attention_mask.dim() == 2 extended_attention_mask = attention_mask[:, None, None, :] extended_attention_mask = extended_attention_mask.to(dtype=self.dtype) # fp16 compatibility extended_attention_mask = (1.0 - extended_attention_mask) * -10000.0 head_mask = self.get_head_mask(head_mask, self.config.num_hidden_layers) if inputs_embeds is None: inputs_embeds = self.wte(input_ids) position_embeds = self.wpe(position_ids) hidden_states = inputs_embeds + position_embeds hidden_states = self.drop(hidden_states) output_shape = input_shape + (hidden_states.size(-1),) all_self_attentions = () if output_attentions else None all_hidden_states = () if output_hidden_states else None for i, block in enumerate(self.h): if output_hidden_states: all_hidden_states = all_hidden_states + (hidden_states,) outputs = block( hidden_states, attention_mask=extended_attention_mask, head_mask=head_mask[i], output_attentions=output_attentions, ) hidden_states = outputs[0] if output_attentions: all_self_attentions = all_self_attentions + (outputs[1],) hidden_states = self.ln_f(hidden_states) hidden_states = hidden_states.view(*output_shape) if output_hidden_states: all_hidden_states = all_hidden_states + (hidden_states,) pooled_output = None # max-pooled output if attention_mask is not None: pooled_output = (hidden_states * attention_mask[:, :, None]).sum(1) / attention_mask.sum(1)[:, None] if not return_dict: return tuple( v for v in [hidden_states, pooled_output, all_hidden_states, all_self_attentions] if v is not None ) return BaseModelOutputWithPooling( last_hidden_state=hidden_states, pooler_output=pooled_output, hidden_states=all_hidden_states, attentions=all_self_attentions ) class CodeSageForSequenceClassification(CodeSagePreTrainedModel): def __init__(self, config): super().__init__(config) self.num_labels = config.num_labels self.config = config self.encoder = CodeSageModel(config) classifier_dropout = ( config.classifier_dropout if config.classifier_dropout is not None else config.residual_dropout_prob ) self.dropout = nn.Dropout(classifier_dropout) self.classifier = nn.Linear(config.hidden_size, config.num_labels) # Initialize weights and apply final processing self.post_init() def forward( self, input_ids=None, attention_mask=None, position_ids=None, head_mask=None, inputs_embeds=None, labels=None, output_attentions=None, output_hidden_states=None, return_dict=None, ): return_dict = return_dict if return_dict is not None else self.config.use_return_dict assert attention_mask is not None, "attention_mask is needed to perform max-pooling" outputs = self.encoder( input_ids, attention_mask=attention_mask, position_ids=position_ids, head_mask=head_mask, inputs_embeds=inputs_embeds, output_attentions=output_attentions, output_hidden_states=output_hidden_states, return_dict=return_dict, ) pooled_output = outputs[1] pooled_output = self.dropout(pooled_output) logits = self.classifier(pooled_output) loss = None if labels is not None: if self.config.problem_type is None: if self.num_labels == 1: self.config.problem_type = "regression" elif self.num_labels > 1 and (labels.dtype == torch.long or labels.dtype == torch.int): self.config.problem_type = "single_label_classification" else: self.config.problem_type = "multi_label_classification" if self.config.problem_type == "regression": loss_fct = MSELoss() if self.num_labels == 1: loss = loss_fct(logits.squeeze(), labels.squeeze()) else: loss = loss_fct(logits, labels) elif self.config.problem_type == "single_label_classification": loss_fct = CrossEntropyLoss() loss = loss_fct(logits.view(-1, self.num_labels), labels.view(-1)) elif self.config.problem_type == "multi_label_classification": loss_fct = BCEWithLogitsLoss() loss = loss_fct(logits, labels) if not return_dict: output = (logits,) + outputs[2:] return ((loss,) + output) if loss is not None else output return SequenceClassifierOutput( loss=loss, logits=logits, hidden_states=outputs.hidden_states, attentions=outputs.attentions, )