esper / clipcap.py
jiwan-chung's picture
demo init
0bf81ba
import os
import math
import logging
import json
from pathlib import Path
from typing import Tuple, Optional, Union
import torch
import torch.nn as nn
from torch.nn import functional as F
from transformers import AutoModelForCausalLM, AutoTokenizer, GPTJForCausalLM
logging.basicConfig(level=os.environ.get("LOGLEVEL", "INFO"))
log = logging.getLogger(__name__)
def load_weights(self, Module, path, name, default_name, prev_name=None, **kwargs):
hparams = None
assert isinstance(default_name, str), f'invalid default transformer name: {default_name}'
model = get_transformer_module(Module, default_name, **kwargs)
setattr(self, name, model)
return hparams
def get_transformer_module(Module, default_name, **kwargs):
if default_name == 'EleutherAI/gpt-j-6B':
kwargs = {**kwargs, **dict(revision="float16", torch_dtype=torch.float16, low_cpu_mem_usage=True)}
model = Module.from_pretrained(default_name, **kwargs)
return model
class MLP(nn.Module):
def __init__(self, sizes: Tuple[int, ...], bias=True, act=nn.Tanh):
super(MLP, self).__init__()
self.divider = math.sqrt(sizes[-1] / sizes[0])
layers = []
for i in range(len(sizes) - 1):
layers.append(nn.Linear(sizes[i], sizes[i + 1], bias=bias))
if i < len(sizes) - 2:
layers.append(act())
self.model = nn.Sequential(*layers)
def forward(self, x: torch.Tensor) -> torch.Tensor:
x = x / self.divider # scaling for the initial stability
x = self.model(x)
return x
class MlpTransformer(nn.Module):
def __init__(self, in_dim, h_dim, out_d: Optional[int] = None, act=F.relu, dropout=0.):
super().__init__()
out_d = out_d if out_d is not None else in_dim
self.fc1 = nn.Linear(in_dim, h_dim)
self.act = act
self.fc2 = nn.Linear(h_dim, out_d)
self.dropout = nn.Dropout(dropout)
def forward(self, x):
x = self.fc1(x)
x = self.act(x)
x = self.dropout(x)
x = self.fc2(x)
x = self.dropout(x)
return x
class MultiHeadAttention(nn.Module):
def __init__(self, dim_self, dim_ref, num_heads, bias=True, dropout=0.):
super().__init__()
self.num_heads = num_heads
head_dim = dim_self // num_heads
self.scale = head_dim ** -0.5
self.to_queries = nn.Linear(dim_self, dim_self, bias=bias)
self.to_keys_values = nn.Linear(dim_ref, dim_self * 2, bias=bias)
self.project = nn.Linear(dim_self, dim_self)
self.dropout = nn.Dropout(dropout)
def forward(self, x, y=None, mask=None):
y = y if y is not None else x
b, n, c = x.shape
_, m, d = y.shape
# b n h dh
queries = self.to_queries(x).reshape(b, n, self.num_heads, c // self.num_heads)
# b m 2 h dh
keys_values = self.to_keys_values(y).reshape(b, m, 2, self.num_heads, c // self.num_heads)
keys, values = keys_values[:, :, 0], keys_values[:, :, 1]
attention = torch.einsum('bnhd,bmhd->bnmh', queries, keys) * self.scale
if mask is not None:
if mask.dim() == 2:
mask = mask.unsqueeze(1)
attention = attention.masked_fill(mask.unsqueeze(3), float("-inf"))
attention = attention.softmax(dim=2)
out = torch.einsum('bnmh,bmhd->bnhd', attention, values).reshape(b, n, c)
out = self.project(out)
return out, attention
class TransformerLayer(nn.Module):
def __init__(self, dim_self, dim_ref, num_heads, mlp_ratio=4., bias=False, dropout=0., act=F.relu,
norm_layer: nn.Module = nn.LayerNorm):
super().__init__()
self.norm1 = norm_layer(dim_self)
self.attn = MultiHeadAttention(dim_self, dim_ref, num_heads, bias=bias, dropout=dropout)
self.norm2 = norm_layer(dim_self)
self.mlp = MlpTransformer(dim_self, int(dim_self * mlp_ratio), act=act, dropout=dropout)
def forward_with_attention(self, x, y=None, mask=None):
x_, attention = self.attn(self.norm1(x), y, mask)
x = x + x_
x = x + self.mlp(self.norm2(x))
return x, attention
def forward(self, x, y=None, mask=None):
x = x + self.attn(self.norm1(x), y, mask)[0]
x = x + self.mlp(self.norm2(x))
return x
class Transformer(nn.Module):
def forward_with_attention(self, x, y=None, mask=None):
attentions = []
for layer in self.layers:
x, att = layer.forward_with_attention(x, y, mask)
attentions.append(att)
return x, attentions
def forward(self, x, y=None, mask=None):
for i, layer in enumerate(self.layers):
if i % 2 == 0 and self.enc_dec: # cross
x = layer(x, y)
elif self.enc_dec: # self
x = layer(x, x, mask)
else: # self or cross
x = layer(x, y, mask)
return x
def __init__(self, dim_self: int, num_heads: int, num_layers: int, dim_ref: Optional[int] = None,
mlp_ratio: float = 2., act=F.relu, norm_layer: nn.Module = nn.LayerNorm, enc_dec: bool = False):
