Function __connect_addr

asyncpg/connect_utils.py:1066–1138

(
    params,
    retry,
    addr,
    loop,
    config,
    connection_class,
    record_class,
    params_input,
)

async def __connect_addr(
    params,
    retry,
    addr,
    loop,
    config,
    connection_class,
    record_class,
    params_input,
):
    connected = _create_future(loop)

    proto_factory = lambda: protocol.Protocol(
        addr, connected, params, record_class, loop)

    if isinstance(addr, str):
        # UNIX socket
        connector = loop.create_unix_connection(proto_factory, addr)

    elif params.ssl and params.ssl_negotiation is SSLNegotiation.direct:
        # if ssl and ssl_negotiation is `direct`, skip STARTTLS and perform
        # direct SSL connection
        connector = loop.create_connection(
            proto_factory, *addr, ssl=params.ssl
        )

    elif params.ssl:
        connector = _create_ssl_connection(
            proto_factory, *addr, loop=loop, ssl_context=params.ssl,
            ssl_is_advisory=params.sslmode == SSLMode.prefer)
    else:
        connector = loop.create_connection(proto_factory, *addr)

    tr, pr = await connector

    try:
        await connected
    except (
        exceptions.InvalidAuthorizationSpecificationError,
        exceptions.ConnectionDoesNotExistError,  # seen on Windows
    ):
        tr.close()

        # retry=True here is a redundant check because we don't want to
        # accidentally raise the internal _RetryConnectSignal to the user
        if retry and (
            params.sslmode == SSLMode.allow and not pr.is_ssl or
            params.sslmode == SSLMode.prefer and pr.is_ssl
        ):
            # Trigger retry when:
            #   1. First attempt with sslmode=allow, ssl=None failed
            #   2. First attempt with sslmode=prefer, ssl=ctx failed while the
            #      server claimed to support SSL (returning "S" for SSLRequest)
            #      (likely because pg_hba.conf rejected the connection)
            raise _RetryConnectSignal()

        else:
            # but will NOT retry if: