refactor(mgmt_api): use `select_table` congruously.

apps/emqx_gateway/src/emqx_gateway_api_clients.erl

@@ -201,9 +201,9 @@ query(Tab, {Qs, []}, Continuation, Limit) ->
 
 query(Tab, {Qs, Fuzzy}, Continuation, Limit) ->
     Ms = qs2ms(Qs),
-    MatchFun = match_fun(Ms, Fuzzy),
+    FuzzyFilterFun = fuzzy_filter_fun(Fuzzy),
-    emqx_mgmt_api:traverse_table(Tab, MatchFun, Continuation, Limit,
+    emqx_mgmt_api:select_table(Tab, {Ms, FuzzyFilterFun}, Continuation, Limit,
-                                 fun format_channel_info/1).
+                               fun format_channel_info/1).
 
 qs2ms(Qs) ->
     {MtchHead, Conds} = qs2ms(Qs, 2, {#{}, []}),
@@ -247,32 +247,26 @@ ms(created_at, X) ->
     #{session => #{created_at => X}}.
 
 %%--------------------------------------------------------------------
-%% Match funcs
+%% Fuzzy filter funcs
 
-match_fun(Ms, Fuzzy) ->
+fuzzy_filter_fun(Fuzzy) ->
-    MsC = ets:match_spec_compile(Ms),
     REFuzzy = lists:map(fun({K, like, S}) ->
         {ok, RE} = re:compile(S),
         {K, like, RE}
                         end, Fuzzy),
-    fun(Rows) ->
+    fun(MsRaws) when is_list(MsRaws) ->
-        case ets:match_spec_run(Rows, MsC) of
+            lists:filter( fun(E) -> run_fuzzy_filter(E, REFuzzy) end
-            [] -> [];
+                        , MsRaws)
-            Ls ->
-                lists:filter(fun(E) ->
-                    run_fuzzy_match(E, REFuzzy)
-                             end, Ls)
-        end
     end.
 
-run_fuzzy_match(_, []) ->
+run_fuzzy_filter(_, []) ->
     true;
-run_fuzzy_match(E = {_, #{clientinfo := ClientInfo}, _}, [{Key, _, RE}|Fuzzy]) ->
+run_fuzzy_filter(E = {_, #{clientinfo := ClientInfo}, _}, [{Key, _, RE}|Fuzzy]) ->
     Val = case maps:get(Key, ClientInfo, "") of
               undefined -> "";
               V -> V
           end,
-    re:run(Val, RE, [{capture, none}]) == match andalso run_fuzzy_match(E, Fuzzy).
+    re:run(Val, RE, [{capture, none}]) == match andalso run_fuzzy_filter(E, Fuzzy).
 
 %%--------------------------------------------------------------------
 %% format funcs

apps/emqx_management/src/emqx_mgmt_api.erl

@@ -27,7 +27,6 @@
 %% first_next query APIs
 -export([ node_query/5
         , cluster_query/4
-        , traverse_table/5
         , select_table/5
         ]).
 
@@ -197,40 +196,6 @@ rpc_call(Node, M, F, A, T) ->
 %% Table Select
 %%--------------------------------------------------------------------
 
-traverse_table(Tab, MatchFun, Start, Limit, FmtFun) ->
-    ets:safe_fixtable(Tab, true),
-    {NStart, Rows} = traverse_n_by_one(Tab, ets:first(Tab), MatchFun, Start, Limit, []),
-    ets:safe_fixtable(Tab, false),
-    {NStart, lists:map(FmtFun, Rows)}.
-
-%% @private
-traverse_n_by_one(_, '$end_of_table', _, Start, _, Acc) ->
-    {Start, lists:flatten(lists:reverse(Acc))};
-traverse_n_by_one(_, _, _, Start, _Limit=0, Acc) ->
-    {Start, lists:flatten(lists:reverse(Acc))};
-traverse_n_by_one(Tab, K, MatchFun, Start, Limit, Acc) ->
-    GetRows = fun _GetRows('$end_of_table', _, Ks) ->
-                      {'$end_of_table', Ks};
-                  _GetRows(Kn,  1, Ks) ->
-                      {ets:next(Tab, Kn), [ets:lookup(Tab, Kn) | Ks]};
-                  _GetRows(Kn, N, Ks) ->
-                      _GetRows(ets:next(Tab, Kn), N-1, [ets:lookup(Tab, Kn) | Ks])
-              end,
-    {K2, Rows} = GetRows(K, 100, []),
-    case MatchFun(lists:flatten(lists:reverse(Rows))) of
-        [] ->
-            traverse_n_by_one(Tab, K2, MatchFun, Start, Limit, Acc);
-        Ls ->
-            case Start - length(Ls) of
-                N when N > 0 -> %% Skip
-                    traverse_n_by_one(Tab, K2, MatchFun, N, Limit, Acc);
-                _ ->
-                    Got = lists:sublist(Ls, Start+1, Limit),
-                    NLimit = Limit - length(Got),
-                    traverse_n_by_one(Tab, K2, MatchFun, 0, NLimit, [Got|Acc])
-            end
-    end.
-
 select_table(Tab, {Ms, FuzzyFilterFun}, ?FRESH_SELECT, Limit, FmtFun)
   when is_function(FuzzyFilterFun) andalso Limit > 0 ->
     case ets:select(Tab, Ms, Limit) of

apps/emqx_management/src/emqx_mgmt_api_clients.erl

@@ -562,9 +562,9 @@ query(Tab, {Qs, []}, Continuation, Limit) ->
 
 query(Tab, {Qs, Fuzzy}, Continuation, Limit) ->
     Ms = qs2ms(Qs),
-    MatchFun = match_fun(Ms, Fuzzy),
+    FuzzyFilterFun = fuzzy_filter_fun(Fuzzy),
-    emqx_mgmt_api:traverse_table(Tab, MatchFun, Continuation, Limit,
+    emqx_mgmt_api:select_table(Tab, {Ms, FuzzyFilterFun}, Continuation, Limit,
-                                 fun format_channel_info/1).
+                               fun format_channel_info/1).
 
 %%--------------------------------------------------------------------
 %% QueryString to Match Spec
@@ -616,30 +616,24 @@ ms(created_at, X) ->
 %%--------------------------------------------------------------------
 %% Match funcs
 
-match_fun(Ms, Fuzzy) ->
+fuzzy_filter_fun(Fuzzy) ->
-    MsC = ets:match_spec_compile(Ms),
     REFuzzy = lists:map(fun({K, like, S}) ->
         {ok, RE} = re:compile(S),
         {K, like, RE}
                         end, Fuzzy),
-    fun(Rows) ->
+    fun(MsRaws) when is_list(MsRaws) ->
-        case ets:match_spec_run(Rows, MsC) of
+            lists:filter( fun(E) -> run_fuzzy_filter(E, REFuzzy) end
-            [] -> [];
+                        , MsRaws)
-            Ls ->
-                lists:filter(fun(E) ->
-                    run_fuzzy_match(E, REFuzzy)
-                             end, Ls)
-        end
     end.
 
-run_fuzzy_match(_, []) ->
+run_fuzzy_filter(_, []) ->
     true;
-run_fuzzy_match(E = {_, #{clientinfo := ClientInfo}, _}, [{Key, _, RE}|Fuzzy]) ->
+run_fuzzy_filter(E = {_, #{clientinfo := ClientInfo}, _}, [{Key, _, RE}|Fuzzy]) ->
     Val = case maps:get(Key, ClientInfo, "") of
               undefined -> "";
               V -> V
           end,
-    re:run(Val, RE, [{capture, none}]) == match andalso run_fuzzy_match(E, Fuzzy).
+    re:run(Val, RE, [{capture, none}]) == match andalso run_fuzzy_filter(E, Fuzzy).
 
 %%--------------------------------------------------------------------
 %% format funcs

apps/emqx_management/src/emqx_mgmt_api_subscriptions.erl

@@ -154,22 +154,19 @@ query(Tab, {Qs, []}, Continuation, Limit) ->
 
 query(Tab, {Qs, Fuzzy}, Continuation, Limit) ->
     Ms = qs2ms(Qs),
-    MatchFun = match_fun(Ms, Fuzzy),
+    FuzzyFilterFun = fuzzy_filter_fun(Fuzzy),
-    emqx_mgmt_api:traverse_table(Tab, MatchFun, Continuation, Limit, fun format/1).
+    emqx_mgmt_api:select_table(Tab, {Ms, FuzzyFilterFun}, Continuation, Limit, fun format/1).
 
-match_fun(Ms, Fuzzy) ->
+fuzzy_filter_fun(Fuzzy) ->
-    MsC = ets:match_spec_compile(Ms),
+    fun(MsRaws) when is_list(MsRaws) ->
-    fun(Rows) ->
+            lists:filter( fun(E) -> run_fuzzy_filter(E, Fuzzy) end
-         case ets:match_spec_run(Rows, MsC) of
+                        , MsRaws)
-             [] -> [];
-             Ls -> lists:filter(fun(E) -> run_fuzzy_match(E, Fuzzy) end, Ls)
-         end
     end.
 
-run_fuzzy_match(_, []) ->
+run_fuzzy_filter(_, []) ->
     true;
-run_fuzzy_match(E = {{_, Topic}, _}, [{topic, match, TopicFilter}|Fuzzy]) ->
+run_fuzzy_filter(E = {{_, Topic}, _}, [{topic, match, TopicFilter}|Fuzzy]) ->
-    emqx_topic:match(Topic, TopicFilter) andalso run_fuzzy_match(E, Fuzzy).
+    emqx_topic:match(Topic, TopicFilter) andalso run_fuzzy_filter(E, Fuzzy).
 
 %%--------------------------------------------------------------------
 %% Query String to Match Spec