Unified Weight Adapter system for better maintainability and future feature of Lora system (#7540)

comfy/weight_adapter/lora.py

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+import logging
+from typing import Optional
+
+import torch
+import comfy.model_management
+from .base import WeightAdapterBase, weight_decompose, pad_tensor_to_shape
+
+
+class LoRAAdapter(WeightAdapterBase):
+    name = "lora"
+
+    def __init__(self, loaded_keys, weights):
+        self.loaded_keys = loaded_keys
+        self.weights = weights
+
+    @classmethod
+    def load(
+        cls,
+        x: str,
+        lora: dict[str, torch.Tensor],
+        alpha: float,
+        dora_scale: torch.Tensor,
+        loaded_keys: set[str] = None,
+    ) -> Optional["LoRAAdapter"]:
+        if loaded_keys is None:
+            loaded_keys = set()
+
+        reshape_name = "{}.reshape_weight".format(x)
+        regular_lora = "{}.lora_up.weight".format(x)
+        diffusers_lora = "{}_lora.up.weight".format(x)
+        diffusers2_lora = "{}.lora_B.weight".format(x)
+        diffusers3_lora = "{}.lora.up.weight".format(x)
+        mochi_lora = "{}.lora_B".format(x)
+        transformers_lora = "{}.lora_linear_layer.up.weight".format(x)
+        A_name = None
+
+        if regular_lora in lora.keys():
+            A_name = regular_lora
+            B_name = "{}.lora_down.weight".format(x)
+            mid_name = "{}.lora_mid.weight".format(x)
+        elif diffusers_lora in lora.keys():
+            A_name = diffusers_lora
+            B_name = "{}_lora.down.weight".format(x)
+            mid_name = None
+        elif diffusers2_lora in lora.keys():
+            A_name = diffusers2_lora
+            B_name = "{}.lora_A.weight".format(x)
+            mid_name = None
+        elif diffusers3_lora in lora.keys():
+            A_name = diffusers3_lora
+            B_name = "{}.lora.down.weight".format(x)
+            mid_name = None
+        elif mochi_lora in lora.keys():
+            A_name = mochi_lora
+            B_name = "{}.lora_A".format(x)
+            mid_name = None
+        elif transformers_lora in lora.keys():
+            A_name = transformers_lora
+            B_name = "{}.lora_linear_layer.down.weight".format(x)
+            mid_name = None
+
+        if A_name is not None:
+            mid = None
+            if mid_name is not None and mid_name in lora.keys():
+                mid = lora[mid_name]
+                loaded_keys.add(mid_name)
+            reshape = None
+            if reshape_name in lora.keys():
+                try:
+                    reshape = lora[reshape_name].tolist()
+                    loaded_keys.add(reshape_name)
+                except:
+                    pass
+            weights = (lora[A_name], lora[B_name], alpha, mid, dora_scale, reshape)
+            loaded_keys.add(A_name)
+            loaded_keys.add(B_name)
+            return cls(loaded_keys, weights)
+        else:
+            return None
+
+    def calculate_weight(
+        self,
+        weight,
+        key,
+        strength,
+        strength_model,
+        offset,
+        function,
+        intermediate_dtype=torch.float32,
+        original_weight=None,
+    ):
+        v = self.weights
+        mat1 = comfy.model_management.cast_to_device(
+            v[0], weight.device, intermediate_dtype
+        )
+        mat2 = comfy.model_management.cast_to_device(
+            v[1], weight.device, intermediate_dtype
+        )
+        dora_scale = v[4]
+        reshape = v[5]
+
+        if reshape is not None:
+            weight = pad_tensor_to_shape(weight, reshape)
+
+        if v[2] is not None:
+            alpha = v[2] / mat2.shape[0]
+        else:
+            alpha = 1.0
+
+        if v[3] is not None:
+            # locon mid weights, hopefully the math is fine because I didn't properly test it
+            mat3 = comfy.model_management.cast_to_device(
+                v[3], weight.device, intermediate_dtype
+            )
+            final_shape = [mat2.shape[1], mat2.shape[0], mat3.shape[2], mat3.shape[3]]
+            mat2 = (
+                torch.mm(
+                    mat2.transpose(0, 1).flatten(start_dim=1),
+                    mat3.transpose(0, 1).flatten(start_dim=1),
+                )
+                .reshape(final_shape)
+                .transpose(0, 1)
+            )
+        try:
+            lora_diff = torch.mm(
+                mat1.flatten(start_dim=1), mat2.flatten(start_dim=1)
+            ).reshape(weight.shape)
+            if dora_scale is not None:
+                weight = weight_decompose(
+                    dora_scale,
+                    weight,
+                    lora_diff,
+                    alpha,
+                    strength,
+                    intermediate_dtype,
+                    function,
+                )
+            else:
+                weight += function(((strength * alpha) * lora_diff).type(weight.dtype))
+        except Exception as e:
+            logging.error("ERROR {} {} {}".format(self.name, key, e))
+        return weight