transformer/trans.py

# Copyright 2024 Black Forest Labs, The HuggingFace Team and The InstantX 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.
#
# This was modied from the control net repo


import inspect
from typing import Any, Callable, Dict, List, Optional, Tuple, Union

from torch.distributed.fsdp.fully_sharded_data_parallel import FullyShardedDataParallel

import numpy as np
import torch
from transformers import (
    CLIPTextModel,
    CLIPTokenizer,
    T5EncoderModel,
    T5TokenizerFast,
)

from diffusers.image_processor import PipelineImageInput, VaeImageProcessor
from diffusers.loaders import FluxLoraLoaderMixin, FromSingleFileMixin
from diffusers.models.autoencoders import AutoencoderKL
###  MERGEING THESE ###
# from src.models.transformer import FluxTransformer2DModel
# from src.models.controlnet_flux import FluxControlNetModel
#############

##########################################
########### ATTENTION MERGE ##############
##########################################

import torch
from torch import Tensor, FloatTensor
from torch.nn import functional as F
from einops import rearrange
from diffusers.models.attention_processor import Attention
from diffusers.models.embeddings import apply_rotary_emb



def fa3_sdpa(
    q,
    k,
    v,
):
    # flash attention 3 sdpa drop-in replacement
    q, k, v = [x.permute(0, 2, 1, 3) for x in [q, k, v]]
    out = flash_attn_func(q, k, v)[0]
    return out.permute(0, 2, 1, 3)


class FluxSingleAttnProcessor3_0:
    r"""
    Processor for implementing scaled dot-product attention (enabled by default if you're using PyTorch 2.0).
    """

    def __init__(self):
        if not hasattr(F, "scaled_dot_product_attention"):
            raise ImportError(
                "AttnProcessor2_0 requires PyTorch 2.0, to use it, please upgrade PyTorch to 2.0."
            )

    def __call__(
        self,
        attn,
        hidden_states: Tensor,
        encoder_hidden_states: Tensor = None,
        attention_mask: FloatTensor = None,
        image_rotary_emb: Tensor = None,
    ) -> Tensor:
        input_ndim = hidden_states.ndim

        if input_ndim == 4:
            batch_size, channel, height, width = hidden_states.shape
            hidden_states = hidden_states.view(
                batch_size, channel, height * width
            ).transpose(1, 2)

        batch_size, _, _ = (
            hidden_states.shape
            if encoder_hidden_states is None
            else encoder_hidden_states.shape
        )

        query = attn.to_q(hidden_states)
        if encoder_hidden_states is None:
            encoder_hidden_states = hidden_states

        key = attn.to_k(encoder_hidden_states)
        value = attn.to_v(encoder_hidden_states)

        inner_dim = key.shape[-1]
        head_dim = inner_dim // attn.heads

        query = query.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)

        key = key.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
        value = value.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)

        if attn.norm_q is not None:
            query = attn.norm_q(query)
        if attn.norm_k is not None:
            key = attn.norm_k(key)

        # Apply RoPE if needed
        if image_rotary_emb is not None:
            query = apply_rotary_emb(query, image_rotary_emb)
            key = apply_rotary_emb(key, image_rotary_emb)

        # the output of sdp = (batch, num_heads, seq_len, head_dim)
        # TODO: add support for attn.scale when we move to Torch 2.1
        # hidden_states = F.scaled_dot_product_attention(query, key, value, dropout_p=0.0, is_causal=False)
        hidden_states = fa3_sdpa(query, key, value)
        hidden_states = rearrange(hidden_states, "B H L D -> B L (H D)")

        hidden_states = hidden_states.transpose(1, 2).reshape(
            batch_size, -1, attn.heads * head_dim
        )
        hidden_states = hidden_states.to(query.dtype)

        if input_ndim == 4:
            hidden_states = hidden_states.transpose(-1, -2).reshape(
                batch_size, channel, height, width
            )

        return hidden_states


class FluxAttnProcessor3_0:
    """Attention processor used typically in processing the SD3-like self-attention projections."""

    def __init__(self):
        if not hasattr(F, "scaled_dot_product_attention"):
            raise ImportError(
                "FluxAttnProcessor3_0 requires PyTorch 2.0, to use it, please upgrade PyTorch to 2.0."
            )

    def __call__(
        self,
        attn,
        hidden_states: FloatTensor,
        encoder_hidden_states: FloatTensor = None,
        attention_mask: FloatTensor = None,
        image_rotary_emb: Tensor = None,
    ) -> FloatTensor:
        input_ndim = hidden_states.ndim
        if input_ndim == 4:
            batch_size, channel, height, width = hidden_states.shape
            hidden_states = hidden_states.view(
                batch_size, channel, height * width
            ).transpose(1, 2)
        context_input_ndim = encoder_hidden_states.ndim
        if context_input_ndim == 4:
            batch_size, channel, height, width = encoder_hidden_states.shape
            encoder_hidden_states = encoder_hidden_states.view(
                batch_size, channel, height * width
            ).transpose(1, 2)

        batch_size = encoder_hidden_states.shape[0]

        # `sample` projections.
        query = attn.to_q(hidden_states)
        key = attn.to_k(hidden_states)
        value = attn.to_v(hidden_states)

        inner_dim = key.shape[-1]
        head_dim = inner_dim // attn.heads

        query = query.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
        key = key.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
        value = value.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)

        if attn.norm_q is not None:
            query = attn.norm_q(query)
        if attn.norm_k is not None:
            key = attn.norm_k(key)

