add type specs

src/riak_kv_wterl_backend.erl

@@ -50,9 +50,9 @@
 %%-define(CAPABILITIES, [async_fold, indexes]).
 -define(CAPABILITIES, [async_fold]).
 
--record(state, {conn :: reference(),
+-record(state, {conn :: wterl:connection(),
                 table :: string(),
-                session :: reference(),
+                session :: wterl:session(),
                 partition :: integer()}).
 
 -type state() :: #state{}.
@@ -109,9 +109,9 @@ start(Partition, Config) ->
 
 %% @doc Stop the wterl backend
 -spec stop(state()) -> ok.
-stop(#state{session=SRef}) ->
+stop(#state{conn=ConnRef, session=SRef}) ->
     ok = wterl:session_close(SRef),
-    wterl_conn:close().
+    wterl_conn:close(ConnRef).
 
 %% @doc Retrieve an object from the wterl backend
 -spec get(riak_object:bucket(), riak_object:key(), state()) ->
@@ -246,7 +246,7 @@ fold_objects(FoldObjectsFun, Acc, Opts, #state{conn=ConnRef, table=Table}) ->
                 {ok, SRef} = wterl:session_open(ConnRef),
                 {ok, Cursor} = wterl:cursor_open(SRef, Table),
                 try
-                    wterl:fold(Cursor, FoldFun, Acc)
+                    wterl:fold_keys(Cursor, FoldFun, Acc)
                 catch
                     {break, AccFinal} ->
                         AccFinal

src/wterl.erl

@@ -20,8 +20,6 @@
 %%
 %% -------------------------------------------------------------------
 -module(wterl).
-
-
 -export([conn_open/2,
          conn_close/1,
          cursor_close/1,
@@ -62,6 +60,16 @@
          config_to_bin/1,
          fold_keys/3]).
 
+-type config() :: binary().
+-type config_list() :: [{atom(), any()}].
+-opaque connection() :: reference().
+-opaque session() :: reference().
+-opaque cursor() :: reference().
+-type key() :: binary().
+-type value() :: binary().
+
+-export_type([connection/0, session/0]).
+
 -on_load(init/0).
 
 -define(nif_stub, nif_stub_error(?LINE)).
@@ -74,6 +82,7 @@ nif_stub_error(Line) ->
 -include_lib("eunit/include/eunit.hrl").
 -endif.
 
+-spec init() -> ok | {error, any()}.
 init() ->
     PrivDir = case code:priv_dir(?MODULE) of
                   {error, bad_name} ->
@@ -85,109 +94,147 @@ init() ->
               end,
     erlang:load_nif(filename:join(PrivDir, ?MODULE), 0).
 
+-spec conn_open(string(), config()) -> {ok, connection()} | {error, term()}.
 conn_open(_HomeDir, _Config) ->
     ?nif_stub.
 
+-spec conn_close(connection()) -> ok | {error, term()}.
 conn_close(_ConnRef) ->
     ?nif_stub.
 
+-spec session_open(connection()) -> {ok, reference()} | {error, term()}.
 session_open(_ConnRef) ->
     ?nif_stub.
 
+-spec session_close(session()) -> ok | {error, term()}.
 session_close(_Ref) ->
     ?nif_stub.
 
+-spec session_create(session(), string()) -> ok | {error, term()}.
+-spec session_create(session(), string(), config()) -> ok | {error, term()}.
 session_create(Ref, Name) ->
     session_create(Ref, Name, ?EMPTY_CONFIG).
 session_create(_Ref, _Name, _Config) ->
     ?nif_stub.
 
+-spec session_drop(session(), string()) -> ok | {error, term()}.
+-spec session_drop(session(), string(), config()) -> ok | {error, term()}.
 session_drop(Ref, Name) ->
     session_drop(Ref, Name, ?EMPTY_CONFIG).
 session_drop(_Ref, _Name, _Config) ->
     ?nif_stub.
 
+-spec session_delete(session(), string(), key()) -> ok | {error, term()}.
 session_delete(_Ref, _Table, _Key) ->
     ?nif_stub.
 
+-spec session_get(session(), string(), key()) -> {ok, value()} | not_found | {error, term()}.
 session_get(_Ref, _Table, _Key) ->
     ?nif_stub.
 
+-spec session_put(session(), string(), key(), value()) -> ok | {error, term()}.
 session_put(_Ref, _Table, _Key, _Value) ->
     ?nif_stub.
 
