Update app.py

app.py

@@ -1,167 +1,253 @@
 import gradio as gr
 import os
-from huggingface_hub import login
-import torch
-from transformers import AutoTokenizer, AutoModelForCausalLM
-import transformers
+
 from langchain_community.document_loaders import PyPDFLoader
 from langchain.text_splitter import RecursiveCharacterTextSplitter
 from langchain_community.vectorstores import Chroma
 from langchain.chains import ConversationalRetrievalChain
 from langchain_community.embeddings import HuggingFaceEmbeddings 
 from langchain_community.llms import HuggingFacePipeline
+from langchain.chains import ConversationChain
 from langchain.memory import ConversationBufferMemory
+from langchain_community.llms import HuggingFaceEndpoint
 import spaces
 from pathlib import Path
 import chromadb
 from unidecode import unidecode
-import re
 
-# Global variables
-global_llm = None
-global_tokenizer = None
-hf_token = os.environ.get("HUGGINGFACEHUB_API_TOKEN")
+from transformers import AutoTokenizer
+import transformers
+import torch
+import tqdm 
+import accelerate
+import re
 
-if not hf_token:
-    raise ValueError("Hugging Face token not found. Please set the HF_TOKEN environment variable.")
 
-# Log in to Hugging Face
-login(token=hf_token)
 
-list_llm = ["mistralai/Mistral-7B-Instruct-v0.2", "mistralai/Mixtral-8x7B-Instruct-v0.1", "mistralai/Mistral-7B-Instruct-v0.1"]
+# default_persist_directory = './chroma_HF/'
+list_llm = ["mistralai/Mistral-7B-Instruct-v0.2", "mistralai/Mixtral-8x7B-Instruct-v0.1", "mistralai/Mistral-7B-Instruct-v0.1", \
+    "google/gemma-7b-it","google/gemma-2b-it", \
+    "HuggingFaceH4/zephyr-7b-beta", "HuggingFaceH4/zephyr-7b-gemma-v0.1", \
+    "meta-llama/Llama-2-7b-chat-hf", "microsoft/phi-2", \
+    "TinyLlama/TinyLlama-1.1B-Chat-v1.0", "mosaicml/mpt-7b-instruct", "tiiuae/falcon-7b-instruct", \
+    "google/flan-t5-xxl"
+]
 list_llm_simple = [os.path.basename(llm) for llm in list_llm]
 
 @spaces.GPU
+# Load PDF document and create doc splits
 def load_doc(list_file_path, chunk_size, chunk_overlap):
+    # Processing for one document only
+    # loader = PyPDFLoader(file_path)
+    # pages = loader.load()
     loaders = [PyPDFLoader(x) for x in list_file_path]
     pages = []
     for loader in loaders:
         pages.extend(loader.load())
+    # text_splitter = RecursiveCharacterTextSplitter(chunk_size = 600, chunk_overlap = 50)
     text_splitter = RecursiveCharacterTextSplitter(
-        chunk_size=chunk_size, 
-        chunk_overlap=chunk_overlap)
+        chunk_size = chunk_size, 
+        chunk_overlap = chunk_overlap)
     doc_splits = text_splitter.split_documents(pages)
     return doc_splits
 
+
+# Create vector database
 def create_db(splits, collection_name):
-    if torch.cuda.is_available():
-        os.environ["CUDA_VISIBLE_DEVICES"] = "0"
-    
-    embedding = HuggingFaceEmbeddings(
-        model_name="sentence-transformers/all-MiniLM-L6-v2",
-        model_kwargs={"use_auth_token": hf_token}
-    )
+    embedding = HuggingFaceEmbeddings()
     new_client = chromadb.EphemeralClient()
     vectordb = Chroma.from_documents(
         documents=splits,
         embedding=embedding,
         client=new_client,
         collection_name=collection_name,
+        # persist_directory=default_persist_directory
     )
     return vectordb
 
+
+# Load vector database
+def load_db():
+    embedding = HuggingFaceEmbeddings()
+    vectordb = Chroma(
+        # persist_directory=default_persist_directory, 
+        embedding_function=embedding)
+    return vectordb
+
+
+# Initialize langchain LLM chain
+def initialize_llmchain(llm_model, temperature, max_tokens, top_k, vector_db, progress=gr.Progress()):
+    progress(0.1, desc="Initializing HF tokenizer...")
+    # HuggingFacePipeline uses local model
+    # Note: it will download model locally...
+    # tokenizer=AutoTokenizer.from_pretrained(llm_model)
+    # progress(0.5, desc="Initializing HF pipeline...")
+    # pipeline=transformers.pipeline(
+    #     "text-generation",
+    #     model=llm_model,
+    #     tokenizer=tokenizer,
+    #     torch_dtype=torch.bfloat16,
+    #     trust_remote_code=True,
+    #     device_map="auto",
+    #     # max_length=1024,
+    #     max_new_tokens=max_tokens,
+    #     do_sample=True,
+    #     top_k=top_k,
+    #     num_return_sequences=1,
+    #     eos_token_id=tokenizer.eos_token_id
+    #     )
+    # llm = HuggingFacePipeline(pipeline=pipeline, model_kwargs={'temperature': temperature})
+    
+    # HuggingFaceHub uses HF inference endpoints
+    progress(0.5, desc="Initializing HF Hub...")
+    # Use of trust_remote_code as model_kwargs
+    # Warning: langchain issue
+    # URL: https://github.com/langchain-ai/langchain/issues/6080
+    if llm_model == "mistralai/Mixtral-8x7B-Instruct-v0.1":
+        llm = HuggingFaceEndpoint(
+            repo_id=llm_model, 
+            # model_kwargs={"temperature": temperature, "max_new_tokens": max_tokens, "top_k": top_k, "load_in_8bit": True}
+            temperature = temperature,
+            max_new_tokens = max_tokens,
+            top_k = top_k,
+            load_in_8bit = True,
+        )
+    elif llm_model in ["HuggingFaceH4/zephyr-7b-gemma-v0.1","mosaicml/mpt-7b-instruct"]:
+        raise gr.Error("LLM model is too large to be loaded automatically on free inference endpoint")
+        llm = HuggingFaceEndpoint(
+            repo_id=llm_model, 
+            temperature = temperature,
+            max_new_tokens = max_tokens,
+            top_k = top_k,
+        )
+    elif llm_model == "microsoft/phi-2":
+        # raise gr.Error("phi-2 model requires 'trust_remote_code=True', currently not supported by langchain HuggingFaceHub...")
+        llm = HuggingFaceEndpoint(
+            repo_id=llm_model, 
+            # model_kwargs={"temperature": temperature, "max_new_tokens": max_tokens, "top_k": top_k, "trust_remote_code": True, "torch_dtype": "auto"}
+            temperature = temperature,
+            max_new_tokens = max_tokens,
+            top_k = top_k,
+            trust_remote_code = True,
+            torch_dtype = "auto",
+        )
+    elif llm_model == "TinyLlama/TinyLlama-1.1B-Chat-v1.0":
+        llm = HuggingFaceEndpoint(
+            repo_id=llm_model, 
+            # model_kwargs={"temperature": temperature, "max_new_tokens": 250, "top_k": top_k}
+            temperature = temperature,
+            max_new_tokens = 250,
+            top_k = top_k,
+        )
+    elif llm_model == "meta-llama/Llama-2-7b-chat-hf":
+        raise gr.Error("Llama-2-7b-chat-hf model requires a Pro subscription...")
+        llm = HuggingFaceEndpoint(
+            repo_id=llm_model, 
+            # model_kwargs={"temperature": temperature, "max_new_tokens": max_tokens, "top_k": top_k}
+            temperature = temperature,
+            max_new_tokens = max_tokens,
+            top_k = top_k,
+        )
+    else:
+        llm = HuggingFaceEndpoint(
+            repo_id=llm_model, 
+            # model_kwargs={"temperature": temperature, "max_new_tokens": max_tokens, "top_k": top_k, "trust_remote_code": True, "torch_dtype": "auto"}
+            # model_kwargs={"temperature": temperature, "max_new_tokens": max_tokens, "top_k": top_k}
+            temperature = temperature,
+            max_new_tokens = max_tokens,
+            top_k = top_k,
+        )
+    
+    progress(0.75, desc="Defining buffer memory...")
+    memory = ConversationBufferMemory(
+        memory_key="chat_history",
+        output_key='answer',
+        return_messages=True
+    )
+    # retriever=vector_db.as_retriever(search_type="similarity", search_kwargs={'k': 3})
+    retriever=vector_db.as_retriever()
+    progress(0.8, desc="Defining retrieval chain...")
+    qa_chain = ConversationalRetrievalChain.from_llm(
+        llm,
+        retriever=retriever,
+        chain_type="stuff", 
+        memory=memory,
+        # combine_docs_chain_kwargs={"prompt": your_prompt})
+        return_source_documents=True,
+        #return_generated_question=False,
+        verbose=False,
+    )
+    progress(0.9, desc="Done!")
+    return qa_chain
+
+
+# Generate collection name for vector database
+#  - Use filepath as input, ensuring unicode text
 def create_collection_name(filepath):
+    # Extract filename without extension
     collection_name = Path(filepath).stem
-    collection_name = collection_name.replace(" ", "-")
+    # Fix potential issues from naming convention
+    ## Remove space
+    collection_name = collection_name.replace(" ","-") 
+    ## ASCII transliterations of Unicode text
     collection_name = unidecode(collection_name)
+    ## Remove special characters
+    #collection_name = re.findall("[\dA-Za-z]*", collection_name)[0]
     collection_name = re.sub('[^A-Za-z0-9]+', '-', collection_name)
+    ## Limit length to 50 characters
     collection_name = collection_name[:50]
+    ## Minimum length of 3 characters
     if len(collection_name) < 3:
         collection_name = collection_name + 'xyz'
+    ## Enforce start and end as alphanumeric character
     if not collection_name[0].isalnum():
         collection_name = 'A' + collection_name[1:]
     if not collection_name[-1].isalnum():
         collection_name = collection_name[:-1] + 'Z'
+    print('Filepath: ', filepath)
+    print('Collection name: ', collection_name)
     return collection_name
 
