[AGIPD][CORRECT] Add reading of AGIPD number of cells from CONTROL data

This add retrieving of the numbers of cells for AGIPD from CONTROL data. It's needed because the estimation by the maximum cell Id in INSTRUMENT data doesn't work if the DAQ filters data.

src/cal_tools/agipdlib.py

@@ -53,12 +53,19 @@ class AgipdCtrl:
         self.ctrl_src = ctrl_src
         self.raise_error = raise_error
 
-    def get_num_cells(self) -> Optional[int]:
-        """Read number of memory cells from fast data.
+    def _get_num_cells_ctrl(self) -> Optional[int]:
+        """Get number of cells from CONTROL source."""
+        # Attempt to look for number of cells in slow data
+        ncell_src = (
+            self.ctrl_src, "bunchStructure.nPulses.value")
+        if (
+            ncell_src[0] in self.run_dc.all_sources and
+            ncell_src[1] in self.run_dc.keys_for_source(ncell_src[0])
+        ):
+            return int(self.run_dc[ncell_src].as_single_value(reduce_by='max'))
 
-        :return mem_cells: Number of memory cells
-        return None, if no data available.
-        """
+    def _get_num_cells_instr(self) -> Optional[int]:
+        """Get number of cells from INSTRUMENT source."""
         cells = np.squeeze(
             self.run_dc[
                 self.image_src, "image.cellId"].drop_empty_trains().ndarray()
@@ -70,6 +77,20 @@ class AgipdCtrl:
         dists = [abs(o - maxcell) for o in options]
         return options[np.argmin(dists)]
 
+    def get_num_cells(self) -> Optional[int]:
+        """Read number of memory cells from fast data.
+
+        :return mem_cells: Number of memory cells
+        return None, if no data available.
+        """
+        ncell = self._get_num_cells_ctrl()
+        if ncell is not None:
+            return ncell
+        # The method implemented in this function doesn't suit for filtered
+        # data. If DAQ filters data and the last cell is removed, the
+        # function returns wrong value
+        return self._get_num_cells_instr()
+
     def _get_acq_rate_ctrl(self) -> Optional[float]:
         """Get acquisition (repetition) rate from CONTROL source."""
         # Attempt to look for acquisition rate in slow data
@@ -83,9 +104,6 @@ class AgipdCtrl:
             # about bucketing the rate for managing meta-data.
             return round(float(self.run_dc[rep_rate_src].as_single_value()), 1)
 
-    def _get_acq_rate_instr(self) -> Optional[float]:
-        """Get acquisition (repetition rate) from INSTRUMENT source."""
-
     def _get_acq_rate_instr(self) -> Optional[float]:
         """Get acquisition (repetition rate) from INSTRUMENT source."""