Add 'include/types.hrl' and introduce some common types

src/emqx.erl

@@ -15,6 +15,7 @@
 -module(emqx).
 
 -include("emqx.hrl").
+-include("types.hrl").
 
 %% Start/Stop the application
 -export([start/0, restart/1, is_running/1, stop/0]).
@@ -167,8 +168,10 @@ reboot() ->
 %%------------------------------------------------------------------------------
 %% Internal functions
 %%------------------------------------------------------------------------------
+
 reload_config(ConfFile) ->
     {ok, [Conf]} = file:consult(ConfFile),
     lists:foreach(fun({App, Vals}) ->
                       [application:set_env(App, Par, Val) || {Par, Val} <- Vals]
                   end, Conf).
+

src/emqx_banned.erl

@@ -18,6 +18,7 @@
 
 -include("emqx.hrl").
 -include("logger.hrl").
+-include("types.hrl").
 
 %% Mnesia bootstrap
 -export([mnesia/1]).
@@ -50,7 +51,7 @@ mnesia(copy) ->
     ok = ekka_mnesia:copy_table(?TAB).
 
 %% @doc Start the banned server.
--spec(start_link() -> emqx_types:startlink_ret()).
+-spec(start_link() -> startlink_ret()).
 start_link() ->
     gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
 

src/emqx_broker.erl

@@ -18,6 +18,7 @@
 
 -include("emqx.hrl").
 -include("logger.hrl").
+-include("types.hrl").
 
 -export([start_link/2]).
 -export([subscribe/1, subscribe/2, subscribe/3]).
@@ -53,7 +54,7 @@
 %% Guards
 -define(is_subid(Id), (is_binary(Id) orelse is_atom(Id))).
 
--spec(start_link(atom(), pos_integer()) -> emqx_types:startlink_ret()).
+-spec(start_link(atom(), pos_integer()) -> startlink_ret()).
 start_link(Pool, Id) ->
     ok = create_tabs(),
     gen_server:start_link({local, emqx_misc:proc_name(?BROKER, Id)},
@@ -322,7 +323,7 @@ subscribed(SubId, Topic) when ?is_subid(SubId) ->
     SubPid = emqx_broker_helper:lookup_subpid(SubId),
     ets:member(?SUBOPTION, {SubPid, Topic}).
 
--spec(get_subopts(pid(), emqx_topic:topic()) -> emqx_types:subopts() | undefined).
+-spec(get_subopts(pid(), emqx_topic:topic()) -> maybe(emqx_types:subopts())).
 get_subopts(SubPid, Topic) when is_pid(SubPid), is_binary(Topic) ->
     lookup_value(?SUBOPTION, {SubPid, Topic});
 get_subopts(SubId, Topic) when ?is_subid(SubId) ->

src/emqx_broker_helper.erl

@@ -17,6 +17,7 @@
 -behaviour(gen_server).
 
 -include("logger.hrl").
+-include("types.hrl").
 
 -export([start_link/0]).
 -export([register_sub/2]).
@@ -35,7 +36,7 @@
 
 -define(BATCH_SIZE, 100000).
 
--spec(start_link() -> emqx_types:startlink_ret()).
+-spec(start_link() -> startlink_ret()).
 start_link() ->
     gen_server:start_link({local, ?HELPER}, ?MODULE, [], []).
 
@@ -50,7 +51,7 @@ register_sub(SubPid, SubId) when is_pid(SubPid) ->
             error(subid_conflict)
     end.
 
--spec(lookup_subid(pid()) -> emqx_types:subid() | undefined).
+-spec(lookup_subid(pid()) -> maybe(emqx_types:subid())).
 lookup_subid(SubPid) when is_pid(SubPid) ->
     emqx_tables:lookup_value(?SUBMON, SubPid).
 

src/emqx_client.erl

@@ -16,6 +16,7 @@
 
 -behaviour(gen_statem).
 
+-include("types.hrl").
 -include("emqx_mqtt.hrl").
 
 -export([start_link/0, start_link/1]).
@@ -112,12 +113,12 @@
                 bridge_mode     :: boolean(),
                 client_id       :: binary(),
                 clean_start     :: boolean(),
-                username        :: binary() | undefined,
+                username        :: maybe(binary()),
-                password        :: binary() | undefined,
+                password        :: maybe(binary()),
                 proto_ver       :: emqx_mqtt_types:version(),
                 proto_name      :: iodata(),
                 keepalive       :: non_neg_integer(),
-                keepalive_timer :: reference() | undefined,
+                keepalive_timer :: maybe(reference()),
                 force_ping      :: boolean(),
                 paused          :: boolean(),
                 will_flag       :: boolean(),

src/emqx_cm.erl

@@ -18,6 +18,7 @@
 
 -include("emqx.hrl").
 -include("logger.hrl").
+-include("types.hrl").
 
 -export([start_link/0]).
 
@@ -46,7 +47,7 @@
 -define(BATCH_SIZE, 100000).
 
 %% @doc Start the connection manager.
--spec(start_link() -> emqx_types:startlink_ret()).
+-spec(start_link() -> startlink_ret()).
 start_link() ->
     gen_server:start_link({local, ?CM}, ?MODULE, [], []).
 
@@ -121,7 +122,7 @@ set_conn_stats(ClientId, ConnPid, Stats) when is_binary(ClientId), is_pid(ConnPi
     ets:insert(?CONN_STATS_TAB, {Conn, Stats}).
 
 %% @doc Lookup connection pid.
--spec(lookup_conn_pid(emqx_types:client_id()) -> pid() | undefined).
+-spec(lookup_conn_pid(emqx_types:client_id()) -> maybe(pid())).
 lookup_conn_pid(ClientId) when is_binary(ClientId) ->
     emqx_tables:lookup_value(?CONN_TAB, ClientId).
 

src/emqx_gc.erl

@@ -21,6 +21,8 @@
 
 -module(emqx_gc).
 
+-include("types.hrl").
+
 -export([init/1, run/3, info/1, reset/1]).
 
 -type(opts() :: #{count => integer(),
@@ -35,7 +37,7 @@
 -define(ENABLED(X), (is_integer(X) andalso X > 0)).
 
 %% @doc Initialize force GC state.
--spec(init(opts() | false) -> gc_state() | undefined).
+-spec(init(opts() | false) -> maybe(gc_state())).
 init(#{count := Count, bytes := Bytes}) ->
     Cnt = [{cnt, {Count, Count}} || ?ENABLED(Count)],
     Oct = [{oct, {Bytes, Bytes}} || ?ENABLED(Bytes)],
@@ -61,7 +63,7 @@ run([{K, N}|T], St) ->
     end.
 
 %% @doc Info of GC state.
--spec(info(gc_state()) -> map() | undefined).
+-spec(info(gc_state()) -> maybe(map())).
 info({?MODULE, St}) ->
     St;
 info(undefined) ->

src/emqx_hooks.erl

@@ -17,6 +17,7 @@
 -behaviour(gen_server).
 
 -include("logger.hrl").
+-include("types.hrl").
 
 -export([start_link/0, stop/0]).
 
@@ -42,7 +43,7 @@
 -define(TAB, ?MODULE).
 -define(SERVER, ?MODULE).
 
--spec(start_link() -> emqx_types:startlink_ret()).
+-spec(start_link() -> startlink_ret()).
 start_link() ->
     gen_server:start_link({local, ?SERVER}, ?MODULE, [], [{hibernate_after, 1000}]).
 

src/emqx_metrics.erl

@@ -15,6 +15,7 @@
 -module(emqx_metrics).
 
 -include("logger.hrl").
+-include("types.hrl").
 -include("emqx_mqtt.hrl").
 
 -export([start_link/0]).
@@ -87,7 +88,7 @@
 -define(SERVER, ?MODULE).
 
 %% @doc Start the metrics server.
--spec(start_link() -> emqx_types:startlink_ret()).
+-spec(start_link() -> startlink_ret()).
 start_link() ->
     gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).
 

src/emqx_mqueue.erl

@@ -46,6 +46,7 @@
 -module(emqx_mqueue).
 
 -include("emqx.hrl").
+-include("types.hrl").
 -include("emqx_mqtt.hrl").
 
 -export([init/1]).
@@ -117,7 +118,7 @@ stats(#mqueue{max_len = MaxLen, dropped = Dropped} = MQ) ->
     [{len, len(MQ)}, {max_len, MaxLen}, {dropped, Dropped}].
 
 %% @doc Enqueue a message.
--spec(in(message(), mqueue()) -> {undefined | message(), mqueue()}).
+-spec(in(message(), mqueue()) -> {maybe(message()), mqueue()}).
 in(#message{qos = ?QOS_0}, MQ = #mqueue{store_qos0 = false}) ->
     {_Dropped = undefined, MQ};
 in(Msg = #message{topic = Topic}, MQ = #mqueue{default_p = Dp,

src/emqx_pd.erl

@@ -15,11 +15,13 @@
 %% @doc The utility functions for erlang process dictionary.
 -module(emqx_pd).
 
+-include("types.hrl").
+
 -export([update_counter/2, get_counter/1, reset_counter/1]).
 
 -type(key() :: term()).
 
--spec(update_counter(key(), number()) -> undefined | number()).
+-spec(update_counter(key(), number()) -> maybe(number())).
 update_counter(Key, Inc) ->
     put(Key, get_counter(Key) + Inc).
 

src/emqx_pool.erl

@@ -17,6 +17,7 @@
 -behaviour(gen_server).
 
 -include("logger.hrl").
+-include("types.hrl").
 
 -export([start_link/2]).
 -export([submit/1, submit/2]).
@@ -34,7 +35,7 @@
 -type(task() :: fun() | mfa() | {fun(), Args :: list(any())}).
 
 %% @doc Start pool.
--spec(start_link(atom(), pos_integer()) -> emqx_types:startlink_ret()).
+-spec(start_link(atom(), pos_integer()) -> startlink_ret()).
 start_link(Pool, Id) ->
     gen_server:start_link({local, emqx_misc:proc_name(?MODULE, Id)},
                           ?MODULE, [Pool, Id], [{hibernate_after, 1000}]).

src/emqx_router.erl

@@ -18,6 +18,7 @@
 
 -include("emqx.hrl").
 -include("logger.hrl").
+-include("types.hrl").
 -include_lib("ekka/include/ekka.hrl").
 
 %% Mnesia bootstrap
@@ -65,7 +66,7 @@ mnesia(copy) ->
 %% Start a router
 %%------------------------------------------------------------------------------
 
--spec(start_link(atom(), pos_integer()) -> emqx_types:startlink_ret()).
+-spec(start_link(atom(), pos_integer()) -> startlink_ret()).
 start_link(Pool, Id) ->
     gen_server:start_link({local, emqx_misc:proc_name(?MODULE, Id)},
                           ?MODULE, [Pool, Id], [{hibernate_after, 1000}]).

src/emqx_router_helper.erl

@@ -18,6 +18,7 @@
 
 -include("emqx.hrl").
 -include("logger.hrl").
+-include("types.hrl").
 
 %% Mnesia bootstrap
 -export([mnesia/1]).
@@ -61,7 +62,7 @@ mnesia(copy) ->
 %%------------------------------------------------------------------------------
 
 %% @doc Starts the router helper
--spec(start_link() ->  emqx_types:startlink_ret()).
+-spec(start_link() -> startlink_ret()).
 start_link() ->
     gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
 

src/emqx_session.erl

@@ -43,6 +43,7 @@
 -include("emqx.hrl").
 -include("emqx_mqtt.hrl").
 -include("logger.hrl").
+-include("types.hrl").
 
 -export([start_link/1]).
 -export([info/1, attrs/1]).
@@ -77,7 +78,7 @@
           client_id :: binary(),
 
           %% Username
-          username :: binary() | undefined,
+          username :: maybe(binary()),
 
           %% Connection pid binding with session
           conn_pid :: pid(),
@@ -107,7 +108,7 @@
           retry_interval = 20000 :: timeout(),
 
           %% Retry Timer
-          retry_timer :: reference() | undefined,
+          retry_timer :: maybe(reference()),
 
           %% All QoS1, QoS2 messages published to when client is disconnected.
           %% QoS 1 and QoS 2 messages pending transmission to the Client.
@@ -125,19 +126,19 @@
           await_rel_timeout = 20000 :: timeout(),
 
           %% Awaiting PUBREL Timer
-          await_rel_timer :: reference() | undefined,
+          await_rel_timer :: maybe(reference()),
 
           %% Session Expiry Interval
           expiry_interval = 7200 :: timeout(),
 
           %% Expired Timer
-          expiry_timer :: reference() | undefined,
+          expiry_timer :: maybe(reference()),
 
           %% Enable Stats
           enable_stats :: boolean(),
 
           %% Stats timer
-          stats_timer  :: reference() | undefined,
+          stats_timer :: maybe(reference()),
 
           %% GC State
           gc_state,
@@ -147,7 +148,7 @@
 
           will_msg :: emqx:message(),
 
-          will_delay_timer :: reference() | undefined
+          will_delay_timer :: maybe(reference())
 
          }).
 

src/emqx_session_sup.erl

@@ -17,6 +17,7 @@
 -behaviour(gen_server).
 
 -include("logger.hrl").
+-include("types.hrl").
 
 -export([start_link/1]).
 -export([start_session/1, count_sessions/0]).
@@ -38,7 +39,7 @@
 -define(BATCH_EXIT, 100000).
 
 %% @doc Start session supervisor.
--spec(start_link(map()) -> emqx_types:startlink_ret()).
+-spec(start_link(map()) -> startlink_ret()).
 start_link(SessSpec) when is_map(SessSpec) ->
     gen_server:start_link({local, ?SUP}, ?MODULE, [SessSpec], []).
 
@@ -47,7 +48,7 @@ start_link(SessSpec) when is_map(SessSpec) ->
 %%------------------------------------------------------------------------------
 
 %% @doc Start a session.
--spec(start_session(map()) -> emqx_types:startlink_ret()).
+-spec(start_session(map()) -> startlink_ret()).
 start_session(SessAttrs) ->
     gen_server:call(?SUP, {start_session, SessAttrs}, infinity).
 

src/emqx_shared_sub.erl

@@ -19,6 +19,7 @@
 -include("emqx.hrl").
 -include("emqx_mqtt.hrl").
 -include("logger.hrl").
+-include("types.hrl").
 
 %% Mnesia bootstrap
 -export([mnesia/1]).
@@ -70,7 +71,7 @@ mnesia(copy) ->
 %% API
 %%------------------------------------------------------------------------------
 
--spec(start_link() -> emqx_types:startlink_ret()).
+-spec(start_link() -> startlink_ret()).
 start_link() ->
     gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).
 

src/emqx_sm.erl

@@ -18,6 +18,7 @@
 
 -include("emqx.hrl").
 -include("logger.hrl").
+-include("types.hrl").
 
 -export([start_link/0]).
 
@@ -55,7 +56,7 @@
 
 -define(BATCH_SIZE, 100000).
 
--spec(start_link() -> emqx_types:startlink_ret()).
+-spec(start_link() -> startlink_ret()).
 start_link() ->
     gen_server:start_link({local, ?SM}, ?MODULE, [], []).
 

src/emqx_sm_locker.erl

@@ -15,13 +15,14 @@
 -module(emqx_sm_locker).
 
 -include("emqx.hrl").
+-include("types.hrl").
 
 -export([start_link/0]).
 
 -export([trans/2, trans/3]).
 -export([lock/1, lock/2, unlock/1]).
 
--spec(start_link() -> emqx_types:startlink_ret()).
+-spec(start_link() -> startlink_ret()).
 start_link() ->
     ekka_locker:start_link(?MODULE).
 
@@ -29,7 +30,7 @@ start_link() ->
 trans(ClientId, Fun) ->
     trans(ClientId, Fun, undefined).
 
--spec(trans(emqx_types:client_id() | undefined,
+-spec(trans(maybe(emqx_types:client_id()),
             fun(([node()])-> any()), ekka_locker:piggyback()) -> any()).
 trans(undefined, Fun, _Piggyback) ->
     Fun([]);

src/emqx_sm_registry.erl

@@ -18,6 +18,7 @@
 
 -include("emqx.hrl").
 -include("logger.hrl").
+-include("types.hrl").
 
 -export([start_link/0]).
 -export([is_enabled/0]).
@@ -36,7 +37,7 @@
 -type(session_pid() :: pid()).
 
 %% @doc Start the global session manager.
--spec(start_link() -> emqx_types:startlink_ret()).
+-spec(start_link() -> startlink_ret()).
 start_link() ->
     gen_server:start_link({local, ?REGISTRY}, ?MODULE, [], []).
 

src/emqx_stats.erl

@@ -18,6 +18,7 @@
 
 -include("emqx.hrl").
 -include("logger.hrl").
+-include("types.hrl").
 
 -export([start_link/0, start_link/1, stop/0]).
 
@@ -82,11 +83,11 @@
 -type opts() :: #{tick_ms := timeout()}.
 
