# Copyright (c) Alibaba Cloud. # # This source code is licensed under the license found in the # LICENSE file in the root directory of this source tree. import importlib import math from typing import TYPE_CHECKING, Optional, Tuple, Union, Callable, List import torch import torch.nn.functional as F import torch.utils.checkpoint from torch.cuda.amp import autocast from torch.nn import CrossEntropyLoss from transformers import PreTrainedTokenizer, GenerationConfig, StoppingCriteriaList from transformers.generation.logits_process import LogitsProcessorList if TYPE_CHECKING: from transformers.generation.streamers import BaseStreamer from transformers.generation.utils import GenerateOutput from transformers.modeling_outputs import ( BaseModelOutputWithPast, CausalLMOutputWithPast, ) from transformers.modeling_utils import PreTrainedModel from transformers.utils import logging try: from einops import rearrange except ImportError: rearrange = None from torch import nn try: from flash_attn.layers.rotary import apply_rotary_emb_func from einops import rearrange use_flash_rotary = True print("use flash_attn rotary") except ImportError: use_flash_rotary = False print("import flash_attn rotary fail") try: from flash_attn.ops.rms_norm import rms_norm print("use flash_attn rms_norm") except ImportError: rms_norm = None print("import flash_attn rms_norm fail") from .configuration_qwen import QWenConfig from .qwen_generation_utils import ( HistoryType, make_context, decode_tokens, get_stop_words_ids, StopWordsLogitsProcessor, ) logger = logging.get_logger(__name__) _CHECKPOINT_FOR_DOC = "qwen" _CONFIG_FOR_DOC = "QWenConfig" QWen_PRETRAINED_MODEL_ARCHIVE_LIST = ["qwen-7b"] try: from flash_attn.flash_attn_interface import flash_attn_unpadded_func except ImportError: flash_attn_unpadded_func = None class FlashSelfAttention(torch.nn.Module): def __init__( self, causal=False, softmax_scale=None, attention_dropout=0.0, ): super().__init__() assert flash_attn_unpadded_func is not None, ( "Please install FlashAttention first, " "e.g., with pip install flash-attn" ) assert ( rearrange is not None ), "Please install einops first, e.g., with pip install einops" self.causal = causal self.softmax_scale = softmax_scale self.dropout_p = attention_dropout def forward(self, q, k, v): assert all((i.dtype in [torch.float16, torch.bfloat16] for i in (q, k, v))) assert all((i.is_cuda for i in (q, k, v))) batch_size, seqlen_q = q.shape[0], q.shape[1] seqlen_k = k.shape[1] q, k, v = [rearrange(x, "b s ... -> (b s) ...") for x in [q, k, v]] cu_seqlens_q = torch.arange( 0, (batch_size + 1) * seqlen_q, step=seqlen_q, dtype=torch.int32, device=q.device, ) if self.training: assert seqlen_k == seqlen_q is_causal = self.causal cu_seqlens_k = cu_seqlens_q else: is_causal = seqlen_q == seqlen_k cu_seqlens_k = torch.arange( 0, (batch_size + 1) * seqlen_k, step=seqlen_k, dtype=torch.int32, device=q.device, ) self.dropout_p = 0 output = flash_attn_unpadded_func( q, k, v, cu_seqlens_q, cu_seqlens_k, seqlen_q, seqlen_k, self.dropout_p, softmax_scale=self.softmax_scale, causal=is_causal, ) output = rearrange(output, "(b s) ... -> b s ...", b=batch_size) return output class QWenAttention(nn.Module): def __init__(self, config, layer_number=None): super().__init__() max_positions = config.max_position_embeddings self.register_buffer( "bias", torch.tril( torch.ones((max_positions, max_positions), dtype=torch.bool) ).view(1, 1, max_positions, max_positions), persistent=False, ) self.register_buffer("masked_bias", torch.tensor(-1e4), persistent=False) self.layer_number = max(1, layer_number) self.params_dtype = config.params_dtype self.seq_length = config.seq_length self.hidden_size = config.hidden_size self.split_size = config.hidden_size self.num_heads = config.num_attention_heads self.head_dim = self.hidden_size // self.num_heads self.use_flash_attn = config.use_flash_attn self.scale_attn_weights = True self.layer_idx = None self.projection_size = config.kv_channels * config.num_attention_heads assert self.projection_size % config.num_attention_heads == 0 self.hidden_size_per_attention_head = ( self.projection_size // config.num_attention_heads ) self.c_attn = nn.Linear(config.hidden_size, 3 * self.projection_size) self.c_proj = nn.Linear( config.hidden_size, self.projection_size, bias=not config.no_bias ) if self.use_flash_attn: self.core_attention_flash = FlashSelfAttention( causal=True, attention_dropout=config.attn_pdrop ) self.bf16 = config.bf16 if config.rotary_pct == 1.0: self.rotary_ndims = None else: assert config.rotary_pct < 1 self.rotary_ndims = int( self.hidden_size_per_attention_head * config.rotary_pct ) dim = ( self.rotary_ndims if self.rotary_ndims is not None else self.hidden_size_per_attention_head ) self.rotary_emb = RotaryEmbedding( dim, base=config.rotary_emb_base ) self.use_dynamic_ntk = config.use_dynamic_ntk self.use_logn_attn = config.use_logn_attn logn_list = [math.log(i, self.seq_length) if i > self.seq_length else 1 for i in range(1, 32768)] self.logn_tensor = torch.Tensor(logn_list)[None, :, None, None] self._ntk_cached = 1.0 self.attn_dropout = nn.Dropout(config.attn_pdrop) def _attn(self, query, key, value, attention_mask=None, head_mask=None): attn_weights = torch.matmul(query, key.transpose(-1, -2)) if self.scale_attn_weights: attn_weights = attn_weights / torch.full( [], value.size(-1) ** 0.5, dtype=attn_weights.dtype, device=attn_weights.device, ) query_length, key_length = query.size(-2), key.size(-2) causal_mask = self.bias[ :, :, key_length - query_length : key_length, :key_length ] mask_value = torch.finfo(attn_weights.dtype).min mask_value = torch.full([], mask_value, dtype=attn_weights.dtype).to( attn_weights.device ) attn_weights = torch.where( causal_mask, attn_weights.to(attn_weights.dtype), mask_value ) attn_weights = nn.functional.softmax(attn_weights, dim=-1) attn_weights = attn_weights.type(value.dtype) attn_weights = self.attn_dropout(attn_weights) if head_mask is not None: attn_weights = attn_weights * head_mask attn_output = torch.matmul(attn_weights, value) attn_output = attn_output.transpose(1, 2) return attn_output, attn_weights def _upcast_and_reordered_attn( self, query, key, value, attention_mask=None, head_mask=None ): bsz, num_heads, q_seq_len, dk = query.size() _, _, k_seq_len, _ = key.size() attn_weights = torch.empty( bsz * num_heads, q_seq_len, k_seq_len, dtype=torch.float32, device=query.device, ) scale_factor = 1.0 if self.scale_attn_weights: scale_factor /= float(value.size(-1)) ** 0.5 with autocast(enabled=False): q, k = query.reshape(-1, q_seq_len, dk), key.transpose(-1, -2).reshape( -1, dk, k_seq_len ) attn_weights = torch.baddbmm( attn_weights, q.float(), k.float(), beta=0, alpha=scale_factor ) attn_weights = attn_weights.reshape(bsz, num_heads, q_seq_len, k_seq_len) query_length, key_length = query.size(-2), key.size(-2) causal_mask = self.bias[ :, :, key_length - query_length : key_length, :key_length ] mask_value = torch.finfo(attn_weights.dtype).min mask_value = torch.tensor(mask_value, dtype=attn_weights.dtype).to( attn_weights.device ) attn_weights = torch.where(causal_mask, attn_weights, mask_value) if attention_mask is not None: attn_weights = attn_weights + attention_mask attn_weights = nn.functional.softmax(attn_weights, dim=-1) if attn_weights.dtype != torch.float32: raise RuntimeError( "Error with upcasting, attn_weights does not have dtype torch.float32" ) attn_weights = attn_weights.type(value.dtype) attn_weights = self.attn_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): new_shape = tensor.size()[:-1] + (num_heads, attn_head_size) tensor = tensor.view(new_shape) return tensor def _merge_heads(self, tensor, num_heads, attn_head_size): tensor = tensor.contiguous() new_shape = tensor.size()[:-2] + (num_heads * attn_head_size,) return tensor.view(new_shape) def forward( self, hidden_states: Optional[Tuple[torch.FloatTensor]], layer_past: Optional[Tuple[torch.Tensor]] = None, attention_mask: Optional[torch.FloatTensor] = None, head_mask: Optional[torch.FloatTensor] = None, encoder_hidden_states: Optional[torch.Tensor] = None, encoder_attention_mask: Optional[torch.FloatTensor] = None, output_attentions: Optional[bool] = False, use_cache: Optional[bool] = False, ): mixed_x_layer = self.c_attn(hidden_states) query, key, value = mixed_x_layer.split(self.split_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) kv_seq_len = hidden_states.size()[1] if layer_past: # layer past[0] shape: bs * seq_len * head_num * dim kv_seq_len += layer_past[0].shape[1] if self.use_dynamic_ntk and kv_seq_len == hidden_states.size()[1]: context_value = math.log(kv_seq_len / self.seq_length, 2) + 1 ntk_alpha = 2 ** math.ceil(context_value) - 1 ntk_alpha = max(ntk_alpha, 1) self._ntk_cached = ntk_alpha else: ntk_alpha = self._ntk_cached rotary_pos_emb = self.rotary_emb(kv_seq_len, ntk_alpha=ntk_alpha).to(hidden_states.device) if rotary_pos_emb is not None: if isinstance(rotary_pos_emb, tuple): rotary_pos_emb = rotary_pos_emb else: rotary_pos_emb = (rotary_pos_emb,) * 2 if rotary_pos_emb is not None: q_pos_emb, k_pos_emb = rotary_pos_emb # Slice the pos emb for current inference cur_len = query.shape[1] q_pos_emb = q_pos_emb[:, -cur_len:, :, :] k_pos_emb = k_pos_emb[:, -cur_len:, :, :] query = apply_rotary_pos_emb(query, q_pos_emb) key = apply_rotary_pos_emb(key, k_pos_emb) if layer_past is not None: past_key, past_value = layer_past[0], layer_past[1] key = torch.cat((past_key, key), dim=1) value = torch.cat((past_value, value), dim=1) if use_cache: present = (key, value) else: present = None if self.use_logn_attn: if self.logn_tensor.device != query.device: self.logn_tensor = self.logn_tensor.to(query.device).type_as(query) seq_start = key.size(0) - query.size(0) seq_end = key.size(0) logn_tensor = self.logn_tensor[:, seq_start:seq_end, :, :] query = query * logn_tensor.expand_as(query) if self.use_flash_attn: q, k, v = query, key, value context_layer = self.core_attention_flash(q, k, v) context_layer = rearrange( context_layer, "b s h d -> b s (h d)" ).contiguous() else: query = query.permute(0, 2, 1, 3) key = key.permute(0, 2, 1, 3) value = value.permute(0, 2, 1, 3) attn_output, attn_weight = self._attn( query, key, value, attention_mask, head_mask ) context_layer = self._merge_heads( attn_output, self.num_heads, self.head_dim ) attn_output = self.c_proj(context_layer) outputs = (attn_output, present) if output_attentions: if self.use_flash_attn: raise ValueError("Cannot output attentions while using flash-attn") else: outputs += (attn_weight,) return outputs class QWenMLP(nn.Module): def __init__(self, config): super().__init__() self.w1 = nn.Linear( config.hidden_size, config.ffn_hidden_size // 2, bias=not config.no_bias ) self.w2 = nn.Linear( config.hidden_size, config.ffn_hidden_size // 2, bias=not config.no_bias ) ff_dim_in = config.ffn_hidden_size // 2 self.c_proj = nn.Linear(ff_dim_in, config.hidden_size, bias=not config.no_bias) def forward(self, hidden_states): a1 = self.w1(hidden_states) a2 = self.w2(hidden_states) intermediate_parallel = a1 * F.silu(a2) output = self.c_proj(intermediate_parallel) return output class QWenBlock(nn.Module): def __init__(self, config, layer_idx=None, num_expert=1): super().