        # `context` projections.
        encoder_hidden_states_query_proj = attn.add_q_proj(encoder_hidden_states)
        encoder_hidden_states_key_proj = attn.add_k_proj(encoder_hidden_states)
        encoder_hidden_states_value_proj = attn.add_v_proj(encoder_hidden_states)

        encoder_hidden_states_query_proj = encoder_hidden_states_query_proj.view(
            batch_size, -1, attn.heads, head_dim
        ).transpose(1, 2)
        encoder_hidden_states_key_proj = encoder_hidden_states_key_proj.view(
            batch_size, -1, attn.heads, head_dim
        ).transpose(1, 2)
        encoder_hidden_states_value_proj = encoder_hidden_states_value_proj.view(
            batch_size, -1, attn.heads, head_dim
        ).transpose(1, 2)

        if attn.norm_added_q is not None:
            encoder_hidden_states_query_proj = attn.norm_added_q(
                encoder_hidden_states_query_proj
            )
        if attn.norm_added_k is not None:
            encoder_hidden_states_key_proj = attn.norm_added_k(
                encoder_hidden_states_key_proj
            )

        # attention
        query = torch.cat([encoder_hidden_states_query_proj, query], dim=2)
        key = torch.cat([encoder_hidden_states_key_proj, key], dim=2)
        value = torch.cat([encoder_hidden_states_value_proj, value], dim=2)

        if image_rotary_emb is not None:

            query = apply_rotary_emb(query, image_rotary_emb)
            key = apply_rotary_emb(key, image_rotary_emb)

        # hidden_states = F.scaled_dot_product_attention(query, key, value, dropout_p=0.0, is_causal=False)
        hidden_states = fa3_sdpa(query, key, value)
        hidden_states = rearrange(hidden_states, "B H L D -> B L (H D)")

        hidden_states = hidden_states.transpose(1, 2).reshape(
            batch_size, -1, attn.heads * head_dim
        )
        hidden_states = hidden_states.to(query.dtype)

        encoder_hidden_states, hidden_states = (
            hidden_states[:, : encoder_hidden_states.shape[1]],
            hidden_states[:, encoder_hidden_states.shape[1] :],
        )

        # linear proj
        hidden_states = attn.to_out[0](hidden_states)
        # dropout
        hidden_states = attn.to_out[1](hidden_states)
        encoder_hidden_states = attn.to_add_out(encoder_hidden_states)

        if input_ndim == 4:
            hidden_states = hidden_states.transpose(-1, -2).reshape(
                batch_size, channel, height, width
            )
        if context_input_ndim == 4:
            encoder_hidden_states = encoder_hidden_states.transpose(-1, -2).reshape(
                batch_size, channel, height, width
            )

        return hidden_states, encoder_hidden_states



class FluxFusedSDPAProcessor:
    """
    Fused QKV processor using PyTorch's scaled_dot_product_attention.
    Uses fused projections but splits for attention computation.
    """

    def __init__(self):
        if not hasattr(F, "scaled_dot_product_attention"):
            raise ImportError(
                "FluxFusedSDPAProcessor requires PyTorch 2.0+ for scaled_dot_product_attention"
            )

    def __call__(
        self,
        attn,
        hidden_states: FloatTensor,
        encoder_hidden_states: FloatTensor = None,
        attention_mask: FloatTensor = None,
        image_rotary_emb: Tensor = None,
    ) -> FloatTensor:
        input_ndim = hidden_states.ndim
        if input_ndim == 4:
            batch_size, channel, height, width = hidden_states.shape
            hidden_states = hidden_states.view(
                batch_size, channel, height * width
            ).transpose(1, 2)

        context_input_ndim = (
            encoder_hidden_states.ndim if encoder_hidden_states is not None else None
        )
        if context_input_ndim == 4:
            batch_size, channel, height, width = encoder_hidden_states.shape
            encoder_hidden_states = encoder_hidden_states.view(
                batch_size, channel, height * width
            ).transpose(1, 2)

        batch_size = (
            encoder_hidden_states.shape[0]
            if encoder_hidden_states is not None
            else hidden_states.shape[0]
        )

        # Single attention case (no encoder states)
        if encoder_hidden_states is None:
            # Use fused QKV projection
            qkv = attn.to_qkv(hidden_states)  # (batch, seq_len, 3 * inner_dim)
            inner_dim = qkv.shape[-1] // 3
            head_dim = inner_dim // attn.heads
            seq_len = hidden_states.shape[1]

            # Split and reshape
            qkv = qkv.view(batch_size, seq_len, 3, attn.heads, head_dim)
            query, key, value = qkv.unbind(
                dim=2
            )  # Each is (batch, seq_len, heads, head_dim)

            # Transpose to (batch, heads, seq_len, head_dim)
            query = query.transpose(1, 2)
            key = key.transpose(1, 2)
            value = value.transpose(1, 2)

            # Apply norms if needed
            if attn.norm_q is not None:
                query = attn.norm_q(query)
            if attn.norm_k is not None:
                key = attn.norm_k(key)

            # Apply RoPE if needed
            if image_rotary_emb is not None:
                query = apply_rotary_emb(query, image_rotary_emb)
                key = apply_rotary_emb(key, image_rotary_emb)

            # SDPA
            hidden_states = F.scaled_dot_product_attention(
                query,
                key,
                value,
                attn_mask=attention_mask,
                dropout_p=0.0,
                is_causal=False,
            )

