modeling_vcgn.py

from typing import List, Union
import torch
import torch.nn.functional as F
from transformers import PreTrainedModel, BertTokenizer
from transformers.utils import is_remote_url, download_url
from pathlib import Path
from configuration_vgcn import VGCNConfig
import pickle as pkl
import numpy as np
import scipy.sparse as sp




def get_torch_gcn(gcn_vocab_adj_tf, gcn_vocab_adj,gcn_config:VGCNConfig):

    def sparse_scipy2torch(coo_sparse):
        # coo_sparse=coo_sparse.tocoo()
        i = torch.LongTensor(np.vstack((coo_sparse.row, coo_sparse.col)))
        v = torch.from_numpy(coo_sparse.data)
        return torch.sparse.FloatTensor(i, v, torch.Size(coo_sparse.shape))

    def normalize_adj(adj):
        """
            Symmetrically normalize adjacency matrix.
        """

        D_matrix = np.array(adj.sum(axis=1)) # D-degree matrix as array (Diagonal, rest is 0.)
        D_inv_sqrt = np.power(D_matrix, -0.5).flatten()
        D_inv_sqrt[np.isinf(D_inv_sqrt)] = 0.
        d_mat_inv_sqrt = sp.diags(D_inv_sqrt) # array to matrix
        return adj.dot(d_mat_inv_sqrt).transpose().dot(d_mat_inv_sqrt) # D^(-1/2) . A . D^(-1/2)

    gcn_vocab_adj_tf.data *= (gcn_vocab_adj_tf.data > gcn_config.tf_threshold)
    gcn_vocab_adj_tf.eliminate_zeros()

    gcn_vocab_adj.data *= (gcn_vocab_adj.data > gcn_config.npmi_threshold)
    gcn_vocab_adj.eliminate_zeros()

    if gcn_config.vocab_type == 'pmi':
        gcn_vocab_adj_list = [gcn_vocab_adj]
    elif gcn_config.vocab_type == 'tf':
        gcn_vocab_adj_list = [gcn_vocab_adj_tf]
    elif gcn_config.vocab_type == 'all':
        gcn_vocab_adj_list = [gcn_vocab_adj_tf, gcn_vocab_adj]
    else:
        raise ValueError(f"vocab_type must be 'pmi', 'tf' or 'all', got {gcn_config.vocab_type}")

    norm_gcn_vocab_adj_list = []
    for i in range(len(gcn_vocab_adj_list)):
        adj = gcn_vocab_adj_list[i]
        adj = normalize_adj(adj)
        norm_gcn_vocab_adj_list.append(sparse_scipy2torch(adj.tocoo()))
    
    for t in norm_gcn_vocab_adj_list:
        t.requires_grad = False

    del gcn_vocab_adj_list

    return norm_gcn_vocab_adj_list



class VCGNModelForTextClassification(PreTrainedModel):
    config_class = VGCNConfig

    def __init__(self, config):
        super().__init__(config)

        self.pre_trained_model_name = ''
        self.remove_stop_words = False
        self.tokenizer = None
        self.norm_gcn_vocab_adj_list = None
        self.gcn_vocab_size = config.vocab_size
           

        self.load_adj_matrix(config.gcn_adj_matrix)

        self.model = VGCN_Bert(
          config,
          gcn_adj_matrix=self.norm_gcn_vocab_adj_list, 
          gcn_adj_dim=config.vocab_size, 
          gcn_adj_num=len(self.norm_gcn_vocab_adj_list), 
          gcn_embedding_dim=config.gcn_embedding_dim,

        )

    def load_adj_matrix(self, adj_matrix):
        filename = None
        if Path(adj_matrix).is_file():
            filename = Path(adj_matrix)
            #load file           
        elif (Path(__file__).parent / Path(adj_matrix)).is_file():
            filename = Path(__file__).parent / Path(adj_matrix)
        elif is_remote_url(adj_matrix):
            filename = download_url(adj_matrix)


        gcn_vocab_adj_tf, gcn_vocab_adj, adj_config = pkl.load(open(filename, 'rb'))


        self.pre_trained_model_name = adj_config['bert_model']
        self.remove_stop_words = adj_config['remove_stop_words']
        self.tokenizer =  BertTokenizer.from_pretrained(self.pre_trained_model_name)
        self.norm_gcn_vocab_adj_list =  get_torch_gcn(gcn_vocab_adj_tf, gcn_vocab_adj, self.config)

    def _prep_batch(self, batch: torch.Tensor):

        vocab_size = self.tokenizer.vocab_size

        batch_gcn_swop_eye = F.one_hot(batch, vocab_size).float().to(self.device) # shape (batch_size, seq_len, vocab_size)
        batch_gcn_swop_eye = batch_gcn_swop_eye.transpose(1,2) # shape (batch_size,  vocab_size, seq_len)
                                                                                  # set all [PAD] tokens to 0
        batch_gcn_swop_eye[:, self.tokenizer.pad_token_id, :] = 0
        batch_gcn_swop_eye[:, self.tokenizer.cls_token_id, :] = 0
        batch_gcn_swop_eye[:, self.tokenizer.sep_token_id, :] = 0

        batch_gcn_swop_eye = F.pad(batch_gcn_swop_eye,(0,self.config.gcn_embedding_dim,0,0,0,0),value=0)

        batch = F.pad(batch, (0, self.config.gcn_embedding_dim), 'constant', 0)
        
        #fill gcn tokens with [SEP]
        mask = torch.zeros(batch.shape[0], batch.shape[1] + 1, dtype=batch.dtype, device=self.device)
        mask2 = torch.zeros(batch.shape[0], batch.shape[1] + 1, dtype=batch.dtype, device=self.device)

        pos_start = (batch==self.tokenizer.pad_token_id).int().argmax(1)

        mask[(torch.arange(batch.shape[0]), pos_start)] = 1
        mask2[(torch.arange(batch.shape[0]), pos_start+self.config.gcn_embedding_dim)] = 1

        mask = mask.cumsum(1)[:, :-1].bool()
        mask2 = mask2.cumsum(1)[:, :-1].bool()

        mask = mask & ~mask2

        batch.masked_fill_(mask, self.tokenizer.sep_token_id)

        return batch, batch_gcn_swop_eye
    
    def text_to_batch(self, text: Union[List[str], str]):
        if isinstance(text, str):
            text = [text]
        encoded = self.tokenizer.batch_encode_plus(text, padding=True, truncation=True, return_tensors='pt', max_length=self.config.max_seq_len-self.config.gcn_embedding_dim)
        return encoded['input_ids'].to(self.device)

    def forward(self, input:Union[torch.Tensor, List[str], str], labels=None):

        if not isinstance(input, torch.Tensor):
            input = self.text_to_batch(input)
        
        input, batch_gcn_swop_eye = self._prep_batch(input)

        segment_ids = torch.zeros_like(input).int().to(self.device)
        input_mask = (input>0).int().to(self.device)


        logits = self.model(batch_gcn_swop_eye, input, segment_ids, input_mask )
        if labels is not None:
            loss = torch.nn.cross_entropy(logits, labels)
            return {"loss": loss, "logits": logits}
        return {"logits": logits}

    def predict(self, text: Union[List[str], str], as_dict=True):
        with torch.no_grad():
            logits = self.forward(text)['logits']
            if as_dict:
                label_id = torch.argmax(logits, dim=1).cpu().numpy()
                label = [self.config.id2label[l] for l in label_id]
                return {
                    "logits": logits,
                    "label_id": label_id,
                    "label": label,
                    }
            else:
                return torch.argmax(logits, dim=1).cpu().numpy()
        
    @property
    def device(self):
        return next(self.parameters()).device

import torch
import torch.nn as nn
import torch.nn.init as init
import math

from transformers import BertModel
from transformers.models.bert.modeling_bert import BertEmbeddings, BertPooler,BertEncoder

class VocabGraphConvolution(nn.Module):
    """Vocabulary GCN module.

    Params:
        `voc_dim`: The size of vocabulary graph
        `num_adj`: The number of the adjacency matrix of Vocabulary graph
        `hid_dim`: The hidden dimension after XAW
        `out_dim`: The output dimension after Relu(XAW)W
        `dropout_rate`: The dropout probabilitiy for all fully connected
                layers in the embeddings, encoder, and pooler.

    Inputs:
        `vocab_adj_list`: The list of the adjacency matrix
        `X_dv`: the feature of mini batch document, can be TF-IDF (batch, vocab), or word embedding (batch, word_embedding_dim, vocab)

    Outputs:
        The graph embedding representation, dimension (batch, `out_dim`) or (batch, word_embedding_dim, `out_dim`)

    """
    def __init__(self,adj_matrix,voc_dim, num_adj, hid_dim, out_dim, dropout_rate=0.2):
        super(VocabGraphConvolution, self).__init__()
        if type(adj_matrix) is not list:
            self.adj_matrix=adj_matrix
        else:
            self.adj_matrix=torch.nn.ParameterList([torch.nn.Parameter(x) for x in adj_matrix])
            for p in self.adj_matrix:
                p.requires_grad=False

        self.voc_dim=voc_dim
        self.num_adj=num_adj
        self.hid_dim=hid_dim
        self.out_dim=out_dim

        for i in range(self.num_adj):
            setattr(self, 'W%d_vh'%i, nn.Parameter(torch.randn(voc_dim, hid_dim)))

        self.fc_hc=nn.Linear(hid_dim,out_dim) 
        self.act_func = nn.ReLU()
        self.dropout = nn.Dropout(dropout_rate)

        self.reset_parameters()

    def reset_parameters(self):
        for n,p in self.named_parameters():
            if n.startswith('W') :
                init.kaiming_uniform_(p, a=math.sqrt(5))

    def forward(self, X_dv, add_linear_mapping_term=False):
        for i in range(self.num_adj):
            H_vh=self.adj_matrix[i].mm(getattr(self, 'W%d_vh'%i))
            # H_vh=self.dropout(F.elu(H_vh))
            H_vh=self.dropout(H_vh)
            H_dh=X_dv.matmul(H_vh)

            if add_linear_mapping_term:
                H_linear=X_dv.matmul(getattr(self, 'W%d_vh'%i))
                H_linear=self.dropout(H_linear)
                H_dh+=H_linear

            if i == 0:
                fused_H = H_dh
            else:
                fused_H += H_dh

        out=self.fc_hc(fused_H)
        return out


class VGCNBertEmbeddings(BertEmbeddings):
    """Construct the embeddings from word, VGCN graph, position and token_type embeddings.

    Params:
        `config`: a BertConfig class instance with the configuration to build a new model
        `gcn_adj_dim`: The size of vocabulary graph
        `gcn_adj_num`: The number of the adjacency matrix of Vocabulary graph
        `gcn_embedding_dim`: The output dimension after VGCN

    Inputs:
        `vocab_adj_list`: The list of the adjacency matrix
        `gcn_swop_eye`: The transform matrix for transform the token sequence (sentence) to the Vocabulary order (BoW order)
        `input_ids`: a torch.LongTensor of shape [batch_size, sequence_length]
            with the word token indices in the vocabulary. Items in the batch should begin with the special "CLS" token. (see the tokens preprocessing logic in the scripts
            `extract_features.py`, `run_classifier.py` and `run_squad.py`)
        `token_type_ids`: an optional torch.LongTensor of shape [batch_size, sequence_length] with the token
            types indices selected in [0, 1]. Type 0 corresponds to a `sentence A` and type 1 corresponds to
            a `sentence B` token (see BERT paper for more details).
        `attention_mask`: an optional torch.LongTensor of shape [batch_size, sequence_length] with indices
            selected in [0, 1]. It's a mask to be used if the input sequence length is smaller than the max
            input sequence length in the current batch. It's the mask that we typically use for attention when
            a batch has varying length sentences.

    Outputs:
        the word embeddings fused by VGCN embedding, position embedding and token_type embeddings.

    """
    def __init__(self, config, gcn_adj_matrix, gcn_adj_dim, gcn_adj_num, gcn_embedding_dim):
        super(VGCNBertEmbeddings, self).__init__(config)
        assert gcn_embedding_dim>=0
        self.gcn_adj_matrix=gcn_adj_matrix
        self.gcn_embedding_dim=gcn_embedding_dim
        self.vocab_gcn=VocabGraphConvolution(gcn_adj_matrix,gcn_adj_dim, gcn_adj_num, 128, gcn_embedding_dim) #192/256

    def forward(self, gcn_swop_eye, input_ids, token_type_ids=None, attention_mask=None):
        words_embeddings = self.word_embeddings(input_ids)
        vocab_input=gcn_swop_eye.matmul(words_embeddings).transpose(1,2)
        
        if self.gcn_embedding_dim>0:
            gcn_vocab_out = self.vocab_gcn(vocab_input)
         
            gcn_words_embeddings=words_embeddings.clone()
            for i in range(self.gcn_embedding_dim):
                tmp_pos=(attention_mask.sum(-1)-2-self.gcn_embedding_dim+1+i)+torch.arange(0,input_ids.shape[0]).to(input_ids.device)*input_ids.shape[1]
                gcn_words_embeddings.flatten(start_dim=0, end_dim=1)[tmp_pos,:]=gcn_vocab_out[:,:,i]

        seq_length = input_ids.size(1)
        position_ids = torch.arange(seq_length, dtype=torch.long, device=input_ids.device)
        position_ids = position_ids.unsqueeze(0).expand_as(input_ids)
        if token_type_ids is None:
            token_type_ids = torch.zeros_like(input_ids)

        position_embeddings = self.position_embeddings(position_ids)
        token_type_embeddings = self.token_type_embeddings(token_type_ids)

        if self.gcn_embedding_dim>0:
            embeddings = gcn_words_embeddings + position_embeddings + token_type_embeddings
        else:
            embeddings = words_embeddings + position_embeddings + token_type_embeddings

        embeddings = self.LayerNorm(embeddings)
        embeddings = self.dropout(embeddings)
        return embeddings


class VGCN_Bert(BertModel):
    """VGCN-BERT model for text classification. It inherits from Huggingface's BertModel.

