emqx_backend_redisモジュールは、redis統計、モジュールのロードおよびアンロードインターフェイスを定義するメインの作業モジュールです。
1.emqx_metricsモジュール
2.emqxモジュールのフック機能
3.emqx_topicモジュール
-module(emqx_backend_redis).
-include("../include/emqx_backend_redis.hrl").
-include_lib("../include/emqx.hrl").
%% API
-export([pool_name/1,compile_cmd/1]).
-export([register_metrics/0,load/0,unload/0]).
-export([
on_client_connected/3,%% 已经连接的客户端
on_subscribe_lookup/3,%% 订阅查询
on_client_disconnected/4, %% 断开的客户查询
on_message_fetch_for_queue/4,
on_message_fetch_for_pubsub/4,
on_message_fetch_for_keep_latest/4,
on_retain_lookup/4,%% 保留消息查询
on_message_publish/2, %% 消息发布
on_message_store_keep_latest/2,%%消息存储
on_message_retain/2,
on_retain_delete/2,%% 保留消息删除
on_message_acked_for_queue/3,
on_message_acked_for_pubsub/3,
on_message_acked_for_keep_latest/3,
run_redis_commands/2, %% redis命令
run_redis_commands/3,
run_redis_commands/4]).
pool_name(Pool)->
list_to_atom(lists:concat([emqx_backend_redis,'_',Pool])).
%% 统计
register_metrics() ->
[emqx_metrics:new(MetricName) || MetricName
<- ['backend.redis.client_connected',
'backend.redis.subscribe_lookup',
'backend.redis.client_disconnected',
'backend.redis.message_fetch_for_queue',
'backend.redis.message_fetch_for_pubsub',
'backend.redis.message_fetch_for_keep_latest',
'backend.redis.retain_lookup',
'backend.redis.message_publish',
'backend.redis.message_store_keep_latest',
'backend.redis.message_retain',
'backend.redis.retain_delete',
'backend.redis.message_acked_for_queue',
'backend.redis.message_acked_for_pubsub',
'backend.redis.message_acked_for_keep_latest']].
%% 载入钩子函数，在emqx_backend_redis.conf文件里面定义的
load()->
%% 钩子函数列表
HookList = parse_hook(application:get_env(emqx_backend_redis, hooks, [])),
%% 从HookList取出参数，然后执行函数
lists:foreach(
fun ({Hook,Action,Pool,Filter,ExpiredTime}) ->
case proplists:get_value(<<"function">>, Action) of
undefined ->
Commands = proplists:get_value(<<"commands">>, Action, []),
Cmds = compile_cmds(Commands),
load_(Hook, run_redis_commands, ExpiredTime, {Filter, Pool, Cmds});
Fun ->
load_(Hook, b2a(Fun), ExpiredTime, {Filter, Pool, undefined})
end
end, HookList),
io:format("~s is loaded.~n", [emqx_backend_redis]),
ok.
load_(Hook, Fun, ExpiredTime, {Filter, Pool, undefined}) ->
load_(Hook, Fun, ExpiredTime, {Filter, Pool});
load_(Hook, Fun, ExpiredTime, Params) ->
case Hook of
'client.connected' ->
emqx:hook(Hook, fun emqx_backend_redis:Fun/3, [Params]);
'client.disconnected' ->
emqx:hook(Hook, fun emqx_backend_redis:Fun/4, [Params]);
'session.subscribed' ->
emqx:hook(Hook, fun emqx_backend_redis:Fun/4, [Params]);
'session.unsubscribed' ->
emqx:hook(Hook, fun emqx_backend_redis:Fun/4, [Params]);
'message.publish' ->
Expired = case ExpiredTime =< 0 of
true -> 7200;
false -> ExpiredTime
end,
emqx:hook(Hook, fun emqx_backend_redis:Fun/2, [erlang:append_element(Params, Expired)]);
'message.acked' ->
emqx:hook(Hook, fun emqx_backend_redis:Fun/3, [Params]);
'message.delivered' ->
emqx:hook(Hook, fun emqx_backend_redis:Fun/3, [Params])
end.
