chore: import upstream snapshot with attribution

invokeai/backend/stable_diffusion/diffusion/custom_atttention.py

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+from dataclasses import dataclass
+from typing import List, Optional, cast
+
+import torch
+import torch.nn.functional as F
+from diffusers.models.attention_processor import Attention, AttnProcessor2_0
+
+from invokeai.backend.ip_adapter.ip_attention_weights import IPAttentionProcessorWeights
+from invokeai.backend.stable_diffusion.diffusion.regional_ip_data import RegionalIPData
+from invokeai.backend.stable_diffusion.diffusion.regional_prompt_data import RegionalPromptData
+
+
+@dataclass
+class IPAdapterAttentionWeights:
+    ip_adapter_weights: IPAttentionProcessorWeights
+    skip: bool
+    negative: bool
+
+
+class CustomAttnProcessor2_0(AttnProcessor2_0):
+    """A custom implementation of AttnProcessor2_0 that supports additional Invoke features.
+    This implementation is based on
+    https://github.com/huggingface/diffusers/blame/fcfa270fbd1dc294e2f3a505bae6bcb791d721c3/src/diffusers/models/attention_processor.py#L1204
+    Supported custom features:
+    - IP-Adapter
+    - Regional prompt attention
+    """
+
+    def __init__(
+        self,
+        ip_adapter_attention_weights: Optional[List[IPAdapterAttentionWeights]] = None,
+    ):
+        """Initialize a CustomAttnProcessor2_0.
+        Note: Arguments that are the same for all attention layers are passed to __call__(). Arguments that are
+        layer-specific are passed to __init__().
+        Args:
+            ip_adapter_weights: The IP-Adapter attention weights. ip_adapter_weights[i] contains the attention weights
+                for the i'th IP-Adapter.
+        """
+        super().__init__()
+        self._ip_adapter_attention_weights = ip_adapter_attention_weights
+
+    def __call__(
+        self,
+        attn: Attention,
+        hidden_states: torch.Tensor,
+        encoder_hidden_states: Optional[torch.Tensor] = None,
+        attention_mask: Optional[torch.Tensor] = None,
+        temb: Optional[torch.Tensor] = None,
+        # For Regional Prompting:
+        regional_prompt_data: Optional[RegionalPromptData] = None,
+        percent_through: Optional[torch.Tensor] = None,
+        # For IP-Adapter:
+        regional_ip_data: Optional[RegionalIPData] = None,
+        *args,
+        **kwargs,
+    ) -> torch.FloatTensor:
+        """Apply attention.
+        Args:
+            regional_prompt_data: The regional prompt data for the current batch. If not None, this will be used to
+                apply regional prompt masking.
+            regional_ip_data: The IP-Adapter data for the current batch.
+        """
+        # If true, we are doing cross-attention, if false we are doing self-attention.
+        is_cross_attention = encoder_hidden_states is not None
+
+        # Start unmodified block from AttnProcessor2_0.
+        # vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
+        residual = hidden_states
+        if attn.spatial_norm is not None:
+            hidden_states = attn.spatial_norm(hidden_states, temb)
+
+        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, sequence_length, _ = (
+            hidden_states.shape if encoder_hidden_states is None else encoder_hidden_states.shape
+        )
+        # ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+        # End unmodified block from AttnProcessor2_0.
+
+        _, query_seq_len, _ = hidden_states.shape
+        # Handle regional prompt attention masks.
+        if regional_prompt_data is not None and is_cross_attention:
+            assert percent_through is not None
+            prompt_region_attention_mask = regional_prompt_data.get_cross_attn_mask(
+                query_seq_len=query_seq_len, key_seq_len=sequence_length
+            )
+
+            if attention_mask is None:
+                attention_mask = prompt_region_attention_mask
+            else:
+                attention_mask = prompt_region_attention_mask + attention_mask
+
+        # Start unmodified block from AttnProcessor2_0.
+        # vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
+        if attention_mask is not None:
+            attention_mask = attn.prepare_attention_mask(attention_mask, sequence_length, batch_size)
+            # scaled_dot_product_attention expects attention_mask shape to be
+            # (batch, heads, source_length, target_length)
+            attention_mask = attention_mask.view(batch_size, attn.heads, -1, attention_mask.shape[-1])
+
+        if attn.group_norm is not None:
+            hidden_states = attn.group_norm(hidden_states.transpose(1, 2)).transpose(1, 2)
+
+        query = attn.to_q(hidden_states)
+
+        if encoder_hidden_states is None:
+            encoder_hidden_states = hidden_states
+        elif attn.norm_cross:
+            encoder_hidden_states = attn.norm_encoder_hidden_states(encoder_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)
+
+        # 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, attn_mask=attention_mask, dropout_p=0.0, is_causal=False
+        )
+
+        hidden_states = hidden_states.transpose(1, 2).reshape(batch_size, -1, attn.heads * head_dim)
+        hidden_states = hidden_states.to(query.dtype)
+        # ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+        # End unmodified block from AttnProcessor2_0.
