static file caching/serving seems to work

src/fd_sfc.erl

@@ -5,6 +5,8 @@
 
 -export([
     %% caller context
+    base_path/0,
+    renew/0, query/1,
     start_link/0,
 
     %% process context
@@ -15,8 +17,24 @@
 -include("$zx_include/zx_logger.hrl").
 
 
--record(s, {cache = fd_sfc_cache:new() :: fd_sfc_cache:cache()}).
--type state() :: #s{}.
+-record(s, {base_path  = base_path()                   :: file:filename(),
+            cache      = fd_sfc_cache:new(base_path()) :: fd_sfc_cache:cache(),
+            auto_renew = 5_000                         :: pos_integer()}).
+%-type state() :: #s{}.
+
+
+%%-----------------------------------------------------------------------------
+%% caller context
+%%-----------------------------------------------------------------------------
+
+base_path() ->
+    filename:join([zx:get_home(), "priv", "static"]).
+
+renew() ->
+    gen_server:cast(?MODULE, renew).
+
+query(Path) ->
+    gen_server:call(?MODULE, {query, Path}).
 
 start_link() ->
     gen_server:start_link({local, ?MODULE}, ?MODULE, none, []).
@@ -31,19 +49,31 @@ start_link() ->
 init(none) ->
     log(info, "starting fd_cache"),
     InitState = #s{},
+    erlang:send_after(3_000, self(), auto_renew),
     {ok, InitState}.
 
 
+handle_call({query, Path}, _, State = #s{cache = Cache}) ->
+    Reply = fd_sfc_cache:query(Path, Cache),
+    {reply, Reply, State};
 handle_call(Unexpected, From, State) ->
     tell("~tp: unexpected call from ~tp: ~tp", [?MODULE, Unexpected, From]),
     {noreply, State}.
 
 
+handle_cast(renew, State) ->
+    NewState = i_renew(State),
+    {noreply, NewState};
 handle_cast(Unexpected, State) ->
     tell("~tp: unexpected cast: ~tp", [?MODULE, Unexpected]),
     {noreply, State}.
 
 
+handle_info(auto_renew, State = #s{auto_renew = MS}) ->
+    log(info, "~tp: auto_renew", [?MODULE]),
+    erlang:send_after(MS, self(), auto_renew),
+    NewState = i_renew(State),
+    {noreply, NewState};
 handle_info(Unexpected, State) ->
     tell("~tp: unexpected info: ~tp", [?MODULE, Unexpected]),
     {noreply, State}.
@@ -54,3 +84,13 @@ code_change(_, State, _) ->
 
 terminate(_, _) ->
     ok.
+
+
+%%-----------------------------------------------------------------------------
+%% internals
+%%-----------------------------------------------------------------------------
+
+i_renew(State = #s{base_path = BasePath}) ->
+    NewCache = fd_sfc_cache:new(BasePath),
+    NewState = State#s{cache = NewCache},
+    NewState.