Add basic Gemma llm inference node for testing

nodes.py

@@ -13,7 +13,7 @@ sys.path.append(script_directory)
 
 import lumina_models
 from transport import ODE
-from transformers import AutoModel, AutoTokenizer
+from transformers import AutoModel, AutoTokenizer, GemmaForCausalLM
 
 from contextlib import nullcontext
 try:
@@ -101,6 +101,13 @@ class DownloadAndLoadGemmaModel:
                     "default": 'bf16'
                     }),
             },
+        "optional": {
+            "mode": ([ 'text_encode','LLM'],
+                    {
+                    "default": 'text_encode'
+                    }),
+            }
+
         }
 
     RETURN_TYPES = ("GEMMAODEL",)
@@ -108,7 +115,7 @@ class DownloadAndLoadGemmaModel:
     FUNCTION = "loadmodel"
     CATEGORY = "LuminaWrapper"
 
-    def loadmodel(self, precision):
+    def loadmodel(self, precision, mode='text_encode'):
         device = mm.get_torch_device()
         dtype = {"bf16": torch.bfloat16, "fp16": torch.float16, "fp32": torch.float32}[precision]
 
@@ -127,16 +134,25 @@ class DownloadAndLoadGemmaModel:
 
         attn_implementation = "flash_attention_2" if FLASH_ATTN_AVAILABLE and precision != "fp32" else "sdpa"
         print(f"Gemma attention mode: {attn_implementation}")
-        text_encoder = AutoModel.from_pretrained(
-            gemma_path, 
-            torch_dtype=dtype, 
-            device_map=device, 
-            attn_implementation=attn_implementation,
-            ).eval()
+        if mode == 'text_encode':
+            text_encoder = AutoModel.from_pretrained(
+                gemma_path, 
+                torch_dtype=dtype, 
+                device_map=device, 
+                attn_implementation=attn_implementation,
+                ).eval()
+        elif mode == 'LLM':
+            text_encoder = GemmaForCausalLM.from_pretrained(
+                gemma_path,
+                torch_dtype=dtype, 
+                device_map=device,
+                attn_implementation=attn_implementation
+                ).eval()
 
         gemma_model = {
             'tokenizer': tokenizer,
-            'text_encoder': text_encoder
+            'text_encoder': text_encoder,
+
         }
 
         return (gemma_model,)
@@ -300,6 +316,54 @@ class LuminaGemmaTextEncodeArea:
         }
         
         return (lumina_embeds,)
+    
+class GemmaSampler:
+    @classmethod
+    def INPUT_TYPES(s):
+        return {
+            "required": {
+                "gemma_model": ("GEMMAODEL", ),
+                "prompt": ("STRING", {"multiline": True, "default": "",}),
+                "max_length": ("INT", {"default": 128, "min": 1, "max": 512, "step": 1}),
+            },
+            "optional": {
+                "keep_model_loaded": ("BOOLEAN", {"default": False}),
+            }
+        }
+    
+    RETURN_TYPES = ("STRING",)
+    RETURN_NAMES =("string",)
+    FUNCTION = "process"
+    CATEGORY = "LuminaWrapper"
+
+    def process(self, gemma_model, prompt, max_length, keep_model_loaded=False):
+        device = mm.get_torch_device()
+        offload_device = mm.unet_offload_device()
+
+        tokenizer = gemma_model['tokenizer']
+        model = gemma_model['text_encoder']
+        model.to(device)
+
+        text_inputs = tokenizer(
+            prompt,
+            return_tensors="pt",
+        )
+
+        text_input_ids = text_inputs.input_ids.to(device)
+
+        result = model.generate(
+            text_input_ids,
+            max_length=max_length,
+        )
+        decoded = tokenizer.batch_decode(result, skip_special_tokens=True, clean_up_tokenization_spaces=False)[0]
+
+        print(decoded)
+
+        if not keep_model_loaded:
+            print("Offloading text encoder...")
+            model.to(offload_device)
+        
+        return (decoded,)
 
 class LuminaT2ISampler:
     @classmethod
@@ -427,7 +491,8 @@ NODE_CLASS_MAPPINGS = {
     "DownloadAndLoadGemmaModel": DownloadAndLoadGemmaModel,
     "LuminaGemmaTextEncode": LuminaGemmaTextEncode,
     "LuminaGemmaTextEncodeArea": LuminaGemmaTextEncodeArea,
-    "LuminaTextAreaAppend": LuminaTextAreaAppend
+    "LuminaTextAreaAppend": LuminaTextAreaAppend,
+    "GemmaSampler": GemmaSampler
 }
 NODE_DISPLAY_NAME_MAPPINGS = {
     "LuminaT2ISampler": "Lumina T2I Sampler",
@@ -435,5 +500,6 @@ NODE_DISPLAY_NAME_MAPPINGS = {
     "DownloadAndLoadGemmaModel": "DownloadAndLoadGemmaModel",
     "LuminaGemmaTextEncode": "Lumina Gemma Text Encode",
     "LuminaGemmaTextEncodeArea": "Lumina Gemma Text Encode Area",
-    "LuminaTextAreaAppend": "Lumina Text Area Append"
+    "LuminaTextAreaAppend": "Lumina Text Area Append",
+    "GemmaSampler": "Gemma Sampler"
 }