Google LevelDB Integration

class LevelDBHook(BaseHook):
    """
    Plyvel Wrapper to Interact With LevelDB Database.
    
    Provides connectivity and database operations for LevelDB through
    the Plyvel library wrapper.
    """
    def __init__(self, leveldb_conn_id: str = "leveldb_default"): ...
    
    def get_conn(
        self,
        name: str = "/tmp/testdb/",
        create_if_missing: bool = False,
        **kwargs
    ) -> plyvel.DB:
        """
        Create Plyvel DB connection.
        
        Args:
            name: Path to create database (e.g. '/tmp/testdb/')
            create_if_missing: Whether a new database should be created if needed
            kwargs: Other options for plyvel.DB creation
            
        Returns:
            plyvel.DB: Database connection object
        """
    
    def close_conn(self) -> None:
        """Close database connection."""
    
    def run(
        self,
        command: str,
        key: bytes,
        value: bytes | None = None,
        keys: list[bytes] | None = None,
        values: list[bytes] | None = None,
    ) -> bytes | None:
        """
        Execute operation with LevelDB.
        
        Args:
            command: Command ('put', 'get', 'delete', 'write_batch')
            key: Key for operation (bytes)
            value: Value for put operation (bytes)
            keys: Keys for write_batch operation (list[bytes])
            values: Values for write_batch operation (list[bytes])
            
        Returns:
            bytes | None: Value from get operation or None
        """
    
    def put(self, key: bytes, value: bytes) -> None:
        """
        Put a single value into LevelDB by key.
        
        Args:
            key: Key for put operation
            value: Value for put operation
        """
    
    def get(self, key: bytes) -> bytes:
        """
        Get a single value from LevelDB by key.
        
        Args:
            key: Key for get operation
            
        Returns:
            bytes: Value associated with key
        """
    
    def delete(self, key: bytes) -> None:
        """
        Delete a single value in LevelDB by key.
        
        Args:
            key: Key for delete operation
        """
    
    def write_batch(self, keys: list[bytes], values: list[bytes]) -> None:
        """
        Write batch of values in LevelDB by keys.
        
        Args:
            keys: Keys for batch write operation
            values: Values for batch write operation
        """

class LevelDBOperator(BaseOperator):
    """
    Execute command in LevelDB.
    
    Performs database operations using LevelDB through the Plyvel wrapper,
    supporting put, get, delete, and write_batch operations.
    """
    def __init__(
        self,
        *,
        command: str,
        key: bytes,
        value: bytes | None = None,
        keys: list[bytes] | None = None,
        values: list[bytes] | None = None,
        leveldb_conn_id: str = "leveldb_default",
        name: str = "/tmp/testdb/",
        create_if_missing: bool = True,
        create_db_extra_options: dict[str, Any] | None = None,
        **kwargs,
    ):
        """
        Initialize LevelDB operator.
        
        Args:
            command: LevelDB command ('put', 'get', 'delete', 'write_batch')
            key: Key for operation (bytes)
            value: Value for put operation (bytes, optional)
            keys: Keys for write_batch operation (list[bytes], optional)
            values: Values for write_batch operation (list[bytes], optional)
            leveldb_conn_id: Airflow connection ID for LevelDB
            name: Database path
            create_if_missing: Whether to create database if it doesn't exist
            create_db_extra_options: Extra options for database creation
        """
    
    def execute(self, context: Context) -> str | None:
        """
        Execute LevelDB command.
        
        Returns:
            str | None: Value from get operation (decoded to string) or None
        """

class LevelDBHookException(AirflowException):
    """Exception specific for LevelDB operations."""

from airflow import DAG
from airflow.providers.google.leveldb.operators.leveldb import LevelDBOperator
from datetime import datetime

dag = DAG(
    'leveldb_example',
    default_args={'start_date': datetime(2023, 1, 1)},
    schedule_interval='@daily',
    catchup=False
)

# Put a value
put_data = LevelDBOperator(
    task_id='put_data',
    command='put',
    key=b'user:123',
    value=b'{"name": "John", "age": 30}',
    name='/tmp/mydb/',
    create_if_missing=True,
    dag=dag
)

# Get a value
get_data = LevelDBOperator(
    task_id='get_data',
    command='get',
    key=b'user:123',
    name='/tmp/mydb/',
    dag=dag
)

# Write batch data
batch_write = LevelDBOperator(
    task_id='batch_write',
    command='write_batch',
    keys=[b'user:124', b'user:125'],
    values=[b'{"name": "Jane", "age": 25}', b'{"name": "Bob", "age": 35}'],
    name='/tmp/mydb/',
    dag=dag
)

put_data >> get_data >> batch_write

from airflow.providers.google.leveldb.hooks.leveldb import LevelDBHook

def process_leveldb_data():
    hook = LevelDBHook(leveldb_conn_id='my_leveldb_conn')
    
    # Connect to database
    db = hook.get_conn(name='/path/to/db/', create_if_missing=True)
    
    try:
        # Put data
        hook.put(b'key1', b'value1')
        
        # Get data
        value = hook.get(b'key1')
        print(f"Retrieved: {value.decode()}")
        
        # Batch operations
        hook.write_batch(
            keys=[b'batch1', b'batch2'],
            values=[b'data1', b'data2']
        )
        
    finally:
        # Always close connection
        hook.close_conn()

from typing import Any
import plyvel

# LevelDB specific types
LevelDBConnection = plyvel.DB
DatabasePath = str
DatabaseKey = bytes
DatabaseValue = bytes
BatchKeys = list[bytes]
BatchValues = list[bytes]
CreateOptions = dict[str, Any]