[2856] Add "load" command handler

src/lib/python/isc/memmgr/builder.py

@@ -13,6 +13,9 @@
 # NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 # WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
+from isc.datasrc import ConfigurableClientList
+from isc.memmgr.datasrc_info import SegmentInfo
+
 class MemorySegmentBuilder:
     """The builder runs in a different thread in the memory manager. It
     waits for commands from the memory manager, and then executes them
@@ -61,6 +64,43 @@ class MemorySegmentBuilder:
         self._response_queue.append(('bad_command',))
         self._shutdown = True
 
+    def __handle_load(self, zname, dsrc_info, rrclass, dsrc_name):
+        clist = dsrc_info.clients_map[rrclass]
+        sgmt_info = dsrc_info.segment_info_map[(rrclass, dsrc_name)]
+        clist.reset_memory_segment(dsrc_name,
+                                   ConfigurableClientList.READ_ONLY,
+                                   sgmt_info.get_reset_param(SegmentInfo.WRITER))
+
+        if zname is not None:
+            zones = [(None, zname)]
+        else:
+            zones = clist.get_zone_table_accessor(dsrc_name, True)
+
+        for _, zname in zones:
+            cache_load_error = (zname is None) # install empty zone initially
+            writer = clist.get_cached_zone_writer(zname, catch_load_error,
+                                                  dsrc_name)
+            try:
+                error = writer.load()
+                if error is not None:
+                    # FIXME: log the error
+                    continue
+            except Exception:
+                # FIXME: log it
+                continue
+            writer.install()
+            writer.cleanup()
+
+        # need to reset the segment so readers can read it (note: memmgr
+        # itself doesn't have to keep it open, but there's currently no
+        # public API to just clear the segment)
+        clist.reset_memory_segment(dsrc_name,
+                                   ConfigurableClientList.READ_ONLY,
+                                   sgmt_info.get_reset_param(SegmentInfo.WRITER))
+
+        self._response_queue.append(('load-completed', dsrc_info, rrclass,
+                                     dsrc_name))
+
     def run(self):
         """ This is the method invoked when the builder thread is
             started.  In this thread, be careful when modifying
@@ -87,7 +127,9 @@ class MemorySegmentBuilder:
                 # "shutdown" command, which just exits the thread.
                 for command_tuple in local_command_queue:
                     command = command_tuple[0]
-                    if command == 'shutdown':
+                    if command == 'load':
+                        self.__handle_load()
+                    elif command == 'shutdown':
                         self.__handle_shutdown()
                         # When the shutdown command is received, we do
                         # not process any further commands.