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# Copyright 2023 The HuggingFace Team. All rights reserved. | |
# | |
# Licensed under the Apache License, Version 2.0 (the "License"); | |
# you may not use this file except in compliance with the License. | |
# You may obtain a copy of the License at | |
# | |
# http://www.apache.org/licenses/LICENSE-2.0 | |
# | |
# Unless required by applicable law or agreed to in writing, software | |
# distributed under the License is distributed on an "AS IS" BASIS, | |
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
# See the License for the specific language governing permissions and | |
# limitations under the License. | |
import functools | |
import math | |
import flax.linen as nn | |
import jax | |
import jax.numpy as jnp | |
from einops import repeat | |
# from diffusers.models.attention_flax import FlaxBasicTransformerBlock | |
from diffusers.models.attention_flax import FlaxFeedForward, jax_memory_efficient_attention | |
def rearrange_3(array, f): | |
F, D, C = array.shape | |
return jnp.reshape(array, (F // f, f, D, C)) | |
def rearrange_4(array): | |
B, F, D, C = array.shape | |
return jnp.reshape(array, (B * F, D, C)) | |
class FlaxCrossFrameAttention(nn.Module): | |
r""" | |
A Flax multi-head attention module as described in: https://arxiv.org/abs/1706.03762 | |
Parameters: | |
query_dim (:obj:`int`): | |
Input hidden states dimension | |
heads (:obj:`int`, *optional*, defaults to 8): | |
Number of heads | |
dim_head (:obj:`int`, *optional*, defaults to 64): | |
Hidden states dimension inside each head | |
dropout (:obj:`float`, *optional*, defaults to 0.0): | |
Dropout rate | |
use_memory_efficient_attention (`bool`, *optional*, defaults to `False`): | |
enable memory efficient attention https://arxiv.org/abs/2112.05682 | |
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32): | |
Parameters `dtype` | |
batch_size: The number that represents actual batch size, other than the frames. | |
For example, using calling unet with a single prompt and num_images_per_prompt=1, batch_size should be | |
equal to 2, due to classifier-free guidance. | |
""" | |
query_dim: int | |
heads: int = 8 | |
dim_head: int = 64 | |
dropout: float = 0.0 | |
use_memory_efficient_attention: bool = False | |
dtype: jnp.dtype = jnp.float32 | |
batch_size : int = 2 | |
def setup(self): | |
inner_dim = self.dim_head * self.heads | |
self.scale = self.dim_head**-0.5 | |
# Weights were exported with old names {to_q, to_k, to_v, to_out} | |
self.query = nn.Dense(inner_dim, use_bias=False, dtype=self.dtype, name="to_q") | |
self.key = nn.Dense(inner_dim, use_bias=False, dtype=self.dtype, name="to_k") | |
self.value = nn.Dense(inner_dim, use_bias=False, dtype=self.dtype, name="to_v") | |
self.add_k_proj = nn.Dense(inner_dim, use_bias=False, dtype=self.dtype) | |
self.add_v_proj = nn.Dense(inner_dim, use_bias=False, dtype=self.dtype) | |
self.proj_attn = nn.Dense(self.query_dim, dtype=self.dtype, name="to_out_0") | |
def reshape_heads_to_batch_dim(self, tensor): | |
batch_size, seq_len, dim = tensor.shape | |
head_size = self.heads | |
tensor = tensor.reshape(batch_size, seq_len, head_size, dim // head_size) | |
tensor = jnp.transpose(tensor, (0, 2, 1, 3)) | |
tensor = tensor.reshape(batch_size * head_size, seq_len, dim // head_size) | |
return tensor | |
def reshape_batch_dim_to_heads(self, tensor): | |
batch_size, seq_len, dim = tensor.shape | |
head_size = self.heads | |
tensor = tensor.reshape(batch_size // head_size, head_size, seq_len, dim) | |