            # Reshape back
            hidden_states = hidden_states.transpose(1, 2).reshape(
                batch_size, -1, attn.heads * head_dim
            )
            hidden_states = hidden_states.to(query.dtype)

            if input_ndim == 4:
                hidden_states = hidden_states.transpose(-1, -2).reshape(
                    batch_size, channel, height, width
                )

            return hidden_states

        # Joint attention case (with encoder states)
        else:
            # Process self-attention QKV
            qkv = attn.to_qkv(hidden_states)
            inner_dim = qkv.shape[-1] // 3
            head_dim = inner_dim // attn.heads
            seq_len = hidden_states.shape[1]

            qkv = qkv.view(batch_size, seq_len, 3, attn.heads, head_dim)
            query, key, value = qkv.unbind(dim=2)

            # Transpose to (batch, heads, seq_len, head_dim)
            query = query.transpose(1, 2)
            key = key.transpose(1, 2)
            value = value.transpose(1, 2)

            # Apply norms if needed
            if attn.norm_q is not None:
                query = attn.norm_q(query)
            if attn.norm_k is not None:
                key = attn.norm_k(key)

            # Process encoder QKV
            encoder_seq_len = encoder_hidden_states.shape[1]
            encoder_qkv = attn.to_added_qkv(encoder_hidden_states)
            encoder_qkv = encoder_qkv.view(
                batch_size, encoder_seq_len, 3, attn.heads, head_dim
            )
            encoder_query, encoder_key, encoder_value = encoder_qkv.unbind(dim=2)

            # Transpose to (batch, heads, seq_len, head_dim)
            encoder_query = encoder_query.transpose(1, 2)
            encoder_key = encoder_key.transpose(1, 2)
            encoder_value = encoder_value.transpose(1, 2)

            # Apply encoder norms if needed
            if attn.norm_added_q is not None:
                encoder_query = attn.norm_added_q(encoder_query)
            if attn.norm_added_k is not None:
                encoder_key = attn.norm_added_k(encoder_key)

            # Concatenate encoder and self-attention
            query = torch.cat([encoder_query, query], dim=2)
            key = torch.cat([encoder_key, key], dim=2)
            value = torch.cat([encoder_value, value], dim=2)

            # Apply RoPE if needed
            if image_rotary_emb is not None:
                query = apply_rotary_emb(query, image_rotary_emb)
                key = apply_rotary_emb(key, image_rotary_emb)

            # SDPA
            hidden_states = F.scaled_dot_product_attention(
                query,
                key,
                value,
                attn_mask=attention_mask,
                dropout_p=0.0,
                is_causal=False,
            )

            # Reshape: (batch, heads, seq_len, head_dim) -> (batch, seq_len, heads * head_dim)
            hidden_states = hidden_states.transpose(1, 2).reshape(
                batch_size, -1, attn.heads * head_dim
            )
            hidden_states = hidden_states.to(query.dtype)

            # Split encoder and self outputs
            encoder_hidden_states = hidden_states[:, :encoder_seq_len]
            hidden_states = hidden_states[:, encoder_seq_len:]

            # Output projections
            hidden_states = attn.to_out[0](hidden_states)
            hidden_states = attn.to_out[1](hidden_states)  # dropout
            encoder_hidden_states = attn.to_add_out(encoder_hidden_states)

            # Reshape if needed
            if input_ndim == 4:
                hidden_states = hidden_states.transpose(-1, -2).reshape(
                    batch_size, channel, height, width
                )
            if context_input_ndim == 4:
                encoder_hidden_states = encoder_hidden_states.transpose(-1, -2).reshape(
                    batch_size, channel, height, width
                )

            return hidden_states, encoder_hidden_states


class FluxSingleFusedSDPAProcessor:
    """
    Fused QKV processor for single attention (no encoder states).
    Simpler version for self-attention only blocks.
    """

    def __init__(self):
        if not hasattr(F, "scaled_dot_product_attention"):
            raise ImportError(
                "FluxSingleFusedSDPAProcessor requires PyTorch 2.0+ for scaled_dot_product_attention"
            )

    def __call__(
        self,
        attn,
        hidden_states: Tensor,
        encoder_hidden_states: Tensor = None,
        attention_mask: FloatTensor = None,
        image_rotary_emb: Tensor = None,
    ) -> Tensor:
        input_ndim = hidden_states.ndim
        if input_ndim == 4:
            batch_size, channel, height, width = hidden_states.shape
            hidden_states = hidden_states.view(
                batch_size, channel, height * width
            ).transpose(1, 2)

        batch_size, seq_len, _ = hidden_states.shape

        # Use fused QKV projection
        qkv = attn.to_qkv(hidden_states)  # (batch, seq_len, 3 * inner_dim)
        inner_dim = qkv.shape[-1] // 3
        head_dim = inner_dim // attn.heads

        # Split and reshape in one go
        qkv = qkv.view(batch_size, seq_len, 3, attn.heads, head_dim)
        qkv = qkv.permute(2, 0, 3, 1, 4)  # (3, B, H, L, D) – still strided
        query, key, value = [
            t.contiguous() for t in qkv.unbind(0)  # make each view dense
        ]
        # Now each is (batch, heads, seq_len, head_dim)

        # Apply norms if needed
        if attn.norm_q is not None:
            query = attn.norm_q(query)
        if attn.norm_k is not None:
            key = attn.norm_k(key)

        # Apply RoPE if needed
        if image_rotary_emb is not None:
            query = apply_rotary_emb(query, image_rotary_emb)
            key = apply_rotary_emb(key, image_rotary_emb)