+-spec session_rename(session(), string(), string()) -> ok | {error, term()}.
+-spec session_rename(session(), string(), string(), config()) -> ok | {error, term()}.
 session_rename(Ref, OldName, NewName) ->
     session_rename(Ref, OldName, NewName, ?EMPTY_CONFIG).
 session_rename(_Ref, _OldName, _NewName, _Config) ->
     ?nif_stub.
 
+-spec session_salvage(session(), string()) -> ok | {error, term()}.
+-spec session_salvage(session(), string(), config()) -> ok | {error, term()}.
 session_salvage(Ref, Name) ->
     session_salvage(Ref, Name, ?EMPTY_CONFIG).
 session_salvage(_Ref, _Name, _Config) ->
     ?nif_stub.
 
+-spec session_sync(session(), string()) -> ok | {error, term()}.
+-spec session_sync(session(), string(), config()) -> ok | {error, term()}.
 session_sync(Ref, Name) ->
     session_sync(Ref, Name, ?EMPTY_CONFIG).
 session_sync(_Ref, _Name, _Config) ->
     ?nif_stub.
 
+-spec session_truncate(session(), string()) -> ok | {error, term()}.
+-spec session_truncate(session(), string(), config()) -> ok | {error, term()}.
 session_truncate(Ref, Name) ->
     session_truncate(Ref, Name, ?EMPTY_CONFIG).
 session_truncate(_Ref, _Name, _Config) ->
     ?nif_stub.
 
+-spec session_upgrade(session(), string()) -> ok | {error, term()}.
+-spec session_upgrade(session(), string(), config()) -> ok | {error, term()}.
 session_upgrade(Ref, Name) ->
     session_upgrade(Ref, Name, ?EMPTY_CONFIG).
 session_upgrade(_Ref, _Name, _Config) ->
     ?nif_stub.
 
+-spec session_verify(session(), string()) -> ok | {error, term()}.
+-spec session_verify(session(), string(), config()) -> ok | {error, term()}.
 session_verify(Ref, Name) ->
     session_verify(Ref, Name, ?EMPTY_CONFIG).
 session_verify(_Ref, _Name, _Config) ->
     ?nif_stub.
 
+-spec cursor_open(session(), string()) -> {ok, cursor()} | {error, term()}.
 cursor_open(_Ref, _Table) ->
     ?nif_stub.
 
+-spec cursor_close(cursor()) -> ok | {error, term()}.
 cursor_close(_Cursor) ->
     ?nif_stub.
 
+-spec cursor_next(cursor()) -> {ok, key(), value()} | not_found | {error, term()}.
 cursor_next(_Cursor) ->
     ?nif_stub.
 
+-spec cursor_next_key(cursor()) -> {ok, key()} | not_found | {error, term()}.
 cursor_next_key(_Cursor) ->
     ?nif_stub.
 
+-spec cursor_next_value(cursor()) -> {ok, value()} | not_found | {error, term()}.
 cursor_next_value(_Cursor) ->
     ?nif_stub.
 
+-spec cursor_prev(cursor()) -> {ok, key(), value()} | not_found | {error, term()}.
 cursor_prev(_Cursor) ->
     ?nif_stub.
 
+-spec cursor_prev_key(cursor()) -> {ok, key()} | not_found | {error, term()}.
 cursor_prev_key(_Cursor) ->
     ?nif_stub.
 
+-spec cursor_prev_value(cursor()) -> {ok, value()} | not_found | {error, term()}.
 cursor_prev_value(_Cursor) ->
     ?nif_stub.
 
+-spec cursor_search(cursor(), key()) -> {ok, value()} | {error, term()}.
 cursor_search(_Cursor, _Key) ->
     ?nif_stub.
 
+-spec cursor_search_near(cursor(), key()) -> {ok, value()} | {error, term()}.
 cursor_search_near(_Cursor, _Key) ->
     ?nif_stub.
 
+-spec cursor_reset(cursor()) -> ok | {error, term()}.
 cursor_reset(_Cursor) ->
     ?nif_stub.
 
+-spec cursor_insert(cursor(), key(), value()) -> ok | {error, term()}.
 cursor_insert(_Cursor, _Key, _Value) ->
     ?nif_stub.
 
+-spec cursor_update(cursor(), key(), value()) -> ok | {error, term()}.
 cursor_update(_Cursor, _Key, _Value) ->
     ?nif_stub.
 
+-spec cursor_remove(cursor(), key(), value()) -> ok | {error, term()}.
 cursor_remove(_Cursor, _Key, _Value) ->
     ?nif_stub.
 
+-spec fold_keys(cursor(), fun(), any()) -> any().
 fold_keys(Cursor, Fun, Acc0) ->
     fold_keys(Cursor, Fun, Acc0, cursor_next_key(Cursor)).
 fold_keys(_Cursor, _Fun, Acc, not_found) ->
@@ -232,6 +279,7 @@ config_encode(bool, false) ->
 config_encode(_Type, _Value) ->
     invalid.
 
+-spec config_to_bin(config_list()) -> config().
 config_to_bin(Opts) ->
     config_to_bin(Opts, []).
 config_to_bin([], Acc) ->

src/wterl_conn.erl

@@ -30,35 +30,41 @@
 
 %% API
 -export([start_link/0, stop/0,
-         open/1, is_open/0, get/0, close/0]).
+         open/1, is_open/0, get/0, close/1]).
 
 %% gen_server callbacks
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
          terminate/2, code_change/3]).
 
--record(state, {conn,
+-record(state, {conn :: reference(),
-                monitors}).
+                monitors :: ets:tid()}).
 
 %% ====================================================================
 %% API
 %% ====================================================================
 
+-spec start_link() -> {ok, pid()} | {error, term()}.
 start_link() ->
     gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
 
+-spec stop() -> ok.
 stop() ->
     gen_server:cast(?MODULE, stop).
 
+-spec open(string()) -> {ok, wterl:connection()} | {error, term()}.
 open(Dir) ->
     gen_server:call(?MODULE, {open, Dir, self()}, infinity).
 
+-spec is_open() -> boolean().
 is_open() ->
     gen_server:call(?MODULE, is_open, infinity).
 
+-spec get() -> {ok, reference()} | {error, term()}.
 get() ->
     gen_server:call(?MODULE, get, infinity).
 
-close() ->
+-spec close(wterl:connection()) -> ok.
+close(_Conn) ->
     gen_server:call(?MODULE, {close, self()}, infinity).
 
 %% ====================================================================
@@ -99,7 +105,7 @@ handle_call({close, Caller}, _From, #state{conn=ConnRef, monitors=Monitors}=Stat
     true = ets:delete(Monitors, Monitor),
     NState = case ets:info(Monitors, size) of
                  0 ->
-                     close(ConnRef),
+                     do_close(ConnRef),
                      ets:delete(Monitors),
                      State#state{conn=undefined, monitors=undefined};
                  _ ->
@@ -110,7 +116,7 @@ handle_call({close, Caller}, _From, #state{conn=ConnRef, monitors=Monitors}=Stat
 handle_cast(stop, #state{conn=undefined}=State) ->
     {noreply, State};
 handle_cast(stop, #state{conn=ConnRef, monitors=Monitors}=State) ->
-    close(ConnRef),
+    do_close(ConnRef),
     ets:foldl(fun({Monitor, _}, _) ->
                       true = erl:demonitor(Monitor, [flush])
               end, true, Monitors),
@@ -124,7 +130,7 @@ handle_info({'DOWN', Monitor, _, _, _}, #state{conn=ConnRef, monitors=Monitors}=
                      true = ets:delete(Monitors, Monitor),
                      case ets:info(Monitors, size) of
                          0 ->
-                             close(ConnRef),
+                             do_close(ConnRef),
                              ets:delete(Monitors),
                              State#state{conn=undefined, monitors=undefined};
                          _ ->
@@ -138,7 +144,7 @@ handle_info(_Info, State) ->
     {noreply, State}.
 
 terminate(_Reason, #state{conn = ConnRef}) ->
-    close(ConnRef),
+    do_close(ConnRef),
     ok.
 
 code_change(_OldVsn, State, _Extra) ->
@@ -148,9 +154,9 @@ code_change(_OldVsn, State, _Extra) ->
 %% Internal functions
 %% ====================================================================
 
-close(undefined) ->
+do_close(undefined) ->
     ok;
-close(ConnRef) ->
+do_close(ConnRef) ->
     wterl:conn_close(ConnRef).
 
 
@@ -182,18 +188,18 @@ simple_test_() ->
        end}]}.
 
 open_one() ->
-    {ok, _Ref} = open("test/wterl-backend"),
+    {ok, Ref} = open("test/wterl-backend"),
     true = is_open(),
-    close(),
+    close(Ref),
     false = is_open(),
     ok.
 
 open_and_wait(Pid) ->
-    {ok, _Ref} = open("test/wterl-backend"),
+    {ok, Ref} = open("test/wterl-backend"),
     Pid ! open,
     receive
         close ->
-            close(),
+            close(Ref),
             Pid ! close;
         exit ->
             exit(normal)