__init__() self.num_expert = num_expert self.layer_number = layer_idx self.apply_residual_connection_post_layernorm = ( config.apply_residual_connection_post_layernorm ) hidden_size = config.hidden_size self.apply_residual_connection_post_layernorm = ( config.apply_residual_connection_post_layernorm ) self.bf16 = config.bf16 self.ln_1 = RMSNorm( hidden_size, eps=config.layer_norm_epsilon, ) self.attn = QWenAttention(config, layer_number=layer_idx) self.ln_2 = RMSNorm( hidden_size, eps=config.layer_norm_epsilon, ) self.mlp = QWenMLP(config) def forward( self, hidden_states: Optional[Tuple[torch.FloatTensor]], layer_past: Optional[Tuple[torch.Tensor]] = None, attention_mask: Optional[torch.FloatTensor] = None, head_mask: Optional[torch.FloatTensor] = None, encoder_hidden_states: Optional[torch.Tensor] = None, encoder_attention_mask: Optional[torch.FloatTensor] = None, use_cache: Optional[bool] = False, output_attentions: Optional[bool] = False, ): layernorm_output = self.ln_1(hidden_states) attn_outputs = self.attn( layernorm_output, layer_past=layer_past, attention_mask=attention_mask, head_mask=head_mask, use_cache=use_cache, output_attentions=output_attentions, ) attn_output = attn_outputs[0] outputs = attn_outputs[1:] if self.apply_residual_connection_post_layernorm: residual = layernorm_output else: residual = hidden_states layernorm_input = attn_output + residual layernorm_output = self.ln_2(layernorm_input) if self.apply_residual_connection_post_layernorm: residual = layernorm_output else: residual = layernorm_input mlp_output = self.mlp(layernorm_output) hidden_states = residual + mlp_output if use_cache: outputs = (hidden_states,) + outputs else: outputs = (hidden_states,) + outputs[1:] return outputs class QWenPreTrainedModel(PreTrainedModel): config_class = QWenConfig base_model_prefix = "transformer" is_parallelizable = False supports_gradient_checkpointing = True _no_split_modules = ["QWenBlock"] def __init__(self, *inputs, **kwargs): super().__init__(*inputs, **kwargs) def _init_weights(self, module): """Initialize the weights.""" if isinstance(module, nn.Linear): 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, RMSNorm): module.weight.data.fill_(1.0) for name, p in module.named_parameters(): if name == "c_proj.weight": p.data.normal_( mean=0.0, std=( self.config.initializer_range / math.sqrt(2 * self.config.n_layer) ), ) def _set_gradient_checkpointing(self, module, value=False): if isinstance(module, QWenModel): module.gradient_checkpointing = value class QWenModel(QWenPreTrainedModel): _keys_to_ignore_on_load_missing = ["attn.masked_bias"] def __init__(self, config): super().__init__(config) self.vocab_size = config.padded_vocab_size self.num_hidden_layers = config.num_hidden_layers self.embed_dim = config.hidden_size max_sequence_length = config.max_position_embeddings self.position_embedding_type = config.pos_emb self.gradient_checkpointing = False if self.position_embedding_type == "learned": self.wpe = nn.Embedding(max_sequence_length, self.embed_dim) self.init_method(self.position_embeddings.weight) self._position_embeddings_key = "position_embeddings" self.init_method(self.position_embeddings.weight) else: self.wpe = None self._position_embeddings_key = "" self.wte = nn.Embedding(self.vocab_size, self.embed_dim) self.drop = nn.Dropout(config.embd_pdrop) self.h = nn.ModuleList( [ QWenBlock( config, layer_idx=i, ) for i in range(config.num_hidden_layers) ] ) self.ln_f = RMSNorm( self.embed_dim, eps=config.layer_norm_epsilon, ) self.post_init() def get_input_embeddings(self): return self.wte def set_input_embeddings(self, new_embeddings): self.wte = new_embeddings def forward( self, input_ids: Optional[torch.LongTensor] = None, past_key_values: Optional[Tuple[Tuple[torch.Tensor]]] = None, attention_mask: Optional[torch.FloatTensor] = None, token_type_ids: Optional[torch.LongTensor] = None, position_ids: Optional[torch.LongTensor] = None, head_mask: Optional[torch.FloatTensor] = None, inputs_embeds: Optional[torch.FloatTensor] = None, encoder_hidden_states: Optional[torch.Tensor] = None, encoder_attention_mask: Optional[torch.FloatTensor] = None, use_cache: Optional[bool] = None, output_attentions: Optional[bool] = None, output_hidden_states: Optional[bool] = None, return_dict: Optional[bool] = 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 ) 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 ) if input_ids is not None and inputs_embeds is not None: raise ValueError( "You cannot specify both input_ids and inputs_embeds at the same time" ) elif input_ids is not None: input_shape = input_ids.size() input_ids = input_ids.view(-1, input_shape[-1]) batch_size = input_ids.shape[0] elif inputs_embeds is not None: input_shape = inputs_embeds.size()[:-1] batch_size = inputs_embeds.shape[0] 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 token_type_ids is not None: token_type_ids = token_type_ids.view(-1, input_shape[-1]) if position_ids is not None: position_ids = position_ids.view(-1, input_shape[-1]) if past_key_values is None: past_length = 0 past_key_values = tuple([None] * len(self.h)) else: past_length = past_key_values[0][0].size(-2) if position_ids is None: position_ids = torch.arange( past_length, input_shape[-1] + past_length, dtype=torch.long, device=device, ) position_ids = position_ids.unsqueeze(0).view(-1, input_shape[-1]) if attention_mask is not None: if batch_size <= 0: raise ValueError("batch_size has to be defined and > 0") attention_mask = attention_mask.view(batch_size, -1) attention_mask = attention_mask[:, None, None, :] attention_mask = attention_mask.to(dtype=self.dtype) attention_mask = (1.0 - attention_mask) * torch.finfo(self.dtype).min encoder_attention_mask = None head_mask = self.get_head_mask(head_mask, self.config.n_layer) if inputs_embeds is None: inputs_embeds = self.wte(input_ids) hidden_states = inputs_embeds if self.wpe is not None: position_embeds = self.wpe(position_ids) hidden_states = hidden_states + position_embeds hidden_states = self.drop(hidden_states) output_shape = input_shape + (hidden_states.size(-1),) if self.gradient_checkpointing and self.training: if use_cache: logger.warning_once( "`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`..." ) use_cache = False presents = () if use_cache else None all_self_attentions = () if output_attentions else None all_hidden_states = () if output_hidden_states else None for i, (block, layer_past) in enumerate(zip(self.h, past_key_values)): if output_hidden_states: all_hidden_states = all_hidden_states + (hidden_states,) if self.gradient_checkpointing and self.training: def create_custom_forward(module): def custom_forward(*inputs): # None for past_key_value return module(*inputs, use_cache, output_attentions) return custom_forward outputs = torch.utils.checkpoint.checkpoint( create_custom_forward(block), hidden_states, None, attention_mask, head_mask[i], encoder_hidden_states, encoder_attention_mask, ) else: outputs = block( hidden_states, layer_past=layer_past, attention_mask=attention_mask, head_mask=head_mask[i], encoder_hidden_states=encoder_hidden_states, encoder_attention_mask=encoder_attention_mask, use_cache=use_cache, output_attentions=output_attentions, ) hidden_states = outputs[0] if use_cache is True: presents = presents + (outputs[2 if output_attentions else 1],) 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 not return_dict: return tuple( v for v in [hidden_states, presents, all_hidden_states] if v is not None ) return BaseModelOutputWithPast( last_hidden_state=hidden_states, past_key_values=presents, hidden_states=all_hidden_states, attentions=all_self_attentions, ) class QWenLMHeadModel(QWenPreTrainedModel): _keys_to_ignore_on_load_missing = [r"h\.\d+\.attn\.rotary_emb\.inv_freq"] _keys_to_ignore_on_load_unexpected = [r"h\.\d+\.attn\.masked_bias"] def __init__(self, config): super().