        # SDPA
        hidden_states = F.scaled_dot_product_attention(
            query, key, value, attn_mask=attention_mask, dropout_p=0.0, is_causal=False
        )

        # Reshape back
        hidden_states = rearrange(hidden_states, "B H L D -> B L (H D)")
        hidden_states = hidden_states.to(query.dtype)

        if input_ndim == 4:
            hidden_states = hidden_states.transpose(-1, -2).reshape(
                batch_size, channel, height, width
            )

        return hidden_states

#################################
##### TRANSFORMER MERGE #########
#################################

from typing import Any, Dict, List, Optional, Tuple, Union

import torch
import torch.nn as nn
import torch.nn.functional as F
import numpy as np

from diffusers.configuration_utils import ConfigMixin, register_to_config
from diffusers.loaders import FromOriginalModelMixin, PeftAdapterMixin
from diffusers.models.attention import FeedForward
from diffusers.models.attention_processor import (
    Attention,
    AttentionProcessor,
)
from diffusers.models.modeling_utils import ModelMixin
from diffusers.models.normalization import (
    AdaLayerNormContinuous,
    AdaLayerNormZero,
    AdaLayerNormZeroSingle,
)
from diffusers.utils import (
    USE_PEFT_BACKEND,
    is_torch_version,
    logging,
    scale_lora_layers,
    unscale_lora_layers,
)
from diffusers.utils.torch_utils import maybe_allow_in_graph
from diffusers.models.embeddings import (
    CombinedTimestepGuidanceTextProjEmbeddings,
    CombinedTimestepTextProjEmbeddings,
    FluxPosEmbed,
)

from diffusers.models.modeling_outputs import Transformer2DModelOutput
from diffusers import FluxTransformer2DModel as OriginalFluxTransformer2DModel


logger = logging.get_logger(__name__)  # pylint: disable=invalid-name

is_flash_attn_available = False



class FluxAttnProcessor2_0:
    """Attention processor used typically in processing the SD3-like self-attention projections."""

    def __init__(self):
        if not hasattr(F, "scaled_dot_product_attention"):
            raise ImportError(
                "FluxAttnProcessor2_0 requires PyTorch 2.0, to use it, please upgrade PyTorch to 2.0."
            )

    def __call__(
        self,
        attn: Attention,
        hidden_states: torch.FloatTensor,
        encoder_hidden_states: torch.FloatTensor = None,
        attention_mask: Optional[torch.FloatTensor] = None,
        image_rotary_emb: Optional[torch.Tensor] = None,
    ) -> torch.FloatTensor:
        batch_size, _, _ = (
            hidden_states.shape
            if encoder_hidden_states is None
            else encoder_hidden_states.shape
        )

        # `sample` projections.
        query = attn.to_q(hidden_states)
        key = attn.to_k(hidden_states)
        value = attn.to_v(hidden_states)

        inner_dim = key.shape[-1]
        head_dim = inner_dim // attn.heads

        query = query.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
        key = key.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
        value = value.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)

        if attn.norm_q is not None:
            query = attn.norm_q(query)
        if attn.norm_k is not None:
            key = attn.norm_k(key)

        # the attention in FluxSingleTransformerBlock does not use `encoder_hidden_states`
        if encoder_hidden_states is not None:
            # `context` projections.
            encoder_hidden_states_query_proj = attn.add_q_proj(encoder_hidden_states)
            encoder_hidden_states_key_proj = attn.add_k_proj(encoder_hidden_states)
            encoder_hidden_states_value_proj = attn.add_v_proj(encoder_hidden_states)

            encoder_hidden_states_query_proj = encoder_hidden_states_query_proj.view(
                batch_size, -1, attn.heads, head_dim
            ).transpose(1, 2)
            encoder_hidden_states_key_proj = encoder_hidden_states_key_proj.view(
                batch_size, -1, attn.heads, head_dim
            ).transpose(1, 2)
            encoder_hidden_states_value_proj = encoder_hidden_states_value_proj.view(
                batch_size, -1, attn.heads, head_dim
            ).transpose(1, 2)

            if attn.norm_added_q is not None:
                encoder_hidden_states_query_proj = attn.norm_added_q(
                    encoder_hidden_states_query_proj
                )
            if attn.norm_added_k is not None:
                encoder_hidden_states_key_proj = attn.norm_added_k(
                    encoder_hidden_states_key_proj
                )

            # attention
            query = torch.cat([encoder_hidden_states_query_proj, query], dim=2)
            key = torch.cat([encoder_hidden_states_key_proj, key], dim=2)
            value = torch.cat([encoder_hidden_states_value_proj, value], dim=2)

        if image_rotary_emb is not None:
            from diffusers.models.embeddings import apply_rotary_emb

            query = apply_rotary_emb(query, image_rotary_emb)
            key = apply_rotary_emb(key, image_rotary_emb)

        if attention_mask is not None:
            #print ('Attention Used')
            attention_mask = attention_mask.unsqueeze(1).unsqueeze(2)
            attention_mask = (attention_mask > 0).bool()
            # Edit 17 - match attn dtype to query d-type
            attention_mask = attention_mask.to(
                device=hidden_states.device, dtype=query.dtype
            )

        hidden_states = F.scaled_dot_product_attention(
            query,
            key,
            value,
            dropout_p=0.0,
            is_causal=False,
            attn_mask=attention_mask,
        )
        hidden_states = hidden_states.transpose(1, 2).reshape(
            batch_size, -1, attn.heads * head_dim
        )
        hidden_states = hidden_states.to(query.dtype)

        if encoder_hidden_states is not None:
            encoder_hidden_states, hidden_states = (
                hidden_states[:, : encoder_hidden_states.shape[1]],
                hidden_states[:, encoder_hidden_states.shape[1] :],
            )

            # linear proj
            hidden_states = attn.to_out[0](hidden_states)
            # dropout
            hidden_states = attn.to_out[1](hidden_states)
            encoder_hidden_states = attn.to_add_out(encoder_hidden_states)

            return hidden_states, encoder_hidden_states
        return hidden_states


def expand_flux_attention_mask(
    hidden_states: torch.Tensor,
    attn_mask: torch.Tensor,
) -> torch.Tensor:
    """
    Expand a mask so that the image is included.
    """
    bsz = attn_mask.shape[0]
    assert bsz == hidden_states.shape[0]
    residual_seq_len = hidden_states.shape[1]
    mask_seq_len = attn_mask.shape[1]

    expanded_mask = torch.ones(bsz, residual_seq_len)
    expanded_mask[:, :mask_seq_len] = attn_mask

    return expanded_mask


@maybe_allow_in_graph
class FluxSingleTransformerBlock(nn.Module):
    r"""
    A Transformer block following the MMDiT architecture, introduced in Stable Diffusion 3.

    Reference: https://arxiv.org/abs/2403.03206

    Parameters:
        dim (`int`): The number of channels in the input and output.
        num_attention_heads (`int`): The number of heads to use for multi-head attention.
        attention_head_dim (`int`): The number of channels in each head.
        context_pre_only (`bool`): Boolean to determine if we should add some blocks associated with the
            processing of `context` conditions.
    """

    def __init__(self, dim, num_attention_heads, attention_head_dim, mlp_ratio=4.0):
        super().__init__()
        self.mlp_hidden_dim = int(dim * mlp_ratio)

        self.norm = AdaLayerNormZeroSingle(dim)
        self.proj_mlp = nn.Linear(dim, self.mlp_hidden_dim)
        self.act_mlp = nn.GELU(approximate="tanh")
        self.proj_out = nn.Linear(dim + self.mlp_hidden_dim, dim)

        processor = FluxAttnProcessor2_0()
        self.attn = Attention(
            query_dim=dim,
            cross_attention_dim=None,
            dim_head=attention_head_dim,
            heads=num_attention_heads,
            out_dim=dim,
            bias=True,
            processor=processor,
            qk_norm="rms_norm",
            eps=1e-6,
            pre_only=True,
        )

    def forward(
        self,
        hidden_states: torch.FloatTensor,
        temb: torch.FloatTensor,
        image_rotary_emb=None,
        attention_mask: Optional[torch.Tensor] = None,
    ):
        residual = hidden_states
        norm_hidden_states, gate = self.norm(hidden_states, emb=temb)
        mlp_hidden_states = self.act_mlp(self.proj_mlp(norm_hidden_states))

        if attention_mask is not None:
            attention_mask = expand_flux_attention_mask(
                hidden_states,
                attention_mask,
            )

        attn_output = self.attn(
            hidden_states=norm_hidden_states,
            image_rotary_emb=image_rotary_emb,
            attention_mask=attention_mask,
        )

        hidden_states = torch.cat([attn_output, mlp_hidden_states], dim=2)
        gate = gate.unsqueeze(1)
        hidden_states = gate * self.proj_out(hidden_states)
        hidden_states = residual + hidden_states

        if hidden_states.dtype == torch.float16:
            hidden_states = hidden_states.clip(-65504, 65504)

        return hidden_states


@maybe_allow_in_graph
class FluxTransformerBlock(nn.Module):
    r"""
    A Transformer block following the MMDiT architecture, introduced in Stable Diffusion 3.

    Reference: https://arxiv.org/abs/2403.03206

    Parameters:
        dim (`int`): The number of channels in the input and output.
        num_attention_heads (`int`): The number of heads to use for multi-head attention.
        attention_head_dim (`int`): The number of channels in each head.
        context_pre_only (`bool`): Boolean to determine if we should add some blocks associated with the
            processing of `context` conditions.
    """

    def __init__(
        self, dim, num_attention_heads, attention_head_dim, qk_norm="rms_norm", eps=1e-6
    ):
        super().__init__()

        self.norm1 = AdaLayerNormZero(dim)

        self.norm1_context = AdaLayerNormZero(dim)

        if hasattr(F, "scaled_dot_product_attention"):
            processor = FluxAttnProcessor2_0()
        else:
            raise ValueError(
                "The current PyTorch version does not support the `scaled_dot_product_attention` function."
            )
        self.attn = Attention(
            query_dim=dim,
            cross_attention_dim=None,
            added_kv_proj_dim=dim,
            dim_head=attention_head_dim,
            heads=num_attention_heads,
            out_dim=dim,
            context_pre_only=False,
            bias=True,
            processor=processor,
            qk_norm=qk_norm,
            eps=eps,
        )

        self.norm2 = nn.LayerNorm(dim, elementwise_affine=False, eps=1e-6)
        self.ff = FeedForward(dim=dim, dim_out=dim, activation_fn="gelu-approximate")

        self.norm2_context = nn.LayerNorm(dim, elementwise_affine=False, eps=1e-6)
        self.ff_context = FeedForward(
            dim=dim, dim_out=dim, activation_fn="gelu-approximate"
        )