-def initialize_global_llm(llm_model, temperature, max_tokens, top_k, progress=gr.Progress()):
-    global global_llm, global_tokenizer
-    
-    if global_llm is None:
-        progress(0.1, desc="Initializing HF tokenizer...")
-        global_tokenizer = AutoTokenizer.from_pretrained(llm_model, use_auth_token=hf_token)
-        
-        progress(0.3, desc="Loading model...")
-        try:
-            model = AutoModelForCausalLM.from_pretrained(
-                llm_model, 
-                use_auth_token=hf_token,
-                torch_dtype=torch.float16, 
-                device_map="auto"
-            )
-        except RuntimeError as e:
-            if "CUDA out of memory" in str(e):
-                raise gr.Error("GPU memory exceeded. Try a smaller model or reduce batch size.")
-            else:
-                raise e
-        
-        progress(0.5, desc="Initializing HF pipeline...")
-        pipeline = transformers.pipeline(
-            "text-generation",
-            model=model,
-            tokenizer=global_tokenizer,
-            torch_dtype=torch.float16,
-            device_map="auto",
-            max_new_tokens=max_tokens,
-            do_sample=True,
-            top_k=top_k,
-            num_return_sequences=1,
-            eos_token_id=global_tokenizer.eos_token_id
-        )
-        global_llm = HuggingFacePipeline(pipeline=pipeline, model_kwargs={'temperature': temperature})
-        
-        progress(0.9, desc="LLM initialization complete!")
-        return "LLM initialized successfully!"
-    else:
-        progress(0.9, desc="Using previously initialized LLM.")
-        return "Using previously initialized LLM."
 
