Test Case: python-instruct-1762

  1import json  2import logging  3from typing import Dict, Optional, Any  4​  5# Configure logging  6logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(levelname)s - %(message)s')  7​  8​  9class User: 10    """ 11    A mock User class for demonstration purposes.  Replace with your actual User class. 12    """ 13​ 14    def __init__(self, user_id: int, username: str): 15        self.id = user_id 16        self.username = username 17​ 18    def __repr__(self): 19        return f"User(id={self.id}, username='{self.username}')" 20​ 21​ 22class Database: 23    """ 24    A mock Database class for demonstration purposes.  Replace with your actual database interaction. 25    """ 26​ 27    def __init__(self): 28        pass 29​ 30    def get_vms_by_user(self, user: User) -> Optional[str]: 31        """ 32        Simulates retrieving VM data from the database.  Returns a JSON string. 33        """ 34        if user.id == 1: 35            # Simulate some VM data 36            vm_data = [ 37                {"vm_id": "vm1", "name": "MyVM1", "state": "running"}, 38                {"vm_id": "vm2", "name": "MyVM2", "state": "stopped"}, 39            ] 40            return json.dumps(vm_data) 41        elif user.id == 2: 42            # Simulate no VMs for this user 43            return json.dumps([]) 44        else: 45            # Simulate an error or no data 46            return None 47​ 48​ 49class Cache: 50    """ 51    A mock Cache class for demonstration purposes.  Replace with your actual caching mechanism. 52    """ 53​ 54    def __init__(self): 55        self.cache = {} 56​ 57    def get(self, key: str) -> Optional[str]: 58        """ 59        Simulates retrieving data from the cache. 60        """ 61        return self.cache.get(key) 62​ 63    def set(self, key: str, value: str, expiry: int = 300) -> None: 64        """ 65        Simulates setting data in the cache. 66        """ 67        self.cache[key] = value 68​ 69​ 70def get_virtual_machines_for_user(user: User, cache: Optional[Cache] = None, db: Optional[Database] = None) -> Dict[str, str]: 71    """ 72    Retrieves a dictionary of virtual machines associated with the user. 73​ 74    Args: 75        user: The User object. 76        cache: An optional Cache object. 77        db: An optional Database object. 78​ 79    Returns: 80        A dictionary of virtual machines with their states, keyed by VM ID. 81        Returns an empty dictionary if no VMs are found or if an error occurs. 82    """ 83    if db is None: 84        db = Database()  # Instantiate a Database object if none is provided 85​ 86    vm_data = None 87​ 88    try: 89        if cache: 90            cache_key = f"vms_for_user_{user.id}" 91            vm_data = cache.get(cache_key) 92​ 93        if not vm_data: 94            logging.info(f"VM data not found in cache for user {user.id}. Retrieving from database.") 95            vm_data = db.get_vms_by_user(user) 96​ 97            if vm_data and cache: 98                cache_key = f"vms_for_user_{user.id}" 99                cache.set(cache_key, vm_data)100        else:101            logging.info(f"VM data found in cache for user {user.id}.")102​103        if vm_data:104            try:105                vms = json.loads(vm_data)106                if not isinstance(vms, list):107                    logging.error(f"Unexpected data format from database/cache: {type(vms)}")108                    return {}109​110                vm_dict = {vm["vm_id"]: vm["state"] for vm in vms if isinstance(vm, dict) and "vm_id" in vm and "state" in vm}111                return vm_dict112            except json.JSONDecodeError as e:113                logging.error(f"Error decoding VM data: {e}")114                return {}115        else:116            logging.info(f"No VM data found for user {user.id}.")117            return {}118​119    except Exception as e:120        logging.exception(f"An unexpected error occurred: {e}")121        return {}122​123​124if __name__ == '__main__':125    # Example Usage126    user1 = User(user_id=1, username="testuser")127    user2 = User(user_id=2, username="anotheruser")128    user3 = User(user_id=3, username="nouser")129​130    cache = Cache()131    db = Database()132​133    vms1 = get_virtual_machines_for_user(user1, cache, db)134    print(f"VMs for {user1}: {vms1}")135​136    vms2 = get_virtual_machines_for_user(user2, cache, db)137    print(f"VMs for {user2}: {vms2}")138​139    vms3 = get_virtual_machines_for_user(user3, cache, db)140    print(f"VMs for {user3}: {vms3}")141​142    # Retrieve from cache again143    vms1_cached = get_virtual_machines_for_user(user1, cache, db)144    print(f"VMs for {user1} (cached): {vms1_cached}")

None