        # let chunk size default to None
        self._chunk_size = None
        self._chunk_dim = 0

    def forward(
        self,
        hidden_states: torch.FloatTensor,
        encoder_hidden_states: torch.FloatTensor,
        temb: torch.FloatTensor,
        image_rotary_emb=None,
        attention_mask: Optional[torch.Tensor] = None,
    ):
        norm_hidden_states, gate_msa, shift_mlp, scale_mlp, gate_mlp = self.norm1(
            hidden_states, emb=temb
        )

        norm_encoder_hidden_states, c_gate_msa, c_shift_mlp, c_scale_mlp, c_gate_mlp = (
            self.norm1_context(encoder_hidden_states, emb=temb)
        )

        if attention_mask is not None:
            attention_mask = expand_flux_attention_mask(
                torch.cat([encoder_hidden_states, hidden_states], dim=1),
                attention_mask,
            )

        # Attention.
        attention_outputs = self.attn(
            hidden_states=norm_hidden_states,
            encoder_hidden_states=norm_encoder_hidden_states,
            image_rotary_emb=image_rotary_emb,
            attention_mask=attention_mask,
        )
        if len(attention_outputs) == 2:
            attn_output, context_attn_output = attention_outputs
        elif len(attention_outputs) == 3:
            attn_output, context_attn_output, ip_attn_output = attention_outputs

        # Process attention outputs for the `hidden_states`.
        attn_output = gate_msa.unsqueeze(1) * attn_output
        hidden_states = hidden_states + attn_output

        norm_hidden_states = self.norm2(hidden_states)
        norm_hidden_states = (
            norm_hidden_states * (1 + scale_mlp[:, None]) + shift_mlp[:, None]
        )

        ff_output = self.ff(norm_hidden_states)
        ff_output = gate_mlp.unsqueeze(1) * ff_output

        hidden_states = hidden_states + ff_output
        if len(attention_outputs) == 3:
            hidden_states = hidden_states + ip_attn_output

        # Process attention outputs for the `encoder_hidden_states`.
        context_attn_output = c_gate_msa.unsqueeze(1) * context_attn_output
        encoder_hidden_states = encoder_hidden_states + context_attn_output

        norm_encoder_hidden_states = self.norm2_context(encoder_hidden_states)
        norm_encoder_hidden_states = (
            norm_encoder_hidden_states * (1 + c_scale_mlp[:, None])
            + c_shift_mlp[:, None]
        )

        context_ff_output = self.ff_context(norm_encoder_hidden_states)
        encoder_hidden_states = (
            encoder_hidden_states + c_gate_mlp.unsqueeze(1) * context_ff_output
        )

        if encoder_hidden_states.dtype == torch.float16:
            encoder_hidden_states = encoder_hidden_states.clip(-65504, 65504)

        return encoder_hidden_states, hidden_states


class LibreFluxTransformer2DModel(
    ModelMixin, ConfigMixin, PeftAdapterMixin, FromOriginalModelMixin
):
    """
    The Transformer model introduced in Flux.

    Reference: https://blackforestlabs.ai/announcing-black-forest-labs/

    Parameters:
        patch_size (`int`): Patch size to turn the input data into small patches.
        in_channels (`int`, *optional*, defaults to 16): The number of channels in the input.
        num_layers (`int`, *optional*, defaults to 18): The number of layers of MMDiT blocks to use.
        num_single_layers (`int`, *optional*, defaults to 18): The number of layers of single DiT blocks to use.
        attention_head_dim (`int`, *optional*, defaults to 64): The number of channels in each head.
        num_attention_heads (`int`, *optional*, defaults to 18): The number of heads to use for multi-head attention.
        joint_attention_dim (`int`, *optional*): The number of `encoder_hidden_states` dimensions to use.
        pooled_projection_dim (`int`): Number of dimensions to use when projecting the `pooled_projections`.
        guidance_embeds (`bool`, defaults to False): Whether to use guidance embeddings.
    """

    _supports_gradient_checkpointing = True

    @register_to_config
    def __init__(
        self,
        patch_size: int = 1,
        in_channels: int = 64,
        num_layers: int = 19,
        num_single_layers: int = 38,
        attention_head_dim: int = 128,
        num_attention_heads: int = 24,
        joint_attention_dim: int = 4096,
        pooled_projection_dim: int = 768,
        guidance_embeds: bool = False,
        axes_dims_rope: Tuple[int] = (16, 56, 56),
    ):
        super().__init__()
        self.out_channels = in_channels
        self.inner_dim = (
            self.config.num_attention_heads * self.config.attention_head_dim
        )

        self.pos_embed = FluxPosEmbed(theta=10000, axes_dim=axes_dims_rope)
        text_time_guidance_cls = (
            CombinedTimestepGuidanceTextProjEmbeddings  ### 3 input forward (timestep, guidance, pooled_projection)
            if guidance_embeds
            else CombinedTimestepTextProjEmbeddings  #### 2 input forward (timestep, pooled_projection)
        )
        self.time_text_embed = text_time_guidance_cls(
            embedding_dim=self.inner_dim,
            pooled_projection_dim=self.config.pooled_projection_dim,
        )

        self.context_embedder = nn.Linear(
            self.config.joint_attention_dim, self.inner_dim
        )
        self.x_embedder = torch.nn.Linear(self.config.in_channels, self.inner_dim)

        self.transformer_blocks = nn.ModuleList(
            [
                FluxTransformerBlock(
                    dim=self.inner_dim,
                    num_attention_heads=self.config.num_attention_heads,
                    attention_head_dim=self.config.attention_head_dim,
                )
                for i in range(self.config.num_layers)
            ]
        )

        self.single_transformer_blocks = nn.ModuleList(
            [
                FluxSingleTransformerBlock(
                    dim=self.inner_dim,
                    num_attention_heads=self.config.num_attention_heads,
                    attention_head_dim=self.config.attention_head_dim,
                )
                for i in range(self.config.num_single_layers)
            ]
        )

        self.norm_out = AdaLayerNormContinuous(
            self.inner_dim, self.inner_dim, elementwise_affine=False, eps=1e-6
        )
        self.proj_out = nn.Linear(
            self.inner_dim, patch_size * patch_size * self.out_channels, bias=True
        )

        self.gradient_checkpointing = False
        # added for users to disable checkpointing every nth step
        self.gradient_checkpointing_interval = None

    def set_gradient_checkpointing_interval(self, value: int):
        self.gradient_checkpointing_interval = value

