refactor(ft): prefer plain `files` over `exports` in generic APIs

So there's no more `exports` magically becomings `files` in the
REST API which was slightly confusing.

apps/emqx_ft/src/emqx_ft_api.erl

@@ -67,9 +67,9 @@ schema("/file_transfer/files") ->
     }.
 
 '/file_transfer/files'(get, #{}) ->
-    case emqx_ft_storage:exports() of
-        {ok, Transfers} ->
-            {200, #{<<"files">> => lists:map(fun format_export_info/1, Transfers)}};
+    case emqx_ft_storage:files() of
+        {ok, Files} ->
+            {200, #{<<"files">> => lists:map(fun format_file_info/1, Files)}};
         {error, _} ->
             {503, error_msg('SERVICE_UNAVAILABLE', <<"Service unavailable">>)}
     end.
@@ -84,7 +84,7 @@ roots() ->
 %% Helpers
 %%--------------------------------------------------------------------
 
-format_export_info(
+format_file_info(
     Info = #{
         name := Name,
         size := Size,

apps/emqx_ft/src/emqx_ft_storage.erl

@@ -24,7 +24,7 @@
         store_segment/2,
         assemble/2,
 
-        exports/0,
+        files/0,
 
         with_storage_type/2,
         with_storage_type/3
@@ -34,13 +34,13 @@
 -type storage() :: emqx_config:config().
 
 -export_type([assemble_callback/0]).
--export_type([export_info/0]).
+-export_type([file_info/0]).
 -export_type([export_data/0]).
 -export_type([reader/0]).
 
 -type assemble_callback() :: fun((ok | {error, term()}) -> any()).
 
--type export_info() :: #{
+-type file_info() :: #{
     transfer := emqx_ft:transfer(),
     name := file:name(),
     size := _Bytes :: non_neg_integer(),
@@ -68,8 +68,8 @@
 -callback assemble(storage(), emqx_ft:transfer(), _Size :: emqx_ft:bytes()) ->
     ok | {async, pid()} | {error, term()}.
 
--callback exports(storage()) ->
-    {ok, [export_info()]} | {error, term()}.
+-callback files(storage()) ->
+    {ok, [file_info()]} | {error, term()}.
 
 %%--------------------------------------------------------------------
 %% API
@@ -104,11 +104,11 @@ assemble(Transfer, Size) ->
     Mod = mod(),
     Mod:assemble(storage(), Transfer, Size).
 
--spec exports() ->
-    {ok, [export_info()]} | {error, term()}.
-exports() ->
+-spec files() ->
+    {ok, [file_info()]} | {error, term()}.
+files() ->
     Mod = mod(),
-    Mod:exports(storage()).
+    Mod:files(storage()).
 
 -spec with_storage_type(atom(), atom() | function()) -> any().
 with_storage_type(Type, Fun) ->

apps/emqx_ft/src/emqx_ft_storage_exporter.erl

@@ -57,7 +57,7 @@
     ok | {error, _Reason}.
 
 -callback list(options()) ->
-    {ok, [emqx_ft_storage:export_info()]} | {error, _Reason}.
+    {ok, [emqx_ft_storage:file_info()]} | {error, _Reason}.
 
 %%
 

apps/emqx_ft/src/emqx_ft_storage_fs.erl

@@ -44,7 +44,7 @@
 -export([get_subdir/2]).
 -export([get_subdir/3]).
 
--export([exports/1]).
+-export([files/1]).
 
 -export_type([storage/0]).
 -export_type([filefrag/1]).
@@ -209,7 +209,7 @@ assemble(Storage, Transfer, Size) ->
 
 %%
 
-exports(Storage) ->
+files(Storage) ->
     emqx_ft_storage_exporter:list(Storage).
 
 %%

apps/emqx_ft/src/proto/emqx_ft_storage_exporter_fs_proto_v1.erl

@@ -29,7 +29,7 @@ introduced_in() ->
     "5.0.17".
 
 -spec list_exports([node()]) ->
-    emqx_rpc:erpc_multicall([emqx_ft_storage:export_info()]).
+    emqx_rpc:erpc_multicall([emqx_ft_storage:file_info()]).
 list_exports(Nodes) ->
     erpc:multicall(
         Nodes,

apps/emqx_ft/test/emqx_ft_SUITE.erl

@@ -216,7 +216,7 @@ t_simple_transfer(Config) ->
         emqtt:publish(C, mk_fin_topic(FileId, Filesize), <<>>, 1)
     ),
 
-    [Export] = list_exports(?config(clientid, Config)),
+    [Export] = list_files(?config(clientid, Config)),
     ?assertEqual(
         {ok, iolist_to_binary(Data)},
         read_export(Export)
@@ -234,7 +234,7 @@ t_nasty_clientids_fileids(_Config) ->
     ok = lists:foreach(
         fun({ClientId, FileId}) ->
             ok = emqx_ft_test_helpers:upload_file(ClientId, FileId, "justfile", ClientId),
-            [Export] = list_exports(ClientId),
+            [Export] = list_files(ClientId),
             ?assertEqual({ok, ClientId}, read_export(Export))
         end,
         Transfers
@@ -463,7 +463,7 @@ t_switch_node(Config) ->
 
     %% Now check consistency of the file
 
-    [Export] = list_exports(ClientId),
+    [Export] = list_files(ClientId),
     ?assertEqual(
         {ok, iolist_to_binary(Data)},
         read_export(Export)
@@ -539,7 +539,7 @@ t_unreliable_migrating_client(Config) ->
     ],
     _Context = run_commands(Commands, Context),
 
-    Exports = list_exports(?config(clientid, Config)),
+    Exports = list_files(?config(clientid, Config)),
 
     % NOTE
     % The cluster had 2 assemblers running on two different nodes, because client sent `fin`
@@ -659,9 +659,9 @@ meta(FileName, Data) ->
         size => byte_size(FullData)
     }.
 
-list_exports(ClientId) ->
-    {ok, Exports} = emqx_ft_storage:exports(),
-    [Export || Export = #{transfer := {CId, _}} <- Exports, CId == ClientId].
+list_files(ClientId) ->
+    {ok, Files} = emqx_ft_storage:files(),
+    [File || File = #{transfer := {CId, _}} <- Files, CId == ClientId].
 
 read_export(#{path := AbsFilepath}) ->
     % TODO: only works for the local filesystem exporter right now

apps/emqx_ft/test/emqx_ft_storage_fs_SUITE.erl

@@ -83,7 +83,7 @@ t_multinode_ready_transfers(Config) ->
             #{transfer := {<<"c/1">>, <<"f:1">>}, name := "fn1"},
             #{transfer := {<<"c/2">>, <<"f:2">>}, name := "fn2"}
         ],
-        lists:sort(list_exports(Config))
+        lists:sort(list_files(Config))
     ).
 
 %%--------------------------------------------------------------------
@@ -103,6 +103,6 @@ storage(Config) ->
         }
     }.
 
-list_exports(Config) ->
-    {ok, Exports} = emqx_ft_storage_fs:exports(storage(Config)),
-    Exports.
+list_files(Config) ->
+    {ok, Files} = emqx_ft_storage_fs:files(storage(Config)),
+    Files.