tensor = jnp.transpose(tensor, (0, 2, 1, 3)) | |
tensor = tensor.reshape(batch_size // head_size, seq_len, dim * head_size) | |
return tensor | |
def __call__(self, hidden_states, context=None, deterministic=True): | |
is_cross_attention = context is not None | |
context = hidden_states if context is None else context | |
query_proj = self.query(hidden_states) | |
key_proj = self.key(context) | |
value_proj = self.value(context) | |
# Sparse Attention | |
if not is_cross_attention: | |
video_length = 1 if key_proj.shape[0] < self.batch_size else key_proj.shape[0] // self.batch_size | |
first_frame_index = [0] * video_length | |
# rearrange keys to have batch and frames in the 1st and 2nd dims respectively | |
key_proj = rearrange_3(key_proj, video_length) | |
key_proj = key_proj[:, first_frame_index] | |
# rearrange values to have batch and frames in the 1st and 2nd dims respectively | |
value_proj = rearrange_3(value_proj, video_length) | |
value_proj = value_proj[:, first_frame_index] | |
# rearrange back to original shape | |
key_proj = rearrange_4(key_proj) | |
value_proj = rearrange_4(value_proj) | |
query_states = self.reshape_heads_to_batch_dim(query_proj) | |
key_states = self.reshape_heads_to_batch_dim(key_proj) | |
value_states = self.reshape_heads_to_batch_dim(value_proj) | |
if self.use_memory_efficient_attention: | |
query_states = query_states.transpose(1, 0, 2) | |
key_states = key_states.transpose(1, 0, 2) | |
value_states = value_states.transpose(1, 0, 2) | |
# this if statement create a chunk size for each layer of the unet | |
# the chunk size is equal to the query_length dimension of the deepest layer of the unet | |
flatten_latent_dim = query_states.shape[-3] | |
if flatten_latent_dim % 64 == 0: | |
query_chunk_size = int(flatten_latent_dim / 64) | |
elif flatten_latent_dim % 16 == 0: | |
query_chunk_size = int(flatten_latent_dim / 16) | |
elif flatten_latent_dim % 4 == 0: | |
query_chunk_size = int(flatten_latent_dim / 4) | |
else: | |
query_chunk_size = int(flatten_latent_dim) | |
hidden_states = jax_memory_efficient_attention( | |
query_states, key_states, value_states, query_chunk_size=query_chunk_size, key_chunk_size=4096 * 4 | |
) | |
hidden_states = hidden_states.transpose(1, 0, 2) | |
else: | |
# compute attentions | |
attention_scores = jnp.einsum("b i d, b j d->b i j", query_states, key_states) | |
attention_scores = attention_scores * self.scale | |
attention_probs = nn.softmax(attention_scores, axis=2) | |
# attend to values | |
hidden_states = jnp.einsum("b i j, b j d -> b i d", attention_probs, value_states) | |
hidden_states = self.reshape_batch_dim_to_heads(hidden_states) | |
hidden_states = self.proj_attn(hidden_states) | |
return hidden_states | |
class FlaxLoRALinearLayer(nn.Module): | |
out_features: int | |
dtype: jnp.dtype = jnp.float32 | |
rank: int=4 | |
def setup(self): | |
self.down = nn.Dense(self.rank, use_bias=False, kernel_init=nn.initializers.normal(stddev=1 / self.rank), dtype=self.dtype, name="down_lora") | |
self.up = nn.Dense(self.out_features, use_bias=False, kernel_init=nn.initializers.zeros, dtype=self.dtype, name="up_lora") | |
def __call__(self, hidden_states): | |
down_hidden_states = self.down(hidden_states) | |
up_hidden_states = self.up(down_hidden_states) | |
return up_hidden_states | |
class LoRAPositionalEncoding(nn.Module): | |
d_model : int # Hidden dimensionality of the input. | |
rank: int=4 | |
dtype: jnp.dtype = jnp.float32 | |
max_len : int = 200 # Maximum length of a sequence to expect. | |