__init__(config) self.transformer = QWenModel(config) self.lm_head = nn.Linear(config.n_embd, config.vocab_size, bias=False) self.post_init() def get_output_embeddings(self): return self.lm_head def set_output_embeddings(self, new_embeddings): self.lm_head = new_embeddings def prepare_inputs_for_generation( self, input_ids, past_key_values=None, inputs_embeds=None, **kwargs ): token_type_ids = kwargs.get("token_type_ids", None) if past_key_values: input_ids = input_ids[:, -1].unsqueeze(-1) if token_type_ids is not None: token_type_ids = token_type_ids[:, -1].unsqueeze(-1) attention_mask = kwargs.get("attention_mask", None) position_ids = kwargs.get("position_ids", None) if attention_mask is not None and position_ids is None: position_ids = attention_mask.long().cumsum(-1) - 1 position_ids.masked_fill_(attention_mask == 0, 1) if past_key_values: position_ids = position_ids[:, -1].unsqueeze(-1) else: position_ids = None if inputs_embeds is not None and past_key_values is None: model_inputs = {"inputs_embeds": inputs_embeds} else: model_inputs = {"input_ids": input_ids} model_inputs.update( { "past_key_values": past_key_values, "use_cache": kwargs.get("use_cache"), "position_ids": position_ids, "attention_mask": attention_mask, "token_type_ids": token_type_ids, } ) return model_inputs def forward( self, input_ids: Optional[torch.LongTensor] = None, past_key_values: Optional[Tuple[Tuple[torch.Tensor]]] = None, attention_mask: Optional[torch.FloatTensor] = None, token_type_ids: Optional[torch.LongTensor] = None, position_ids: Optional[torch.LongTensor] = None, head_mask: Optional[torch.FloatTensor] = None, inputs_embeds: Optional[torch.FloatTensor] = None, encoder_hidden_states: Optional[torch.Tensor] = None, encoder_attention_mask: 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, CausalLMOutputWithPast]: return_dict = ( return_dict if return_dict is not None else self.config.use_return_dict ) transformer_outputs = self.transformer( input_ids, past_key_values=past_key_values, attention_mask=attention_mask, token_type_ids=token_type_ids, position_ids=position_ids, head_mask=head_mask, inputs_embeds=inputs_embeds, encoder_hidden_states=encoder_hidden_states, encoder_attention_mask=encoder_attention_mask, use_cache=use_cache, output_attentions=output_attentions, output_hidden_states=output_hidden_states, return_dict=return_dict, ) hidden_states = transformer_outputs[0] lm_logits = self.lm_head(hidden_states) loss = None if labels is not None: labels = labels.to(lm_logits.device) shift_logits = lm_logits[..., :-1, :].contiguous() shift_labels = labels[..., 1:].contiguous() loss_fct = CrossEntropyLoss() loss = loss_fct( shift_logits.view(-1, shift_logits.size(-1)), shift_labels.view(-1) ) if not return_dict: output = (lm_logits,) + transformer_outputs[1:] return ((loss,) + output) if loss is not None else output return CausalLMOutputWithPast( loss=loss, logits=lm_logits, past_key_values=transformer_outputs.past_key_values, hidden_states=transformer_outputs.hidden_states, attentions=transformer_outputs.attentions, ) @staticmethod def _reorder_cache( past_key_values: Tuple[Tuple[torch.Tensor]], beam_idx: torch.Tensor ) -> Tuple[Tuple[torch.Tensor]]: return tuple( tuple( past_state.index_select(0, beam_idx.to(past_state.device)) for past_state in layer_past ) for layer_past in past_key_values ) def chat( self, tokenizer: PreTrainedTokenizer, query: str, history: Optional[HistoryType], system: str = "You are a helpful assistant.", append_history: bool = True, ) -> Tuple[str, HistoryType]: if history is None: history = [] raw_text, context_tokens = make_context( tokenizer, query, history=history, system=system, max_window_size=6144, chat_format=self.generation_config.chat_format, ) stop_words_ids = get_stop_words_ids( self.generation_config.chat_format, tokenizer ) input_ids = torch.tensor([context_tokens]).to(self.device) outputs = self.generate( input_ids, stop_words_ids=stop_words_ids, return_dict_in_generate=False, ) response = decode_tokens( outputs[0], tokenizer, raw_text_len=len(raw_text), context_length=len(context_tokens), chat_format=self.generation_config.chat_format, verbose=False, ) if append_history: history.append((query, response)) return response, history def generate( self, inputs: Optional[torch.Tensor] = None, generation_config: Optional[GenerationConfig] = None, logits_processor: Optional[LogitsProcessorList] = None, stopping_criteria: Optional[StoppingCriteriaList] = None, prefix_allowed_tokens_fn: Optional[Callable[[int, torch.Tensor], List[int]]] = None, synced_gpus: Optional[bool] = None, streamer: Optional["BaseStreamer"] = None, **kwargs, ) -> Union[GenerateOutput, torch.LongTensor]: # Process stop_words_ids. stop_words_ids = kwargs.pop('stop_words_ids', None) if stop_words_ids is None and generation_config is not None: stop_words_ids = getattr(generation_config, 'stop_words_ids', None) if stop_words_ids is None: stop_words_ids = getattr(self.generation_config, 'stop_words_ids', None) if stop_words_ids is not None: stop_words_logits_processor = StopWordsLogitsProcessor( stop_words_ids=stop_words_ids, eos_token_id=self.generation_config.eos_token_id) if logits_processor is None: logits_processor = LogitsProcessorList([stop_words_logits_processor]) else: logits_processor.append(stop_words_logits_processor) return super().generate( inputs, generation_config, logits_processor, stopping_criteria, prefix_allowed_tokens_fn, synced_gpus, streamer, **kwargs, ) class RotaryEmbedding(torch.nn.Module): def __init__(self, dim, base=10000): super().__init__() self.dim = dim self.base = base inv_freq = 1.0 / (base ** (torch.arange(0, dim, 2).float() / dim)) self.register_buffer("inv_freq", inv_freq) if importlib.util.find_spec("einops") is None: raise RuntimeError("einops is required for Rotary Embedding") self._rotary_pos_emb_cache = None self._seq_len_cached = 0 self._ntk_alpha_cached = 1.0 def update_rotary_pos_emb_cache(self, max_seq_len, offset=0, ntk_alpha=1.0): seqlen = max_seq_len + offset if seqlen > self._seq_len_cached or ntk_alpha != self._ntk_alpha_cached: base = self.base * ntk_alpha ** (self.dim / (self.dim - 2)) self.inv_freq = 1.0 / (base ** (torch.arange(0, self.dim, 2, device=self.inv_freq.device).float() / self.dim)) self._seq_len_cached = seqlen self._ntk_alpha_cached = ntk_alpha seq = torch.arange(seqlen, device=self.inv_freq.device) freqs = torch.outer(seq.type_as(self.inv_freq), self.inv_freq) emb = torch.cat((freqs, freqs), dim=-1) from einops import rearrange self._rotary_pos_emb_cache = rearrange(emb, "n d -> 1 n 1 d") def forward(self, max_seq_len, offset=0, ntk_alpha=1.0): self.update_rotary_pos_emb_cache(max_seq_len, offset, ntk_alpha) return self._rotary_pos_emb_cache[:, offset : offset + max_seq_len] def _rotate_half(x): from einops import rearrange x = rearrange(x, "... (j d) -> ... j d", j=2) x1, x2 = x.unbind(dim=-2) return torch.cat((-x2, x1), dim=-1) def apply_rotary_pos_emb(t, freqs, use_flash_rotary=False): if use_flash_rotary: t_ = t.float() freqs = freqs.squeeze(0).squeeze(1) cos = freqs[:, : freqs.shape[-1] // 2].cos() sin = freqs[:, : freqs.shape[-1] // 2].sin() output = apply_rotary_emb_func(t_, cos, sin).type_as(t) return output else: rot_dim = freqs.shape[-1] t_, t_pass_ = t[..., :rot_dim], t[..., rot_dim:] t_ = t_.float() t_pass_ = t_pass_.float() t_ = (t_ * freqs.cos()) + (_rotate_half(t_) * freqs.sin()) return torch.cat((t_, t_pass_), dim=-1).type_as(t) class RMSNorm(torch.nn.Module): def __init__(self, dim: int, eps: float = 1e-6): super().__init__() self.eps = eps self.weight = nn.Parameter(torch.ones(dim)) def _norm(self, x): return x * torch.rsqrt(x.pow(2).mean(-1, keepdim=True) + self.eps) def forward(self, x): if rms_norm is not None: return rms_norm(x, self.weight, self.eps) else: output = self._norm(x.float()).type_as(x) return output * self.weight