[feature]: support flux cache_dit (#1145)

Co-authored-by: Jiangyun Zhu <riverclouds.zhu@qq.com>

docs/user_guide/diffusion_acceleration.md

@@ -50,6 +50,7 @@ The following table shows which models are currently supported by each accelerat
 | **Z-Image** | `Tongyi-MAI/Z-Image-Turbo` | ✅ | ✅ | ❌ | ❌ | ❌ |
 | **Stable-Diffusion3.5** | `stabilityai/stable-diffusion-3.5` | ❌ | ✅ | ❌ | ❌ | ✅ |
 | **Bagel** | `ByteDance-Seed/BAGEL-7B-MoT` | ✅ | ✅ | ❌ | ❌ | ❌ |
+| **FLUX.1-dev** | `black-forest-labs/FLUX.1-dev` | ❌ | ✅ | ❌ | ❌ | ❌ |
 
 ### VideoGen
 

vllm_omni/diffusion/cache/cache_dit_backend.py

@@ -273,19 +273,77 @@ def enable_cache_for_longcat_image(pipeline: Any, cache_config: Any) -> Callable
 
 
 def enable_cache_for_flux(pipeline: Any, cache_config: Any) -> Callable[[int], None]:
-    """Enable cache-dit for Flux dual-transformer architecture.
-
-    Flux uses two transformers (transformer and transformer_2) that need
-    to be enabled together using BlockAdapter.
+    """Enable cache-dit for Flux.1-dev pipeline.
 
     Args:
         pipeline: The Flux pipeline instance.
         cache_config: DiffusionCacheConfig instance with cache configuration.
-
     Returns:
-        A refresh function that can be called to update cache context with new num_inference_steps.
+        A refresh function that can be called with a new ``num_inference_steps``
+        to update the cache context for the pipeline.
     """
-    raise NotImplementedError("cache-dit is not implemented for Flux pipeline.")
+    # Build DBCacheConfig for transformer
+    db_cache_config = _build_db_cache_config(cache_config)
+
+    calibrator = None
+    if cache_config.enable_taylorseer:
+        taylorseer_order = cache_config.taylorseer_order
+        calibrator = TaylorSeerCalibratorConfig(taylorseer_order=taylorseer_order)
+        logger.info(f"TaylorSeer enabled with order={taylorseer_order}")
+
+    # Build ParamsModifier for transformer
+    modifier = ParamsModifier(
+        cache_config=db_cache_config,
+        calibrator_config=calibrator,
+    )
+
+    logger.info(
+        f"Enabling cache-dit on Flux transformer with BlockAdapter: "
+        f"Fn={db_cache_config.Fn_compute_blocks}, "
+        f"Bn={db_cache_config.Bn_compute_blocks}, "
+        f"W={db_cache_config.max_warmup_steps}, "
+    )
+
+    # Enable cache-dit using BlockAdapter for transformer
+    cache_dit.enable_cache(
+        (
+            BlockAdapter(
+                transformer=pipeline.transformer,
+                blocks=[
+                    pipeline.transformer.transformer_blocks,
+                    pipeline.transformer.single_transformer_blocks,
+                ],
+                forward_pattern=[ForwardPattern.Pattern_1, ForwardPattern.Pattern_1],
+                params_modifiers=[modifier],
+            )
+        ),
+        cache_config=db_cache_config,
+    )
+
+    def refresh_cache_context(pipeline: Any, num_inference_steps: int, verbose: bool = True) -> None:
+        """Refresh cache context for the transformer with new num_inference_steps.
+
+        Args:
+            pipeline: The Flux pipeline instance.
+            num_inference_steps: New number of inference steps.
+        """
+        if cache_config.scm_steps_mask_policy is None:
+            cache_dit.refresh_context(pipeline.transformer, num_inference_steps=num_inference_steps, verbose=verbose)
+        else:
+            cache_dit.refresh_context(
+                pipeline.transformer,
+                cache_config=DBCacheConfig().reset(
+                    num_inference_steps=num_inference_steps,
+                    steps_computation_mask=cache_dit.steps_mask(
+                        mask_policy=cache_config.scm_steps_mask_policy,
+                        total_steps=num_inference_steps,
+                    ),
+                    steps_computation_policy=cache_config.scm_steps_policy,
+                ),
+                verbose=verbose,
+            )
+
+    return refresh_cache_context
 
 
 def enable_cache_for_sd3(pipeline: Any, cache_config: Any) -> Callable[[int], None]: