Make it possible to select backend perm storage

4 files changed, 179 insertions, 140 deletions

diff --git a/src/fsdb.erl b/src/fsdb.erl
new file mode 100644
index 0000000..3e1b9b9
--- /dev/null
+++ b/src/fsdb.erl
@@ -0,0 +1,157 @@
+%%% Copyright (c) 2014-2015, NORDUnet A/S.
+%%% See LICENSE for licensing information.
+
+-module(fsdb).
+-behaviour(gen_server).
+
+-export([start_link/2, stop/1, init_module/0]).
+-export([getvalue/2, addvalue/3, commit/1, commit/2]).
+
+%% gen_server callbacks.
+-export([init/1, handle_call/3, terminate/2, handle_cast/2, handle_info/2,
+         code_change/3]).
+
+-record(state, {name, dirtylistname}).
+
+-define(DIRECTORY_TABLE, perm_directory).
+
+init_module() ->
+    case ets:info(?DIRECTORY_TABLE) of
+	undefined -> ok;
+	_ -> ets:delete(?DIRECTORY_TABLE)
+    end,
+    ets:new(?DIRECTORY_TABLE, [set, public, named_table]).
+
+start_link(Name, Filename) ->
+    gen_server:start_link({local, Name}, ?MODULE,
+                          [Name, Filename], []).
+
+stop(Name) ->
+    gen_server:call(Name, stop).
+
+addfsyncfiles(Name, Files) ->
+    gen_server:call(Name, {addfsyncfiles, Files}).
+
+init([Name, Filename]) ->
+    Dirtylistname = list_to_atom(atom_to_list(Name) ++ "_dirty"),
+    true = ets:insert(?DIRECTORY_TABLE, {Name, Filename ++ "/"}),
+    ets:new(Dirtylistname, [set, public, named_table]),
+    {ok, #state{name = Name, dirtylistname = Dirtylistname}}.
+
+handle_cast(_Request, State) ->
+    {noreply, State}.
+
+handle_info(_Info, State) ->
+    {noreply, State}.
+
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.
+
+terminate(_Reason, _State) ->
+    io:format("~p terminating~n", [?MODULE]),
+    ok.
+
+handle_call({addfsyncfiles, Files}, _From, State) ->
+    Insert = lists:map(fun (File) -> {File} end, Files),
+    ets:insert(State#state.dirtylistname, Insert),
+    {reply, ok, State};
+handle_call({commit, Timeout}, _From, State) ->
+    lager:debug("doing commit for ~p", [State#state.name]),
+    Files = lists:map(fun ([File]) -> File end, ets:match(State#state.dirtylistname, {'$1'})),
+    util:fsync(Files, Timeout),
+    ets:delete_all_objects(State#state.dirtylistname),
+    {reply, ok, State};
+handle_call(stop, _From, State) ->
+    {stop, normal, stopped, State}.
+
+getvalue(Name, Key) ->
+    [{_, Filename}] = ets:lookup(?DIRECTORY_TABLE, Name),
+    readfile(Filename, Key).
+
+addvalue(Name, Key, Value) ->
+    [{_, Filename}] = ets:lookup(?DIRECTORY_TABLE, Name),
+    {Result, FsyncFiles} = ensurefile(Filename, Key, Value),
+    addfsyncfiles(Name, FsyncFiles),
+    Result.
+
+commit(Name) ->
+    commit(Name, 5000).
+
+commit(Name, Timeout) ->
+    gen_server:call(Name, {commit, Timeout}, Timeout).
+
+-spec readfile_and_verify(string(), binary()) -> ok | differ | {error, atom()}.
+readfile_and_verify(Name, Content) ->
