Change Set_Delta to Increment_Delta; Don't Remove DB File on Clear

Increment is really what was needed.  Gracefully handles a delta
of None for example if a user used refresh=False

Partially Fixes #292
Fixes #243

insteon_mqtt/db/Device.py

@@ -176,17 +176,14 @@ def is_current(self, delta):
         return delta == self.delta
 
     #-----------------------------------------------------------------------
-    def set_delta(self, delta):
-        """Set the current database delta.
+    def increment_delta(self):
+        """Increments the current database delta by 1
 
-        This records the input delta as the current value.  If the input
-        isn't None, the database is also saved to record this value.
-
-        Args:
-          delta:  (int) The database delta.  None to clear the delta.
+        Bumps up the delta by one, rolling it over to 0 if necessary.  Will
+        ignore a delta which is None.
         """
-        self.delta = delta
-        if delta is not None:
+        if self.delta is not None:
+            self.delta += 1
             self.delta = self.delta % 256  # Roll over db if it goes past 256
             self.save()
 
@@ -275,19 +272,18 @@ def get_meta(self, key):
 
     #-----------------------------------------------------------------------
     def clear(self):
-        """Clear the complete database of entries.
+        """Clear the cached database of entries
 
-        This also removes the saved file if it exists.  It does NOT modify
-        the database on the device.
+        This also saves the empty database to file.  It does NOT modify
+        the database on the device.  Nor does it clear the meta entries in
+        the database file.
         """
         self.delta = None
         self.entries.clear()
         self.unused.clear()
         self.groups.clear()
         self.last.mem_loc = START_MEM_LOC
-
-        if self.save_path and os.path.exists(self.save_path):
-            os.remove(self.save_path)
+        self.save()
 
     #-----------------------------------------------------------------------
     def set_path(self, path):

insteon_mqtt/db/DeviceModifyManagerI1.py

@@ -164,7 +164,7 @@ def handle_lsb_write_response(self, msg, on_done):
                    completion of the modification
         """
         # Increment the delta 1
-        self.db.set_delta(self.db.delta + 1)
+        self.db.increment_delta()
         self.handle_lsb_response(msg, on_done)
 
     #-------------------------------------------------------------------

insteon_mqtt/db/Modem.py

@@ -196,10 +196,7 @@ def clear(self):
         self.entries = []
         self.groups = {}
         self.aliases = {}
-        self._meta = {}
-
-        if self.save_path and os.path.exists(self.save_path):
-            os.remove(self.save_path)
+        self.save()
 
     #-----------------------------------------------------------------------
     def find_group(self, group):

insteon_mqtt/handler/DeviceDbModify.py

@@ -73,7 +73,7 @@ def msg_received(self, protocol, msg):
                     LOG.info("Updating entry: %s", self.entry)
                     self.db.add_entry(self.entry)
                     # Increment the delta 1
-                    self.db.set_delta(self.db.delta + 1)
+                    self.db.increment_delta()
                     self.on_done(True, "Device database update complete",
                                  self.entry)
 

insteon_mqtt/handler/DeviceRefresh.py

@@ -105,7 +105,7 @@ def msg_received(self, protocol, msg):
                     # w/ the current value and save the database.
                     def on_done(success, message, data):
                         if success:
-                            self.device.db.set_delta(msg.cmd1)
+                            self.device.db.delta = msg.cmd1
                             LOG.ui("%s database download complete\n%s",
                                    self.addr, self.device.db)
                         self.on_done(success, message, data)

tests/db/test_Device.py

@@ -17,8 +17,13 @@ def test_basic(self):
         assert obj.is_current(0) is False
         obj.delta = 1
         assert obj.is_current(1) is True
-        obj.set_delta(None)
+        obj.increment_delta()
         assert obj.is_current(1) is False
+        assert obj.is_current(2) is True
+        # test roll over at 256
+        obj.delta = 255
+        obj.increment_delta()
+        assert obj.is_current(0) is True
 
         assert obj.engine is None
         obj.set_engine(1)
@@ -109,11 +114,15 @@ def test_basic(self):
         assert len(obj2.unused) == 1
         assert len(obj2.groups) == 2
 
+        obj2.set_meta('test', 2)
         obj2.clear()
         assert len(obj2) == 0
         assert len(obj2.entries) == 0
         assert len(obj2.unused) == 0
         assert len(obj2.groups) == 0
+        assert len(obj2._meta) == 1
+        assert obj2.get_meta('test') == 2
+
 
     #-----------------------------------------------------------------------
     def test_add_multi_group(self):

tests/db/test_Modem.py

@@ -77,6 +77,37 @@ def test_basic(self):
         assert obj2.entries[1] == obj.entries[1]
         assert obj2.entries[2] == obj.entries[2]
 
+    #-----------------------------------------------------------------------
+    def test_clear(self):
+        obj = IM.db.Modem()
+        assert len(obj) == 0
+
+        addr = IM.Address('12.34.ab')
+        data = bytes([0xff, 0x00, 0x00])
+        e = IM.db.ModemEntry(addr, 0x01, True, data, db=obj)
+        obj.add_entry(e)
+
+        addr = IM.Address('12.34.ac')
+        data = bytes([0xff, 0x00, 0x00])
+        e = IM.db.ModemEntry(addr, 0x01, True, data, db=obj)
+        obj.add_entry(e)
+
+        addr = IM.Address('12.34.ad')
+        data = bytes([0xff, 0x00, 0x00])
+        e = IM.db.ModemEntry(addr, 0x02, True, data, db=obj)
+        obj.add_entry(e)
+
+        assert len(obj) == 3
+
+        obj.set_meta('test', 2)
+        obj.clear()
+        assert len(obj) == 0
+        assert len(obj.entries) == 0
+        assert len(obj.groups) == 0
+        assert len(obj.aliases) == 0
+        assert len(obj._meta) == 1
+        assert obj.get_meta('test') == 2
+
     #-----------------------------------------------------------------------
     def test_add_on_device_empty_ctrl(self, test_device, test_entry_dev1_ctrl):
         # add_on_device(self, entry, on_done=None)