merge_gdl_archives.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

"""
Name
    merge_gdl_archives - merge multiple download archives into one

Usage
    merge_gdl_archives.py merged.sqlite old1.sqlite old2.sqlite ...
"""

import sqlite3
import sys


def open_database(path):
    db = sqlite3.connect(path, timeout=60, check_same_thread=False)
    db.isolation_level = None
    return db


def main():
    with open_database(sys.argv[1]) as main_db:
        main_cursor = main_db.cursor()

        main_cursor.execute("CREATE TABLE IF NOT EXISTS archive "
                            "(entry PRIMARY KEY) WITHOUT ROWID")

        for db_path in sys.argv[2:]:
            with open_database(db_path) as db:
                main_cursor.execute("BEGIN TRANSACTION")

                for row in db.execute("SELECT entry FROM archive"):
                    main_cursor.execute(
                        "INSERT OR IGNORE INTO archive VALUES (?)", (row[0],))

                main_cursor.execute("COMMIT")


if __name__ == "__main__":
    main()