CogniLite / model_cognilite.py
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Init Program
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from sympy import false
import test
from transformers import PretrainedConfig
# 定义了模型的超参数和配置
class CogniLiteConfig(PretrainedConfig):
model_type = "minimind"
def __init__(
self,
dropout: float = 0.0,
bos_token_id: int = 1,
eos_token_id: int = 2,
hidden_act: str = 'silu',
hidden_size: int = 768,
intermediate_size: int = None,
max_position_embeddings: int = 32768,
num_attention_heads: int = 8,
num_hidden_layers: int = 16,
num_key_value_heads: int = 2,
vocab_size: int = 6400,
rms_norm_eps: float = 1e-05,
rope_theta: int = 1000000.0,
**kwargs
):
super().__init__(**kwargs)
# 各种模型超参数
self.dropout = dropout
self.bos_token_id = bos_token_id
self.eos_token_id = eos_token_id
self.hidden_act = hidden_act
self.hidden_size = hidden_size
self.intermediate_size = intermediate_size
self.max_position_embeddings = max_position_embeddings
self.num_attention_heads = num_attention_heads
self.num_hidden_layers = num_hidden_layers
self.num_key_value_heads = num_key_value_heads
self.vocab_size = vocab_size
self.rms_norm_eps = rms_norm_eps
self.rope_theta = rope_theta
import math
import torch
from torch import nn
from transformers.activations import ACT2FN
from typing import Optional, Tuple, List, Union
import torch.nn.functional as F
# RMSNorm 层实现,Root Mean Square Layer Normalization
class RMSNorm(torch.nn.Module):
def __init__(self, dim: int, eps: float = 1e-5):
super().__init__()
self.eps = eps
self.weight = nn.Parameter(torch.ones(dim))
def _norm(self, x):
# 归一化操作
return x * torch.rsqrt(x.pow(2).mean(-1, keepdim=True) + self.eps)
def forward(self, x):
# 应用归一化和缩放
return self.weight * self._norm(x.float()).type_as(x)
# 预计算旋转位置编码的频率
def precompute_freqs_cis(dim: int, end: int = int(32 * 1024), theta: float = 1e6):
# 生成旋转位置编码所需的 cos 和 sin
freqs = 1.0 / (theta ** (torch.arange(0, dim, 2)[: (dim // 2)].float() / dim))
t = torch.arange(end, device=freqs.device)
freqs = torch.outer(t, freqs).float()
freqs_cos = torch.cat([torch.cos(freqs), torch.cos(freqs)], dim=-1)
freqs_sin = torch.cat([torch.sin(freqs), torch.sin(freqs)], dim=-1)
return freqs_cos, freqs_sin
# 应用旋转位置编码到 Q、K
def apply_rotary_pos_emb(q, k, cos, sin, position_ids=None, unsqueeze_dim=1):
def rotate_half(x):
# 将向量一分为二,后一半取负并交换
return torch.cat((-x[..., x.shape[-1] // 2:], x[..., : x.shape[-1] // 2]), dim=-1)
q_embed = (q * cos.unsqueeze(unsqueeze_dim)) + (rotate_half(q) * sin.unsqueeze(unsqueeze_dim))
k_embed = (k * cos.unsqueeze(unsqueeze_dim)) + (rotate_half(k) * sin.unsqueeze(unsqueeze_dim))
return q_embed, k_embed
# 将 KV 头重复扩展到所有 attention head
def repeat_kv(x: torch.Tensor, n_rep: int) -> torch.Tensor:
"""torch.repeat_interleave(x, dim=2, repeats=n_rep)"""
bs, slen, num_key_value_heads, head_dim = x.shape
if n_rep == 1:
return x
return (
x[:, :, :, None, :]
.expand(bs, slen, num_key_value_heads, n_rep, head_dim)
.reshape(bs, slen, num_key_value_heads * n_rep, head_dim)
)
# 注意力机制实现
class Attention(nn.Module):
def __init__(self, args: CogniLiteConfig):
super().__init__()
# 处理 KV 头数
self.num_key_value_heads = args.num_attention_heads if args.num_key_value_heads is None else args.num_key_value_heads
assert args.num_attention_heads % self.num_key_value_heads == 0
self.n_local_heads = args.num_attention_heads
self.n_local_kv_heads = self.num_key_value_heads
self.n_rep = self.n_local_heads // self.n_local_kv_heads
self.head_dim = args.hidden_size // args.num_attention_heads
# QKV 投影
self.q_proj = nn.Linear(args.hidden_size, args.num_attention_heads * self.head_dim, bias=False)
