pyocf: reintroduce trace device

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

tests/functional/pyocf/types/volume.py

@@ -473,6 +473,56 @@ class ErrorDevice(Volume):
         return self.vol.get_copy()
 
 
+class TraceDevice(Volume):
+    class IoType(IntEnum):
+        Data = 1
+        Flush = 2
+        Discard = 3
+
+    def __init__(self, vol, trace_fcn=None, uuid=None):
+        self.vol = vol
+        super().__init__(uuid)
+        self.trace_fcn = trace_fcn
+
+    def _trace(self, io, io_type):
+        submit = True
+
+        if self.trace_fcn:
+            submit = self.trace_fcn(self, io, io_type)
+
+        return submit
+
+    def do_submit_io(self, io):
+        submit = self._trace(io, TraceDevice.IoType.Data)
+
+        if submit:
+            self.vol.do_submit_io(io)
+
+    def do_submit_flush(self, io):
+        submit = self._trace(io, TraceDevice.IoType.Flush)
+
+        if submit:
+            self.vol.do_submit_flush(io)
+
+    def get_length(self):
+        return self.vol.get_length()
+
+    def get_max_io_size(self):
+        return self.vol.get_max_io_size()
+
+    def do_submit_discard(self, discard):
+        return self.vol.do_submit_discard(discard)
+
+    def dump(self, offset=0, size=0, ignore=VOLUME_POISON, **kwargs):
+        return self.vol.dump(offset, size, ignore=ignore, **kwargs)
+
+    def md5(self):
+        return self.vol.md5()
+
+    def get_copy(self):
+        return self.vol.get_copy()
+
+
 lib = OcfLib.getInstance()
 lib.ocf_io_get_priv.restype = POINTER(VolumeIoPriv)
 lib.ocf_io_get_volume.argtypes = [c_void_p]