app/main.py

#!/usr/bin/env python
# coding: utf-8
from os import listdir
from os.path import isdir
from fastapi import FastAPI, HTTPException, Request, responses, Body
from fastapi.middleware.cors import CORSMiddleware
from llama_cpp import Llama

from pydantic import BaseModel
from enum import Enum
from typing import Optional

# MODEL LOADING, FUNCTIONS, AND TESTING

print("Loading model...")
SAllm = Llama(model_path="/models/final-gemma2b_SA-Q8_0.gguf", mmap=False, mlock=True)
FIllm = Llama(model_path="/models/final-gemma7b_FI-Q8_0.gguf", mmap=False, mlock=True)
      # n_gpu_layers=28, # Uncomment to use GPU acceleration
      # seed=1337, # Uncomment to set a specific seed
      # n_ctx=2048, # Uncomment to increase the context window
#)

def extract_restext(response):
  return response['choices'][0]['text'].strip()

def ask_fi(question, max_new_tokens=200, temperature=0.5):
  prompt = f"""###User: {question}\n###Assistant:"""
  result = extract_restext(FIllm(prompt, max_tokens=max_new_tokens, temperature=temperature, stop=["###User:", "###Assistant:"], echo=False))
  return result
    
def check_sentiment(text):
  prompt = f'Analyze the sentiment of the tweet enclosed in square brackets, determine if it is positive or negative, and return the answer as the corresponding sentiment label "positive" or  "negative" [{text}] ='
  response = SAllm(prompt, max_tokens=3, stop=["\n"], echo=False, temperature=0.5)
  # print(response)
  result = extract_restext(response)
  if "positive" in result:
    return "positive"
  elif "negative" in result:
    return "negative"
  else:
    return "unknown"

# TESTING THE MODEL
print("Testing model...")
assert "positive" in check_sentiment("ดอกไม้ร้านนี้สวยจัง")
assert ask_fi("Hello!, How are you today?")
print("Ready.")


# START OF FASTAPI APP
app = FastAPI(
    title = "Gemma Finetuned API",
    description="Gemma Finetuned API for Sentiment Analysis and Finance Questions.",
    version="1.0.0",
)

origins = ["*"]
app.add_middleware(
    CORSMiddleware,
    allow_origins=origins,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"]
)


# API DATA CLASSES
class SA_Result(str, Enum):
  positive = "positive"
  negative = "negative"
  unknown = "unknown"

class SA_Response(BaseModel):
  code: int = 200
  text: Optional[str] = None
  result: SA_Result = None

class FI_Response(BaseModel):
  code: int = 200
  question: Optional[str] = None
  answer: str = None
  config: Optional[dict] = None


# API ROUTES
@app.get('/')
def docs():
  "Redirects the user from the main page to the docs."
  return responses.RedirectResponse('./docs')

@app.post('/classifications/sentiment')
async def perform_sentiment_analysis(prompt: str = Body(..., embed=True, example="I like eating fried chicken")) -> SA_Response:
  """Performs a sentiment analysis using a finetuned version of Gemma-7b"""
  if prompt:
    try:
      print(f"Checking sentiment for {prompt}")
      result = check_sentiment(prompt)
      print(f"Result: {result}")
      return SA_Response(result=result, text=prompt)
    except Exception as e:
      return HTTPException(500, SA_Response(code=500, result=str(e), text=prompt))
  else:
    return HTTPException(400, SA_Response(code=400, result="Request argument 'prompt' not provided."))


@app.post('/questions/finance')
async def ask_gemmaFinanceTH(
    prompt: str = Body(..., embed=True, example="What's the best way to invest my money"),
    temperature: float = Body(0.5, embed=True), 
    max_new_tokens: int = Body(200, embed=True)
) -> FI_Response:
  """
  Ask a finetuned Gemma a finance-related question, just for fun.
  NOTICE: IT MAY PRODUCE RANDOM/INACCURATE ANSWERS. PLEASE SEEK PROFESSIONAL ADVICE BEFORE DOING ANYTHING SERIOUS.
  """
  if prompt:
    try:
      print(f'Asking FI with the question "{prompt}"')
      result = ask_fi(prompt, max_new_tokens=max_new_tokens, temperature=temperature)
      print(f"Result: {result}")
      return FI_Response(answer=result, question=prompt, config={"temperature": temperature, "max_new_tokens": max_new_tokens})
    except Exception as e:
      return HTTPException(500, FI_Response(code=500, answer=str(e), question=prompt))
  else:
    return HTTPException(400, FI_Response(code=400, answer="Request argument 'prompt' not provided."))