+# Initialize database
 def initialize_database(list_file_obj, chunk_size, chunk_overlap, progress=gr.Progress()):
-    if list_file_obj is None or len(list_file_obj) == 0:
-        return None, None, "Error: No files uploaded. Please upload PDF files first."
-
+    # Create list of documents (when valid)
     list_file_path = [x.name for x in list_file_obj if x is not None]
-    if not list_file_path:
-        return None, None, "Error: No valid files found. Please upload PDF files."
-
+    # Create collection_name for vector database
     progress(0.1, desc="Creating collection name...")
     collection_name = create_collection_name(list_file_path[0])
     progress(0.25, desc="Loading document...")
+    # Load document and create splits
     doc_splits = load_doc(list_file_path, chunk_size, chunk_overlap)
+    # Create or load vector database
     progress(0.5, desc="Generating vector database...")
+    # global vector_db
     vector_db = create_db(doc_splits, collection_name)
     progress(0.9, desc="Done!")
     return vector_db, collection_name, "Complete!"
 
+
 def initialize_LLM(llm_option, llm_temperature, max_tokens, top_k, vector_db, progress=gr.Progress()):
+    # print("llm_option",llm_option)
     llm_name = list_llm[llm_option]
-    global_llm = initialize_global_llm(llm_name, llm_temperature, max_tokens, top_k, progress)
-    
-    memory = ConversationBufferMemory(
-        memory_key="chat_history",
-        output_key='answer',
-        return_messages=True
-    )
-    retriever = vector_db.as_retriever()
-    qa_chain = ConversationalRetrievalChain.from_llm(
-        global_llm,
-        retriever=retriever,
-        chain_type="stuff", 
-        memory=memory,
-        return_source_documents=True,
-        verbose=False,
-    )
+    print("llm_name: ",llm_name)
+    qa_chain = initialize_llmchain(llm_name, llm_temperature, max_tokens, top_k, vector_db, progress)
     return qa_chain, "Complete!"
 
+
 def format_chat_history(message, chat_history):
     formatted_chat_history = []
     for user_message, bot_message in chat_history:
         formatted_chat_history.append(f"User: {user_message}")
         formatted_chat_history.append(f"Assistant: {bot_message}")
     return formatted_chat_history
+    
 
 def conversation(qa_chain, message, history):
     formatted_chat_history = format_chat_history(message, history)
+    #print("formatted_chat_history",formatted_chat_history)
+   
+    # Generate response using QA chain
     response = qa_chain({"question": message, "chat_history": formatted_chat_history})
     response_answer = response["answer"]
     if response_answer.find("Helpful Answer:") != -1:
@@ -170,12 +256,28 @@ def conversation(qa_chain, message, history):
     response_source1 = response_sources[0].page_content.strip()
     response_source2 = response_sources[1].page_content.strip()
     response_source3 = response_sources[2].page_content.strip()
+    # Langchain sources are zero-based
     response_source1_page = response_sources[0].metadata["page"] + 1
     response_source2_page = response_sources[1].metadata["page"] + 1
     response_source3_page = response_sources[2].metadata["page"] + 1
+    # print ('chat response: ', response_answer)
+    # print('DB source', response_sources)
     
+    # Append user message and response to chat history
     new_history = history + [(message, response_answer)]
+    # return gr.update(value=""), new_history, response_sources[0], response_sources[1] 
     return qa_chain, gr.update(value=""), new_history, response_source1, response_source1_page, response_source2, response_source2_page, response_source3, response_source3_page
+    
+
+def upload_file(file_obj):
+    list_file_path = []
+    for idx, file in enumerate(file_obj):
+        file_path = file_obj.name
+        list_file_path.append(file_path)
+    # print(file_path)
+    # initialize_database(file_path, progress)
+    return list_file_path
+
 
 def demo():
     with gr.Blocks(theme="base") as demo:
@@ -184,38 +286,50 @@ def demo():
         collection_name = gr.State()
         
         gr.Markdown(
-        """<center><h2>GPU-Accelerated PDF-based Chatbot</center></h2>
+        """<center><h2>PDF-based chatbot</center></h2>
         <h3>Ask any questions about your PDF documents</h3>""")
         gr.Markdown(
-        """<b>Note:</b> This AI assistant uses GPU acceleration for faster processing. 
-        It performs retrieval-augmented generation (RAG) from your PDF documents using Langchain and open-source LLMs. 
-        This chatbot takes past questions into account and includes document references.""")
+        """<b>Note:</b> This AI assistant, using Langchain and open-source LLMs, performs retrieval-augmented generation (RAG) from your PDF documents. \
+        The user interface explicitely shows multiple steps to help understand the RAG workflow. 
+        This chatbot takes past questions into account when generating answers (via conversational memory), and includes document references for clarity purposes.<br>
+        <br><b>Warning:</b> This space uses the free CPU Basic hardware from Hugging Face. Some steps and LLM models used below (free inference endpoints) can take some time to generate a reply.
+        """)
         
-        with gr.Tab("Step 1 - Initialize LLM"):
-            llm_btn = gr.Radio(list_llm_simple, label="LLM models", value=list_llm_simple[0], type="index", info="Choose your LLM model")
-            with gr.Accordion("Advanced options - LLM model", open=False):
-                slider_temperature = gr.Slider(minimum=0.01, maximum=1.0, value=0.7, step=0.1, label="Temperature", info="Model temperature", interactive=True)
-                slider_maxtokens = gr.Slider(minimum=224, maximum=4096, value=1024, step=32, label="Max Tokens", info="Model max tokens", interactive=True)
-                slider_topk = gr.Slider(minimum=1, maximum=10, value=3, step=1, label="top-k samples", info="Model top-k samples", interactive=True)
-            llm_progress = gr.Textbox(value="Not initialized", label="LLM initialization status")
-            init_llm_btn = gr.Button("Initialize LLM")
-
-        with gr.Tab("Step 2 - Upload PDF"):
-            document = gr.Files(height=100, file_count="multiple", file_types=["pdf"], interactive=True, label="Upload your PDF documents (single or multiple)")
+        with gr.Tab("Step 1 - Upload PDF"):
+            with gr.Row():
+                document = gr.Files(height=100, file_count="multiple", file_types=["pdf"], interactive=True, label="Upload your PDF documents (single or multiple)")
+                # upload_btn = gr.UploadButton("Loading document...", height=100, file_count="multiple", file_types=["pdf"], scale=1)
         
-        with gr.Tab("Step 3 - Process document"):
-            db_btn = gr.Radio(["ChromaDB"], label="Vector database type", value = "ChromaDB", type="index", info="Choose your vector database")
+        with gr.Tab("Step 2 - Process document"):
+            with gr.Row():
+                db_btn = gr.Radio(["ChromaDB"], label="Vector database type", value = "ChromaDB", type="index", info="Choose your vector database")
             with gr.Accordion("Advanced options - Document text splitter", open=False):
-                slider_chunk_size = gr.Slider(minimum = 100, maximum = 1000, value=600, step=20, label="Chunk size", info="Chunk size", interactive=True)
-                slider_chunk_overlap = gr.Slider(minimum = 10, maximum = 200, value=40, step=10, label="Chunk overlap", info="Chunk overlap", interactive=True)
-            db_progress = gr.Textbox(label="Vector database initialization", value="None")
-            db_btn = gr.Button("Generate vector database")
+                with gr.Row():
+                    slider_chunk_size = gr.Slider(minimum = 100, maximum = 1000, value=600, step=20, label="Chunk size", info="Chunk size", interactive=True)
+                with gr.Row():
+                    slider_chunk_overlap = gr.Slider(minimum = 10, maximum = 200, value=40, step=10, label="Chunk overlap", info="Chunk overlap", interactive=True)
+            with gr.Row():
+                db_progress = gr.Textbox(label="Vector database initialization", value="None")
+            with gr.Row():
+                db_btn = gr.Button("Generate vector database")
             
-        with gr.Tab("Step 4 - Initialize QA chain"):
-            llm_progress = gr.Textbox(value="None",label="QA chain initialization")
-            qachain_btn = gr.Button("Initialize Question Answering chain")
+        with gr.Tab("Step 3 - Initialize QA chain"):
+            with gr.Row():
+                llm_btn = gr.Radio(list_llm_simple, \
+                    label="LLM models", value = list_llm_simple[0], type="index", info="Choose your LLM model")
+            with gr.Accordion("Advanced options - LLM model", open=False):
+                with gr.Row():
+                    slider_temperature = gr.Slider(minimum = 0.01, maximum = 1.0, value=0.7, step=0.1, label="Temperature", info="Model temperature", interactive=True)
+                with gr.Row():
+                    slider_maxtokens = gr.Slider(minimum = 224, maximum = 4096, value=1024, step=32, label="Max Tokens", info="Model max tokens", interactive=True)
+                with gr.Row():
+                    slider_topk = gr.Slider(minimum = 1, maximum = 10, value=3, step=1, label="top-k samples", info="Model top-k samples", interactive=True)
+            with gr.Row():
+                llm_progress = gr.Textbox(value="None",label="QA chain initialization")
+            with gr.Row():
+                qachain_btn = gr.Button("Initialize Question Answering chain")
 