self.k_proj = nn.Linear(args.hidden_size, self.num_key_value_heads * self.head_dim, bias=False)
self.v_proj = nn.Linear(args.hidden_size, self.num_key_value_heads * self.head_dim, bias=False)
self.o_proj = nn.Linear(args.num_attention_heads * self.head_dim, args.hidden_size, bias=False)
self.attn_dropout = nn.Dropout(args.dropout)
self.resid_dropout = nn.Dropout(args.dropout)
self.dropout = args.dropout
# 是否使用 flash attention
self.flash = hasattr(torch.nn.functional, 'scaled_dot_product_attention')
def forward(self,
x: torch.Tensor,
position_embeddings: Tuple[torch.Tensor, torch.Tensor], # cos 和 sin
past_key_value: Optional[Tuple[torch.Tensor, torch.Tensor]] = None,
use_cache=False,
attention_mask: Optional[torch.Tensor] = None):
bsz, seq_len, _ = x.shape
# QKV 投影并 reshape
xq, xk, xv = self.q_proj(x), self.k_proj(x), self.v_proj(x)
xq = xq.view(bsz, seq_len, self.n_local_heads, self.head_dim)
xk = xk.view(bsz, seq_len, self.n_local_kv_heads, self.head_dim)
xv = xv.view(bsz, seq_len, self.n_local_kv_heads, self.head_dim)
cos, sin = position_embeddings
# 应用旋转位置编码
xq, xk = apply_rotary_pos_emb(xq, xk, cos[:seq_len], sin[:seq_len])
# 拼接 KV cache
if past_key_value is not None:
xk = torch.cat([past_key_value[0], xk], dim=1)
xv = torch.cat([past_key_value[1], xv], dim=1)
past_kv = (xk, xv) if use_cache else None
# KV 头扩展到所有 attention head
xq, xk, xv = (
xq.transpose(1, 2),
repeat_kv(xk, self.n_rep).transpose(1, 2),
repeat_kv(xv, self.n_rep).transpose(1, 2)
)
# 使用 flash attention 或常规 attention
if self.flash and seq_len != 1:
dropout_p = self.dropout if self.training else 0.0
attn_mask = None
if attention_mask is not None:
attn_mask = attention_mask.view(bsz, 1, 1, -1).expand(bsz, self.n_local_heads, seq_len, -1)
attn_mask = attn_mask.bool() if attention_mask is not None else None
output = F.scaled_dot_product_attention(xq, xk, xv, attn_mask=attn_mask, dropout_p=dropout_p, is_causal=True)
else:
# 计算注意力分数
scores = (xq @ xk.transpose(-2, -1)) / math.sqrt(self.head_dim)
scores = scores + torch.triu(
torch.full((seq_len, seq_len), float("-inf"), device=scores.device),
diagonal=1
).unsqueeze(0).unsqueeze(0) # 上三角 mask
if attention_mask is not None:
extended_attention_mask = attention_mask.unsqueeze(1).unsqueeze(2)
extended_attention_mask = (1.0 - extended_attention_mask) * -1e9
scores = scores + extended_attention_mask
scores = F.softmax(scores.float(), dim=-1).type_as(xq)
scores = self.attn_dropout(scores)
output = scores @ xv
# 恢复 shape 并输出
output = output.transpose(1, 2).reshape(bsz, seq_len, -1)
output = self.resid_dropout(self.o_proj(output))
return output, past_kv
# 前馈网络实现
class FeedForward(nn.Module):
def __init__(self, config: CogniLiteConfig):
super().__init__()
# 自动推断中间层维度
if config.intermediate_size is None:
intermediate_size = int(config.hidden_size * 8 / 3)
config.intermediate_size = 64 * ((intermediate_size + 64 - 1) // 64)
self.gate_proj = nn.Linear(config.hidden_size, config.intermediate_size, bias=False)
self.down_proj = nn.Linear(config.intermediate_size, config.hidden_size, bias=False)
self.up_proj = nn.Linear(config.hidden_size, config.intermediate_size, bias=False)
self.dropout = nn.Dropout(config.dropout)
self.act_fn = ACT2FN[config.hidden_act]
def forward(self, x):
# SwiGLU 激活
return self.dropout(self.down_proj(self.act_fn(self.gate_proj(x)) * self.up_proj(x)))
# Transformer Block
class TransformerBlock(nn.Module):
def __init__(self, layer_id: int, config: CogniLiteConfig):
super().__init__()
self.num_attention_heads = config.num_attention_heads
self.hidden_size = config.hidden_size
self.head_dim = config.hidden_size // config.num_attention_heads
self.self_attn = Attention(config)
