dau_driver.testing
==================

.. py:module:: dau_driver.testing

.. autoapi-nested-parse::

   Shared test doubles for DAU driver consumers.

   Used by the dau-driver, dau, and dau-polars test suites so the fake device's
   semantics cannot drift between packages. Not imported by production code.



Classes
-------

.. autoapisummary::

   dau_driver.testing.FakeTransport


Functions
---------

.. autoapisummary::

   dau_driver.testing.default_int32_capabilities
   dau_driver.testing.fake_device
   dau_driver.testing.golden_aggregation_trigger


Module Contents
---------------

.. py:class:: FakeTransport

   In-memory DeviceTransport: records DMA traffic and register writes.

   Advertises a current (register map 0.3) shell by default, including the
   job capacity a host batches against — an all-zero register file models a
   shell nobody builds any more, and every job test would be exercising the
   not-advertised refusal instead of the path it means to test. Tests that
   want an older shell clear or lower these.


   .. py:attribute:: DEFAULT_INPUT_ROW_CAPACITY
      :value: 16384



   .. py:attribute:: DEFAULT_OUTPUT_RECORD_CAPACITY
      :value: 819



   .. py:attribute:: h2c_writes
      :type:  list[tuple[int, bytes]]
      :value: []



   .. py:attribute:: c2h_reads
      :type:  list[tuple[int, int]]
      :value: []



   .. py:attribute:: c2h_payloads
      :type:  dict[int, bytes]


   .. py:attribute:: registers
      :type:  dict[int, int]


   .. py:attribute:: register_reads
      :type:  list[int]
      :value: []



   .. py:method:: read_u32(offset: int) -> int


   .. py:method:: write_u32(offset: int, value: int) -> None


   .. py:method:: read_dma(device_address: int, byte_count: int) -> bytes


   .. py:method:: write_dma(device_address: int, data: bytes | bytearray | memoryview) -> int


.. py:function:: default_int32_capabilities(operators: tuple[dau_core.capabilities.OperatorCapability, ...] | None = None, *, max_transfer_bytes: int = 4096) -> dau_core.capabilities.DeviceCapabilities

   The standard fake INT32 aggregation device capability set.


.. py:function:: fake_device(tmp_path: pathlib.Path, transport: FakeTransport, *, capabilities: dau_core.capabilities.DeviceCapabilities | None = None) -> dau_driver.device.DauDevice

   A DauDevice backed by a FakeTransport (paths are never opened).


.. py:function:: golden_aggregation_trigger(transport: FakeTransport, output_address: int)

   A StreamTrigger that emulates the aggregation hardware: decode the
   encoded input batch, compute the golden scalar, stage the result stream
   at ``output_address`` for the subsequent C2H read.