def setup(self): | |
# Create matrix of [SeqLen, HiddenDim] representing the positional encoding for max_len inputs | |
pe = jnp.zeros((self.max_len, self.d_model), dtype=self.dtype) | |
position = jnp.arange(0, self.max_len, dtype=self.dtype)[:,None] | |
div_term = jnp.exp(jnp.arange(0, self.d_model, 2) * (-jnp.log(10000.0) / self.d_model)) | |
pe = pe.at[:, 0::2].set(jnp.sin(position * div_term)) | |
pe = pe.at[:, 1::2].set(jnp.cos(position * div_term)) | |
self.pe = pe | |
self.lora_pe = FlaxLoRALinearLayer(self.d_model, rank=self.rank, dtype=self.dtype) | |
def __call__(self, x): | |
#x is (F // f, f, D, C) | |
b, f, d, c = x.shape | |
pe = repeat(self.lora_pe(self.pe[:f]), 'f c -> b f d c', b=b, d=d) | |
return x + pe | |
class FlaxLoRACrossFrameAttention(nn.Module): | |
r""" | |
A Flax multi-head attention module as described in: https://arxiv.org/abs/1706.03762 | |
Parameters: | |
query_dim (:obj:`int`): | |
Input hidden states dimension | |
heads (:obj:`int`, *optional*, defaults to 8): | |
Number of heads | |
dim_head (:obj:`int`, *optional*, defaults to 64): | |
Hidden states dimension inside each head | |
dropout (:obj:`float`, *optional*, defaults to 0.0): | |
Dropout rate | |
use_memory_efficient_attention (`bool`, *optional*, defaults to `False`): | |
enable memory efficient attention https://arxiv.org/abs/2112.05682 | |
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32): | |
Parameters `dtype` | |
batch_size: The number that represents actual batch size, other than the frames. | |
For example, using calling unet with a single prompt and num_images_per_prompt=1, batch_size should be | |
equal to 2, due to classifier-free guidance. | |
""" | |
query_dim: int | |
heads: int = 8 | |
dim_head: int = 64 | |
dropout: float = 0.0 | |
use_memory_efficient_attention: bool = False | |
dtype: jnp.dtype = jnp.float32 | |
batch_size : int = 2 | |
rank: int=4 | |
def setup(self): | |
inner_dim = self.dim_head * self.heads | |
self.scale = self.dim_head**-0.5 | |
# Weights were exported with old names {to_q, to_k, to_v, to_out} | |
self.query = nn.Dense(inner_dim, use_bias=False, dtype=self.dtype, name="to_q") | |
self.key = nn.Dense(inner_dim, use_bias=False, dtype=self.dtype, name="to_k") | |
self.value = nn.Dense(inner_dim, use_bias=False, dtype=self.dtype, name="to_v") | |
self.add_k_proj = nn.Dense(inner_dim, use_bias=False, dtype=self.dtype) | |
self.add_v_proj = nn.Dense(inner_dim, use_bias=False, dtype=self.dtype) | |
self.proj_attn = nn.Dense(self.query_dim, dtype=self.dtype, name="to_out_0") | |
self.to_q_lora = FlaxLoRALinearLayer(inner_dim, rank=self.rank, dtype=self.dtype) | |
self.to_k_lora = FlaxLoRALinearLayer(inner_dim, rank=self.rank, dtype=self.dtype) | |
self.to_v_lora = FlaxLoRALinearLayer(inner_dim, rank=self.rank, dtype=self.dtype) | |
self.to_out_lora = FlaxLoRALinearLayer(inner_dim, rank=self.rank, dtype=self.dtype) | |
def reshape_heads_to_batch_dim(self, tensor): | |
batch_size, seq_len, dim = tensor.shape | |
head_size = self.heads | |
tensor = tensor.reshape(batch_size, seq_len, head_size, dim // head_size) | |
tensor = jnp.transpose(tensor, (0, 2, 1, 3)) | |
tensor = tensor.reshape(batch_size * head_size, seq_len, dim // head_size) | |
return tensor | |
def reshape_batch_dim_to_heads(self, tensor): | |
batch_size, seq_len, dim = tensor.shape | |
head_size = self.heads | |
tensor = tensor.reshape(batch_size // head_size, head_size, seq_len, dim) | |
tensor = jnp.transpose(tensor, (0, 2, 1, 3)) | |
tensor = tensor.reshape(batch_size // head_size, seq_len, dim * head_size) | |