+
+        # Apply IP-Adapter conditioning.
+        if is_cross_attention:
+            if self._ip_adapter_attention_weights:
+                assert regional_ip_data is not None
+                ip_masks = regional_ip_data.get_masks(query_seq_len=query_seq_len)
+
+                assert (
+                    len(regional_ip_data.image_prompt_embeds)
+                    == len(self._ip_adapter_attention_weights)
+                    == len(regional_ip_data.scales)
+                    == ip_masks.shape[1]
+                )
+
+                for ipa_index, ipa_embed in enumerate(regional_ip_data.image_prompt_embeds):
+                    ipa_weights = self._ip_adapter_attention_weights[ipa_index].ip_adapter_weights
+                    ipa_scale = regional_ip_data.scales[ipa_index]
+                    ip_mask = ip_masks[0, ipa_index, ...]
+
+                    # The batch dimensions should match.
+                    assert ipa_embed.shape[0] == encoder_hidden_states.shape[0]
+                    # The token_len dimensions should match.
+                    assert ipa_embed.shape[-1] == encoder_hidden_states.shape[-1]
+
+                    ip_hidden_states = ipa_embed
+
+                    # Expected ip_hidden_state shape: (batch_size, num_ip_images, ip_seq_len, ip_image_embedding)
+
+                    if not self._ip_adapter_attention_weights[ipa_index].skip:
+                        # apply the IP-Adapter weights to the negative embeds
+                        if self._ip_adapter_attention_weights[ipa_index].negative:
+                            ip_hidden_states = torch.cat([ip_hidden_states[1], ip_hidden_states[0] * 0], dim=0)
+
+                        ip_key = ipa_weights.to_k_ip(ip_hidden_states)
+                        ip_value = ipa_weights.to_v_ip(ip_hidden_states)
+
+                        # Expected ip_key and ip_value shape:
+                        # (batch_size, num_ip_images, ip_seq_len, head_dim * num_heads)
+
+                        ip_key = ip_key.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
+                        ip_value = ip_value.view(batch_size, -1, attn.heads, head_dim).transpose(1, 2)
+
+                        # Expected ip_key and ip_value shape:
+                        # (batch_size, num_heads, num_ip_images * ip_seq_len, head_dim)
+
+                        # TODO: add support for attn.scale when we move to Torch 2.1
+                        ip_hidden_states = F.scaled_dot_product_attention(
+                            query, ip_key, ip_value, attn_mask=None, dropout_p=0.0, is_causal=False
+                        )
+
+                        # Expected ip_hidden_states shape: (batch_size, num_heads, query_seq_len, head_dim)
+                        ip_hidden_states = ip_hidden_states.transpose(1, 2).reshape(
+                            batch_size, -1, attn.heads * head_dim
+                        )
+
+                        ip_hidden_states = ip_hidden_states.to(query.dtype)
+
+                        # Expected ip_hidden_states shape: (batch_size, query_seq_len, num_heads * head_dim)
+                        hidden_states = hidden_states + ipa_scale * ip_hidden_states * ip_mask
+            else:
+                # If IP-Adapter is not enabled, then regional_ip_data should not be passed in.
+                assert regional_ip_data is None
+
+        # Start unmodified block from AttnProcessor2_0.
+        # vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
+        # linear proj
+        hidden_states = attn.to_out[0](hidden_states)
+        # dropout
+        hidden_states = attn.to_out[1](hidden_states)
+
+        if input_ndim == 4:
+            batch_size, channel, height, width = hidden_states.shape
+            hidden_states = hidden_states.transpose(-1, -2).reshape(batch_size, channel, height, width)
+
+        if attn.residual_connection:
+            hidden_states = hidden_states + residual
+
+        hidden_states = hidden_states / attn.rescale_output_factor
+        # ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+        # End of unmodified block from AttnProcessor2_0
+
+        # casting torch.Tensor to torch.FloatTensor to avoid type issues
+        return cast(torch.FloatTensor, hidden_states)