generated from xuyuqing/ailab
608 lines
24 KiB
Python
608 lines
24 KiB
Python
# Copyright (c) 2023, Baichuan Intelligent Technology. All rights reserved.
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import math
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from typing import List, Optional, Tuple, Union
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import torch
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import torch.utils.checkpoint
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from torch.nn import CrossEntropyLoss
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from transformers import PreTrainedModel
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from transformers.activations import ACT2FN
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from transformers.modeling_outputs import BaseModelOutputWithPast, CausalLMOutputWithPast
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from transformers.utils import logging
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from transformers.generation.utils import GenerationConfig
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from .configuration_baichuan import BaichuanConfig
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logger = logging.get_logger(__name__)
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def _get_interleave(n):
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def _get_interleave_power_of_2(n):
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start = (2 ** (-2 ** -(math.log2(n) - 3)))
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ratio = start
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return [start * ratio ** i for i in range(n)]
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if math.log2(n).is_integer():
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return _get_interleave_power_of_2(n)
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else:
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closest_power_of_2 = 2 ** math.floor(math.log2(n))
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return _get_interleave_power_of_2(closest_power_of_2) + \
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_get_interleave(2 * closest_power_of_2)[0::2][:n - closest_power_of_2]
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def _fill_with_neg_inf(t):
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"""FP16-compatible function that fills a tensor with -inf."""
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return t.float().fill_(float("-inf")).type_as(t)
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def _gen_alibi_mask(n_head, max_pos):
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"""used in inference only"""
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slopes = torch.Tensor(_get_interleave(n_head))
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alibi = slopes.unsqueeze(1).unsqueeze(1) * torch.arange(max_pos).unsqueeze(0).unsqueeze(0).expand(
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n_head, -1, -1)
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alibi = alibi.view(n_head, 1, max_pos)
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alibi_mask = torch.triu(
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_fill_with_neg_inf(torch.zeros([max_pos, max_pos])), 1
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)
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alibi_mask = alibi_mask.unsqueeze(0) + alibi
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return alibi_mask
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def _buffered_future_mask(tensor, maxpos, alibi, attn_heads):
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"""used in training only"""
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dim = tensor.size(1)
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_future_mask = torch.triu(
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_fill_with_neg_inf(torch.zeros([maxpos, maxpos])), 1
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)
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_future_mask = _future_mask.unsqueeze(0) + alibi
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_future_mask = _future_mask.to(tensor)
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return _future_mask[:tensor.shape[0] * attn_heads, :maxpos, :maxpos]
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class RMSNorm(torch.nn.Module):
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def __init__(self, hidden_size, epsilon=1e-6):
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super().__init__()
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self.weight = torch.nn.Parameter(torch.empty(hidden_size))
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self.epsilon = epsilon
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def forward(self, hidden_states):
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variance = hidden_states.to(torch.float32).pow(2).mean(-1, keepdim=True)
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hidden_states = hidden_states * torch.rsqrt(variance + self.epsilon)
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# convert into half-precision
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if self.weight.dtype in [torch.float16, torch.bfloat16]:
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hidden_states = hidden_states.to(self.weight.dtype)
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return self.weight * hidden_states
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class MLP(torch.nn.Module):
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def __init__(
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self,
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hidden_size: int,
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intermediate_size: int,
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hidden_act: str,
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):
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super().__init__()
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self.gate_proj = torch.nn.Linear(hidden_size, intermediate_size, bias=False)
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self.down_proj = torch.nn.Linear(intermediate_size, hidden_size, bias=False)
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self.up_proj = torch.nn.Linear(hidden_size, intermediate_size, bias=False)
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self.act_fn = ACT2FN[hidden_act]
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def forward(self, x):
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return self.down_proj(self.act_fn(self.gate_proj(x)) * self.up_proj(x))
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class BaichuanAttention(torch.nn.Module):
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def __init__(self, config: BaichuanConfig):
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super().__init__()
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self.config = config
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self.hidden_size = config.hidden_size
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self.num_heads = config.num_attention_heads
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self.head_dim = self.hidden_size // self.num_heads
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self.max_position_embeddings = config.model_max_length
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if (self.head_dim * self.num_heads) != self.hidden_size:
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raise ValueError(
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f"hidden_size {self.hidden_size} is not divisible by num_heads {self.num_heads}"
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)
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self.W_pack = torch.nn.Linear(self.hidden_size, 3 * self.hidden_size, bias=False)
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self.o_proj = torch.nn.Linear(self.num_heads * self.head_dim, self.hidden_size, bias=False)
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def _shape(self, tensor: torch.Tensor, seq_len: int, bsz: int):
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return tensor.view(bsz, seq_len, self.num_heads, self.head_dim).transpose(1, 2).contiguous()
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def forward(
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self,
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hidden_states: torch.Tensor,
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attention_mask: Optional[torch.Tensor] = None,
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past_key_value: Optional[Tuple[torch.Tensor]] = None,
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output_attentions: bool = False,
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use_cache: bool = False,
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) -> Tuple[torch.Tensor, Optional[torch.Tensor], Optional[Tuple[torch.Tensor]]]:
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bsz, q_len, _ = hidden_states.size()
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proj = self.W_pack(hidden_states)
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proj = proj.unflatten(-1, (3, self.hidden_size)).unsqueeze(0).transpose(0, -2).squeeze(-2)
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query_states = proj[0].view(bsz, q_len, self.num_heads, self.head_dim).transpose(1, 2)
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key_states = proj[1].view(bsz, q_len, self.num_heads, self.head_dim).transpose(1, 2)
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value_states = proj[2].view(bsz, q_len, self.num_heads, self.head_dim).transpose(1, 2)
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kv_seq_len = key_states.shape[-2]
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if past_key_value is not None:
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kv_seq_len += past_key_value[0].shape[-2]
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if past_key_value is not None:
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# reuse k, v, self_attention
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key_states = torch.cat([past_key_value[0], key_states], dim=2)
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value_states = torch.cat([past_key_value[1], value_states], dim=2)
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past_key_value = (key_states, value_states) if use_cache else None
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attn_weights = torch.matmul(query_states, key_states.transpose(2, 3)) / math.sqrt(self.head_dim)
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if attention_mask is not None:
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if q_len == 1: # inference with cache
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if len(attention_mask.size()) == 4:
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attention_mask = attention_mask[:, :, -1:, :]
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else:
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attention_mask = attention_mask[:, -1:, :]
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attn_weights = attn_weights + attention_mask
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attn_weights = torch.max(attn_weights, torch.tensor(torch.finfo(attn_weights.dtype).min))
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attn_weights = torch.nn.functional.softmax(attn_weights, dim=-1)
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attn_output = torch.matmul(attn_weights, value_states)
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attn_output = attn_output.transpose(1, 2)
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attn_output = attn_output.reshape(bsz, q_len, self.hidden_size)
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attn_output = self.o_proj(attn_output)
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if not output_attentions:
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attn_weights = None
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return attn_output, attn_weights, past_key_value
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class BaichuanLayer(torch.nn.Module):
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def __init__(self, config: BaichuanConfig):
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super().__init__()
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self.hidden_size = config.hidden_size
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self.self_attn = BaichuanAttention(config=config)
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self.mlp = MLP(
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hidden_size=self.hidden_size,
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intermediate_size=config.intermediate_size,
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hidden_act=config.hidden_act,
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)
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self.input_layernorm = RMSNorm(config.hidden_size, epsilon=config.rms_norm_eps)
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self.post_attention_layernorm = RMSNorm(config.hidden_size, epsilon=config.rms_norm_eps)
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def forward(
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self,
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hidden_states: torch.Tensor,
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attention_mask: Optional[torch.Tensor] = None,
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past_key_value: Optional[Tuple[torch.Tensor]] = None,
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output_attentions: Optional[bool] = False,
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use_cache: Optional[bool] = False,
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) -> Tuple[torch.FloatTensor, Optional[Tuple[torch.FloatTensor, torch.FloatTensor]]]:
