Create model.py

model.py

@@ -0,0 +1,81 @@
+from threading import Thread
+from typing import Iterator
+
+#import torch
+from transformers.utils import logging
+from ctransformers import AutoModelForCausalLM, AutoTokenizer
+from transformers import TextIteratorStreamer
+
+logging.set_verbosity_info()
+logger = logging.get_logger("transformers")
+
+config = {'max_new_tokens': 256, 'repetition_penalty': 1.1, 
+          'temperature': 0.1, 'stream': True}
+model_id = 'TheBloke/Llama-2-7B-Chat-GGML'
+device = "cpu"
+
+
+model = AutoModelForCausalLM.from_pretrained(model_id, model_type="llama", lib='avx2', hf=True)
+tokenizer = AutoTokenizer.from_pretrained(model)
+
+def get_prompt(message: str, chat_history: list[tuple[str, str]],
+               system_prompt: str) -> str:
+    logger.info("get_prompt chat_history=%s",chat_history)
+    logger.info("get_prompt system_prompt=%s",system_prompt)
+    texts = [f'<s>[INST] <<SYS>>\n{system_prompt}\n<</SYS>>\n\n']
+    logger.info("texts=%s",texts)
+    # The first user input is _not_ stripped
+    do_strip = False
+    for user_input, response in chat_history:
+        user_input = user_input.strip() if do_strip else user_input
+        do_strip = True
+        texts.append(f'{user_input} [/INST] {response.strip()} </s><s>[INST] ')
+    message = message.strip() if do_strip else message
+    logger.info("get_prompt message=%s",message)
+    texts.append(f'{message} [/INST]')
+    logger.info("get_prompt final texts=%s",texts)
+    return ''.join(texts)
+
+
+def get_input_token_length(message: str, chat_history: list[tuple[str, str]], system_prompt: str) -> int:
+    logger.info("get_input_token_length=%s",message)
+    prompt = get_prompt(message, chat_history, system_prompt)
+    logger.info("prompt=%s",prompt)
+    input_ids = tokenizer([prompt], return_tensors='np', add_special_tokens=False)['input_ids']
+    logger.info("input_ids=%s",input_ids)
+    return input_ids.shape[-1]
+
+
+def run(message: str,
+        chat_history: list[tuple[str, str]],
+        system_prompt: str,
+        max_new_tokens: int = 1024,
+        temperature: float = 0.8,
+        top_p: float = 0.95,
+        top_k: int = 50) -> Iterator[str]:
+    prompt = get_prompt(message, chat_history, system_prompt)
+    inputs = tokenizer([prompt], return_tensors='pt', add_special_tokens=False).to(device)
+
+    streamer = TextIteratorStreamer(tokenizer,
+                                    timeout=10.,
+                                    skip_prompt=True,
+                                    skip_special_tokens=True)
+    generate_kwargs = dict(
+        inputs,
+        streamer=streamer,
+        max_new_tokens=max_new_tokens,
+        do_sample=True,
+        top_p=top_p,
+        top_k=top_k,
+        temperature=temperature,
+        num_beams=1,
+        bits=4,
+        groupsize=128,
+    )
+    t = Thread(target=model.generate, kwargs=generate_kwargs)
+    t.start()
+
+    outputs = []
+    for text in streamer:
+        outputs.append(text)
+        yield ''.join(outputs)