Elaborate on audit_log:rediscover_logs/N. Remove unused `audit_log_…

…disk:async_send_msg/2`.
freza · Jan 18, 2012 · 0b7ffd8 · 0b7ffd8
1 parent 449187e
commit 0b7ffd8
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diff --git a/README.md b/README.md
@@ -15,7 +15,7 @@ Lightweight audit logging library.
 ## History
 
 * 2005-2010 Chandrashekhar Mullaparthi
-* 2010-2011 Jachym Holecek
+* 2010-2012 Jachym Holecek
 
 ## Features
 
@@ -150,11 +150,15 @@ audit_log:clean_old(Log) -> ok | {error, _}.
   automatically according to log options.
 
 ```erlang
-audit_log:rediscover_logs() -> [{Log, Ret}].
+audit_log:rediscover_logs() -> ok.
+audit_log:rediscover_logs(App) -> ok.
 ```
 
-* Ensure all currently known logs are up and running. `Ret` is the return value
+* Ensure all logs are up and running, either for given application or for all loaded
-  of `audit_log:open_log/N`.
+  applications. List of logs and default options are read from `audit_log` key in
+  application resource file (`*.app`) ensuring all logs are loaded in configuration
+  table. Subsequently it is ensured worker processes are running for all entries in
+  that table.
 
 ### Maintenance API
 
@@ -186,7 +190,9 @@ audit_log:create_db(Mnesia_opts) -> Mnesia_ret.
 
 * This can be used to manually create configuration table in cases where default
   table options aren't desirable. Should be called before `audit_log` is first
-  started.
+  started. By default configuration table is set up at application startup
+  ensuring disc copies replica exists on current node and with `local_content`
+  flag set.
 
 ### Utility API
 

diff --git a/src/audit_log.erl b/src/audit_log.erl
@@ -29,11 +29,11 @@
 
 -export([open_log/1, open_log/2, audit_msg/2, audit_msg/3, syslog_msg/1, syslog_msg/2, close_log/1]).
 -export([get_config/0, get_config/1, set_config/1, set_config/2, get_status/0, get_status/1]).
--export([change_file/1, clean_old/1, rediscover_logs/0]).
+-export([change_file/1, clean_old/1, rediscover_logs/0, rediscover_logs/1]).
 -export([create_db/0, create_db/1]).
 
 -import(audit_log_lib, [get_env/3]).
--import(lists, [foreach/2, keysort/2]).
+-import(lists, [keysort/2]).
 
 -include("audit_log_db.hrl").
 
@@ -57,18 +57,8 @@ open_log(Log) ->
     open_log(Log, []).
 
 open_log(Log, Opts) ->
-    mnesia:activity(transaction, fun () -> do_set_config(Log, Opts) end),
+    mnesia:activity(transaction, fun () -> edit_log(Log, Opts, false) end),
-    try audit_log_sup:add_worker(Log) of
+    start_log(Log).
-	{ok, _} ->
-	    {ok, started};
-	{error, {already_started, _}} ->
-	    {ok, running};
-	{error, _} = Err ->
-	    Err
-    catch
-	exit : {noproc, _} ->
-	    {ok, added}
-    end.
 
 close_log(Log) ->
     try audit_log_sup:del_worker(Log) catch
@@ -84,30 +74,37 @@ clean_old(Log) ->
     audit_log_disk:clean_old(Log).
 
 rediscover_logs() ->
-    %% Applications can use this to ensure all logs are usable.
+    mnesia:activity(transaction, fun () -> scan_all_specs() end),
-    [{Log, open_log(Log)} || Log <- mnesia:dirty_all_keys(audit_log_conf)].
+    [start_log(Log) || Log <- mnesia:dirty_all_keys(audit_log_conf)],
+    ok.
+
+rediscover_logs(App) ->
+    mnesia:activity(transaction, fun () -> scan_app_specs(App) end),
+    [start_log(Log) || Log <- mnesia:dirty_all_keys(audit_log_conf)],
+    ok.
 
