fix

apps/iot/include/iot.hrl

@@ -61,7 +61,7 @@
     %% 当前最新值
     last_value = 0 :: number(),
     %% 历史值序列, 队列；保存最近的100数值, 格式为: [{ts, value}]
-    serial_values = [] :: queue(),
+    queue = [] :: queus:queue(),
     %% 最后更新时间
     update_ts = 0 :: integer()
 }).

apps/iot/src/iot_util.erl

@@ -13,6 +13,7 @@
 -export([timestamp/0, number_format/2, current_time/0]).
 -export([step/3, chunks/2, rand_bytes/1]).
 -export([json_data/1, json_error/2]).
+-export([queue_limited_in/3]).
 
 %% 时间，精确到毫秒
 timestamp() ->
@@ -66,4 +67,13 @@ json_error(ErrCode, ErrMessage) when is_integer(ErrCode), is_binary(ErrMessage)
 rand_bytes(Size) when is_integer(Size) ->
     Bytes = crypto:strong_rand_bytes(Size),
     S = lists:flatten([integer_to_list(E, 16) || <<E:4>> <= Bytes]),
-    string:to_lower(S).
+    string:to_lower(S).
+
+queue_limited_in(Item, Q, Num) when is_integer(Num) ->
+    case queue:len(Q) >= Num of
+        true ->
+            Q1 = queue:drop(Q),
+            queue:in(Item, Q1);
+        false ->
+            queue:in(Item, Q)
+    end.

apps/iot/src/model/host_model.erl

@@ -12,13 +12,19 @@
 -include_lib("stdlib/include/qlc.hrl").
 
 %% API
--export([get_all_hosts/0, insert/4, change_status/2, delete/1, table_size/0]).
+-export([get_hosts/2, insert/4, change_status/2, delete/1, table_size/0]).
 
 %% 获取app信息
-get_all_hosts() ->
+get_hosts(Start, Limit) when is_integer(Limit), is_integer(Start), Start >= 0, Limit > 0 ->
     Fun = fun() ->
         Q = qlc:q([E || E <- mnesia:table(host)]),
-        qlc:e(Q)
+        QC = qlc:cursor(Q),
+        case qlc:next_answers(QC, Start + Limit) of
+            Answers when is_list(Answers) ->
+                lists:sublist(Answers, Start + 1, Limit);
+            _ ->
+                []
+        end
           end,
     case mnesia:transaction(Fun) of
         {atomic, Items} when is_list(Items) ->

apps/iot/src/model/terminal_model.erl

@@ -13,7 +13,7 @@
 
 %% API
 -export([get_all_terminals/0, get_status_stat/0]).
--export([change_status/2, delete/1]).
+-export([change_status/2, delete/1, update_metric/4]).
 
 %% 获取app信息
 get_all_terminals() ->
@@ -88,30 +88,33 @@ update_metric(TerminalId, MetricName, MetricSymbol, MetricValue) when is_binary(
             [] ->
                 mnesia:abort(<<"terminal not found">>);
             [Terminal = #terminal{metrics = Metrics}] ->
+                Ts = iot_util:current_time(),
                 NMetrics = case lists:any(fun(#terminal_metric{symbol = Symbol}) -> Symbol =:= MetricSymbol end, Metrics) of
                                true ->
-                                   lists:map(fun(Metric=#terminal_metric{symbol = Symbol, serial_values = SerialValues}) ->
+                                   lists:map(fun(Metric=#terminal_metric{symbol = Symbol, queue = Q}) ->
                                        case Symbol =:= MetricSymbol of
                                            true ->
-                                               NSerialValues = case queue:len(SerialValues) >= 100 of
-                                                                   true ->
-                                                                       SerialValues0 = queue:drop(SerialValues),
-                                                                       queue:in(MetricValue, SerialValues0);
-                                                                   false ->
-                                                                       queue:in(MetricValue, SerialValues)
-                                                               end,
+                                               Q1 = iot_util:queue_limited_in({Ts, MetricValue}, Q, 100),
                                                Metric#terminal_metric{
                                                    name = MetricName,
                                                    last_value = MetricValue,
-                                                   update_ts = iot_util:current_time(),
-                                                   serial_values = NSerialValues
+                                                   update_ts = Ts,
+                                                   queue = Q1
                                                };
                                            false ->
                                                Metric
                                        end
                                              end, Metrics);
                                false ->
-                                   Metrics#terminal_metric{}
+                                   Q0 = queue:new(),
+                                   Metric = #terminal_metric{
+                                       name = MetricName,
+                                       symbol = MetricSymbol,
+                                       last_value = MetricValue,
+                                       update_ts = Ts,
+                                       queue = queue:in({Ts, MetricValue}, Q0)
+                                   },
+                                   Metrics ++ [Metric]
                            end,
                 mnesia:write(terminal, Terminal#terminal{metrics = NMetrics}, write)
         end