%% 卸载钩子
unload() ->
HookList = parse_hook(application:get_env(emqx_backend_redis, hooks, [])),
lists:foreach(
fun ({Hook, Action, _Pool, _Filter, _ExpiredTime}) ->
case proplists:get_value(<<"function">>, Action) of
undefined -> unload_(Hook, run_redis_commands);
Fun -> unload_(Hook, b2a(Fun))
end
end,
HookList),
io:format("~s is unloaded.~n", [emqx_backend_redis]),
ok.
%% 卸载钩子
unload_(Hook, Fun) ->
case Hook of
'client.connected' -> %% 已经连接的客户端钩子函数
emqx:unhook(Hook, fun emqx_backend_redis:Fun/3);
'client.disconnected' -> %% 已经断开的客户端钩子函数
emqx:unhook(Hook, fun emqx_backend_redis:Fun/4);
'session.subscribed' -> %% 已经订阅
emqx:unhook(Hook, fun emqx_backend_redis:Fun/4);
'session.unsubscribed' ->%% 取消订阅
emqx:unhook(Hook, fun emqx_backend_redis:Fun/4);
'message.publish' ->%% 消息发布
emqx:unhook(Hook, fun emqx_backend_redis:Fun/2);
'message.acked' ->%% 消息确认
emqx:unhook(Hook, fun emqx_backend_redis:Fun/3);
'message.delivered' ->%% 消息投递
emqx:unhook(Hook, fun emqx_backend_redis:Fun/3)
end.
%%
on_client_connected(#{clientid := ClientId}, _ConnInfo, {Filter, Pool}) ->
with_filter(
fun () ->
emqx_metrics:inc('backend.redis.client_connected'),
emqx_backend_redis_cli:client_connected(Pool, [{clientid, ClientId}]) end,
undefined,
Filter);
on_client_connected(_Client, _ConnInfo, _Rule) -> ok.
on_subscribe_lookup(#{clientid := ClientId}, _ConnInfo,{Filter, Pool}) ->
with_filter(
fun () ->
emqx_metrics:inc('backend.redis.subscribe_lookup'),
case emqx_backend_redis_cli:subscribe_lookup(Pool, [{clientid,ClientId}]) of
[] -> ok;
TopicTable ->
self() ! {subscribe, TopicTable},
ok
end
end, undefined, Filter);
on_subscribe_lookup(_ClientInfo, _ConnInfo, _Envs) ->
ok.
on_client_disconnected(#{clientid := ClientId}, _Reason,_ConnInfo, {Filter, Pool}) ->
with_filter(fun () ->
emqx_metrics:inc('backend.redis.client_disconnected'),
emqx_backend_redis_cli:client_disconnected(Pool,
[{clientid,ClientId}])end,
undefined,
Filter).
on_message_fetch_for_queue(#{clientid := ClientId}, Topic, Opts, {Filter, Pool}) ->
with_filter(fun () ->
emqx_metrics:inc('backend.redis.message_fetch_for_queue'),
case maps:get(qos, Opts, 0) > 0 andalso
maps:get(is_new, Opts, true)
of
true ->
MsgList =
emqx_backend_redis_cli:message_fetch_for_queue(Pool,
[{clientid,
ClientId},
{topic,
Topic}]),
[self() ! {deliver, Topic, Msg}
|| Msg <- MsgList];
false -> ok
end
end,
Topic,
Filter).
on_message_fetch_for_pubsub(#{clientid := ClientId},Topic, Opts, {Filter, Pool}) ->
with_filter(fun () ->
emqx_metrics:inc('backend.redis.message_fetch_for_pubsub'),
case maps:get(qos, Opts, 0) > 0 andalso
maps:get(is_new, Opts, true)
of
true ->
MsgList =
emqx_backend_redis_cli:message_fetch_for_pubsub(Pool,
[{clientid,
ClientId},
{topic,
Topic}]),
[self() ! {deliver, Topic, Msg}
|| Msg <- MsgList];
false -> ok
end
end,
Topic,
Filter).
on_message_fetch_for_keep_latest(#{clientid := ClientId},Topic, Opts, {Filter, Pool}) ->
with_filter(fun () ->
emqx_metrics:inc('backend.redis.message_fetch_for_keep_latest'),
case maps:get(qos, Opts, 0) > 0 andalso
maps:get(is_new, Opts, true)
of
true ->
MsgList =
emqx_backend_redis_cli:message_fetch_for_keep_latest(Pool,
[{clientid,
ClientId},
{topic,
Topic}]),
[self() ! {deliver, Topic, Msg}
|| Msg <- MsgList];
false -> ok
end
end,
Topic,
Filter).
on_retain_lookup(_Client, Topic, _Opts,{Filter, Pool}) ->
with_filter(fun () ->
emqx_metrics:inc('backend.redis.retain_lookup'),
MsgList = emqx_backend_redis_cli:lookup_retain(Pool,
[{topic,Topic}]),
[self() !