-        with gr.Tab("Step 5 - Chatbot"):
+        with gr.Tab("Step 4 - Chatbot"):
             chatbot = gr.Chatbot(height=300)
             with gr.Accordion("Advanced - Document references", open=False):
                 with gr.Row():
@@ -233,39 +347,33 @@ def demo():
                 submit_btn = gr.Button("Submit message")
                 clear_btn = gr.ClearButton([msg, chatbot], value="Clear conversation")
             
-        # Event handlers
-        init_llm_btn.click(
-            initialize_global_llm,
-            inputs=[llm_btn, slider_temperature, slider_maxtokens, slider_topk],
-            outputs=[llm_progress]
-        )
-        
-        db_btn.click(initialize_database, 
-            inputs=[document, slider_chunk_size, slider_chunk_overlap], 
+        # Preprocessing events
+        #upload_btn.upload(upload_file, inputs=[upload_btn], outputs=[document])
+        db_btn.click(initialize_database, \
+            inputs=[document, slider_chunk_size, slider_chunk_overlap], \
             outputs=[vector_db, collection_name, db_progress])
-        
-        qachain_btn.click(initialize_LLM, 
-            inputs=[llm_btn, slider_temperature, slider_maxtokens, slider_topk, vector_db], 
-            outputs=[qa_chain, llm_progress]).then(lambda:[None,"",0,"",0,"",0], 
-            inputs=None, 
-            outputs=[chatbot, doc_source1, source1_page, doc_source2, source2_page, doc_source3, source3_page], 
+        qachain_btn.click(initialize_LLM, \
+            inputs=[llm_btn, slider_temperature, slider_maxtokens, slider_topk, vector_db], \
+            outputs=[qa_chain, llm_progress]).then(lambda:[None,"",0,"",0,"",0], \
+            inputs=None, \
+            outputs=[chatbot, doc_source1, source1_page, doc_source2, source2_page, doc_source3, source3_page], \
             queue=False)
 
         # Chatbot events
-        msg.submit(conversation, 
-            inputs=[qa_chain, msg, chatbot], 
-            outputs=[qa_chain, msg, chatbot, doc_source1, source1_page, doc_source2, source2_page, doc_source3, source3_page], 
+        msg.submit(conversation, \
+            inputs=[qa_chain, msg, chatbot], \
+            outputs=[qa_chain, msg, chatbot, doc_source1, source1_page, doc_source2, source2_page, doc_source3, source3_page], \
             queue=False)
-        submit_btn.click(conversation, 
-            inputs=[qa_chain, msg, chatbot], 
-            outputs=[qa_chain, msg, chatbot, doc_source1, source1_page, doc_source2, source2_page, doc_source3, source3_page], 
+        submit_btn.click(conversation, \
+            inputs=[qa_chain, msg, chatbot], \
+            outputs=[qa_chain, msg, chatbot, doc_source1, source1_page, doc_source2, source2_page, doc_source3, source3_page], \
             queue=False)
-        clear_btn.click(lambda:[None,"",0,"",0,"",0], 
-            inputs=None, 
-            outputs=[chatbot, doc_source1, source1_page, doc_source2, source2_page, doc_source3, source3_page], 
+        clear_btn.click(lambda:[None,"",0,"",0,"",0], \
+            inputs=None, \
+            outputs=[chatbot, doc_source1, source1_page, doc_source2, source2_page, doc_source3, source3_page], \
             queue=False)
-
     demo.queue().launch(debug=True)
 
+
 if __name__ == "__main__":
-    demo()
+    demo()