    @property
    # Copied from diffusers.models.unets.unet_2d_condition.UNet2DConditionModel.attn_processors
    def attn_processors(self) -> Dict[str, AttentionProcessor]:
        r"""
        Returns:
            `dict` of attention processors: A dictionary containing all attention processors used in the model with
            indexed by its weight name.
        """
        # set recursively
        processors = {}

        def fn_recursive_add_processors(
            name: str,
            module: torch.nn.Module,
            processors: Dict[str, AttentionProcessor],
        ):
            if hasattr(module, "get_processor"):
                processors[f"{name}.processor"] = module.get_processor()

            for sub_name, child in module.named_children():
                fn_recursive_add_processors(f"{name}.{sub_name}", child, processors)

            return processors

        for name, module in self.named_children():
            fn_recursive_add_processors(name, module, processors)

        return processors

    # Copied from diffusers.models.unets.unet_2d_condition.UNet2DConditionModel.set_attn_processor
    def set_attn_processor(
        self, processor: Union[AttentionProcessor, Dict[str, AttentionProcessor]]
    ):
        r"""
        Sets the attention processor to use to compute attention.

        Parameters:
            processor (`dict` of `AttentionProcessor` or only `AttentionProcessor`):
                The instantiated processor class or a dictionary of processor classes that will be set as the processor
                for **all** `Attention` layers.

                If `processor` is a dict, the key needs to define the path to the corresponding cross attention
                processor. This is strongly recommended when setting trainable attention processors.

        """
        count = len(self.attn_processors.keys())

        if isinstance(processor, dict) and len(processor) != count:
            raise ValueError(
                f"A dict of processors was passed, but the number of processors {len(processor)} does not match the"
                f" number of attention layers: {count}. Please make sure to pass {count} processor classes."
            )

        def fn_recursive_attn_processor(name: str, module: torch.nn.Module, processor):
            if hasattr(module, "set_processor"):
                if not isinstance(processor, dict):
                    module.set_processor(processor)
                else:
                    module.set_processor(processor.pop(f"{name}.processor"))

            for sub_name, child in module.named_children():
                fn_recursive_attn_processor(f"{name}.{sub_name}", child, processor)

        for name, module in self.named_children():
            fn_recursive_attn_processor(name, module, processor)

    def forward(
        self,
        hidden_states: torch.Tensor,
        encoder_hidden_states: torch.Tensor = None,
        pooled_projections: torch.Tensor = None,
        timestep: torch.LongTensor = None,
        img_ids: torch.Tensor = None,
        txt_ids: torch.Tensor = None,
        guidance: torch.Tensor = None,
        joint_attention_kwargs: Optional[Dict[str, Any]] = None,
        controlnet_block_samples=None,
        controlnet_single_block_samples=None,
        return_dict: bool = True,
        attention_mask: Optional[torch.Tensor] = None,
        controlnet_blocks_repeat: bool = False,
    ) -> Union[torch.FloatTensor, Transformer2DModelOutput]:
        """
        The [`FluxTransformer2DModel`] forward method.

        Args:
            hidden_states (`torch.FloatTensor` of shape `(batch size, channel, height, width)`):
                Input `hidden_states`.
            encoder_hidden_states (`torch.FloatTensor` of shape `(batch size, sequence_len, embed_dims)`):
                Conditional embeddings (embeddings computed from the input conditions such as prompts) to use.
            pooled_projections (`torch.FloatTensor` of shape `(batch_size, projection_dim)`): Embeddings projected
                from the embeddings of input conditions.
            timestep ( `torch.LongTensor`):
                Used to indicate denoising step.
            block_controlnet_hidden_states: (`list` of `torch.Tensor`):
                A list of tensors that if specified are added to the residuals of transformer blocks.
            joint_attention_kwargs (`dict`, *optional*):
                A kwargs dictionary that if specified is passed along to the `AttentionProcessor` as defined under
                `self.processor` in
                [diffusers.models.attention_processor](https://github.com/huggingface/diffusers/blob/main/src/diffusers/models/attention_processor.py).
            return_dict (`bool`, *optional*, defaults to `True`):
                Whether or not to return a [`~models.transformer_2d.Transformer2DModelOutput`] instead of a plain
                tuple.