{deliver,
Topic,
emqx_message:set_header(retained, true, Msg)}
|| Msg <- MsgList]
end,
Topic,
Filter).
on_message_publish(Msg = #message{flags =
#{retain := true}, payload = <<>>}, _Rule) -> {ok, Msg};
on_message_publish(Msg0 = #message{topic = Topic}, {Filter, Pool, ExpiredTime}) ->
with_filter(fun () ->
emqx_metrics:inc('backend.redis.message_publish'),
Msg = emqx_backend_redis_cli:message_publish(Pool, Msg0, ExpiredTime),
{ok, Msg} end,
Msg0,
Topic,
Filter).
on_message_store_keep_latest(Msg = #message{flags =
#{retain := true},payload = <<>>},_Rule) ->{ok, Msg};
on_message_store_keep_latest(Msg0 = #message{topic = Topic}, {Filter, Pool, ExpiredTime}) ->
with_filter(fun () ->
emqx_metrics:inc('backend.redis.message_store_keep_latest'),
Msg =
emqx_backend_redis_cli:message_store_keep_latest(Pool, Msg0, ExpiredTime),
{ok, Msg}
end,
Msg0,
Topic,
Filter).
on_message_retain(Msg = #message{flags = #{retain := false}}, _Rule) -> {ok, Msg};
on_message_retain(Msg = #message{flags =
#{retain := true}, payload = <<>>}, _Rule) -> {ok, Msg};
on_message_retain(Msg0 = #message{flags = #{retain := true}, topic = Topic, headers = Headers0}, {Filter, Pool, ExpiredTime}) ->
Headers = case erlang:is_map(Headers0) of
true -> Headers0;
false -> #{}
end,
case maps:find(retained, Headers) of
{ok, true} -> {ok, Msg0};
_ ->
with_filter(fun () ->
emqx_metrics:inc('backend.redis.message_retain'),
Msg = emqx_backend_redis_cli:message_retain(Pool, Msg0, ExpiredTime), {ok, Msg} end,
Msg0,
Topic,
Filter)
end;
on_message_retain(Msg, _Rule) -> {ok, Msg}.
on_retain_delete(Msg0 = #message{flags =
#{retain := true}, topic = Topic, payload = <<>>}, {Filter, Pool, _ExpiredTime}) ->
with_filter(fun () ->
emqx_metrics:inc('backend.redis.retain_delete'),
Msg = emqx_backend_redis_cli:delete_retain(Pool, Msg0),
{stop, Msg}
end,
Msg0,
Topic,
Filter);
on_retain_delete(Msg, _Rule) -> {ok, Msg}.
on_message_acked_for_queue(#{clientid := ClientId}, #message{topic = Topic, id = MsgId}, {Filter, Pool}) ->
with_filter(fun () ->
emqx_metrics:inc('backend.redis.message_acked_for_queue'),
emqx_backend_redis_cli:message_acked_for_queue(Pool,
[{clientid,
ClientId},
{topic,
Topic},
{msgid,
MsgId}])
end,
Topic,
Filter).
on_message_acked_for_pubsub(#{clientid := ClientId},
#message{topic = Topic, id = MsgId},
{Filter, Pool}) ->
with_filter(fun () ->
emqx_metrics:inc('backend.redis.message_acked_for_pubsub'),
emqx_backend_redis_cli:message_acked_for_pubsub(Pool,
[{clientid,
ClientId},
{topic,
Topic},
{msgid,
MsgId}])
end,
Topic,
Filter).
on_message_acked_for_keep_latest(#{clientid := ClientId},#message{topic = Topic}, {Filter, Pool}) ->
with_filter(fun () ->
emqx_metrics:inc('backend.redis.message_acked_for_keep_latest'),
emqx_backend_redis_cli:message_acked_for_keep_latest(Pool,
[{clientid,
ClientId},
{topic,
Topic}])
end,
Topic,
Filter).