self.layer_id = layer_id
self.input_layernorm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
self.post_attention_layernorm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
self.mlp = FeedForward(config)
def forward(self, hidden_states, position_embeddings, past_key_value=None, use_cache=False, attention_mask=None):
# 残差连接 + 注意力 + 前馈
residual = hidden_states
hidden_states, present_key_value = self.self_attn(
self.input_layernorm(hidden_states), position_embeddings,
past_key_value, use_cache, attention_mask
)
hidden_states += residual
hidden_states = hidden_states + self.mlp(self.post_attention_layernorm(hidden_states))
return hidden_states, present_key_value
# CogniLite模型主体
class CogniLiteModel(nn.Module):
def __init__(self, config: CogniLiteConfig):
super().__init__()
self.config = config
self.vocab_size, self.num_hidden_layers = config.vocab_size, config.num_hidden_layers
self.embed_tokens = nn.Embedding(config.vocab_size, config.hidden_size)
self.dropout = nn.Dropout(config.dropout)
self.layers = nn.ModuleList([TransformerBlock(l, config) for l in range(self.num_hidden_layers)])
self.norm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
# 注册旋转位置编码的 cos/sin buffer
freqs_cos, freqs_sin = precompute_freqs_cis(dim=config.hidden_size // config.num_attention_heads,
end=config.max_position_embeddings, theta=config.rope_theta)
self.register_buffer("freqs_cos", freqs_cos, persistent=False)
self.register_buffer("freqs_sin", freqs_sin, persistent=False)
def forward(self,
input_ids: Optional[torch.Tensor] = None,
attention_mask: Optional[torch.Tensor] = None,
past_key_values: Optional[List[Tuple[torch.Tensor, torch.Tensor]]] = None,
use_cache: bool = False,
**kwargs):
# input_ids: (batch, seq)
_, seq_length = input_ids.shape
past_key_values = past_key_values or [None] * len(self.layers)
start_pos = past_key_values[0][0].shape[1] if past_key_values[0] is not None else 0
# 词嵌入
hidden_states = self.dropout(self.embed_tokens(input_ids))
# 取出对应位置的 cos/sin
position_embeddings = (
self.freqs_cos[start_pos:start_pos + seq_length],
self.freqs_sin[start_pos:start_pos + seq_length]
)
presents = []
for layer_idx, (layer, past_key_value) in enumerate(zip(self.layers, past_key_values)):
hidden_states, present = layer(
hidden_states,
position_embeddings,
past_key_value=past_key_value,
use_cache=use_cache,
attention_mask=attention_mask
)
presents.append(present)
hidden_states = self.norm(hidden_states)
return hidden_states, presents, 0
class CogniLiteForCausalLM(nn.Module):
def __init__(self, config: CogniLiteConfig = None):
super().__init__()
self.config = config or CogniLiteConfig()
self.model = CogniLiteModel(self.config)
self.lm_head = nn.Linear(self.config.hidden_size, self.config.vocab_size, bias=False)
# 权重共享
self.lm_head.weight = self.model.embed_tokens.weight
def forward(self,
input_ids: Optional[torch.Tensor] = None,
attention_mask: Optional[torch.Tensor] = None,
past_key_values: Optional[List[Tuple[torch.Tensor, torch.Tensor]]] = None,
use_cache: bool = False,
logits_to_keep: Union[int, torch.Tensor] = 0,
**args):
h, past_kvs, aux_loss = self.model(
input_ids=input_ids,
attention_mask=attention_mask,
past_key_values=past_key_values,
use_cache=use_cache,
**args
)
slice_indices = slice(-logits_to_keep, None) if isinstance(logits_to_keep, int) and logits_to_keep > 0 else slice(None)
logits = self.lm_head(h[:, slice_indices, :])
return {
"last_hidden_state": h,
"logits": logits,
"aux_loss": aux_loss,
"past_key_values": past_kvs
}
import safetensors.torch
from transformers import AutoTokenizer
def init_cognilite_model():
print("start loading CogniLite model...")
# CogniLite Total parameters: 104M
# structure: (hidden_size=768, num_hidden_layers=16)
args = {
"device": "cuda" if torch.cuda.is_available() else "cpu",
"hidden_size": 768,
"num_hidden_layers": 16,
}
tokenizer = AutoTokenizer.from_pretrained('./tokenizer/')
state_dict = safetensors.torch.load_file("model.safetensors", device=args["device"])
model = CogniLiteForCausalLM(CogniLiteConfig())
# 加载模型参数
model.load_state_dict(state_dict, strict= True)
print(f'模型参数量: {sum(p.numel() for p in model.parameters() if p.requires_grad)}')
return model.eval().to(args["device"]), tokenizer
import random
import numpy as np
def setup_seed(seed):
random.seed(seed)
np.random.seed(seed)
torch.manual_seed(seed)
torch.cuda.manual_seed(seed)
torch.cuda.manual_seed_all(seed)
torch.backends.cudnn.deterministic = True
torch.backends.cudnn.benchmark = False
def communicate_with_model(random_seed):
model, tokenizer = init_cognilite_model()
print("随机种子是:", random_seed)
setup_seed(random_seed)
prompt= input("你: ")
messages = [{"role": "user", "content": prompt}]
new_prompt = tokenizer.apply_chat_template(
messages,
tokenize=False,
add_generation_prompt=True
)
device = "cuda" if torch.cuda.is_available() else "cpu"
inputs = tokenizer(
new_prompt,
return_tensors="pt",
truncation=True
).to(device)
# shape: [seq_len]
input_ids = inputs["input_ids"][0]
attention_mask = inputs.get("attention_mask", None)
max_new_tokens = 128
eos_token_id = tokenizer.eos_token_id
exit_reason = None
token_list = []
print("模型 token 输出:[", end=' ')
for _ in range(max_new_tokens):
with torch.no_grad():
outputs = model(
input_ids=input_ids.unsqueeze(0),
attention_mask=attention_mask
)
logits = outputs["logits"]
next_token_id = torch.argmax(logits[0, -1], dim=-1).unsqueeze(0)
if next_token_id.item() == eos_token_id:
exit_reason = "EOS token detected"
break
token_list.append(next_token_id.item())
print(next_token_id.item(), end=' ', flush=True)
# 拼接到输入
input_ids = torch.cat([input_ids, next_token_id], dim=0)
# attention_mask 也要扩展
if attention_mask is not None:
attention_mask = torch.cat([attention_mask[0], torch.ones(1, device=device, dtype=attention_mask.dtype)], dim=0).unsqueeze(0)
print("]\n模型文字输出: " + tokenizer.decode(token_list, skip_special_tokens=False))
if exit_reason is None:
print("\n 结束对话原因: 达到最大 Token 数量限制。")
elif exit_reason == "EOS token detected":
print("\n 结束对话原因: EOS token detected.")
if __name__ == "__main__":
random_type = input("请输入随机种子(整数):")
try:
random_seed = int(random_type)
if random_seed <= 0:
print("随机种子不能为非正整数,使用随机值")
random_seed = random.randint(0, 10000)
except ValueError:
print("无效的随机种子,使用随机值")
random_seed = random.randint(0, 10000)
communicate_with_model(random_seed)