🔍 Code Extractor

Persists a chat session to disk by serializing session data to a JSON file, converting datetime objects to ISO format strings.

Purpose

This function saves the current state of a chat session identified by session_id to a JSON file on disk. It is designed to be called within a thread-safe context (while holding session_lock) to prevent race conditions. The function retrieves session data from a global chat_sessions dictionary, converts datetime fields to ISO format strings for JSON serialization, and writes the data to a file in the SESSIONS_DIR directory. Error handling is included to log failures without raising exceptions.

Source Code

def save_session_to_disk(session_id):
    """Persist session to disk - must be called while holding session_lock"""
    try:
        if session_id in chat_sessions:
            session_file = SESSIONS_DIR / f"{session_id}.json"
            session_data = chat_sessions[session_id].copy()
            # Convert datetime objects to strings
            session_data['created_at'] = session_data['created_at'].isoformat()
            session_data['updated_at'] = session_data['updated_at'].isoformat()
            
            with open(session_file, 'w') as f:
                json.dump(session_data, f, indent=2)
    except Exception as e:
        logger.error(f"Failed to save session {session_id}: {e}")

Parameters

Parameter Details

session_id: A unique identifier (typically a string or UUID) for the chat session to be saved. This ID is used to look up the session in the chat_sessions dictionary and to name the output JSON file (e.g., '{session_id}.json').

Return Value

This function does not return any value (implicitly returns None). It performs a side effect of writing session data to disk. If an error occurs during the save operation, it logs the error but does not raise an exception.

Dependencies

• json
• logging
• pathlib

Required Imports

import json
import logging
from pathlib import Path

Usage Example

import json
import logging
from pathlib import Path
from datetime import datetime
from threading import Lock

# Setup
SESSIONS_DIR = Path('./sessions')
SESSIONS_DIR.mkdir(exist_ok=True)
chat_sessions = {}
session_lock = Lock()
logger = logging.getLogger(__name__)
logging.basicConfig(level=logging.INFO)

# Create a sample session
session_id = 'abc123'
chat_sessions[session_id] = {
    'session_id': session_id,
    'user_id': 'user456',
    'messages': [{'role': 'user', 'content': 'Hello'}],
    'created_at': datetime.now(),
    'updated_at': datetime.now()
}

# Save session to disk (must hold lock)
with session_lock:
    save_session_to_disk(session_id)

# Verify the file was created
session_file = SESSIONS_DIR / f'{session_id}.json'
print(f'Session saved: {session_file.exists()}')

Best Practices

• Always call this function while holding the session_lock to prevent concurrent access issues
• Ensure SESSIONS_DIR exists and is writable before calling this function
• The chat_sessions dictionary must contain the session_id as a key before calling
• Session data must include 'created_at' and 'updated_at' as datetime objects
• Consider implementing retry logic or more robust error handling for production use
• The function silently fails on errors (only logs), so check logs for save failures
• Ensure the logger is properly configured before using this function
• Consider adding validation to ensure session data is complete before saving
• For high-frequency saves, consider implementing a write-behind cache or batching mechanism

Tags

Similar Components

AI-powered semantic similarity - components with related functionality:

• function save_session_to_disk_v1 96.6% similar

  Persists a chat session to disk by serializing session data to a JSON file, converting datetime objects to ISO format strings for storage.

  From: /tf/active/vicechatdev/docchat/blueprint.py

• function save_chat_session_to_file 87.0% similar

  Persists a chat session object to a JSON file in the designated chat sessions directory, using the session's ID as the filename.

  From: /tf/active/vicechatdev/vice_ai/complex_app.py

• function load_session_from_disk 74.2% similar

  Loads a session from disk storage by reading a JSON file identified by session_id, deserializing the data, and converting timestamp strings back to datetime objects.

  From: /tf/active/vicechatdev/docchat/app.py

• function load_chat_session_from_file 72.6% similar

  Loads a chat session from a JSON file stored in the CHAT_SESSIONS_DIR directory using the provided session_id as the filename.

  From: /tf/active/vicechatdev/vice_ai/complex_app.py

• function load_all_sessions 71.1% similar

  Loads all chat session data from JSON files stored in a sessions directory into memory on application startup.

  From: /tf/active/vicechatdev/docchat/app.py