run_redis_commands(Msg0 = #message{topic = Topic},{Filter, Pool, Cmdlines, _ExpiredTime}) ->
with_filter(fun () ->
Msg = emqx_backend_redis_cli:run_redis_commands(Pool,Msg0,Cmdlines),
{ok, Msg}
end,
Msg0,
Topic,
Filter).
run_redis_commands(#{clientid := ClientId}, #message{topic = Topic, id = MsgId}, {Filter, Pool, Cmdlines}) ->
with_filter(fun () -> emqx_backend_redis_cli:run_redis_commands(Pool, [{clientid, ClientId}, {topic, Topic}, {msgid, MsgId}], Cmdlines) end, Topic, Filter);
run_redis_commands(#{clientid := ClientId}, _ConnInfo, {Filter, Pool, Cmdlines}) ->
with_filter(fun () -> emqx_backend_redis_cli:run_redis_commands(Pool, [{clientid, ClientId}], Cmdlines) end, undefined, Filter);
run_redis_commands(_, _, _) -> ok.
run_redis_commands(#{clientid := ClientId}, Topic, Opts, {Filter, Pool, Cmdlines})
when is_binary(Topic) ->
with_filter(fun () ->
Qos = maps:get(qos, Opts, 0),
emqx_backend_redis_cli:run_redis_commands(Pool,
[{clientid,
ClientId},
{topic,
Topic},
{qos, Qos}],
Cmdlines)
end,
Topic,
Filter);
run_redis_commands(#{clientid := ClientId}, _Reason,
_ConnInfo, {Filter, Pool, Cmdlines}) ->
with_filter(fun () ->
emqx_backend_redis_cli:run_redis_commands(Pool,
[{clientid,
ClientId}],
Cmdlines)
end,
undefined,
Filter);
run_redis_commands(_, _, _, _) -> ok.
parse_hook(Hooks) -> parse_hook(Hooks, []).
parse_hook([], Acc) -> Acc;
parse_hook([{Hook, Item} | Hooks], Acc) ->
Params = emqx_json:decode(Item),
Action = proplists:get_value(<<"action">>, Params),
Pool = proplists:get_value(<<"pool">>, Params),
Filter = proplists:get_value(<<"topic">>, Params),
ExpiredTime = proplists:get_value(<<"expired_time">>, Params, 7200),
Pools = application:get_env(emqx_backend_redis, pools, []),
Pool1 = case lists:keyfind(b2a(Pool), 1, Pools) of
false -> pool_name(b2a(Pool));
{_, PoolArgs} ->
case proplists:get_value(type, PoolArgs) of
cluster -> {cluster, pool_name(b2a(Pool))};
Type -> {Type, pool_name(b2a(Pool))}
end
end,
parse_hook(Hooks, [{l2a(Hook), Action, Pool1, Filter, ExpiredTime} | Acc]).
compile_cmds([<<"pipeline">> | Cmds]) ->
{pipeline, [compile_cmd(Cmd) || Cmd <- Cmds]};
compile_cmds(Cmds) -> [compile_cmd(Cmd) || Cmd <- Cmds].
compile_cmd(Cmd) ->
compile_cmd(binary:split(Cmd, <<" ">>, [global]), []).
compile_cmd([], Acc) -> lists:reverse(Acc);
compile_cmd([Cmd | Tail], Acc) when Cmd =:= <<>> ->
compile_cmd(Tail, Acc);
compile_cmd([Cmd | Tail], Acc) ->
compile_cmd(Tail, [Cmd | Acc]).
with_filter(Fun, _, undefined) ->
Fun(),
ok;
with_filter(Fun, Topic, Filter) ->
case emqx_topic:match(Topic, Filter) of
true ->
Fun(),
ok;
false -> ok
end.
with_filter(Fun, _, _, undefined) -> Fun();
with_filter(Fun, Msg, Topic, Filter) ->
case emqx_topic:match(Topic, Filter) of
true -> Fun();
false -> {ok, Msg}
end.
l2a(L) -> erlang:list_to_atom(L).
b2a(B) -> erlang:binary_to_atom(B, utf8).