 %%% Maintenance API.
 
 get_config() ->
     Read = fun () ->
-		   [{Log, do_get_config(Log)} || Log <- mnesia:all_keys(audit_log_conf)]
+		   [{Log, edit_log(Log, [], false)} || Log <- mnesia:all_keys(audit_log_conf)]
 	   end,
     keysort(1, mnesia:activity(transaction, Read)).
 
 get_config(Log) ->
-    mnesia:activity(transaction, fun () -> do_get_config(Log) end).
+    mnesia:activity(transaction, fun () -> edit_log(Log, [], false) end).
 
 set_config(Opts) ->
     Edit = fun () ->
-		   foreach(fun (Log) -> do_set_config(Log, Opts) end, All = mnesia:all_keys(audit_log_conf)),
+		   All_logs = mnesia:all_keys(audit_log_conf),
-		   All
+		   [edit_log(Log, Opts, true) || Log <- All_logs],
+		   All_logs
 	   end,
     [(catch audit_log_disk:set_options(Log)) || Log <- mnesia:activity(transaction, Edit)],
     ok.
 
 set_config(Log, Opts) ->
-    mnesia:activity(transaction, fun () -> do_set_config(Log, Opts) end),
+    mnesia:activity(transaction, fun () -> edit_log(Log, Opts, true) end),
     audit_log_disk:set_options(Log).
 
 get_status() ->
@@ -132,13 +129,43 @@ create_db(Opts) ->
 
 %%% Utilities.
 
-do_get_config(Log) ->
+%% Attempt to start log process for some log.
-    [#audit_log_conf{opts = Opts}] = mnesia:read(audit_log_conf, Log),
+start_log(Log) ->
-    Opts.
+    try audit_log_sup:add_worker(Log) of
+	{ok, _} ->
+	    {ok, started};
+	{error, {already_started, _}} ->
+	    {ok, running};
+	{error, _} = Err ->
+	    Err
+    catch
+	exit : {noproc, _} ->
+	    {ok, added}
+    end.
+
+%% Ensure all logs mentioned in *.app files of loaded applications are provisioned in Mnesia.
+scan_all_specs() ->
+    [scan_app_specs(App) || {App, _, _} <- application:loaded_applications()],
+    ok.
+
+scan_app_specs(App) ->
+    [edit_log(Log, Opts, false) || {Log, Opts} <- get_key(App, audit_log, [])],
+    ok.
+
+get_key(App, Key, Def) ->
+    case application:get_key(App, Key) of
+	{ok, Val} ->
+	    Val;
+	undefined ->
+	    Def
+    end.
 
-do_set_config(Log, Opts) ->
+%% NB `edit_log(Log, [], false)` can be used to just fetch log options.
+edit_log(Log, Opts, Do_force) ->
     case mnesia:read(audit_log_conf, Log) of
-	[#audit_log_conf{opts = Prev} = CF] ->
+	[#audit_log_conf{opts = Os}] when Do_force == false ->
+	    Os;
+	[#audit_log_conf{opts = Prev} = CF] when Do_force == true ->
 	    mnesia:write(CF#audit_log_conf{log = Log, opts = Os = merge_opts(Opts, Prev)}),
 	    Os;
 	[] ->

diff --git a/src/audit_log_disk.erl b/src/audit_log_disk.erl
@@ -30,7 +30,6 @@
 
 -export([start_link/1, send_msg/2, set_options/1, get_status/1, change_file/1, clean_old/1]).
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
--export([async_send_msg/2]).
 
 -import(audit_log_lib, [get_value/3, make_two/1, secs_to_midnight/0]).
 -import(filename, [basename/1, dirname/1, rootname/2, absname/1, join/1, split/1]).
@@ -59,9 +58,6 @@ change_file(Pid) ->
 clean_old(Pid) ->
     gen_server:call(Pid, clean_old).
 
-async_send_msg(Pid, Msg) ->
-    gen_server:cast(Pid, {send_msg, Msg}).
-
 %%% Generic server.
 
 -record(state, {
@@ -123,8 +119,6 @@ handle_info({'EXIT', _, Reason}, State) when Reason /= normal ->
 handle_info(_, State) ->
     {noreply, State}.
 
-handle_cast({send_msg, Msg}, State) ->
-    {noreply, write(State, Msg)};
 handle_cast(_, State) ->
     {noreply, State}.