+    case file:read_file(Name) of
+        {ok, ContentsRead} when Content == ContentsRead ->
+            ok;
+        {ok, _ContentsRead} ->
+            differ;
+        {error, Error} ->
+            {error, Error}
+    end.
+
+-spec make_dir(string()) -> ok | {error, atom()}.
+make_dir(Name) ->
+    case file:make_dir(Name) of
+	ok ->
+	    ok;
+	{error, eexist} ->
+	    ok;
+	{error, Error} ->
+	    {error, Error}
+    end.
+
+-spec make_dirs([string()]) -> ok | {error, atom()}.
+make_dirs([]) ->
+    ok;
+make_dirs([Name | Rest]) ->
+    case make_dir(Name) of
+	ok ->
+	    make_dirs(Rest);
+	{error, Error} ->
+	    {error, Error}
+    end.
+
+-spec path_for_key(string(), binary()) -> {[string()], string()}.
+path_for_key(Rootdir, Key) ->
+    Name = hex:bin_to_hexstr(Key),
+    [C1, C2, C3, C4, C5, C6 | _] = Name,
+    Firstlevel = Rootdir ++ [C1, C2],
+    Secondlevel = Firstlevel ++ "/" ++ [C3, C4],
+    Thirdlevel = Secondlevel ++ "/" ++ [C5, C6],
+    Fullpath = Thirdlevel ++ "/" ++ Name,
+    {[Firstlevel, Secondlevel, Thirdlevel], Fullpath}.
+
+ensurefile(Rootdir, Key, Content) ->
+    lager:debug("dir ~p key ~s", [Rootdir, mochihex:to_hex(Key)]),
+    {Dirs, Path} = path_for_key(Rootdir, Key),
+    Result =
+        case readfile_and_verify(Path, Content) of
+            ok ->
+                lager:debug("key ~s existed, fsync", [mochihex:to_hex(Key)]),
+                ok = util:fsync([Path, Rootdir | Dirs]),
+                lager:debug("key ~s fsynced", [mochihex:to_hex(Key)]),
+                ok;
+            differ ->
+                lager:debug("key ~s existed, was different",
+                            [mochihex:to_hex(Key)]),
+                differ;
+            {error, enoent} ->
+                lager:debug("key ~s didn't exist, add", [mochihex:to_hex(Key)]),
+                util:check_error(make_dirs([Rootdir, Rootdir ++ "nursery/"]
+                                           ++ Dirs),
+                                 makedir, "Error creating directory"),
+                NurseryName = Rootdir ++ "nursery/" ++
+                    util:tempfilename(hex:bin_to_hexstr(Key)),
+                util:write_tempfile_and_rename(Path, NurseryName, Content),
+                ok;
+            {error, Error} ->
+                util:exit_with_error(Error, readfile, "Error reading file")
+        end,
+    {Result, [Path, Rootdir | Dirs]}.
+
+-spec readfile(string(), binary()) -> binary() | noentry.
+readfile(Rootdir, Key) ->
+    {_Dirs, Path} = path_for_key(Rootdir, Key),
+    atomic:readfile(Path).
diff --git a/src/perm.erl b/src/perm.erl
index 6c62b59..2e12fdf 100644
--- a/src/perm.erl
+++ b/src/perm.erl
@@ -1,157 +1,36 @@
-%%% Copyright (c) 2014-2015, NORDUnet A/S.
+%%% Copyright (c) 2015, NORDUnet A/S.
 %%% See LICENSE for licensing information.
 
 -module(perm).
--behaviour(gen_server).
 
--export([start_link/2, stop/1, init_directory_table/0]).
+-export([start_link/2, stop/1, init_module/0]).
 -export([getvalue/2, addvalue/3, commit/1, commit/2]).
 
-%% gen_server callbacks.
--export([init/1, handle_call/3, terminate/2, handle_cast/2, handle_info/2,
-         code_change/3]).
-
--record(state, {name, dirtylistname}).
-
--define(DIRECTORY_TABLE, perm_directory).
-
-init_directory_table() ->
-    case ets:info(?DIRECTORY_TABLE) of
-	undefined -> ok;
-	_ -> ets:delete(?DIRECTORY_TABLE)
-    end,
-    ets:new(?DIRECTORY_TABLE, [set, public, named_table]).
-
 start_link(Name, Filename) ->
-    gen_server:start_link({local, Name}, ?MODULE,
-                          [Name, Filename], []).
+    Module = application:get_env(plop, db_backend, fsdb),
+    Module:start_link(Name, Filename).
 
 stop(Name) ->
-    gen_server:call(Name, stop).
-
-addfsyncfiles(Name, Files) ->
-    gen_server:call(Name, {addfsyncfiles, Files}).
-
-init([Name, Filename]) ->
-    Dirtylistname = list_to_atom(atom_to_list(Name) ++ "_dirty"),
-    true = ets:insert(?DIRECTORY_TABLE, {Name, Filename}),
-    ets:new(Dirtylistname, [set, public, named_table]),
-    {ok, #state{name = Name, dirtylistname = Dirtylistname}}.
-
-handle_cast(_Request, State) ->
-    {noreply, State}.
-
-handle_info(_Info, State) ->
-    {noreply, State}.
+    Module = application:get_env(plop, db_backend, fsdb),
+    Module:stop(Name).
 
-code_change(_OldVsn, State, _Extra) ->
-    {ok, State}.
-
-terminate(_Reason, _State) ->
-    io:format("~p terminating~n", [?MODULE]),
-    ok.
-
-handle_call({addfsyncfiles, Files}, _From, State) ->
-    Insert = lists:map(fun (File) -> {File} end, Files),
-    ets:insert(State#state.dirtylistname, Insert),
-    {reply, ok, State};
-handle_call({commit, Timeout}, _From, State) ->
-    lager:debug("doing commit for ~p", [State#state.name]),
-    Files = lists:map(fun ([File]) -> File end, ets:match(State#state.dirtylistname, {'$1'})),
-    util:fsync(Files, Timeout),
-    ets:delete_all_objects(State#state.dirtylistname),
-    {reply, ok, State};
-handle_call(stop, _From, State) ->
-    {stop, normal, stopped, State}.
+init_module() ->
+    Module = application:get_env(plop, db_backend, fsdb),
+    Module:init_module().
 
 getvalue(Name, Key) ->
-    [{_, Filename}] = ets:lookup(?DIRECTORY_TABLE, Name),
-    readfile(Filename, Key).
+    Module = application:get_env(plop, db_backend, fsdb),
+    Module:getvalue(Name, Key).
 
 addvalue(Name, Key, Value) ->
-    [{_, Filename}] = ets:lookup(?DIRECTORY_TABLE, Name),
-    {Result, FsyncFiles} = ensurefile(Filename, Key, Value),
-    addfsyncfiles(Name, FsyncFiles),
-    Result.
+    Module = application:get_env(plop, db_backend, fsdb),
+    Module:addvalue(Name, Key, Value).
 
 commit(Name) ->
-    commit(Name, 5000).
+    Module = application:get_env(plop, db_backend, fsdb),
+    Module:commit(Name).
 
