Add support for the DEL command

acceptance/test_del.py

@@ -0,0 +1,29 @@
+#!/usr/bin/env python
+
+import helpers
+import random
+import sys
+import unittest
+
+class DelTest(helpers.MozzoniTest):
+    def setUp(self):
+        # Generate a random key for each test case to avoid potential
+        # collisions
+        self.key = random.randint(1, sys.maxint)
+
+    def test_del(self):
+        # No keys to remove, but should not error
+        self.assertEqual(0,
+                self.r.delete(self.key))
+
+        # With a set keys the return should be the number of keys deleted
+        self.assertTrue(
+                self.r.set(self.key, 'yey'))
+        self.assertEqual(1,
+                self.r.delete(self.key))
+
+
+
+if __name__ == '__main__':
+    random.seed()
+    unittest.main()

src/mozzoni-command_loader.adb

@@ -13,6 +13,7 @@ package body Mozzoni.Command_Loader is
       Register_Command ("SET", Mozzoni.Commands.Keys.Handle_Set'Access);
       Register_Command ("GET", Mozzoni.Commands.Keys.Handle_Get'Access);
       Register_Command ("EXISTS", Mozzoni.Commands.Keys.Handle_Exists'Access);
+      Register_Command ("DEL", Mozzoni.Commands.Keys.Handle_Del'Access);
    end Load;
 
 end Mozzoni.Command_Loader;

src/mozzoni-commands-keys.adb

@@ -138,4 +138,21 @@ package body Mozzoni.Commands.Keys is
    end Handle_Exists;
 
 
+   procedure Handle_Del (Client : in out Client_Type;
+                         Command : Command_Array_Access) is
+
+      Deleted : Natural := 0;
+   begin
+      for Key_Item of Command (2 .. Command'Length) loop
+         if KeyValue.Remove (Key_Item.Value) then
+            Deleted := Deleted + 1;
+         end if;
+      end loop;
+
+      Client.Write (':');
+      Client.Write (Deleted);
+      Client.Write_Line_Ending;
+   end Handle_Del;
+
+
 end Mozzoni.Commands.Keys;

src/mozzoni-commands-keys.ads

@@ -17,4 +17,8 @@ package Mozzoni.Commands.Keys is
                             Command : Command_Array_Access)
      with Pre => Client.Is_Valid and Command /= null;
 
+   procedure Handle_Del (Client : in out Client_Type;
+                         Command : Command_Array_Access)
+     with Pre => Client.Is_Valid and Command /= null;
+
 end Mozzoni.Commands.Keys;

src/mozzoni-store.adb

@@ -21,6 +21,19 @@ package body Mozzoni.Store is
       end Exists;
 
 
+      function Remove (Key : in Key_Type) return Boolean is
+      -- Need a variable since Delete is an `in out` operation
+         KV : Hashed_Maps.Map := Store;
+      begin
+         if not Hashed_Maps.Contains (KV, Key) then
+            return False;
+         end if;
+
+         Hashed_Maps.Delete (KV, Key);
+         return True;
+      end Remove;
+
+
       function Is_Expired (Key : in Key_Type) return Boolean is
          Value : constant Value_Type := Hashed_Maps.Element (Store, Key);
          Now   : constant Ada.Calendar.Time := Ada.Calendar.Clock;

src/mozzoni-store.ads

@@ -56,6 +56,17 @@ package Mozzoni.Store is
       function Exists (Key : in Key_Type) return Boolean
         with Pre => Mozzoni.Store.Is_Valid_Key (Key);
 
+      -- Remove a Key from the store
+      --
+      -- To avoid too many traversals of the protected object boundary, this
+      -- function will return a Boolean to indicate to the caller that the key
+      -- existed before it was purged.
+      --
+      -- @param Key a valid key
+      -- @return Boolean True if the key existed, otherwise false.
+      function Remove (Key : in Key_Type) return Boolean
+        with Pre => Mozzoni.Store.Is_Valid_Key (Key);
+
       ---
       -- Is_Expired determines whether the given key has expired from the store
       --