return tensor | |
def __call__(self, hidden_states, context=None, deterministic=True, scale=1.): | |
is_cross_attention = context is not None | |
context = hidden_states if context is None else context | |
query_proj = self.query(hidden_states) + scale * self.to_q_lora(hidden_states) | |
key_proj = self.key(context) + scale * self.to_k_lora(context) | |
value_proj = self.value(context) + scale * self.to_v_lora(context) | |
# Sparse Attention | |
if not is_cross_attention: | |
video_length = 1 if key_proj.shape[0] < self.batch_size else key_proj.shape[0] // self.batch_size | |
first_frame_index = [0] * video_length | |
#first frame ==> previous frame | |
previous_frame_index = jnp.array([0] + list(range(video_length - 1))) | |
# rearrange keys to have batch and frames in the 1st and 2nd dims respectively | |
key_proj = rearrange_3(key_proj, video_length) | |
key_proj = key_proj[:, first_frame_index] | |
# rearrange values to have batch and frames in the 1st and 2nd dims respectively | |
value_proj = rearrange_3(value_proj, video_length) | |
value_proj = value_proj[:, first_frame_index] | |
# rearrange back to original shape | |
key_proj = rearrange_4(key_proj) | |
value_proj = rearrange_4(value_proj) | |
query_states = self.reshape_heads_to_batch_dim(query_proj) | |
key_states = self.reshape_heads_to_batch_dim(key_proj) | |
value_states = self.reshape_heads_to_batch_dim(value_proj) | |
if self.use_memory_efficient_attention: | |
query_states = query_states.transpose(1, 0, 2) | |
key_states = key_states.transpose(1, 0, 2) | |
value_states = value_states.transpose(1, 0, 2) | |
# this if statement create a chunk size for each layer of the unet | |
# the chunk size is equal to the query_length dimension of the deepest layer of the unet | |
flatten_latent_dim = query_states.shape[-3] | |
if flatten_latent_dim % 64 == 0: | |
query_chunk_size = int(flatten_latent_dim / 64) | |
elif flatten_latent_dim % 16 == 0: | |
query_chunk_size = int(flatten_latent_dim / 16) | |
elif flatten_latent_dim % 4 == 0: | |
query_chunk_size = int(flatten_latent_dim / 4) | |
else: | |
query_chunk_size = int(flatten_latent_dim) | |
hidden_states = jax_memory_efficient_attention( | |
query_states, key_states, value_states, query_chunk_size=query_chunk_size, key_chunk_size=4096 * 4 | |
) | |
hidden_states = hidden_states.transpose(1, 0, 2) | |
else: | |
# compute attentions | |
attention_scores = jnp.einsum("b i d, b j d->b i j", query_states, key_states) | |
attention_scores = attention_scores * self.scale | |
attention_probs = nn.softmax(attention_scores, axis=2) | |
# attend to values | |
hidden_states = jnp.einsum("b i j, b j d -> b i d", attention_probs, value_states) | |
hidden_states = self.reshape_batch_dim_to_heads(hidden_states) | |
hidden_states = self.proj_attn(hidden_states) + scale * self.to_out_lora(hidden_states) | |
return hidden_states | |
class FlaxBasicTransformerBlock(nn.Module): | |
r""" | |
A Flax transformer block layer with `GLU` (Gated Linear Unit) activation function as described in: | |
https://arxiv.org/abs/1706.03762 | |
Parameters: | |
dim (:obj:`int`): | |
Inner hidden states dimension | |
n_heads (:obj:`int`): | |
Number of heads | |
d_head (:obj:`int`): | |
Hidden states dimension inside each head | |
dropout (:obj:`float`, *optional*, defaults to 0.0): | |
Dropout rate | |
only_cross_attention (`bool`, defaults to `False`): | |
Whether to only apply cross attention. | |
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32): | |
Parameters `dtype` | |