super(Transformer, self).__init__()
dim_ref = dim_ref if dim_ref is not None else dim_self
self.enc_dec = enc_dec
if enc_dec:
num_layers = num_layers * 2
layers = []
for i in range(num_layers):
if i % 2 == 0 and enc_dec: # cross
layers.append(TransformerLayer(dim_self, dim_ref, num_heads, mlp_ratio, act=act, norm_layer=norm_layer))
elif enc_dec: # self
layers.append(TransformerLayer(dim_self, dim_self, num_heads, mlp_ratio, act=act, norm_layer=norm_layer))
else: # self or cross
layers.append(TransformerLayer(dim_self, dim_ref, num_heads, mlp_ratio, act=act, norm_layer=norm_layer))
self.layers = nn.ModuleList(layers)
class TransformerMapper(nn.Module):
def __init__(self, dim_clip: int, dim_embedding: int, prefix_length: int = 10,
clip_length: int = 10, num_layers: int = 8):
super(TransformerMapper, self).__init__()
self.clip_length = clip_length
self.transformer = Transformer(dim_embedding, 8, num_layers)
self.linear = nn.Linear(dim_clip, clip_length * dim_embedding)
self.prefix_const = nn.Parameter(torch.randn(prefix_length, dim_embedding), requires_grad=True)
def forward(self, x):
x = self.linear(x).view(x.shape[0], self.clip_length, -1)
prefix = self.prefix_const.unsqueeze(0).expand(x.shape[0], *self.prefix_const.shape)
prefix = torch.cat((x, prefix), dim=1)
out = self.transformer(prefix)[:, self.clip_length:]
return out
class ClipCap(nn.Module):
def __init__(self, model_name, device, prefix_length: int = 10, clip_length: int = 40, prefix_size: int = 512,
num_layers: int = 1, model_path: str = '', fix_gpt: bool = False,
use_label_prefix: bool = False, label_path: str = '', label_length: int = 10,
use_transformer_mapper: bool = False, use_ptuning_v2: bool = False,
dropout: float = 0,
model_weight: str = '', scalar_output: bool = False):
super(ClipCap, self).__init__()
self.prefix_length = prefix_length
self.prefix_size = prefix_size
self.label_length = label_length
self.scalar_output = scalar_output
self.num_layers = num_layers
self.use_transformer_mapper = use_transformer_mapper
self.use_ptuning_v2 = use_ptuning_v2
self.dropout = nn.Dropout(dropout)
hparams = load_weights(self, AutoModelForCausalLM, model_weight, 'gpt', model_name,
prev_name='model')
self.device = device
self.gpt = self.gpt.to(self.device)
config = self.gpt.config
self.match_n_layer = getattr(config, 'n_layer', getattr(config, 'num_layers', None)) # gpt2 vs. gpt_neo
self.match_n_head = getattr(config, 'n_head', getattr(config, 'num_heads', None))
self.n_embd = getattr(config, 'n_embd', getattr(config, 'hidden_size', None))
self.match_n_embd = self.n_embd // self.match_n_head
self.clip_project = self.get_mapper()
if Path(label_path).is_file():
with open(label_path) as f:
labels = json.load(f)
self.labels = {i: v for v, i in labels.items()}
if not use_label_prefix:
log.info("adding label projections")
self.label_project = nn.Sequential(
nn.Embedding(len(self.labels), self.prefix_size),
self.get_mapper()
)
if os.path.isfile(model_path):
log.info(f"loading model from {model_path}")
weight = torch.load(model_path, map_location=torch.device('cpu'))
weight = {k[len('clip_project.'):]: v for k, v in weight.items()
if k.startswith('clip_project.')}
self.clip_project.load_state_dict(weight)
if fix_gpt:
log.info("fixing gpt parameters")
for param in self.gpt.parameters():
param.requires_grad_(False)
if self.scalar_output:
self.gpt.lm_head = nn.Linear(self.gpt.transformer.embed_dim, 1).to(self.device)
self.clip_project = self.clip_project.to(self.device)
if hasattr(self, 'label_project'):
self.label_project = self.label_project.to(self.device)
def get_mapper(self):
if self.use_ptuning_v2:
total_embd = self.match_n_layer * 2 * self.n_embd
module = MLP((self.prefix_size,
*[self.prefix_size
for i in range(self.num_layers)],
total_embd * self.prefix_length))
elif self.use_transformer_mapper:
log.info("using transformer mapper")
module = TransformerMapper(self.prefix_size, self.n_embd,
self.prefix_length, self.prefix_length, num_layers=self.num_layers) # 8)
else:
module = MLP((self.prefix_size,
*[(self.n_embd * self.prefix_length) // 2
for i in range(self.num_layers)],
self.n_embd * self.prefix_length))
return module
def get_encoder_loss(self, input_ids: torch.Tensor, features: torch.Tensor,
device = None):
input_ids = input_ids[:, :self.prefix_length].to(device)
embedding = self.gpt.transformer.wte(input_ids)
features = features.to(device)
prefix_projections = self.clip_project(features.type_as(embedding)).reshape(-1, self.prefix_length, self.n_embd)
