diff options
Diffstat (limited to 'src/ddoc_cache/src/ddoc_cache_entry.erl')
| -rw-r--r-- | src/ddoc_cache/src/ddoc_cache_entry.erl | 73 |
1 files changed, 22 insertions, 51 deletions
diff --git a/src/ddoc_cache/src/ddoc_cache_entry.erl b/src/ddoc_cache/src/ddoc_cache_entry.erl index 32d3ec1a7..5a1711dd8 100644 --- a/src/ddoc_cache/src/ddoc_cache_entry.erl +++ b/src/ddoc_cache/src/ddoc_cache_entry.erl @@ -43,17 +43,14 @@ do_open/1 ]). - -include("ddoc_cache.hrl"). - -ifndef(TEST). -define(ENTRY_SHUTDOWN_TIMEOUT, 5000). -else. -define(ENTRY_SHUTDOWN_TIMEOUT, 500). -endif. - -record(st, { key, val, @@ -63,28 +60,22 @@ accessed }). - dbname({Mod, Arg}) -> Mod:dbname(Arg). - ddocid({Mod, Arg}) -> Mod:ddocid(Arg). - recover({Mod, Arg}) -> Mod:recover(Arg). - insert({Mod, Arg}, Value) -> Mod:insert(Arg, Value). - start_link(Key, Default) -> Pid = proc_lib:spawn_link(?MODULE, init, [{Key, Default}]), {ok, Pid}. - shutdown(Pid) -> Ref = erlang:monitor(process, Pid), ok = gen_server:cast(Pid, shutdown), @@ -98,7 +89,6 @@ shutdown(Pid) -> erlang:exit({timeout, {entry_shutdown, Pid}}) end. - open(Pid, Key) -> try Resp = gen_server:call(Pid, open), @@ -118,15 +108,12 @@ open(Pid, Key) -> recover(Key) end. - accessed(Pid) -> gen_server:cast(Pid, accessed). - refresh(Pid) -> gen_server:cast(Pid, force_refresh). - init({Key, undefined}) -> true = ets:update_element(?CACHE, Key, {#entry.pid, self()}), St = #st{ @@ -137,7 +124,6 @@ init({Key, undefined}) -> }, ?EVENT(started, Key), gen_server:enter_loop(?MODULE, [], St); - init({Key, Wrapped}) -> Default = ddoc_cache_value:unwrap(Wrapped), Updates = [ @@ -158,7 +144,6 @@ init({Key, Wrapped}) -> ?EVENT(default_started, Key), gen_server:enter_loop(?MODULE, [], St, hibernate). - terminate(_Reason, St) -> #st{ key = Key, @@ -172,30 +157,30 @@ terminate(_Reason, St) -> true = ets:select_delete(?CACHE, CacheMSpec) < 2, % We may have already deleted our LRU entry % during shutdown - if Ts == undefined -> ok; true -> - LruMSpec = [{{{Ts, Key, self()}}, [], [true]}], - true = ets:select_delete(?LRU, LruMSpec) < 2 + if + Ts == undefined -> + ok; + true -> + LruMSpec = [{{{Ts, Key, self()}}, [], [true]}], + true = ets:select_delete(?LRU, LruMSpec) < 2 end, % Blow away any current opener if it exists - if not is_pid(Pid) -> ok; true -> - catch exit(Pid, kill) + if + not is_pid(Pid) -> ok; + true -> catch exit(Pid, kill) end, ok. - handle_call(open, From, #st{opener = Pid} = St) when is_pid(Pid) -> NewSt = St#st{ waiters = [From | St#st.waiters] }, {noreply, NewSt}; - handle_call(open, _From, St) -> {reply, St#st.val, St}; - handle_call(Msg, _From, St) -> {stop, {bad_call, Msg}, {bad_call, Msg}, St}. - handle_cast(accessed, St) -> ?EVENT(accessed, St#st.key), drain_accessed(), @@ -203,7 +188,6 @@ handle_cast(accessed, St) -> accessed = St#st.accessed + 1 }, {noreply, update_lru(NewSt)}; - handle_cast(force_refresh, St) -> % If we had frequent design document updates % they could end up racing accessed events and @@ -211,18 +195,18 @@ handle_cast(force_refresh, St) -> % cache. To prevent this we just make sure that % accessed is set to at least 1 before we % execute a refresh. - NewSt = if St#st.accessed > 0 -> St; true -> - St#st{accessed = 1} - end, + NewSt = + if + St#st.accessed > 0 -> St; + true -> St#st{accessed = 1} + end, % We remove the cache entry value so that any % new client comes to us for the refreshed % value. true = ets:update_element(?CACHE, St#st.key, {#entry.val, undefined}), handle_cast(refresh, NewSt); - handle_cast(refresh, #st{accessed = 0} = St) -> {stop, normal, St}; - handle_cast(refresh, #st{opener = Ref} = St) when is_reference(Ref) -> #st{ key = Key @@ -233,7 +217,6 @@ handle_cast(refresh, #st{opener = Ref} = St) when is_reference(Ref) -> accessed = 0 }, {noreply, NewSt}; - handle_cast(refresh, #st{opener = Pid} = St) when is_pid(Pid) -> catch exit(Pid, kill), receive @@ -244,15 +227,12 @@ handle_cast(refresh, #st{opener = Pid} = St) when is_pid(Pid) -> accessed = 0 }, {noreply, NewSt}; - handle_cast(shutdown, St) -> remove_from_cache(St), {stop, normal, St}; - handle_cast(Msg, St) -> {stop, {bad_cast, Msg}, St}. - handle_info({'DOWN', _, _, Pid, Resp}, #st{key = Key, opener = Pid} = St) -> case Resp of {open_ok, Key, {ok, Val}} -> @@ -275,26 +255,22 @@ handle_info({'DOWN', _, _, Pid, Resp}, #st{key = Key, opener = Pid} = St) -> respond(St#st.waiters, {Status, Other}), {stop, normal, NewSt} end; - handle_info(Msg, St) -> {stop, {bad_info, Msg}, St}. - code_change(_, St, _) -> {ok, St}. - spawn_opener(Key) -> {Pid, _} = erlang:spawn_monitor(?MODULE, do_open, [Key]), Pid. - start_timer() -> TimeOut = config:get_integer( - "ddoc_cache", "refresh_timeout", ?REFRESH_TIMEOUT), + "ddoc_cache", "refresh_timeout", ?REFRESH_TIMEOUT + ), erlang:send_after(TimeOut, self(), {'$gen_cast', refresh}). - do_open(Key) -> try recover(Key) of Resp -> @@ -303,26 +279,21 @@ do_open(Key) -> erlang:exit({open_error, Key, {T, R, S}}) end. - update_lru(#st{key = Key, ts = Ts} = St) -> remove_from_lru(Ts, Key), NewTs = os:timestamp(), true = ets:insert(?LRU, {{NewTs, Key, self()}}), St#st{ts = NewTs}. - update_cache(#st{val = undefined} = St, Val) -> true = ets:update_element(?CACHE, St#st.key, {#entry.val, Val}), ?EVENT(inserted, St#st.key); - update_cache(#st{val = V1} = _St, V2) when {open_ok, {ok, V2}} == V1 -> ?EVENT(update_noop, _St#st.key); - update_cache(St, Val) -> true = ets:update_element(?CACHE, St#st.key, {#entry.val, Val}), ?EVENT(updated, {St#st.key, Val}). - remove_from_cache(St) -> #st{ key = Key, @@ -335,14 +306,15 @@ remove_from_cache(St) -> ?EVENT(removed, St#st.key), ok. - remove_from_lru(Ts, Key) -> - if Ts == undefined -> ok; true -> - LruMSpec = [{{{Ts, Key, self()}}, [], [true]}], - 1 = ets:select_delete(?LRU, LruMSpec) + if + Ts == undefined -> + ok; + true -> + LruMSpec = [{{{Ts, Key, self()}}, [], [true]}], + 1 = ets:select_delete(?LRU, LruMSpec) end. - drain_accessed() -> receive {'$gen_cast', accessed} -> @@ -351,6 +323,5 @@ drain_accessed() -> ok end. - respond(Waiters, Resp) -> [gen_server:reply(W, Resp) || W <- Waiters]. |