日志文件增加压缩功能

apps/iot/src/iot_logger.erl

@@ -12,7 +12,7 @@
 -behaviour(gen_server).
 
 %% API
--export([start_link/1, write/2]).
+-export([start_link/1, start_link/2,  write/2]).
 
 %% gen_server callbacks
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
@@ -22,6 +22,9 @@
 -record(state, {
     file_name :: string(),
     date :: calendar:date(),
+    %% 用来保存历史文件信息
+    queue = queue:new(),
+    counter = 5,
     file
 }).
 
@@ -36,7 +39,12 @@ write(Pid, Data) when is_pid(Pid) ->
 -spec(start_link(FileName :: string()) ->
     {ok, Pid :: pid()} | ignore | {error, Reason :: term()}).
 start_link(FileName) when is_list(FileName) ->
-    gen_server:start_link(?MODULE, [FileName], []).
+    start_link(FileName, 5).
+
+-spec(start_link(FileName :: string(), Counter :: integer()) ->
+    {ok, Pid :: pid()} | ignore | {error, Reason :: term()}).
+start_link(FileName, Counter) when is_list(FileName), is_integer(Counter) ->
+    gen_server:start_link(?MODULE, [FileName, Counter], []).
 
 %%%===================================================================
 %%% gen_server callbacks
@@ -47,12 +55,12 @@ start_link(FileName) when is_list(FileName) ->
 -spec(init(Args :: term()) ->
     {ok, State :: #state{}} | {ok, State :: #state{}, timeout() | hibernate} |
     {stop, Reason :: term()} | ignore).
-init([FileName]) ->
+init([FileName, Counter]) ->
     ensure_dir(),
     FilePath = make_file(FileName, erlang:date()),
-    {ok, File} = file:open(FilePath, [append, binary]),
+    {ok, IoDevice} = file:open(FilePath, [append, binary]),
 
-    {ok, #state{file = File, file_name = FileName, date = get_date()}}.
+    {ok, #state{file = {IoDevice, FilePath}, queue = queue:from_list([FilePath]), file_name = FileName, counter = Counter, date = get_date()}}.
 
 %% @private
 %% @doc Handling call messages
@@ -73,22 +81,34 @@ handle_call(_Request, _From, State = #state{}) ->
     {noreply, NewState :: #state{}} |
     {noreply, NewState :: #state{}, timeout() | hibernate} |
     {stop, Reason :: term(), NewState :: #state{}}).
-handle_cast({write, Data}, State = #state{file = OldFile, file_name = FileName, date = Date}) ->
+handle_cast({write, Data}, State = #state{file = {OldIoDevice, OldFilePath}, queue = Q, counter = Counter, file_name = FileName, date = Date}) ->
     Line = iolist_to_binary([time_prefix(), <<" ">>, format(Data), <<$\n>>]),
     NDate = erlang:date(),
+
     case maybe_new_file(Date, NDate) of
         true ->
-            file:close(OldFile),
+            ok = file:close(OldIoDevice),
+            %% 压缩文件
+            ok = erl_tar:create(OldFilePath ++ ".tar", [OldFilePath], [compressed]),
+            %% 删除原来的文件
+            ok = file:delete(OldFilePath),
 
-            FilePath = make_file(FileName, NDate),
-            {ok, File} = file:open(FilePath, [append, binary]),
-            ok = file:write(File, Line),
-            %% 清理历史的文件, 日志文件保留一个月的
-            delete_old_files(FileName, 30),
+            %% 开启新的文件
+            NewFilePath = make_file(FileName, NDate),
+            {ok, NewIoDevice} = file:open(NewFilePath, [append, binary]),
+            ok = file:write(NewIoDevice, Line),
 
-            {noreply, State#state{file = File, date = get_date()}};
+            NQ = case queue:len(Q) >= Counter - 1 of
+                     true ->
+                         {{value, ExpiredFilePath}, Q2} = queue:out(Q),
+                         ok = file:delete(ExpiredFilePath),
+                         queue:in(NewFilePath, Q2);
+                     false ->
+                         queue:in(NewFilePath, Q)
+                 end,
+            {noreply, State#state{file = {NewIoDevice, NewFilePath}, queue = NQ, date = get_date()}};
         false ->
-            ok = file:write(OldFile, Line),
+            ok = file:write(OldIoDevice, Line),
             {noreply, State}
     end.
 
@@ -158,12 +178,12 @@ get_date() ->
 maybe_new_file({Y, M, D}, {Y0, M0, D0}) ->
     not (Y =:= Y0 andalso M =:= M0 andalso D =:= D0).
 
--spec delete_old_files(FileName :: string(), Days :: integer()) -> no_return().
-delete_old_files(FileName, Days) when is_list(FileName), is_integer(Days) ->
-    Seconds0 = calendar:datetime_to_gregorian_seconds(calendar:local_time()),
-    Seconds = Seconds0 - Days * 86400,
-    lists:foreach(fun(Day) ->
-        {Date, _} = calendar:gregorian_seconds_to_datetime(Seconds - Day * 86400),
-        FilePath = make_file(FileName, Date),
-        filelib:is_file(FilePath) andalso file:delete(FilePath)
-                  end, lists:seq(1, 10)).
+%-spec delete_old_files(FileName :: string(), Days :: integer()) -> no_return().
+%delete_old_files(FileName, Days) when is_list(FileName), is_integer(Days) ->
+%    Seconds0 = calendar:datetime_to_gregorian_seconds(calendar:local_time()),
+%    Seconds = Seconds0 - Days * 86400,
+%    lists:foreach(fun(Day) ->
+%        {Date, _} = calendar:gregorian_seconds_to_datetime(Seconds - Day * 86400),
+%        FilePath = make_file(FileName, Date),
+%        filelib:is_file(FilePath) andalso file:delete(FilePath)
+%                  end, lists:seq(1, 10)).