        Returns:
            If `return_dict` is True, an [`~models.transformer_2d.Transformer2DModelOutput`] is returned, otherwise a
            `tuple` where the first element is the sample tensor.
        """
        if joint_attention_kwargs is not None:
            joint_attention_kwargs = joint_attention_kwargs.copy()
            lora_scale = joint_attention_kwargs.pop("scale", 1.0)
        else:
            lora_scale = 1.0

        if USE_PEFT_BACKEND:
            # weight the lora layers by setting `lora_scale` for each PEFT layer
            scale_lora_layers(self, lora_scale)
        else:
            if (
                joint_attention_kwargs is not None
                and joint_attention_kwargs.get("scale", None) is not None
            ):
                logger.warning(
                    "Passing `scale` via `joint_attention_kwargs` when not using the PEFT backend is ineffective."
                )
        hidden_states = self.x_embedder(hidden_states)

        timestep = timestep.to(hidden_states.dtype) * 1000
        if guidance is not None:
            guidance = guidance.to(hidden_states.dtype) * 1000
        else:
            guidance = None

        #print( self.time_text_embed)
        temb = (
            self.time_text_embed(timestep,pooled_projections)
            # Edit 1 # Charlie   NOT NEEDED - UNDONE
            if guidance is None
            else self.time_text_embed(timestep, guidance, pooled_projections)
        )
        encoder_hidden_states = self.context_embedder(encoder_hidden_states)

        if txt_ids.ndim == 3:
            txt_ids = txt_ids[0]
        if img_ids.ndim == 3:
            img_ids = img_ids[0]

        ids = torch.cat((txt_ids, img_ids), dim=0)

        image_rotary_emb = self.pos_embed(ids)

        # IP adapter
        if (
            joint_attention_kwargs is not None
            and "ip_adapter_image_embeds" in joint_attention_kwargs
        ):
            ip_adapter_image_embeds = joint_attention_kwargs.pop(
                "ip_adapter_image_embeds"
            )
            ip_hidden_states = self.encoder_hid_proj(ip_adapter_image_embeds)
            joint_attention_kwargs.update({"ip_hidden_states": ip_hidden_states})

        for index_block, block in enumerate(self.transformer_blocks):
            if (
                self.training
                and self.gradient_checkpointing
                and (
                    self.gradient_checkpointing_interval is None
                    or index_block % self.gradient_checkpointing_interval == 0
                )
            ):

                def create_custom_forward(module, return_dict=None):
                    def custom_forward(*inputs):
                        if return_dict is not None:
                            return module(*inputs, return_dict=return_dict)
                        else:
                            return module(*inputs)

                    return custom_forward

                ckpt_kwargs: Dict[str, Any] = (
                    {"use_reentrant": False} if is_torch_version(">=", "1.11.0") else {}
                )
                encoder_hidden_states, hidden_states = (
                    torch.utils.checkpoint.checkpoint(
                        create_custom_forward(block),
                        hidden_states,
                        encoder_hidden_states,
                        temb,
                        image_rotary_emb,
                        attention_mask,
                        **ckpt_kwargs,
                    )
                )

            else:
                encoder_hidden_states, hidden_states = block(
                    hidden_states=hidden_states,
                    encoder_hidden_states=encoder_hidden_states,
                    temb=temb,
                    image_rotary_emb=image_rotary_emb,
                    attention_mask=attention_mask,
                )

            # controlnet residual
            if controlnet_block_samples is not None:
                interval_control = len(self.transformer_blocks) / len(
                    controlnet_block_samples
                )
                interval_control = int(np.ceil(interval_control))
                # For Xlabs ControlNet.
                if controlnet_blocks_repeat:
                    hidden_states = (
                        hidden_states
                        + controlnet_block_samples[
                            index_block % len(controlnet_block_samples)
                        ]
                    )
                else:
                    hidden_states = (
                        hidden_states
                        + controlnet_block_samples[index_block // interval_control]
                    )

        # Flux places the text tokens in front of the image tokens in the
        # sequence.
        hidden_states = torch.cat([encoder_hidden_states, hidden_states], dim=1)

        for index_block, block in enumerate(self.single_transformer_blocks):
            if (
                self.training
                and self.gradient_checkpointing
                or (
                    self.gradient_checkpointing_interval is not None
                    and index_block % self.gradient_checkpointing_interval == 0
                )
            ):

                def create_custom_forward(module, return_dict=None):
                    def custom_forward(*inputs):
                        if return_dict is not None:
                            return module(*inputs, return_dict=return_dict)
                        else:
                            return module(*inputs)

                    return custom_forward

                ckpt_kwargs: Dict[str, Any] = (
                    {"use_reentrant": False} if is_torch_version(">=", "1.11.0") else {}
                )
                hidden_states = torch.utils.checkpoint.checkpoint(
                    create_custom_forward(block),
                    hidden_states,
                    temb,
                    image_rotary_emb,
                    attention_mask,
                    **ckpt_kwargs,
                )

            else:
                hidden_states = block(
                    hidden_states=hidden_states,
                    temb=temb,
                    image_rotary_emb=image_rotary_emb,
                    attention_mask=attention_mask,
                )

            # controlnet residual
            if controlnet_single_block_samples is not None:
                interval_control = len(self.single_transformer_blocks) / len(
                    controlnet_single_block_samples
                )
                interval_control = int(np.ceil(interval_control))
                hidden_states[:, encoder_hidden_states.shape[1] :, ...] = (
                    hidden_states[:, encoder_hidden_states.shape[1] :, ...]
                    + controlnet_single_block_samples[index_block // interval_control]
                )

        hidden_states = hidden_states[:, encoder_hidden_states.shape[1] :, ...]

        hidden_states = self.norm_out(hidden_states, temb)
        output = self.proj_out(hidden_states)

        if USE_PEFT_BACKEND:
            # remove `lora_scale` from each PEFT layer
            unscale_lora_layers(self, lora_scale)

        if not return_dict:
            return (output,)

        return Transformer2DModelOutput(sample=output)