Add set_maximum_pixels_per_buffer to the API

handel/interface.py

@@ -23,6 +23,7 @@ __all__ = ['init', 'init_handel', 'exit',
            'get_buffer_length', 'get_raw_buffer', 'get_buffer_data',
            'is_buffer_full', 'is_buffer_overrun', 'set_buffer_done',
            'get_buffer_current_pixel', 'get_current_pixel',
+           'set_maximum_pixels_per_buffer',
            'any_buffer_overrun', 'all_buffer_full', 'set_all_buffer_done',
            'get_all_buffer_data', 'synchronized_poll_data',
            'get_baseline_length', 'get_baseline',
@@ -267,6 +268,18 @@ def set_buffer_done(master, buffer_id):
 
 # Synchronized run
 
+def set_maximum_pixels_per_buffer():
+    """Set the maximum number of pixels per buffer.
+
+    It makes sure all the modules are configured with the same value,
+    in order to be able to perform synchronized run.
+    """
+    set_acquisition_value('num_map_pixels_per_buffer', -1)
+    value = min(get_acquisition_value('num_map_pixels_per_buffer', master)
+                for master in get_master_channels())
+    set_acquisition_value('num_map_pixels_per_buffer', value)
+
+
 def any_buffer_overrun():
     """Return True if an overrun has been detected by the hardware on any
     module, False otherwise.

tests/test_interface.py

@@ -450,6 +450,23 @@ def test_set_buffer_done(interface):
 
 # Synchronized run
 
+def test_set_maximum_pixels_per_buffer(interface):
+    with mock.patch('handel.interface.set_acquisition_value') as m1:
+        with mock.patch('handel.interface.get_acquisition_value') as m2:
+            with mock.patch('handel.interface.get_master_channels') as m3:
+                    m1.return_value = None
+                    m2.side_effect = lambda x, y: 400 if y == 7 else 100
+                    m3.return_value = [0, 3, 7]
+                    assert interface.set_maximum_pixels_per_buffer() is None
+                    assert m1.call_args_list == [
+                        (('num_map_pixels_per_buffer', -1),),
+                        (('num_map_pixels_per_buffer', 100),)]
+                    assert m2.call_args_list == [
+                        (('num_map_pixels_per_buffer', 0),),
+                        (('num_map_pixels_per_buffer', 3),),
+                        (('num_map_pixels_per_buffer', 7),)]
+                    m3.assert_called_once_with()
+
 def test_any_buffer_overrun(interface):
     with mock.patch('handel.interface.get_master_channels') as m1:
         with mock.patch('handel.interface.is_buffer_overrun') as m2: