3 files changed, 320 insertions, 0 deletions
diff --git a/src/io/database_shim.erl b/src/io/database_shim.erl
new file mode 100644
index 0000000..243051b
--- /dev/null
+++ b/src/io/database_shim.erl
@@ -0,0 +1,94 @@
+-module(database_shim).
+-export
+(
+   [
+      generate_db/1,
+      fetch/2,
+      commit/3
+   ]
+).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% LOCAL %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+create_db (_Heir) ->
+   ets:new
+   (
+      db_shim,
+      [
+         set,
+         public,
+         named_table,
+         {keypos, 1},
+         {read_concurrency, true}
+      ]
+   ),
+   io:format("~ndb_shim ets created.~n").
+
+add_to_db (ID, Val) ->
+   io:format("~nadd to db_shim: ~p.~n", [{ID, Val}]),
+   ets:insert(db_shim, {ID, Val}).
+
+generate_char_instances (Battlemap, Characters) ->
+   lists:map
+   (
+      fun (Char) ->
+         {
+            character:get_id(Char),
+            character_instance:new_instance_of
+            (
+               Char,
+               (rand:uniform(2) - 1), % team,
+               {
+                  rand:uniform(battlemap:get_width(Battlemap) - 1), % X
+                  rand:uniform(battlemap:get_heigth(Battlemap) - 1)  % Y
+               }
+            )
+         }
+      end,
+      Characters
+   ).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% EXPORTED %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+generate_db (Heir) ->
+   Pid = self(),
+   spawn(fun () -> create_db(Heir), Pid ! ok, receive ok -> ok end end),
+   receive
+      ok -> ok
+   end,
+   Players = [<<"0">>, <<"1">>],
+   Battlemap = battlemap_shim:generate_random(),
+   Characters = character_shim:generate_random(rand:uniform(12) + 4),
+   CharacterInsts = generate_char_instances(Battlemap, Characters),
+   BattlemapInstance =
+      battlemap_instance_shim:generate_random
+      (
+         CharacterInsts,
+         Players
+      ),
+   add_to_db({battlemap_db, battlemap:get_id(Battlemap)}, Battlemap),
+   lists:map
+   (
+      fun (Char) ->
+         add_to_db({character_db, character:get_id(Char)}, Char)
+      end,
+      Characters
+   ),
+   add_to_db
+   (
+      {battlemap_instance_db, battlemap_instance:get_id(BattlemapInstance)},
+      BattlemapInstance
+   ).
+
+fetch (DB, ObjectID) ->
+   io:format("~ndb_shim lookup: ~p.~n", [{DB, ObjectID}]),
+   case ets:lookup(db_shim, {DB, ObjectID}) of
+      [{_Key, Value}] -> {ok, Value};
+      [] -> nothing
+   end.
+
+commit (DB, ObjectID, Value) ->
+   add_to_db({DB, ObjectID}, Value),
+   timed_cache:invalidate(DB, ObjectID).
diff --git a/src/io/timed_cache.erl b/src/io/timed_cache.erl
new file mode 100644
index 0000000..c86caab
--- /dev/null
+++ b/src/io/timed_cache.erl
@@ -0,0 +1,85 @@
+-module(timed_cache).
+-behavior(gen_server).
+
+%%%% gen_server exports
+-export
+(
+   [
+      init/1,
+      handle_cast/2,
+      handle_call/3, %% No reply will ever be given.
+      terminate/2,
+      code_change/3,
+      format_status/2,
+      handle_info/2
+   ]
+).
+
+%%%% actual interface
+-export
+(
+   [
+      fetch/2,
+      invalidate/2
+   ]
+).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% LOCAL %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+add_to_cache (DB, ObjectID) ->
+   {ok, TimerPID} = gen_server:start(?MODULE, {DB, ObjectID}, []),
+   {ok, Data} = database_shim:fetch(DB, ObjectID),
+   ets:insert(DB, {ObjectID, TimerPID, Data}),
+   Data.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% EXPORTED %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%% gen_server
+
+init ({DB, ObjectID}) ->
+   {ok, {DB, ObjectID}}.
+
+handle_call (invalidate, _, State) ->
+   {stop, normal, State};
+handle_call (ping, _, {DB, ObjectID}) ->
+   {noreply, {DB, ObjectID}, timed_caches_manager:get_timeout(DB)}.
+
+handle_cast (invalidate, State) ->
+   {stop, normal, State};
+handle_cast (ping, {DB, ObjectID}) ->
+   {noreply, {DB, ObjectID}, timed_caches_manager:get_timeout(DB)}.
+
+terminate (_, {DB, ObjectID}) ->
+   ets:delete(DB, ObjectID).
+
+code_change (_, State, _) ->
+   {ok, State}.
+
+format_status (_, [_, State]) ->
+   [{data, [{"State", State}]}].
+
+handle_info(timeout, State) ->
+   {stop, normal, State};
+handle_info(_, {DB, ObjectID}) ->
+   {noreply, {DB, ObjectID}, timed_caches_manager:get_timeout(DB)}.
+
+%%%% interface
+fetch (DB, ObjectID) ->
+   io:format("~nfetch from cache: ~p.~n", [{DB, ObjectID}]),
+   case ets:lookup(DB, ObjectID) of
+      [] -> add_to_cache(DB, ObjectID);
+
+      [{_, TimerPID, Data}] ->
+         gen_server:cast(TimerPID, ping),
+         Data
+   end.
+
+invalidate (DB, ObjectID) ->
+   case ets:lookup(DB, ObjectID) of
+      [] -> ok;
+
+      [{_, TimerPID, _}] ->
+         gen_server:stop(TimerPID)
+   end.
diff --git a/src/io/timed_caches_manager.erl b/src/io/timed_caches_manager.erl
new file mode 100644
index 0000000..ad66fbb
--- /dev/null
+++ b/src/io/timed_caches_manager.erl
@@ -0,0 +1,141 @@
+-module(timed_caches_manager).
+-behavior(gen_server).
+
+%%%% gen_server exports
+-export(
+   [
+      init/1,
+      handle_cast/2,
+      handle_call/3,
+      terminate/2,
+      code_change/3,
+      format_status/2,
+      handle_info/2
+   ]
+).
+
+%%%% actual interface
+-export(
+   [
+      add_cache/3,
+      inherit_cache/3,
+      delete_cache/2,
+      get_timeout/1
+   ]
+)
+.
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% LOCAL %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%%%% Manager %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+delete_cache (DB) ->
+   ets:delete(DB).
+
+add_cache (DB, none) ->
+   io:format("~nTimed Caches Manager added a new cache. ~n"),
+   ets:new(
+      DB,
+      [
+         set,
+         public,
+         named_table,
+         {keypos, 2},
+         {read_concurrency, true},
+         {heir, none}
+      ]
+   );
+add_cache (DB, Heir) ->
+   io:format("~nTimed Caches Manager added a new cache. ~n"),
+   ets:new(
+      DB,
+      [
+         set,
+         public,
+         named_table,
+         {keypos, 2},
+         {read_concurrency, true},
+         {heir, Heir, DB}
+      ]
+   ).
+
+inherit_cache (CacheList, DB, Heir) ->
+   case lists:member(DB, CacheList) of
+      true ->
+         ets:setopts(DB, {heir, Heir, DB}),
+         CacheList;
+
+      false ->
+         [DB|CacheList]
+   end.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% EXPORTED %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%% gen_server
+init (CacheList) ->
+   io:format("~nStarting Timed Caches Manager..."),
+   {ok, CacheList}.
+
+handle_call ({delete, CacheName}, _Caller, State) ->
+   {noreply, delete_cache(State, CacheName)};
+handle_call ({add, CacheName, Heir}, _Caller, State)->
+   {noreply, add_cache(State, CacheName, Heir)};
+handle_call ({inherit, CacheName, Heir}, _Caller, State)->
+   {noreply, inherit_cache(State, CacheName, Heir)};
+handle_call (terminate, _, State) ->
+   {stop, normal, State}.
+
+handle_cast ({delete, CacheName}, State) ->
+   {noreply, delete_cache(State, CacheName)};
+handle_cast ({add, CacheName, Heir}, State)->
+   {noreply, add_cache(State, CacheName, Heir)};
+handle_cast ({inherit, CacheName, Heir}, State)->
+   {noreply, inherit_cache(State, CacheName, Heir)};
+handle_cast (terminate, State) ->
+   {stop, normal, State}.
+
+terminate (_Reason, []) ->
+   ok;
+terminate (Reason, [CacheName|OtherCaches]) ->
+   delete_cache(CacheName),
+   terminate(Reason, OtherCaches).
+
+code_change (_, State, _) ->
+   {ok, State}.
+
+format_status (_, [_, State]) ->
+   [{data, [{"State", State}]}].
+
+handle_info(_, State) ->
+   {noreply, State}.
+
+%%%% actual interface
+delete_cache (CacheList, DB) ->
+   case lists:member(DB, CacheList) of
+      true ->
+         delete_cache(DB),
+         lists:delete(DB, CacheList);
+      false ->
+         CacheList
+   end.
+
+add_cache (CacheList, DB, Heir) ->
+   case lists:member(DB, CacheList) of
+      true when (Heir =:= none) ->
+         CacheList;
+
+      true ->
+         ets:setopts(DB, {heir, Heir, DB}),
+         CacheList;
+
+      false ->
+         add_cache(DB, Heir),
+         [DB|CacheList]
+   end.
+
+get_timeout(battlemap_db) ->
+   60000;
+get_timeout(_) ->
+   60000.