 commit(Name, Timeout) ->
-    gen_server:call(Name, {commit, Timeout}, Timeout).
-
--spec readfile_and_verify(string(), binary()) -> ok | differ | {error, atom()}.
-readfile_and_verify(Name, Content) ->
-    case file:read_file(Name) of
-        {ok, ContentsRead} when Content == ContentsRead ->
-            ok;
-        {ok, _ContentsRead} ->
-            differ;
-        {error, Error} ->
-            {error, Error}
-    end.
-
--spec make_dir(string()) -> ok | {error, atom()}.
-make_dir(Name) ->
-    case file:make_dir(Name) of
-	ok ->
-	    ok;
-	{error, eexist} ->
-	    ok;
-	{error, Error} ->
-	    {error, Error}
-    end.
-
--spec make_dirs([string()]) -> ok | {error, atom()}.
-make_dirs([]) ->
-    ok;
-make_dirs([Name | Rest]) ->
-    case make_dir(Name) of
-	ok ->
-	    make_dirs(Rest);
-	{error, Error} ->
-	    {error, Error}
-    end.
-
--spec path_for_key(string(), binary()) -> {[string()], string()}.
-path_for_key(Rootdir, Key) ->
-    Name = hex:bin_to_hexstr(Key),
-    [C1, C2, C3, C4, C5, C6 | _] = Name,
-    Firstlevel = Rootdir ++ [C1, C2],
-    Secondlevel = Firstlevel ++ "/" ++ [C3, C4],
-    Thirdlevel = Secondlevel ++ "/" ++ [C5, C6],
-    Fullpath = Thirdlevel ++ "/" ++ Name,
-    {[Firstlevel, Secondlevel, Thirdlevel], Fullpath}.
-
-ensurefile(Rootdir, Key, Content) ->
-    lager:debug("dir ~p key ~s", [Rootdir, mochihex:to_hex(Key)]),
-    {Dirs, Path} = path_for_key(Rootdir, Key),
-    Result =
-        case readfile_and_verify(Path, Content) of
-            ok ->
-                lager:debug("key ~s existed, fsync", [mochihex:to_hex(Key)]),
-                ok = util:fsync([Path, Rootdir | Dirs]),
-                lager:debug("key ~s fsynced", [mochihex:to_hex(Key)]),
-                ok;
-            differ ->
-                lager:debug("key ~s existed, was different",
-                            [mochihex:to_hex(Key)]),
-                differ;
-            {error, enoent} ->
-                lager:debug("key ~s didn't exist, add", [mochihex:to_hex(Key)]),
-                util:check_error(make_dirs([Rootdir, Rootdir ++ "nursery/"]
-                                           ++ Dirs),
-                                 makedir, "Error creating directory"),
-                NurseryName = Rootdir ++ "nursery/" ++
-                    util:tempfilename(hex:bin_to_hexstr(Key)),
-                util:write_tempfile_and_rename(Path, NurseryName, Content),
-                ok;
-            {error, Error} ->
-                util:exit_with_error(Error, readfile, "Error reading file")
-        end,
-    {Result, [Path, Rootdir | Dirs]}.
+    Module = application:get_env(plop, db_backend, fsdb),
+    Module:commit(Name, Timeout).
 
--spec readfile(string(), binary()) -> binary() | noentry.
-readfile(Rootdir, Key) ->
-    {_Dirs, Path} = path_for_key(Rootdir, Key),
-    atomic:readfile(Path).
diff --git a/src/permdb.erl b/src/permdb.erl
index 0cb3c2f..cc878f4 100644
--- a/src/permdb.erl
+++ b/src/permdb.erl
@@ -5,7 +5,7 @@
 
 -behaviour(gen_server).
 
--export([start_link/2, stop/1]).
+-export([start_link/2, stop/1, init_module/0]).
 -export([getvalue/2, addvalue/3, commit/1, commit/2]).
 
 %% gen_server callbacks.
@@ -127,6 +127,9 @@ init([Name, Filename]) ->
                 indexfile = IndexFile,
                 requests = queue:new()}}.
 
+init_module() ->
+    ok.
+
 start_link(Name, Filename) ->
     gen_server:start_link({local, Name}, ?MODULE,
                           [Name, Filename], []).
diff --git a/src/plop_app.erl b/src/plop_app.erl
index e154555..dc896e2 100644
--- a/src/plop_app.erl
+++ b/src/plop_app.erl
@@ -9,7 +9,7 @@ start(normal, Args) ->
     hackney:start(),
     http_auth:init_key_table(),
     plop:initsize(),
-    perm:init_directory_table(),
+    perm:init_module(),
     plop_sup:start_link(Args).
 
 stop(_State) ->