* src/ejabberd_update.erl: Support for run-time ejabberd updating

(not completed)
* src/ejabberd_c2s.erl: Added 'update_info' module attribute for
testing ejabberd_update

SVN Revision: 494

src/ejabberd_update.erl

@@ -0,0 +1,113 @@
+%%%-------------------------------------------------------------------
+%%% File    : ejabberd_update.erl
+%%% Author  : Alexey Shchepin <alexey@sevcom.net>
+%%% Purpose : Update ejabberd
+%%% Created : 27 Jan 2006 by Alexey Shchepin <alexey@sevcom.net>
+%%% Id      : $Id: ejabberd_c2s.erl 492 2006-01-25 00:35:12Z alexey $
+%%%-------------------------------------------------------------------
+
+-module(ejabberd_update).
+-author('alexey@sevcom.net').
+
+%% API
+-export([update/0]).
+
+%%====================================================================
+%% API
+%%====================================================================
+update() ->
+    Dir = filename:dirname(code:which(ejabberd)),
+    case file:list_dir(Dir) of
+	{ok, Files} ->
+	    Beams = [list_to_atom(filename:rootname(FN)) ||
+			FN <- Files, lists:suffix(".beam", FN)],
+	    UpdatedBeams =
+		lists:filter(
+		  fun(Module) ->
+			  {ok, {Module, [NewVsn]}} =
+			      beam_lib:version(code:which(Module)),
+			  case code:is_loaded(Module) of
+			      {file, _} ->
+				  Attrs = Module:module_info(attributes),
+				  {value, {vsn, [CurVsn]}} =
+				      lists:keysearch(vsn, 1, Attrs),
+				  NewVsn /= CurVsn;
+			      false ->
+				  false
+			  end
+		  end, Beams),
+	    io:format("beam files: ~p~n", [UpdatedBeams]),
+	    Script = make_script(UpdatedBeams),
+	    io:format("script: ~p~n", [Script]),
+	    LowLevelScript = make_low_level_script(UpdatedBeams, Script),
+	    io:format("low level script: ~p~n", [LowLevelScript]),
+	    Check =
+		release_handler_1:check_script(
+		  LowLevelScript,
+		  [{ejabberd, "", filename:join(Dir, "..")}]),
+	    io:format("check: ~p~n", [Check]),
+	    Eval =
+		release_handler_1:eval_script(
+		  LowLevelScript, [],
+		  [{ejabberd, "", filename:join(Dir, "..")}]),
+	    io:format("eval: ~p~n", [Eval]);
+	{error, Reason} ->
+	    {error, Reason}
+    end.
+
+
+%%--------------------------------------------------------------------
+%%% Internal functions
+%%--------------------------------------------------------------------
+
+%% From systools.hrl
+-record(application, 
+	{name,			%% Name of the application, atom().
+         type = permanent,	%% Application start type, atom().
+	 vsn = "",         	%% Version of the application, string().
+	 id = "",		%% Id of the application, string().
+	 description = "",	%% Description of application, string().
+	 modules = [],		%% [Module | {Module,Vsn}] of modules 
+				%% incorporated in the application, 
+				%% Module = atom(), Vsn = string().
+	 uses = [],		%% [Application] list of applications required
+	 			%% by the application, Application = atom().
+	 includes = [],		%% [Application] list of applications included
+	 			%% by the application, Application = atom().
+	 regs = [],		%% [RegNames] a list of registered process 
+				%% names used by the application, RegNames =
+				%% atom().
+	 env = [],		%% [{Key,Value}] environment variable of 
+	 			%% application, Key = Value = term().
+	 maxT = infinity,	%% Max time an application may exist, 
+				%% integer() | infinity.
+	 maxP = infinity,  	%% Max number of processes in an application,
+	 			%% integer() | infinity.
+	 mod = [],		%% [] | {Mod, StartArgs}, Mod= atom(), 
+				%% StartArgs = list().
+	 start_phases = [],	%% [] | {Phase, PhaseArgs}, Phase = atom(),
+				%% PhaseArgs = list().
+         dir = ""		%% The directory where the .app file was 
+				%% found (internal use).
+	}).
+
+
+make_script(UpdatedBeams) ->
+    lists:map(
+      fun(Module) ->
+	      {ok, {Module, [{attributes, Attrs}]}} =
+		  beam_lib:chunks(code:which(Module), [attributes]),
+	      case lists:keysearch(update_info, 1, Attrs) of
+		  {value, {_, [{update, Extra}]}} ->
+		      {update, Module, {advanced, Extra}};
+		  false ->
+		      {load_module, Module}
+	      end
+      end, UpdatedBeams).
+
+make_low_level_script(UpdatedBeams, Script) ->
+    EJDApp = #application{name = ejabberd,
+			  modules = UpdatedBeams},
+    {ok, LowLevelScript} =
+	systools_rc:translate_scripts([Script], [EJDApp], [EJDApp]),
+    LowLevelScript.