app.py

from fastapi import FastAPI, UploadFile, File
from fastapi.responses import FileResponse
from datasets import load_dataset
from fastapi.middleware.cors import CORSMiddleware
# Loading
import os
import shutil
from os import makedirs,getcwd
from os.path import join,exists,dirname
import torch
import json

app = FastAPI()

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

NUM_PROC = os.cpu_count()
parent_path  = dirname(getcwd())

temp_path  = join(parent_path,'temp')
if not exists(temp_path ):
    makedirs(temp_path )

# Determine device based on GPU availability
device = "cuda" if torch.cuda.is_available() else "cpu"
print(f"Using device: {device}")

import logging

logging.basicConfig(format="%(levelname)s - %(name)s -  %(message)s", level=logging.WARNING)
logging.getLogger("haystack").setLevel(logging.INFO)

@app.post("/uploadfile/")
async def create_upload_file(text_field: str, file: UploadFile = File(...)):
    # Imports
    import time
    from haystack import Document, Pipeline
    from haystack.components.writers import DocumentWriter
    from haystack_integrations.components.retrievers.qdrant import QdrantHybridRetriever
    from haystack_integrations.document_stores.qdrant import QdrantDocumentStore
    from haystack.document_stores.types import DuplicatePolicy
    from haystack_integrations.components.embedders.fastembed import (
     FastembedTextEmbedder,
     FastembedDocumentEmbedder,
     FastembedSparseTextEmbedder,
     FastembedSparseDocumentEmbedder
    )
    
    start_time = time.time()
    
    file_savePath =  join(temp_path,file.filename)

    with open(file_savePath,'wb') as f:
        shutil.copyfileobj(file.file, f)
    
    documents=[]
    
    # Here you can save the file and do other operations as needed
    if '.json' in file_savePath:
        with open(file_savePath) as fd:
            for line in fd:
                obj = json.loads(line)
                document = Document(content=obj[text_field], meta=obj) 
                documents.append(document)
    
    else:
        raise NotImplementedError("This feature is not supported yet")

    # Indexing
    
    document_store = QdrantDocumentStore(
        path="database",
        recreate_index=True,
        use_sparse_embeddings=True,
        embedding_dim = 384
    )
    
    indexing = Pipeline()
    indexing.add_component("sparse_doc_embedder", FastembedSparseDocumentEmbedder(model="prithvida/Splade_PP_en_v1"))
    indexing.add_component("dense_doc_embedder", FastembedDocumentEmbedder(model="BAAI/bge-small-en-v1.5"))
    indexing.add_component("writer", DocumentWriter(document_store=document_store, policy=DuplicatePolicy.OVERWRITE))
    indexing.connect("sparse_doc_embedder", "dense_doc_embedder")
    indexing.connect("dense_doc_embedder", "writer")
    
    indexing.run({"sparse_doc_embedder": {"documents": documents}})
    end_time = time.time()

    elapsed_time = end_time - start_time
    
    return {"filename": file.filename, "message": "Done", "execution_time": elapsed_time}

    
@app.get("/search")
def search(prompt: str):
    import time
    from haystack import Document, Pipeline
    from haystack_integrations.components.retrievers.qdrant import QdrantHybridRetriever
    from haystack_integrations.components.embedders.fastembed import (
     FastembedTextEmbedder,
     FastembedSparseTextEmbedder
    )
    start_time = time.time()
    
    # Querying

    querying = Pipeline()
    querying.add_component("sparse_text_embedder", FastembedSparseTextEmbedder(model="prithvida/Splade_PP_en_v1"))
    querying.add_component("dense_text_embedder", FastembedTextEmbedder(
     model="BAAI/bge-small-en-v1.5", prefix="Represent this sentence for searching relevant passages: ")
     )
    querying.add_component("retriever", QdrantHybridRetriever(document_store=document_store))
    
    querying.connect("sparse_text_embedder.sparse_embedding", "retriever.query_sparse_embedding")
    querying.connect("dense_text_embedder.embedding", "retriever.query_embedding")
    
    question = "Cosa sono i marker tumorali?"
    
    results = querying.run(
        {"dense_text_embedder": {"text": question},
         "sparse_text_embedder": {"text": question}}
    )


    end_time = time.time()

    elapsed_time = end_time - start_time

    print(f"Execution time: {elapsed_time:.6f} seconds")
    
    return results["retriever"]["documents"]

@app.get("/download-database/")
async def download_database():
    import time

    start_time = time.time()
    
    # Path to the database directory
    database_dir = join(os.getcwd(), 'database')
    # Path for the zip file
    zip_path = join(os.getcwd(), 'database.zip')
    
    # Create a zip file of the database directory
    shutil.make_archive(zip_path.replace('.zip', ''), 'zip', database_dir)

    end_time = time.time()

    elapsed_time = end_time - start_time

    print(f"Execution time: {elapsed_time:.6f} seconds")
    
    # Return the zip file as a response for download
    return FileResponse(zip_path, media_type='application/zip', filename='database.zip')
    
@app.get("/")
def api_home():
    return {'detail': 'Welcome to FastAPI Qdrant importer!'}