use_memory_efficient_attention (`bool`, *optional*, defaults to `False`): | |
enable memory efficient attention https://arxiv.org/abs/2112.05682 | |
""" | |
dim: int | |
n_heads: int | |
d_head: int | |
dropout: float = 0.0 | |
only_cross_attention: bool = False | |
dtype: jnp.dtype = jnp.float32 | |
use_memory_efficient_attention: bool = False | |
def setup(self): | |
# self attention (or cross_attention if only_cross_attention is True) | |
self.attn1 = FlaxCrossFrameAttention( | |
self.dim, self.n_heads, self.d_head, self.dropout, self.use_memory_efficient_attention, dtype=self.dtype, | |
) | |
# cross attention | |
self.attn2 = FlaxCrossFrameAttention( | |
self.dim, self.n_heads, self.d_head, self.dropout, self.use_memory_efficient_attention, dtype=self.dtype, | |
) | |
self.ff = FlaxFeedForward(dim=self.dim, dropout=self.dropout, dtype=self.dtype) | |
self.norm1 = nn.LayerNorm(epsilon=1e-5, dtype=self.dtype) | |
self.norm2 = nn.LayerNorm(epsilon=1e-5, dtype=self.dtype) | |
self.norm3 = nn.LayerNorm(epsilon=1e-5, dtype=self.dtype) | |
def __call__(self, hidden_states, context, deterministic=True): | |
# self attention | |
residual = hidden_states | |
if self.only_cross_attention: | |
hidden_states = self.attn1(self.norm1(hidden_states), context, deterministic=deterministic) | |
else: | |
hidden_states = self.attn1(self.norm1(hidden_states), deterministic=deterministic) | |
hidden_states = hidden_states + residual | |
# cross attention | |
residual = hidden_states | |
hidden_states = self.attn2(self.norm2(hidden_states), context, deterministic=deterministic) | |
hidden_states = hidden_states + residual | |
# feed forward | |
residual = hidden_states | |
hidden_states = self.ff(self.norm3(hidden_states), deterministic=deterministic) | |
hidden_states = hidden_states + residual | |
return hidden_states | |
class FlaxLoRABasicTransformerBlock(nn.Module): | |
r""" | |
A Flax transformer block layer with `GLU` (Gated Linear Unit) activation function as described in: | |
https://arxiv.org/abs/1706.03762 | |
Parameters: | |
dim (:obj:`int`): | |
Inner hidden states dimension | |
n_heads (:obj:`int`): | |
Number of heads | |
d_head (:obj:`int`): | |
Hidden states dimension inside each head | |
dropout (:obj:`float`, *optional*, defaults to 0.0): | |
Dropout rate | |
only_cross_attention (`bool`, defaults to `False`): | |
Whether to only apply cross attention. | |
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32): | |
Parameters `dtype` | |
use_memory_efficient_attention (`bool`, *optional*, defaults to `False`): | |
enable memory efficient attention https://arxiv.org/abs/2112.05682 | |
""" | |
dim: int | |
n_heads: int | |
d_head: int | |
dropout: float = 0.0 | |
only_cross_attention: bool = False | |
dtype: jnp.dtype = jnp.float32 | |
use_memory_efficient_attention: bool = False | |
def setup(self): | |
# self attention (or cross_attention if only_cross_attention is True) | |
self.attn1 = FlaxLoRACrossFrameAttention( | |
self.dim, self.n_heads, self.d_head, self.dropout, self.use_memory_efficient_attention, dtype=self.dtype, | |
) | |
# cross attention | |
self.attn2 = FlaxLoRACrossFrameAttention( | |
self.dim, self.n_heads, self.d_head, self.dropout, self.use_memory_efficient_attention, dtype=self.dtype, | |
) | |
self.ff = FlaxFeedForward(dim=self.dim, dropout=self.dropout, dtype=self.dtype) | |
self.norm1 = nn.LayerNorm(epsilon=1e-5, dtype=self.dtype) | |
self.norm2 = nn.LayerNorm(epsilon=1e-5, dtype=self.dtype) | |
self.norm3 = nn.LayerNorm(epsilon=1e-5, dtype=self.dtype) | |