fct = nn.MSELoss()
loss = fct(prefix_projections, embedding.detach())
return loss
def forward(self, *args, **kwargs):
if self.use_ptuning_v2:
return self.forward_prefix(*args, **kwargs)
else:
return self.forward_embedding(*args, **kwargs)
def forward_embedding(self, input_ids: torch.Tensor, features: torch.Tensor,
attention_mask: Optional[torch.Tensor] = None,
labels: Optional[torch.Tensor] = None,
past_key_values = None, device = None, **kwargs):
if device is None:
device = self.device
input_ids = input_ids.to(device)
if features is not None:
features = features.to(device)
if attention_mask is not None:
attention_mask = attention_mask.to(device)
if labels is not None:
labels = labels.to(device)
use_labels = labels is not None and hasattr(self, 'label_project')
embedding = self.gpt.transformer.wte(input_ids)
embed_txt = embedding
prefix_length = self.prefix_length
if use_labels:
prefix_length += self.label_length
if past_key_values is None:
prefix_projections = self.clip_project(features.type_as(embedding)).reshape(-1, self.prefix_length, self.n_embd)
if use_labels:
label_projections = self.label_project(labels.long()).reshape(-1, self.label_length, self.n_embd)
prefix_projections = torch.cat((prefix_projections, label_projections), dim=1)
embedding = torch.cat((prefix_projections.to(embedding.dtype), embedding), dim=1)
if torch.is_tensor(attention_mask):
prefix_mask = torch.ones_like(attention_mask)[:, :1].repeat(1, prefix_length)
attention_mask = torch.cat([prefix_mask, attention_mask], dim=1)
outputs = self.gpt(inputs_embeds=embedding, attention_mask=attention_mask,
past_key_values=past_key_values,
return_dict=True,
output_attentions=False,
output_hidden_states=True)
if past_key_values is None:
outputs.logits = outputs.logits[:, prefix_length:]
return outputs
def forward_prefix(self, input_ids: torch.Tensor, features: torch.Tensor,
attention_mask: Optional[torch.Tensor] = None,
labels: Optional[torch.Tensor] = None,
past_key_values = None, device = None, **kwargs):
if device is None:
device = self.device
input_ids = input_ids.to(device)
if features is not None:
features = features.to(device)
if attention_mask is not None:
attention_mask = attention_mask.to(device)
if labels is not None:
labels = labels.to(device)
use_labels = labels is not None and hasattr(self, 'label_project')
prefix_length = self.prefix_length
if use_labels:
prefix_length += self.label_length
if past_key_values is None:
prefix_projections = self.clip_project(features.type_as(self.clip_project.model[0].weight))
prefix_projections = prefix_projections.reshape(-1, self.prefix_length,
self.match_n_layer * 2, self.match_n_head, self.match_n_embd)
if use_labels:
label_projections = self.label_project(labels.long())
label_projections = label_projections.reshape(-1, self.label_length,
self.match_n_layer * 2, self.match_n_head, self.match_n_embd)
prefix_projections = torch.cat((prefix_projections, label_projections), dim=1)
temp_control = prefix_projections
temp_control = self.dropout(temp_control)
past_key_values = temp_control.permute([2, 0, 3, 1, 4]).split(2)
if torch.is_tensor(attention_mask):
prefix_mask = torch.ones_like(attention_mask)[:, :1].repeat(1, prefix_length)
attention_mask = torch.cat([prefix_mask, attention_mask], dim=1)
outputs = self.gpt(input_ids=input_ids, attention_mask=attention_mask,
past_key_values=past_key_values,
return_dict=True,
output_attentions=False,
output_hidden_states=True)
if past_key_values is None:
outputs.logits = outputs.logits[:, prefix_length:]
return outputs
def prepare_inputs_for_generation(self, input_ids, past=None, **kwargs):
token_type_ids = kwargs.get("token_type_ids", None)
# only last token for inputs_ids if past is defined in kwargs
if past:
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)
features = kwargs.get("features", None)
labels = kwargs.get("labels", None)
if attention_mask is not None and position_ids is None:
# create position_ids on the fly for batch generation
position_ids = attention_mask.long().cumsum(-1) - 1
position_ids.masked_fill_(attention_mask == 0, 1)
if past:
position_ids = position_ids[:, -1].unsqueeze(-1)
else:
position_ids = None
return {
"input_ids": input_ids,
"past_key_values": past,
"use_cache": kwargs.get("use_cache"),
"position_ids": position_ids,
"attention_mask": attention_mask,
"token_type_ids": token_type_ids,
"features": features,
"labels": labels,
}