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import os | |
os.environ['TOKENIZERS_PARALLELISM'] = 'false' # Disable tokenizer parallelism | |
from flask import Flask, request, jsonify | |
from flask_cors import CORS | |
import numpy as np | |
import json | |
import traceback | |
app = Flask(__name__) # Create app object FIRST | |
# Allow requests from the Vercel frontend and localhost for development | |
CORS(app, origins=["http://127.0.0.1:3000", "http://localhost:3000", "https://rag-huggingface.vercel.app"], supports_credentials=True) | |
# --- Configuration --- | |
INDEX_FILE = "index.faiss" | |
MAP_FILE = "index_to_metadata.pkl" | |
EMBEDDING_MODEL = 'all-mpnet-base-v2' | |
# Corrected path joining for model_data_json - relative to app.py location | |
MODEL_DATA_DIR = os.path.join(os.path.dirname(__file__), 'model_data_json') | |
# --- | |
# --- Global variables for resources --- | |
faiss = None | |
pickle = None | |
index = None | |
index_to_metadata = None | |
model = None | |
SentenceTransformer = None # Keep track of the imported class | |
RESOURCES_LOADED = False | |
# --- | |
def load_resources(): | |
"""Loads all necessary resources (model, index, map) only once.""" | |
global faiss, pickle, index, index_to_metadata, model, SentenceTransformer, RESOURCES_LOADED | |
if RESOURCES_LOADED: # Prevent re-loading | |
print("Resources already loaded.") | |
return | |
print("Loading resources...") | |
try: | |
# Deferred Import of Faiss and Pickle inside the function | |
print("Importing Faiss and Pickle...") | |
import faiss as faiss_local | |
import pickle as pickle_local | |
faiss = faiss_local | |
pickle = pickle_local | |
print("Faiss and Pickle imported successfully.") | |
# Load Sentence Transformer Model | |
print(f"Importing SentenceTransformer and loading model: {EMBEDDING_MODEL}") | |
from sentence_transformers import SentenceTransformer as SentenceTransformer_local | |
SentenceTransformer = SentenceTransformer_local # Store the class globally if needed elsewhere | |
model_local = SentenceTransformer(EMBEDDING_MODEL) | |
model = model_local # Assign to global variable | |
print("Sentence transformer model loaded successfully.") | |
# Load FAISS Index | |
index_path = os.path.join(os.path.dirname(__file__), INDEX_FILE) | |
print(f"Loading FAISS index from: {index_path}") | |
if not os.path.exists(index_path): | |
raise FileNotFoundError(f"FAISS index file not found at {index_path}") | |
index_local = faiss.read_index(index_path) | |
index = index_local # Assign to global variable | |
print("FAISS index loaded successfully.") | |
# Load Index-to-Metadata Map | |
map_path = os.path.join(os.path.dirname(__file__), MAP_FILE) | |
print(f"Loading index-to-Metadata map from: {map_path}") | |
if not os.path.exists(map_path): | |
raise FileNotFoundError(f"Metadata map file not found at {map_path}") | |
with open(map_path, 'rb') as f: | |
index_to_metadata_local = pickle.load(f) | |
index_to_metadata = index_to_metadata_local # Assign to global variable | |
print("Index-to-Metadata map loaded successfully.") | |
print("All resources loaded successfully.") | |
RESOURCES_LOADED = True | |
except FileNotFoundError as fnf_error: | |
print(f"Error: {fnf_error}") | |
print(f"Please ensure {INDEX_FILE} and {MAP_FILE} exist in the 'backend' directory relative to app.py.") | |
print("You might need to run 'python build_index.py' first.") | |
RESOURCES_LOADED = False # Keep as False | |
except ImportError as import_error: | |
print(f"Import Error loading resources: {import_error}") | |
traceback.print_exc() | |
RESOURCES_LOADED = False | |
except Exception as e: | |
print(f"Unexpected error loading resources: {e}") | |
traceback.print_exc() # Print full traceback for loading errors | |
RESOURCES_LOADED = False # Keep as False | |
# --- Load resources when the module is imported --- | |
# This should be executed only once by Gunicorn when it imports 'app:app' | |
load_resources() | |
# --- | |
def search(): | |
"""Handles search requests, embedding the query and searching the FAISS index.""" | |
# Check if resources are loaded at the beginning of the request | |
if not RESOURCES_LOADED: | |
# You could attempt to reload here, but it's often better to fail | |
# if the initial load failed, as something is wrong with the environment/files. | |
print("Error: Search request received, but resources are not loaded.") | |
return jsonify({"error": "Backend resources not initialized. Check server logs."}), 500 | |
# Check for necessary components loaded by load_resources | |
if model is None or index is None or index_to_metadata is None or faiss is None: | |
print("Error: Search request received, but some core components (model, index, map, faiss) are None.") | |
return jsonify({"error": "Backend components inconsistency. Check server logs."}), 500 | |
data = request.get_json() | |
if not data or 'query' not in data: | |
return jsonify({"error": "Missing 'query' in request body"}), 400 | |
query = data['query'] | |
top_k = data.get('top_k', 10) # Default to top 10 | |
try: | |
# Embed the query | |
# Ensure model is not None (already checked above, but good practice) | |
if model is None: | |
return jsonify({"error": "Model not loaded."}), 500 | |
query_embedding = model.encode([query], convert_to_numpy=True).astype('float32') | |
# Search the index | |
# Ensure index is not None | |
if index is None: | |
return jsonify({"error": "Index not loaded."}), 500 | |
distances, indices = index.search(query_embedding, top_k) | |
# Get the results with full metadata | |
results = [] | |
if indices.size > 0: # Check if search returned any indices | |
# Ensure index_to_metadata is not None | |
if index_to_metadata is None: | |
print("Error: index_to_metadata is None during result processing.") | |
return jsonify({"error": "Metadata map not loaded."}), 500 | |
for i in range(len(indices[0])): | |
idx = indices[0][i] | |
dist = distances[0][i] | |
# Check index validity MORE robustly | |
if idx < 0 or idx not in index_to_metadata: | |
print(f"Warning: Index {idx} out of bounds or not found in metadata mapping.") | |
continue # Skip this result | |
metadata = index_to_metadata[idx].copy() # Copy to avoid mutating original | |
metadata['distance'] = float(dist) # Add distance to the result dict | |
# --- Add description from model_data_json --- | |
model_id = metadata.get('model_id') | |
description = None | |
# Use the globally defined and corrected MODEL_DATA_DIR | |
if model_id and MODEL_DATA_DIR: | |
filename = model_id.replace('/', '_') + '.json' | |
filepath = os.path.join(MODEL_DATA_DIR, filename) | |
if os.path.exists(filepath): | |
try: | |
with open(filepath, 'r', encoding='utf-8') as f: | |
model_data = json.load(f) | |
description = model_data.get('description') | |
except Exception as e: | |
print(f"Error reading description file {filepath}: {e}") | |
# Keep description as None | |
# else: # Optional: Log if description file doesn't exist | |
# print(f"Description file not found: {filepath}") | |
metadata['description'] = description or 'No description available.' | |
# --- | |
results.append(metadata) # Append the whole metadata dict | |
else: | |
print("Warning: FAISS search returned empty indices.") | |
return jsonify({"results": results}) | |
except Exception as e: | |
print(f"Error during search: {e}") | |
traceback.print_exc() # Print full traceback for search errors | |
return jsonify({"error": "An error occurred during search."}), 500 | |
# The if __name__ == '__main__': block remains removed. |