vector_store_retriever.py

import json
import os
import gradio as gr
import time
import langchain

from pydantic import BaseModel, Field
from typing import Any, Optional, Dict, List, Union
from huggingface_hub import InferenceClient
from langchain.llms.base import LLM
#from langchain.Images import Images

from langchain.llms.base import LLM
#from langchain_core.embeddings import EmbeddingFunction, Embeddings

from langchain.embeddings import HuggingFaceInstructEmbeddings
#from langchain import [all]
#from langchain.Documents import Documents
from langchain.vectorstores import Chroma
from dotenv import load_dotenv
from transformers import AutoTokenizer, AutoModel, Tool

load_dotenv()

path_work = "."
hf_token = os.getenv("HF")

class HuggingFaceInstructEmbeddings(HuggingFaceInstructEmbeddings):
    def __init__(self, model_name: str, model_kwargs: Optional[Dict[str, Any]] = None):
        self.model = AutoModel.from_pretrained(model_name, **(model_kwargs or {}))
        self.tokenizer = AutoTokenizer.from_pretrained(model_name)

    def __call__(self, input: Union[Documents]) -> HuggingFaceInstructEmbeddings:
        if isinstance(input, Documents):
            texts = [doc.text for doc in input]
            embeddings = self._embed_text(texts)
        else:
            # Handle image embeddings if needed
            pass

        return embeddings

    def _embed_text(self, texts: List[str]) -> Embeddings:
        # Your existing logic for text embeddings using Hugging Face models...
        inputs = self.tokenizer(texts, return_tensors="pt", padding=True, truncation=True)
        with torch.no_grad():
            outputs = self.model(**inputs)
        embeddings = outputs.last_hidden_state.mean(dim=1)  # Adjust this based on your specific model

        return embeddings


vectordb = Chroma(
    persist_directory=path_work + '/new_papers',
    embedding_function=HuggingFaceInstructEmbeddings(model_name="sentence-transformers/all-MiniLM-L6-v2", model_kwargs={"device": "cpu"})
)

retriever = vectordb.as_retriever(search_kwargs={"k": 2})#5


class KwArgsModel(BaseModel):
    kwargs: Dict[str, Any] = Field(default_factory=dict)

class CustomInferenceClient(LLM, KwArgsModel):
    model_name: str
    inference_client: InferenceClient

    def __init__(self, model_name: str, hf_token: str, kwargs: Optional[Dict[str, Any]] = None):
        inference_client = InferenceClient(model=model_name, token=hf_token)
        super().__init__(
            model_name=model_name,
            hf_token=hf_token,
            kwargs=kwargs,
            inference_client=inference_client
        )

    def _call(
        self,
        prompt: str,
        stop: Optional[List[str]] = None
    ) -> str:
        if stop is not None:
            raise ValueError("stop kwargs are not permitted.")
        response_gen = self.inference_client.text_generation(prompt, **self.kwargs, stream=True)
        response = ''.join(response_gen)
        return response

    @property
    def _llm_type(self) -> str:
        return "custom"

    @property
    def _identifying_params(self) -> dict:
        return {"model_name": self.model_name}

kwargs = {"max_new_tokens": 256, "temperature": 0.9, "top_p": 0.6, "repetition_penalty": 1.3, "do_sample": True}

model_list = [
    "meta-llama/Llama-2-13b-chat-hf",
    "HuggingFaceH4/zephyr-7b-alpha",
    "meta-llama/Llama-2-70b-chat-hf",
    "tiiuae/falcon-180B-chat"
]

qa_chain = None

def load_model(model_selected):
    global qa_chain
    model_name = model_selected
    llm = CustomInferenceClient(model_name=model_name, hf_token=hf_token, kwargs=kwargs)

    from langchain.chains import RetrievalQA
    qa_chain = RetrievalQA.from_chain_type(
        llm=llm,
        chain_type="stuff",
        retriever=retriever,
        return_source_documents=True,
        verbose=True,
    )
    return qa_chain

load_model("meta-llama/Llama-2-70b-chat-hf")

##########
#####
#########


###
###
###

def predict(message, temperature=0.9, max_new_tokens=512, top_p=0.6, repetition_penalty=1.3):
    temperature = float(temperature)
    if temperature < 1e-2: temperature = 1e-2
    top_p = float(top_p)

    llm_response = qa_chain(message)
    res_result = llm_response['result']

    res_relevant_doc = [source.metadata['source'] for source in llm_response["source_documents"]]
    response = f"{res_result}" + "\n\n" + "[Answer Source Documents (Ctrl + Click!)] :" + "\n" + f" \n {res_relevant_doc}"
    print("response: =====> \n", response, "\n\n")
    tokens = response.split('\n')
    token_list = []
    for idx, token in enumerate(tokens):
        token_dict = {"id": idx + 1, "text": token}
        token_list.append(token_dict)
    response = {"data": {"token": token_list}}
    response = json.dumps(response, indent=4)

    response = json.loads(response)
    data_dict = response.get('data', {})
    token_list = data_dict.get('token', [])

    partial_message = ""
    for token_entry in token_list:
        if token_entry:
            try:
                # Handle missing 'id' key gracefully
                token_id = token_entry.get('id', None)
                token_text = token_entry.get('text', None)

                if token_text:
                    for char in token_text:
                        partial_message += char
                        yield partial_message
                        time.sleep(0.01)
                else:
                    print(f"Warning ==> The key 'text' does not exist or is None in this token entry: {token_entry}")
                    pass

            except KeyError as e:
                print(f"KeyError: {e} occurred for token entry: {token_entry}")
                continue


class TextGeneratorTool(Tool):
    name = "vector_retriever"
    description = "This tool searches in a vector store based on a given prompt."
    inputs = ["prompt"]
    outputs = ["text"]


    def __init__(self):
        #self.retriever = db.as_retriever(search_kwargs={"k": 1})
        pass  # You might want to add some initialization logic here
		
    def __call__(self, prompt: str):
        result = predict(prompt,  0.9, 512, 0.6, 1.4)
        return result