 %% @doc Start stats server
--spec(start_link() -> emqx_types:startlink_ret()).
+-spec(start_link() -> startlink_ret()).
 start_link() ->
     start_link(#{tick_ms => timer:seconds(1)}).
 
--spec(start_link(opts()) -> emqx_types:startlink_ret()).
+-spec(start_link(opts()) -> startlink_ret()).
 start_link(Opts) ->
     gen_server:start_link({local, ?SERVER}, ?MODULE, Opts, []).
 
@@ -112,7 +113,7 @@ getstats() ->
     end.
 
 %% @doc Get stats by name
--spec(getstat(atom()) -> non_neg_integer() | undefined).
+-spec(getstat(atom()) -> maybe(non_neg_integer())).
 getstat(Name) ->
     case ets:lookup(?TAB, Name) of
         [{Name, Val}] -> Val;

src/emqx_sys_mon.erl

@@ -17,6 +17,7 @@
 -behavior(gen_server).
 
 -include("logger.hrl").
+-include("types.hrl").
 
 -export([start_link/1]).
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2,
@@ -24,10 +25,16 @@
 %% compress unused warning
 -export([procinfo/1]).
 
+-type(option() :: {long_gc, false | pos_integer()}
+                | {long_schedule, false | pos_integer()}
+                | {large_heap, pos_integer()}
+                | {busy_port, boolean()}
+                | {busy_dist_port, boolean()}).
+
 -define(SYSMON, ?MODULE).
 
 %% @doc Start system monitor
--spec(start_link(Opts :: list(tuple())) -> emqx_types:startlink_ret()).
+-spec(start_link(list(option())) -> startlink_ret()).
 start_link(Opts) ->
     gen_server:start_link({local, ?SYSMON}, ?MODULE, [Opts], []).
 

src/emqx_types.erl

@@ -15,9 +15,9 @@
 -module(emqx_types).
 
 -include("emqx.hrl").
+-include("types.hrl").
 
 -export_type([zone/0]).
--export_type([startlink_ret/0, ok_or_error/1]).
 -export_type([pubsub/0, topic/0, subid/0, subopts/0]).
 -export_type([client_id/0, username/0, password/0, peername/0, protocol/0]).
 -export_type([credentials/0, session/0]).
@@ -28,8 +28,6 @@
 -export_type([alarm/0, plugin/0, command/0]).
 
 -type(zone() :: atom()).
--type(startlink_ret() :: {ok, pid()} | ignore | {error, term()}).
--type(ok_or_error(Reason) :: ok | {error, Reason}).
 -type(pubsub() :: publish | subscribe).
 -type(topic() :: binary()).
 -type(subid() :: binary() | atom()).
@@ -39,8 +37,8 @@
                     }).
 -type(session() :: #session{}).
 -type(client_id() :: binary() | atom()).
--type(username() :: binary() | undefined).
+-type(username() :: maybe(binary())).
--type(password() :: binary() | undefined).
+-type(password() :: maybe(binary())).
 -type(peername() :: {inet:ip_address(), inet:port_number()}).
 -type(protocol() :: mqtt | 'mqtt-sn' | coap | stomp | none | atom()).
 -type(credentials() :: #{client_id := client_id(),

src/emqx_zone.erl

@@ -18,6 +18,7 @@
 
 -include("emqx.hrl").
 -include("logger.hrl").
+-include("types.hrl").
 
 -export([start_link/0]).
 -export([get_env/2, get_env/3]).
@@ -33,17 +34,17 @@
 -define(TAB, ?MODULE).
 -define(SERVER, ?MODULE).
 
--spec(start_link() -> emqx_types:startlink_ret()).
+-spec(start_link() -> startlink_ret()).
 start_link() ->
     gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).
 
--spec(get_env(emqx_types:zone() | undefined, atom()) -> undefined | term()).
+-spec(get_env(maybe(emqx_types:zone()), atom()) -> maybe(term())).
 get_env(undefined, Key) ->
     emqx_config:get_env(Key);
 get_env(Zone, Key) ->
     get_env(Zone, Key, undefined).
 
--spec(get_env(emqx_types:zone() | undefined, atom(), term()) -> undefined | term()).
+-spec(get_env(maybe(emqx_types:zone()), atom(), term()) -> maybe(term())).
 get_env(undefined, Key, Def) ->
     emqx_config:get_env(Key, Def);
 get_env(Zone, Key, Def) ->