ginka-generator/ginka/transformer/decoder.py
2026-03-10 23:06:23 +08:00

107 lines
4.1 KiB
Python

import time
import torch
import torch.nn as nn
from ..utils import print_memory
class GinkaTransformerDecoder(nn.Module):
def __init__(self, num_classes=32, dim_ff=256, nhead=4, num_layers=4, map_size=13*13):
super().__init__()
self.autoregressive = False
self.dim_ff = dim_ff
self.map_size = map_size
self.embedding = nn.Embedding(num_classes, dim_ff)
self.pos_embedding = nn.Embedding(map_size + 1, dim_ff)
self.encoder = nn.TransformerEncoder(
nn.TransformerEncoderLayer(d_model=dim_ff, dim_feedforward=dim_ff, nhead=nhead, batch_first=True),
num_layers=max(num_layers // 2, 1)
)
self.decoder = nn.TransformerDecoder(
nn.TransformerDecoderLayer(d_model=dim_ff, dim_feedforward=dim_ff, nhead=nhead, batch_first=True),
num_layers=num_layers
)
self.fc = nn.Sequential(
nn.Linear(dim_ff, num_classes)
)
def forward(self, z: torch.Tensor, target_map: torch.Tensor):
# z: [B, dim_ff]
# target_map: [B, H * W]
# training output: [B, H * W, dim_ff]
# evaling output: [B, H * W]
B, L = target_map.shape
memory = self.encoder(z.unsqueeze(1)) # [B, 1, dim_ff]
mask = torch.triu(torch.ones(L + 1, L + 1, dtype=torch.bool)).to(z.device) # [B, H * W, H * W]
# when training, use teacher forcing
if not self.autoregressive:
first_token = torch.tensor([31], dtype=torch.long).to(z.device).repeat(B, 1)
with_first = torch.cat([first_token, target_map], dim=1)
map = self.embedding(with_first)
pos_embed = self.pos_embedding(torch.arange(L + 1, dtype=torch.long).to(z.device))
map = map + pos_embed # [B, H * W, dim_ff]
decoded = self.decoder(map, memory, tgt_mask=mask) # [B, H * W, dim_ff]
output = self.fc(decoded)
return output
# when evaling, use autoregressive generation
else:
output = torch.zeros([B, L + 1], dtype=torch.int).to(z.device)
for idx in range(0, self.map_size):
embed = self.embedding(output)
pos_embed = self.pos_embedding(torch.IntTensor([idx]).repeat(B, 1).to(z.device))
map = embed + pos_embed # [B, H * W, dim_ff]
decoded = self.decoder(map, memory, tgt_mask=mask)
decoded = self.fc(decoded) # [B, H * W, dim_ff]
output[:, idx] = torch.argmax(decoded[:, idx, :], dim=1)
return output
class GinkaTransformerVAEDecoder(nn.Module):
def __init__(
self, latent_dim=32, num_classes=32, dim_ff=256, nhead=4, num_layers=4,
map_size=13*13
):
super().__init__()
self.map_size = map_size
self.input = nn.Sequential(
nn.Linear(latent_dim, dim_ff),
nn.Dropout(0.3),
nn.LayerNorm(dim_ff),
nn.ReLU(),
nn.Linear(dim_ff, dim_ff)
)
self.decoder = GinkaTransformerDecoder(
num_classes=num_classes, dim_ff=dim_ff, nhead=nhead, num_layers=num_layers, map_size=map_size
)
def forward(self, z: torch.Tensor, map: torch.Tensor):
hidden = self.input(z)
output = self.decoder(hidden, map)
return output
if __name__ == "__main__":
device = torch.device("cpu")
input = torch.randn(1, 32).to(device)
map = torch.randint(0, 32, [1, 169]).to(device)
# 初始化模型
model = GinkaTransformerVAEDecoder().to(device)
print_memory("初始化后")
# 前向传播
start = time.perf_counter()
output = model(input, map)
end = time.perf_counter()
print_memory("前向传播后")
print(f"推理耗时: {end - start}")
print(f"输出形状: output={output.shape}")
print(f"Input Embedding parameters: {sum(p.numel() for p in model.input.parameters())}")
print(f"Decoder parameters: {sum(p.numel() for p in model.decoder.parameters())}")
print(f"Total parameters: {sum(p.numel() for p in model.parameters())}")