def __call__(self, hidden_states, context, deterministic=True, scale=1.): | |
# self attention | |
residual = hidden_states | |
if self.only_cross_attention: | |
hidden_states = self.attn1(self.norm1(hidden_states), context, deterministic=deterministic, scale=scale) | |
else: | |
hidden_states = self.attn1(self.norm1(hidden_states), deterministic=deterministic, scale=scale) | |
hidden_states = hidden_states + residual | |
# cross attention | |
residual = hidden_states | |
hidden_states = self.attn2(self.norm2(hidden_states), context, deterministic=deterministic, scale=scale) | |
hidden_states = hidden_states + residual | |
# feed forward | |
residual = hidden_states | |
hidden_states = self.ff(self.norm3(hidden_states), deterministic=deterministic) | |
hidden_states = hidden_states + residual | |
return hidden_states | |
class FlaxCrossFrameTransformer2DModel(nn.Module): | |
r""" | |
A Spatial Transformer layer with Gated Linear Unit (GLU) activation function as described in: | |
https://arxiv.org/pdf/1506.02025.pdf | |
Parameters: | |
in_channels (:obj:`int`): | |
Input number of channels | |
n_heads (:obj:`int`): | |
Number of heads | |
d_head (:obj:`int`): | |
Hidden states dimension inside each head | |
depth (:obj:`int`, *optional*, defaults to 1): | |
Number of transformers block | |
dropout (:obj:`float`, *optional*, defaults to 0.0): | |
Dropout rate | |
use_linear_projection (`bool`, defaults to `False`): tbd | |
only_cross_attention (`bool`, defaults to `False`): tbd | |
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32): | |
Parameters `dtype` | |
use_memory_efficient_attention (`bool`, *optional*, defaults to `False`): | |
enable memory efficient attention https://arxiv.org/abs/2112.05682 | |
""" | |
in_channels: int | |
n_heads: int | |
d_head: int | |
depth: int = 1 | |
dropout: float = 0.0 | |
use_linear_projection: bool = False | |
only_cross_attention: bool = False | |
dtype: jnp.dtype = jnp.float32 | |
use_memory_efficient_attention: bool = False | |
def setup(self): | |
self.norm = nn.GroupNorm(num_groups=32, epsilon=1e-5) | |
inner_dim = self.n_heads * self.d_head | |
if self.use_linear_projection: | |
self.proj_in = nn.Dense(inner_dim, dtype=self.dtype) | |
else: | |
self.proj_in = nn.Conv( | |
inner_dim, | |
kernel_size=(1, 1), | |
strides=(1, 1), | |
padding="VALID", | |
dtype=self.dtype, | |
) | |
self.transformer_blocks = [ | |
FlaxBasicTransformerBlock( | |
inner_dim, | |
self.n_heads, | |
self.d_head, | |
dropout=self.dropout, | |
only_cross_attention=self.only_cross_attention, | |
dtype=self.dtype, | |
use_memory_efficient_attention=self.use_memory_efficient_attention, | |
) | |
for _ in range(self.depth) | |
] | |
if self.use_linear_projection: | |
self.proj_out = nn.Dense(inner_dim, dtype=self.dtype) | |
else: | |
self.proj_out = nn.Conv( | |
inner_dim, | |
kernel_size=(1, 1), | |
strides=(1, 1), | |
padding="VALID", | |
dtype=self.dtype, | |
) | |
def __call__(self, hidden_states, context, deterministic=True): | |
batch, height, width, channels = hidden_states.shape | |
residual = hidden_states | |
hidden_states = self.norm(hidden_states) | |
if self.use_linear_projection: | |
hidden_states = hidden_states.reshape(batch, height * width, channels) | |
hidden_states = self.proj_in(hidden_states) | |
else: | |
hidden_states = self.proj_in(hidden_states) | |
hidden_states = hidden_states.reshape(batch, height * width, channels) | |
for transformer_block in self.transformer_blocks: | |
hidden_states = transformer_block(hidden_states, context, deterministic=deterministic) | |
