Function main

tools/bench_src_index.py:193–267

()

def main() -> None:
    parser = argparse.ArgumentParser(
        description="Benchmark impact of idx_mappings_src index"
    )
    parser.add_argument("db_path", help="Path to the explainshell SQLite database")
    parser.add_argument(
        "--iterations",
        "-n",
        type=int,
        default=2000,
        help="Number of query iterations per benchmark (default: 2000)",
    )
    args = parser.parse_args()

    conn = sqlite3.connect(args.db_path)
    conn.row_factory = sqlite3.Row
    # Match production settings
    conn.execute("PRAGMA journal_mode=WAL")
    conn.execute("PRAGMA cache_size=-64000")  # 64MB cache

    total_mappings = conn.execute("SELECT COUNT(*) FROM mappings").fetchone()[0]
    total_manpages = conn.execute("SELECT COUNT(*) FROM parsed_manpages").fetchone()[0]
    print(f"Database: {args.db_path}")
    print(f"  mappings:        {total_mappings:,}")
    print(f"  parsed_manpages: {total_manpages:,}")
    print(f"  iterations:      {args.iterations:,}")

    sample_size = min(200, total_mappings)
    srcs_single, srcs_multi, srcs_subcmd = collect_sample_srcs(conn, sample_size)
    print(
        f"  sample: {len(srcs_single)} single-dst, "
        f"{len(srcs_multi)} multi-dst, "
        f"{len(srcs_subcmd)} subcommand"
    )

    # --- Without index ---
    conn.execute("DROP INDEX IF EXISTS idx_mappings_src")
    without = run_suite(
        conn,
        "WITHOUT idx_mappings_src",
        srcs_single,
        srcs_multi,
        srcs_subcmd,
        args.iterations,
    )

    # --- With index ---
    conn.execute("CREATE INDEX IF NOT EXISTS idx_mappings_src ON mappings(src)")
    with_ = run_suite(
        conn,
        "WITH idx_mappings_src",
        srcs_single,
        srcs_multi,
        srcs_subcmd,
        args.iterations,
    )

    # --- Comparison ---