    Params:
        `config`: a BertConfig class instance with the configuration to build a new model
        `gcn_adj_dim`: The size of vocabulary graph
        `gcn_adj_num`: The number of the adjacency matrix of Vocabulary graph
        `gcn_embedding_dim`: The output dimension after VGCN
        `num_labels`: the number of classes for the classifier. Default = 2.
        `output_attentions`: If True, also output attentions weights computed by the model at each layer. Default: False
        `keep_multihead_output`: If True, saves output of the multi-head attention module with its gradient.
            This can be used to compute head importance metrics. Default: False

    Inputs:
        `vocab_adj_list`: The list of the adjacency matrix
        `gcn_swop_eye`: The transform matrix for transform the token sequence (sentence) to the Vocabulary order (BoW order)
        `input_ids`: a torch.LongTensor of shape [batch_size, sequence_length]
            with the word token indices in the vocabulary. Items in the batch should begin with the special "CLS" token. (see the tokens preprocessing logic in the scripts
            `extract_features.py`, `run_classifier.py` and `run_squad.py`)
        `token_type_ids`: an optional torch.LongTensor of shape [batch_size, sequence_length] with the token
            types indices selected in [0, 1]. Type 0 corresponds to a `sentence A` and type 1 corresponds to
            a `sentence B` token (see BERT paper for more details).
        `attention_mask`: an optional torch.LongTensor of shape [batch_size, sequence_length] with indices
            selected in [0, 1]. It's a mask to be used if the input sequence length is smaller than the max
            input sequence length in the current batch. It's the mask that we typically use for attention when
            a batch has varying length sentences.
        `labels`: labels for the classification output: torch.LongTensor of shape [batch_size]
            with indices selected in [0, ..., num_labels].
        `head_mask`: an optional torch.Tensor of shape [num_heads] or [num_layers, num_heads] with indices between 0 and 1.
            It's a mask to be used to nullify some heads of the transformer. 1.0 => head is fully masked, 0.0 => head is not masked.

    Outputs:
        Outputs the classification logits of shape [batch_size, num_labels].

    """
    def __init__(self, config, gcn_adj_matrix, gcn_adj_dim, gcn_adj_num, gcn_embedding_dim):
        super(VGCN_Bert, self).__init__(config)
        self.embeddings = VGCNBertEmbeddings(config,gcn_adj_matrix,gcn_adj_dim,gcn_adj_num, gcn_embedding_dim)
        self.encoder = BertEncoder(config)
        self.pooler = BertPooler(config)
        self.gcn_adj_matrix=gcn_adj_matrix
        self.dropout = nn.Dropout(config.hidden_dropout_prob)
        self.classifier = nn.Linear(config.hidden_size, config.num_labels)
        self.will_collect_cls_states=False
        self.all_cls_states=[]
        self.output_attentions=config.output_attentions

        # self.apply(self.init_bert_weights)

    def forward(self, gcn_swop_eye, input_ids, token_type_ids=None, attention_mask=None, output_hidden_states=False, head_mask=None):
        if token_type_ids is None:
            token_type_ids = torch.zeros_like(input_ids)
        if attention_mask is None:
            attention_mask = torch.ones_like(input_ids)
        embedding_output = self.embeddings(gcn_swop_eye, input_ids, token_type_ids,attention_mask)

        # We create a 3D attention mask from a 2D tensor mask. 
        # Sizes are [batch_size, 1, 1, to_seq_length]
        # So we can broadcast to [batch_size, num_heads, from_seq_length, to_seq_length]
        # this attention mask is more simple than the triangular masking of causal attention
        # used in OpenAI GPT, we just need to prepare the broadcast dimension here.
        extended_attention_mask = attention_mask.unsqueeze(1).unsqueeze(2)

        # Since attention_mask is 1.0 for positions we want to attend and 0.0 for
        # masked positions, this operation will create a tensor which is 0.0 for
        # positions we want to attend and -10000.0 for masked positions.
        # Since we are adding it to the raw scores before the softmax, this is
        # effectively the same as removing these entirely.
        extended_attention_mask = extended_attention_mask.to(dtype=next(self.parameters()).dtype) # fp16 compatibility
        extended_attention_mask = (1.0 - extended_attention_mask) * -10000.0

        # 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_as(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

        if self.output_attentions:
            output_all_encoded_layers=True
        encoded_layers = self.encoder(embedding_output,
                                      extended_attention_mask,
                                      output_hidden_states=output_hidden_states,
                                      head_mask=head_mask)
        if self.output_attentions:
            all_attentions, encoded_layers = encoded_layers

        pooled_output = self.pooler(encoded_layers[-1])
        pooled_output = self.dropout(pooled_output)
        logits = self.classifier(pooled_output)

        if self.output_attentions:
            return all_attentions, logits

        return logits