if self.use_linear_projection: | |
hidden_states = self.proj_out(hidden_states) | |
hidden_states = hidden_states.reshape(batch, height, width, channels) | |
else: | |
hidden_states = hidden_states.reshape(batch, height, width, channels) | |
hidden_states = self.proj_out(hidden_states) | |
hidden_states = hidden_states + residual | |
return hidden_states | |
class FlaxLoRACrossFrameTransformer2DModel(nn.Module): | |
r""" | |
A Spatial Transformer layer with Gated Linear Unit (GLU) activation function as described in: | |
https://arxiv.org/pdf/1506.02025.pdf | |
Parameters: | |
in_channels (:obj:`int`): | |
Input number of channels | |
n_heads (:obj:`int`): | |
Number of heads | |
d_head (:obj:`int`): | |
Hidden states dimension inside each head | |
depth (:obj:`int`, *optional*, defaults to 1): | |
Number of transformers block | |
dropout (:obj:`float`, *optional*, defaults to 0.0): | |
Dropout rate | |
use_linear_projection (`bool`, defaults to `False`): tbd | |
only_cross_attention (`bool`, defaults to `False`): tbd | |
dtype (:obj:`jnp.dtype`, *optional*, defaults to jnp.float32): | |
Parameters `dtype` | |
use_memory_efficient_attention (`bool`, *optional*, defaults to `False`): | |
enable memory efficient attention https://arxiv.org/abs/2112.05682 | |
""" | |
in_channels: int | |
n_heads: int | |
d_head: int | |
depth: int = 1 | |
dropout: float = 0.0 | |
use_linear_projection: bool = False | |
only_cross_attention: bool = False | |
dtype: jnp.dtype = jnp.float32 | |
use_memory_efficient_attention: bool = False | |
def setup(self): | |
self.norm = nn.GroupNorm(num_groups=32, epsilon=1e-5) | |
inner_dim = self.n_heads * self.d_head | |
if self.use_linear_projection: | |
self.proj_in = nn.Dense(inner_dim, dtype=self.dtype) | |
else: | |
self.proj_in = nn.Conv( | |
inner_dim, | |
kernel_size=(1, 1), | |
strides=(1, 1), | |
padding="VALID", | |
dtype=self.dtype, | |
) | |
self.transformer_blocks = [ | |
FlaxLoRABasicTransformerBlock( | |
inner_dim, | |
self.n_heads, | |
self.d_head, | |
dropout=self.dropout, | |
only_cross_attention=self.only_cross_attention, | |
dtype=self.dtype, | |
use_memory_efficient_attention=self.use_memory_efficient_attention, | |
) | |
for _ in range(self.depth) | |
] | |
if self.use_linear_projection: | |
self.proj_out = nn.Dense(inner_dim, dtype=self.dtype) | |
else: | |
self.proj_out = nn.Conv( | |
inner_dim, | |
kernel_size=(1, 1), | |
strides=(1, 1), | |
padding="VALID", | |
dtype=self.dtype, | |
) | |
def __call__(self, hidden_states, context, deterministic=True, scale=1.0): | |
batch, height, width, channels = hidden_states.shape | |
residual = hidden_states | |
hidden_states = self.norm(hidden_states) | |
if self.use_linear_projection: | |
hidden_states = hidden_states.reshape(batch, height * width, channels) | |
hidden_states = self.proj_in(hidden_states) | |
else: | |
hidden_states = self.proj_in(hidden_states) | |
hidden_states = hidden_states.reshape(batch, height * width, channels) | |
for transformer_block in self.transformer_blocks: | |
hidden_states = transformer_block(hidden_states, context, deterministic=deterministic, scale=scale) | |
if self.use_linear_projection: | |
hidden_states = self.proj_out(hidden_states) | |
hidden_states = hidden_states.reshape(batch, height, width, channels) | |
else: | |
hidden_states = hidden_states.reshape(batch, height, width, channels) | |
hidden_states = self.proj_out(hidden_states) | |
hidden_states = hidden_states + residual | |
return hidden_states | |