pyocf: flush engine logic test

Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>

tests/functional/tests/engine/test_flush.py

@@ -0,0 +1,72 @@
+#
+# Copyright(c) 2022-2022 Intel Corporation
+# SPDX-License-Identifier: BSD-3-Clause-Clear
+#
+from ctypes import c_int
+
+from pyocf.types.cache import Cache
+from pyocf.types.data import Data
+from pyocf.types.core import Core
+from pyocf.types.io import IoDir
+from pyocf.types.volume import RamVolume, IoFlags, TraceDevice
+from pyocf.types.volume_core import CoreVolume
+from pyocf.utils import Size
+from pyocf.types.shared import OcfCompletion
+
+
+def test_flush_propagation(pyocf_ctx):
+    flushes = {}
+
+    pyocf_ctx.register_volume_type(TraceDevice)
+
+    def trace_flush(vol, io, io_type):
+        nonlocal flushes
+
+        if io_type == TraceDevice.IoType.Flush or int(io.contents._flags) & IoFlags.FLUSH:
+            if vol.uuid not in flushes:
+                flushes[vol.uuid] = []
+            flushes[vol.uuid].append((io.contents._addr, io.contents._bytes))
+
+        return True
+
+    cache_device = TraceDevice(RamVolume(Size.from_MiB(50)), trace_fcn=trace_flush)
+    core_device = TraceDevice(RamVolume(Size.from_MiB(100)), trace_fcn=trace_flush)
+
+    addr = Size.from_MiB(2).B
+    size = Size.from_MiB(1).B
+
+    cache = Cache.start_on_device(cache_device)
+    core = Core.using_device(core_device)
+    cache.add_core(core)
+
+    queue = cache.get_default_queue()
+    vol = CoreVolume(core, open=True)
+
+    flushes = {}
+
+    io = vol.new_io(queue, addr, size, IoDir.WRITE, 0, IoFlags.FLUSH)
+    completion = OcfCompletion([("err", c_int)])
+    io.callback = completion.callback
+    data = Data(byte_count=0)
+    io.set_data(data, 0)
+
+    io.submit_flush()
+    completion.wait()
+
+    assert int(completion.results["err"]) == 0
+
+    assert cache_device.uuid in flushes
+    assert core_device.uuid in flushes
+
+    cache_flushes = flushes[cache_device.uuid]
+    core_flushes = flushes[core_device.uuid]
+
+    assert len(cache_flushes) == 1
+    assert len(core_flushes) == 1
+
+    assert core_flushes[0] == (addr, size)
+
+    # empty flush expected to be sent to cache device
+    assert cache_flushes[0] == (0, 0)
+
+    cache.stop()