Re: [PATCH v4 1/3] dts: rework traffic generator inheritance structure

[Luca Vizzarro <luca.vizzarro@arm.com>]

Hi Patrick,

I am assuming the move of send_packets is because we can't send
arbitrary packets with a perf generator. I believe this should be
explained as it's not clear why the move and it feels counterintuitive
at first.

On Wed, Oct 01, 2025 at 07:16:57PM +0000, Patrick Robb wrote:
> diff --git a/dts/framework/testbed_model/traffic_generator/performance_traffic_generator.py b/dts/framework/testbed_model/traffic_generator/performance_traffic_generator.py
> new file mode 100644
> index 0000000000..6b23faa1a5
> --- /dev/null
> +++ b/dts/framework/testbed_model/traffic_generator/performance_traffic_generator.py
> @@ -0,0 +1,63 @@
> +"""Traffic generators for performance tests which can generate a high number of packets."""
> +
> +from abc import abstractmethod
> +from dataclasses import dataclass
> +
> +from scapy.packet import Packet
> +
> +from framework.testbed_model.topology import Topology
> +
> +from .traffic_generator import TrafficGenerator
> +
> +
> +@dataclass(slots=True)
> +class PerformanceTrafficStats:
> +    """Data structure to store performance statistics for a given test run.
> +
> +    Attributes:
> +        tx_pps: Recorded tx packets per second
> +        tx_bps: Recorded tx bytes per second
> +        rx_pps: Recorded rx packets per second
> +        rx_bps: Recorded rx bytes per second
> +        frame_size: The total length of the frame
nit: missing full stops at the end of each attribute.
> +    """
> +
> +    tx_pps: float
> +    tx_bps: float
> +    rx_pps: float
> +    rx_bps: float
> +
> +    frame_size: int | None = None
> +
> +
> +class PerformanceTrafficGenerator(TrafficGenerator):
> +    """An abstract base class for all performance-oriented traffic generators.
> +
> +    Provides an intermediary interface for performance-based traffic generator.
> +    """
> +
> +    @abstractmethod
> +    def calculate_traffic_and_stats(
> +        self,
> +        packet: Packet,
> +        duration: float,
> +        send_mpps: int | None = None,
> +    ) -> PerformanceTrafficStats:
> +        """Send packet traffic and acquire associated statistics.
> +
> +        If `send_mpps` is provided, attempt to transmit traffic at the `send_mpps` rate.
> +        Otherwise, attempt to transmit at line rate.
> +
> +        Args:
> +            packet: The packet to send.
> +            duration: Performance test duration (in seconds).
> +            send_mpps: The millions packets per second send rate.
> +
> +        Returns:
> +            Performance statistics of the generated test.
> +        """
> +
> +    def setup(self, topology: Topology) -> None:
> +        """Overrides :meth:`.traffic_generator.TrafficGenerator.setup`."""
> +        for port in self._tg_node.ports:
> +            self._tg_node.main_session.configure_port_mtu(2000, port)

should do:
  port.configure_mtu(2000)