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residual = hidden_states
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hidden_states = self.input_layernorm(hidden_states)
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# Self Attention
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hidden_states, self_attn_weights, present_key_value = self.self_attn(
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hidden_states=hidden_states,
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attention_mask=attention_mask,
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past_key_value=past_key_value,
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output_attentions=output_attentions,
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use_cache=use_cache,
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)
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hidden_states = residual + hidden_states
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# Fully Connected
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residual = hidden_states
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hidden_states = self.post_attention_layernorm(hidden_states)
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hidden_states = self.mlp(hidden_states)
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hidden_states = residual + hidden_states
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outputs = (hidden_states,)
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if use_cache:
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outputs += (present_key_value,)
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return outputs
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class BaichuanPreTrainedModel(PreTrainedModel):
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config_class = BaichuanConfig
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base_model_prefix = "model"
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supports_gradient_checkpointing = True
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_no_split_modules = ["BaichuanLayer"]
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_keys_to_ignore_on_load_unexpected = [r"decoder\.version"]
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def _init_weights(self, module):
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std = self.config.initializer_range
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if isinstance(module, torch.nn.Linear):
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module.weight.data.normal_(mean=0.0, std=std)
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if module.bias is not None:
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module.bias.data.zero_()
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elif isinstance(module, torch.nn.Embedding):
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module.weight.data.normal_(mean=0.0, std=std)
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if module.padding_idx is not None:
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module.weight.data[module.padding_idx].zero_()
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def _set_gradient_checkpointing(self, module, value=False):
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if isinstance(module, BaichuanModel):
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module.gradient_checkpointing = value
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class BaichuanModel(BaichuanPreTrainedModel):
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def __init__(self, config: BaichuanConfig):
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super().__init__(config)
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self.padding_idx = config.pad_token_id
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self.vocab_size = config.vocab_size
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self.n_head = config.num_attention_heads
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self.embed_tokens = torch.nn.Embedding(config.vocab_size, config.hidden_size, self.padding_idx)
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self.layers = torch.nn.ModuleList([BaichuanLayer(config) for _ in range(config.num_hidden_layers)])
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self.norm = RMSNorm(config.hidden_size, epsilon=config.rms_norm_eps)
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self.gradient_checkpointing = config.gradient_checkpointing
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self.post_init()
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self.max_cache_pos = config.model_max_length
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self.first_run = True
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self.alibi_mask = None
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def get_input_embeddings(self):
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return self.embed_tokens
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def set_input_embeddings(self, value):
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self.embed_tokens = value
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def get_alibi_mask(self, tensor, seq_length_with_past):
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if self.training:
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slopes = torch.Tensor(_get_interleave(self.n_head))
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alibi = slopes.unsqueeze(1).unsqueeze(1) * torch.arange(seq_length_with_past).unsqueeze(0).unsqueeze(0).expand(
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self.n_head,
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-1, -1)
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alibi = alibi.view(self.n_head, 1, seq_length_with_past)
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mask = _buffered_future_mask(tensor, seq_length_with_past, alibi, self.n_head)
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else:
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if self.first_run:
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self.first_run = False
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self.register_buffer("future_mask", _gen_alibi_mask(self.n_head, self.max_cache_pos).to(tensor), persistent=False)
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if seq_length_with_past > self.max_cache_pos:
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self.max_cache_pos = seq_length_with_past
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self.register_buffer("future_mask", _gen_alibi_mask(self.n_head, self.max_cache_pos).to(tensor), persistent=False)
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mask = self.future_mask[:self.n_head, :seq_length_with_past, :seq_length_with_past]
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return mask
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def forward(
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self,
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input_ids: torch.LongTensor = None,
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attention_mask: Optional[torch.Tensor] = None,
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past_key_values: Optional[List[torch.FloatTensor]] = None,
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inputs_embeds: Optional[torch.FloatTensor] = None,
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use_cache: Optional[bool] = False,
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output_attentions: Optional[bool] = False,
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output_hidden_states: Optional[bool] = False,
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return_dict: Optional[bool] = True,
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) -> Union[Tuple, BaseModelOutputWithPast]:
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if input_ids is not None and inputs_embeds is not None:
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raise ValueError("You cannot provide both input_ids and inputs_embeds simultaneously")
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elif input_ids is not None:
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batch_size, seq_length = input_ids.shape
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elif inputs_embeds is not None:
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batch_size, seq_length, _ = inputs_embeds.shape
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else:
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raise ValueError("You need to provide input_ids or inputs_embeds")
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return_dict = return_dict if return_dict is not None else self.config.use_return_dict
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seq_length_with_past = seq_length
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if past_key_values is not None:
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past_key_values_length = past_key_values[0][0].shape[2]
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seq_length_with_past = seq_length_with_past + past_key_values_length
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if inputs_embeds is None:
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inputs_embeds = self.embed_tokens(input_ids)
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if self.training:
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if self.alibi_mask is None or self.alibi_mask.shape[-1] != seq_length_with_past:
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self.alibi_mask = self.get_alibi_mask(inputs_embeds, seq_length_with_past)
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alibi_mask = self.alibi_mask
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else:
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alibi_mask = self.get_alibi_mask(inputs_embeds, seq_length_with_past)
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if attention_mask is not None:
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if len(attention_mask.shape) == 2:
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expanded_mask = attention_mask.to(alibi_mask.dtype)
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expanded_mask = torch.tril(torch.gt(expanded_mask[:, :, None] * expanded_mask[:, None, :], 0)
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) * torch.eq(expanded_mask[:, :, None] - expanded_mask[:, None, :], 0)
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else:
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expanded_mask = attention_mask
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bsz = inputs_embeds.size(0)
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src_len, tgt_len = alibi_mask.size()[-2:]
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expanded_mask = expanded_mask.unsqueeze(1).expand(bsz, 1, src_len, tgt_len).to(alibi_mask.dtype)
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inverted_mask = 1.0 - expanded_mask
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inverted_mask = inverted_mask.masked_fill(inverted_mask.to(torch.bool), torch.finfo(alibi_mask.dtype).min)
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attention_mask = inverted_mask + alibi_mask.unsqueeze(0)
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else:
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attention_mask = alibi_mask
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hidden_states = inputs_embeds
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if self.gradient_checkpointing and self.training:
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if use_cache:
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logger.warning_once(
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"`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`..."
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)
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use_cache = False
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# decoder layers
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all_hidden_states = () if output_hidden_states else None
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all_self_attns = () if output_attentions else None
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next_decoder_cache = () if use_cache else None
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for idx, decoder_layer in enumerate(self.layers):
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if output_hidden_states:
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all_hidden_states += (hidden_states,)
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past_key_value = past_key_values[idx] if past_key_values is not None else None
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if self.gradient_checkpointing and self.training:
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def create_custom_forward(module):
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def custom_forward(*inputs):
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# None for past_key_value
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return module(*inputs, output_attentions, None)
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return custom_forward
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layer_outputs = torch.utils.checkpoint.checkpoint(
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create_custom_forward(decoder_layer),
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hidden_states,
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attention_mask,
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None,
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)
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else:
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layer_outputs = decoder_layer(
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hidden_states,
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attention_mask=attention_mask,
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past_key_value=past_key_value,
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output_attentions=output_attentions,
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use_cache=use_cache,
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)
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hidden_states = layer_outputs[0]
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if use_cache:
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next_decoder_cache += (layer_outputs[2 if output_attentions else 1],)
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if output_attentions:
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all_self_attns += (layer_outputs[1],)
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hidden_states = self.norm(hidden_states)
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# add hidden states from the last decoder layer
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if output_hidden_states:
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all_hidden_states += (hidden_states,)
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next_cache = next_decoder_cache if use_cache else None
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if not return_dict:
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return tuple(v for v in [hidden_states, next_cache, all_hidden_states, all_self_attns] if v is not None)
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return BaseModelOutputWithPast(
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last_hidden_state=hidden_states,
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past_key_values=next_cache,
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hidden_states=all_hidden_states,
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attentions=all_self_attns,
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)
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class BaichuanForCausalLM(BaichuanPreTrainedModel):
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def __init__(self, config):
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super().__init__(config)
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self.model = BaichuanModel(config)
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self.lm_head = torch.nn.Linear(config.hidden_size, config.vocab_size, bias=False)
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# Initialize weights and apply final processing
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self.post_init()
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def get_input_embeddings(self):
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return self.model.embed_tokens
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def set_input_embeddings(self, value):
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self.model.embed_tokens = value
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def get_output_embeddings(self):
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return self.lm_head
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def set_output_embeddings(self, new_embeddings):
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self.lm_head = new_embeddings
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def set_decoder(self, decoder):
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self.model = decoder
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def get_decoder(self):
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return self.model
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def forward(
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self,
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input_ids: torch.LongTensor = None,
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attention_mask: Optional[torch.Tensor] = None,
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past_key_values: Optional[List[torch.FloatTensor]] = None,
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inputs_embeds: Optional[torch.FloatTensor] = None,
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labels: Optional[torch.LongTensor] = None,
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use_cache: Optional[bool] = None,
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output_attentions: Optional[bool] = False,
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output_hidden_states: Optional[bool] = False,
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return_dict: Optional[bool] = True,
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**kwargs
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) -> Union[Tuple, CausalLMOutputWithPast]:
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return_dict = return_dict if return_dict is not None else self.config.use_return_dict
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# decoder outputs consists of (dec_features, layer_state, dec_hidden, dec_attn)
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outputs = self.model(
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|
input_ids=input_ids,
|
|
attention_mask=attention_mask,
|
|
past_key_values=past_key_values,
|
|
inputs_embeds=inputs_embeds,
|
|
use_cache=use_cache,
|
|
output_attentions=output_attentions,
|
|
output_hidden_states=output_hidden_states,
|
|
return_dict=return_dict,
|
|
)
|
|
|
|
hidden_states = outputs[0]
|
|
logits = self.lm_head(hidden_states)
|
|
|
|
loss = None
|
|
if labels is not None:
|
|
# Shift so that tokens < n predict n
|
|
shift_logits = logits[..., :-1, :].contiguous()
|
|
shift_labels = labels[..., 1:].contiguous()
|
|
# Flatten the tokens
|
|
loss_fct = CrossEntropyLoss()
|
|
shift_logits = shift_logits.view(-1, self.config.vocab_size)
|
|
shift_labels = shift_labels.view(-1)
|
|
# Enable model parallelism
|
|
shift_labels = shift_labels.to(shift_logits.device)
|
|
loss = loss_fct(shift_logits, shift_labels)
|
|
|
|
if not return_dict:
|
|
output = (logits,) + outputs[1:]
|
|
return (loss,) + output if loss is not None else output
|
|
|
|
return CausalLMOutputWithPast(
|
|
loss=loss,
|
|
logits=logits,
|
|
past_key_values=outputs.past_key_values,
|
|
hidden_states=outputs.hidden_states,
|
|
attentions=outputs.attentions,
|
|
)
|
|
|
|
def prepare_inputs_for_generation(
|
|
self,
|
|
input_ids: torch.LongTensor,
|
|
past_key_values: Optional[torch.Tensor] = None,
|
|
attention_mask: Optional[torch.Tensor] = None,
|
|
inputs_embeds: Optional[torch.Tensor] = None,
|
|
**kwargs
|
|
):
|
|
if past_key_values:
|
|
input_ids = input_ids[:, -1:]
|
|
|
|
# if `inputs_embeds` are passed, we only want to use them in the 1st generation step
|
|
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"),
|
|
"attention_mask": attention_mask
|
|
}
|
|
)
|
|
return model_inputs
|
|
|
|
@staticmethod
|
|
def _reorder_cache(past_key_values, beam_idx):
|
|
return tuple(
|
|
tuple(past_state.index_select(0, beam_idx) for past_state in layer_past)
|
|
for layer_past in past_key_values
|
|
)
|
|
|
|
def quantize(self, bits: int):
|
|
try:
|
|
from .quantizer import QLinear
|
|
except ImportError:
|
|
raise ImportError(
|
|
f"Needs QLinear to run quantize."
|
|
)
|
|
|
|
for layer in self.model.layers:
|
|
layer.self_attn.W_pack = QLinear(
|
|
bits=bits,
|
|
weight=layer.self_attn.W_pack.weight,
|
|
bias = None,
|
|
)
|
|
layer.self_attn.o_proj = QLinear(
|
|
bits=bits,
|
|
weight=layer.self_attn.o_proj.weight,
|
|
bias = None,
|
|
)
|
|
layer.mlp.gate_proj = QLinear(
|
|
bits=bits,
|
|
weight=layer.mlp.gate_proj.weight,
|
|
bias = None,
|
|
)
|
|
layer.mlp.down_proj = QLinear(
|
|
bits=bits,
|
|
weight=layer.mlp.down_proj.weight,
|
|
bias = None,
|
|
)
|
|
layer.mlp.up_proj = QLinear(
|
|
bits=bits,
|
|
weight=layer.mlp.up_proj.weight,
|
|
bias = None,
|
|
)
|
|
return self
|
|
|
|
def _build_chat_input(self, tokenizer, messages: List[dict], max_new_tokens: int=0):
|
|
max_new_tokens = max_new_tokens or self.generation_config.max_new_tokens
|
|
max_input_tokens = self.config.model_max_length - max_new_tokens
|
|
max_input_tokens = max(self.config.model_max_length // 2, max_input_tokens)
|
|
total_input, round_input = [], []
|
|
for i, message in enumerate(messages[::-1]):
|
|
content_tokens = tokenizer.encode(message['content'])
|
|
if message['role'] == 'user':
|
|
round_input = [self.generation_config.user_token_id] + content_tokens + round_input
|
|
if total_input and len(total_input) + len(round_input) > max_input_tokens:
|
|
break
|
|
else:
|
|
total_input = round_input + total_input
|
|
if len(total_input) >= max_input_tokens:
|
|
break
|
|
else:
|
|
round_input = []
|
|
elif message['role'] == 'assistant':
|
|
round_input = [
|
|
self.generation_config.assistant_token_id
|
|
] + content_tokens + [
|
|
self.generation_config.eos_token_id
|
|
] + round_input
|
|
else:
|
|
raise ValueError(f"message role not supported yet: {message['role']}")
|
|
total_input = total_input[-max_input_tokens:] # truncate left
|
|
total_input.append(self.generation_config.assistant_token_id)
|
|
total_input = torch.LongTensor([total_input]).to(self.device)
|
|
return total_input
|
|
|
|
@torch.no_grad()
|
|
def chat(self, tokenizer, messages: List[dict], stream=False,
|
|
generation_config: Optional[GenerationConfig]=None):
|
|
generation_config = generation_config or self.generation_config
|
|
input_ids = self._build_chat_input(tokenizer, messages, generation_config.max_new_tokens)
|
|
if stream:
|
|
from transformers_stream_generator.main import NewGenerationMixin, StreamGenerationConfig
|
|
self.__class__.generate = NewGenerationMixin.generate
|
|
self.__class__.sample_stream = NewGenerationMixin.sample_stream
|
|
stream_config = StreamGenerationConfig(**generation_config.to_dict(), do_stream=True)
|
|
|
|
def stream_generator():
|
|
outputs = []
|
|
for token in self.generate(input_ids, generation_config=stream_config):
|
|
outputs.append(token.item())
|
|
yield tokenizer.decode(outputs, skip_special_tokens=True)
|
|
|
|
return stream_generator()
|
|
else:
|
|
self.__class__.generate = PreTrainedModel.generate # disable stream
|
|
outputs = self.generate(input_ids, generation_config=generation_config)
|
|
response = tokenizer.decode(outputs[0][len(input_ids[0]):], skip_special_tokens=True)
|
|
return response
|