Clean up and refactor sampler code.

This should make it much easier to write custom nodes with kdiffusion type
samplers.

comfy/samplers.py

@@ -522,13 +522,17 @@ KSAMPLER_NAMES = ["euler", "euler_ancestral", "heun", "dpm_2", "dpm_2_ancestral"
                   "lms", "dpm_fast", "dpm_adaptive", "dpmpp_2s_ancestral", "dpmpp_sde", "dpmpp_sde_gpu",
                   "dpmpp_2m", "dpmpp_2m_sde", "dpmpp_2m_sde_gpu", "dpmpp_3m_sde", "dpmpp_3m_sde_gpu", "ddpm", "lcm"]
 
-def ksampler(sampler_name, extra_options={}, inpaint_options={}):
-    class KSAMPLER(Sampler):
+class KSAMPLER(Sampler):
+    def __init__(self, sampler_function, extra_options={}, inpaint_options={}):
+        self.sampler_function = sampler_function
+        self.extra_options = extra_options
+        self.inpaint_options = inpaint_options
+
     def sample(self, model_wrap, sigmas, extra_args, callback, noise, latent_image=None, denoise_mask=None, disable_pbar=False):
         extra_args["denoise_mask"] = denoise_mask
         model_k = KSamplerX0Inpaint(model_wrap)
         model_k.latent_image = latent_image
-            if inpaint_options.get("random", False): #TODO: Should this be the default?
+        if self.inpaint_options.get("random", False): #TODO: Should this be the default?
             generator = torch.manual_seed(extra_args.get("seed", 41) + 1)
             model_k.noise = torch.randn(noise.shape, generator=generator, device="cpu").to(noise.dtype).to(noise.device)
         else:
@@ -544,20 +548,33 @@ def ksampler(sampler_name, extra_options={}, inpaint_options={}):
         if callback is not None:
             k_callback = lambda x: callback(x["i"], x["denoised"], x["x"], total_steps)
 
-            sigma_min = sigmas[-1]
-            if sigma_min == 0:
-                sigma_min = sigmas[-2]
-
         if latent_image is not None:
             noise += latent_image
+
+        samples = self.sampler_function(model_k, noise, sigmas, extra_args=extra_args, callback=k_callback, disable=disable_pbar, **self.extra_options)
+        return samples
+
+
+def ksampler(sampler_name, extra_options={}, inpaint_options={}):
     if sampler_name == "dpm_fast":
-                samples = k_diffusion_sampling.sample_dpm_fast(model_k, noise, sigma_min, sigmas[0], total_steps, extra_args=extra_args, callback=k_callback, disable=disable_pbar)
+        def dpm_fast_function(model, noise, sigmas, extra_args, callback, disable):
+            sigma_min = sigmas[-1]
+            if sigma_min == 0:
+                sigma_min = sigmas[-2]
+            total_steps = len(sigmas) - 1
+            return k_diffusion_sampling.sample_dpm_fast(model, noise, sigma_min, sigmas[0], total_steps, extra_args=extra_args, callback=callback, disable=disable)
+        sampler_function = dpm_fast_function
     elif sampler_name == "dpm_adaptive":
-                samples = k_diffusion_sampling.sample_dpm_adaptive(model_k, noise, sigma_min, sigmas[0], extra_args=extra_args, callback=k_callback, disable=disable_pbar)
+        def dpm_adaptive_function(model, noise, sigmas, extra_args, callback, disable):
+            sigma_min = sigmas[-1]
+            if sigma_min == 0:
+                sigma_min = sigmas[-2]
+            return k_diffusion_sampling.sample_dpm_adaptive(model, noise, sigma_min, sigmas[0], extra_args=extra_args, callback=callback, disable=disable)
+        sampler_function = dpm_adaptive_function
     else:
-                samples = getattr(k_diffusion_sampling, "sample_{}".format(sampler_name))(model_k, noise, sigmas, extra_args=extra_args, callback=k_callback, disable=disable_pbar, **extra_options)
-            return samples
-    return KSAMPLER
+        sampler_function = getattr(k_diffusion_sampling, "sample_{}".format(sampler_name))
+
+    return KSAMPLER(sampler_function, extra_options, inpaint_options)
 
 def wrap_model(model):
     model_denoise = CFGNoisePredictor(model)
@@ -618,11 +635,11 @@ def calculate_sigmas_scheduler(model, scheduler_name, steps):
         print("error invalid scheduler", self.scheduler)
     return sigmas
 
-def sampler_class(name):
+def sampler_object(name):
     if name == "uni_pc":
-        sampler = UNIPC
+        sampler = UNIPC()
     elif name == "uni_pc_bh2":
-        sampler = UNIPCBH2
+        sampler = UNIPCBH2()
     elif name == "ddim":
         sampler = ksampler("euler", inpaint_options={"random": True})
     else:
@@ -687,6 +704,6 @@ class KSampler:
                 else:
                     return torch.zeros_like(noise)
 
-        sampler = sampler_class(self.sampler)
+        sampler = sampler_object(self.sampler)
 
-        return sample(self.model, noise, positive, negative, cfg, self.device, sampler(), sigmas, self.model_options, latent_image=latent_image, denoise_mask=denoise_mask, callback=callback, disable_pbar=disable_pbar, seed=seed)
+        return sample(self.model, noise, positive, negative, cfg, self.device, sampler, sigmas, self.model_options, latent_image=latent_image, denoise_mask=denoise_mask, callback=callback, disable_pbar=disable_pbar, seed=seed)

comfy_extras/nodes_custom_sampler.py

@@ -149,7 +149,7 @@ class KSamplerSelect:
     FUNCTION = "get_sampler"
 
     def get_sampler(self, sampler_name):
-        sampler = comfy.samplers.sampler_class(sampler_name)()
+        sampler = comfy.samplers.sampler_object(sampler_name)
         return (sampler, )
 
 class SamplerDPMPP_2M_SDE:
@@ -172,7 +172,7 @@ class SamplerDPMPP_2M_SDE:
             sampler_name = "dpmpp_2m_sde"
         else:
             sampler_name = "dpmpp_2m_sde_gpu"
-        sampler = comfy.samplers.ksampler(sampler_name, {"eta": eta, "s_noise": s_noise, "solver_type": solver_type})()
+        sampler = comfy.samplers.ksampler(sampler_name, {"eta": eta, "s_noise": s_noise, "solver_type": solver_type})
         return (sampler, )
 
 
@@ -196,7 +196,7 @@ class SamplerDPMPP_SDE:
             sampler_name = "dpmpp_sde"
         else:
             sampler_name = "dpmpp_sde_gpu"
-        sampler = comfy.samplers.ksampler(sampler_name, {"eta": eta, "s_noise": s_noise, "r": r})()
+        sampler = comfy.samplers.ksampler(sampler_name, {"eta": eta, "s_noise": s_noise, "r": r})
         return (sampler, )
 
 class SamplerCustom: