File otp_src_19.3.4-shell-history.patch of Package erlang

Overview Repositories Revisions Requests Users Attributes Meta

File otp_src_19.3.4-shell-history.patch of Package erlang (Revision 67b0bdcb550035a7d2b35b4c93c007f7)

Currently displaying revision 67b0bdcb550035a7d2b35b4c93c007f7 , Show latest

diff -Ndurp otp_src_19.3.4/lib/kernel/src/group.erl otp_src_19.3.4-shell-history/lib/kernel/src/group.erl
--- otp_src_19.3.4/lib/kernel/src/group.erl	2017-05-11 18:41:34.000000000 +0300
+++ otp_src_19.3.4-shell-history/lib/kernel/src/group.erl	2017-05-22 14:49:49.755572832 +0300
@@ -33,7 +33,7 @@ start(Drv, Shell, Options) ->
 server(Drv, Shell, Options) ->
     process_flag(trap_exit, true),
     edlin:init(),
-    put(line_buffer, proplists:get_value(line_buffer, Options, [])),
+    put(line_buffer, proplists:get_value(line_buffer, Options, group_history:load())),
     put(read_mode, list),
     put(user_drv, Drv),
     put(expand_fun,
@@ -783,6 +783,7 @@ save_line_buffer("\n", Lines) ->
 save_line_buffer(Line, [Line|_Lines]=Lines) ->
     save_line_buffer(Lines);
 save_line_buffer(Line, Lines) ->
+    group_history:add(Line),
     save_line_buffer([Line|Lines]).
 
 save_line_buffer(Lines) ->
diff -Ndurp otp_src_19.3.4/lib/kernel/src/group_history.erl otp_src_19.3.4-shell-history/lib/kernel/src/group_history.erl
--- otp_src_19.3.4/lib/kernel/src/group_history.erl	1970-01-01 03:00:00.000000000 +0300
+++ otp_src_19.3.4-shell-history/lib/kernel/src/group_history.erl	2017-05-22 14:49:49.755572832 +0300
@@ -0,0 +1,368 @@
+-module(group_history).
+-export([load/0, add/1]).
+
+%% Make a minimal size that should encompass set of lines and then make
+%% a file rotation for N files of this size.
+-define(DEFAULT_HISTORY_FILE, ".erlang-history/log").
+-define(MAX_HISTORY_FILES, 10).
+-define(DEFAULT_SIZE, 1024*512). % 512 kb total default
+-define(DEFAULT_STATUS, enabled).
+-define(MIN_HISTORY_SIZE, (50*1024)). % 50 kb, in bytes
+-define(DEFAULT_DROP, []).
+-define(DISK_LOG_FORMAT, internal). % since we want repairs
+-define(LOG_NAME, '$#group_history').
+-define(VSN, {0,1,0}).
+
+%%%%%%%%%%%%%%
+%%% PUBLIC %%%
+%%%%%%%%%%%%%%
+
+%% @doc Loads the shell history from memory. This function should only be
+%% called from group:server/3 to inject itself in the previous commands
+%% stack.
+-spec load() -> [string()].
+load() ->
+    wait_for_kernel_safe_sup(),
+    case history_status() of
+        enabled ->
+            case open_log() of
+                {ok, ?LOG_NAME} ->
+                    read_full_log(?LOG_NAME);
+                {repaired, ?LOG_NAME, {recovered, Good}, {badbytes, Bad}} ->
+                    report_repairs(?LOG_NAME, Good, Bad),
+                    read_full_log(?LOG_NAME);
+                {error, {need_repair, _FileName}} ->
+                    repair_log(?LOG_NAME);
+                {error, {arg_mismatch, repair, true, false}} ->
+                    repair_log(?LOG_NAME);
+                {error, {name_already_open, _}} ->
+                    show_rename_warning(),
+                    read_full_log(?LOG_NAME);
+                {error, {size_mismatch, Current, New}} ->
+                    show_size_warning(Current, New),
+                    resize_log(?LOG_NAME, Current, New),
+                    load();
+                {error, {invalid_header, {vsn, Version}}} ->
+                    upgrade_version(?LOG_NAME, Version),
+                    load();
+                {error, Reason} ->
+                    handle_open_error(Reason),
+                    disable_history(),
+                    []
+            end;
+        _ ->
+            []
+    end.
+
+%% @doc adds a log line to the erlang history log, if configured to do so.
+-spec add(iodata()) -> ok.
+add(Line) -> add(Line, history_status()).
+
+add(Line, enabled) ->
+    case lists:member(Line, to_drop()) of
+        false ->
+            case disk_log:log(?LOG_NAME, Line) of
+                ok ->
+                    ok;
+                {error, no_such_log} ->
+                    _ = open_log(), % a wild attempt we hope works!
+                    disk_log:log(?LOG_NAME, Line);
+                {error, _Other} ->
+                    % just ignore, we're too late
+                    ok
+            end;
+        true ->
+            ok
+    end;
+add(_Line, disabled) ->
+    ok.
+
+%%%%%%%%%%%%%%%
+%%% PRIVATE %%%
+%%%%%%%%%%%%%%%
+
+%% Because loading the shell happens really damn early, processes we depend on
+%% might not be there yet. Luckily, the load function is called from the shell
+%% after a new process has been spawned, so we can block in here
+wait_for_kernel_safe_sup() ->
+    case whereis(kernel_safe_sup) of
+        undefined ->
+            timer:sleep(50),
+            wait_for_kernel_safe_sup();
+        _ ->
+            ok
+    end.
+
+%% Start a process to open and close the table to repair it, different
+%% from the current shell process. The goal is to intercept error_logger
+%% messages we don't want to output every time the shell closes.
+repair_log(Name) ->
+    R = make_ref(),
+    S = self(),
+    spawn(fun() ->
+        %% ignore size so we can repair a file that needs resizing
+        Opts = lists:keydelete(size, 1, log_options(true)),
+        case disk_log:open(Opts) of
+            {repaired, ?LOG_NAME, {recovered, Good}, {badbytes, Bad}} ->
+                report_repairs(?LOG_NAME, Good, Bad);
+            _ ->
+                ok
+        end,
+        _ = disk_log:close(Name),
+        S ! R
+    end),
+    %% Messages from the IO protocol will only need to be received if we
+    %% currently are the group leader (in this case, the 'user' process).
+    %% if this is not 'user', we can move on.
+    _ = case process_info(self(), registered_name) of
+        {registered_name, user} ->
+            accumulate_and_filter_io(R);
+        _ ->
+            ok
+    end,
+    load().
+
+accumulate_and_filter_io(Ref) -> accumulate_and_filter_io(Ref, []).
+
+accumulate_and_filter_io(Ref, Acc) ->
+    %% We should be fine reordering most IO messages since they don't
+    %% all come from the same process (as they'd block).
+    %% If we're fast enough, we'll even be fine to not change the
+    %% global order.
+    receive
+        {io_request,From,ReplyAs,
+         {put_chars,_Enc,io_lib,format,
+          [Txt, [_]]}} = Msg ->
+            case matches_log(Txt) of
+                true -> From ! {io_reply, ReplyAs, ok};
+                false -> accumulate_and_filter_io(Ref, [Msg|Acc])
+            end;
+        {io_request,From,ReplyAs, {put_chars,_Enc,Txt}} = Msg ->
+            case matches_log(Txt) of
+                true -> From ! {io_reply, ReplyAs, ok};
+                false -> accumulate_and_filter_io(Ref, [Msg|Acc])
+            end;
+        Msg when Msg =/= Ref ->
+            accumulate_and_filter_io(Ref, [Msg|Acc])
+    after 50 -> % give some time since logging is async in disk_log
+        receive
+            Ref -> % done, reinject IO messages we didn't filter
+                [self() ! Msg || Msg <- lists:reverse(Acc)]
+        end
+    end.
+
+matches_log(Txt) ->
+    match =:= re:run(Txt, "disk_log: repairing.*" ?DEFAULT_HISTORY_FILE,
+                     [{capture, none}]).
+
+%% Return whether the shell history is enabled or not
+-spec history_status() -> enabled | disabled.
+history_status() ->
+    case application:get_env(kernel, shell_history) of
+        {ok, enabled} -> enabled;
+        undefined -> ?DEFAULT_STATUS;
+        _ -> disabled
+    end.
+
+%% Open a disk_log file while ensuring the required path is there.
+open_log() ->
+    Opts = log_options(),
+    _ = ensure_path(Opts),
+    disk_log:open(Opts).
+
+%% Return logger options (with repair disabled)
+log_options() -> log_options(false).
+
+%% Return logger options (with repairs configurable)
+log_options(Repair) ->
+    Home = home(),
+    File = filename:join([Home, ?DEFAULT_HISTORY_FILE]),
+    Size = find_wrap_values(),
+    [{name, ?LOG_NAME},
+     {file, File},
+     {repair, Repair},
+     {format, internal},
+     {type, wrap},
+     {size, Size},
+     {distributed, []},
+     {notify, false},
+     {head, {vsn, ?VSN}},
+     {mode, read_write}].
+
+-spec ensure_path([{file, string()} | {atom(), _}, ...]) -> ok | {error, term()}.
+ensure_path(Opts) ->
+    {file, Path} = lists:keyfind(file, 1, Opts),
+    filelib:ensure_dir(Path).
+
+%% @private read the logs from an already open file. Treat closed files
+%% as wrong and returns an empty list to avoid crash loops in the shell.
+-spec read_full_log(term()) -> [string()].
+read_full_log(Name) ->
+    case disk_log:chunk(Name, start) of
+        {error, no_such_log} ->
+            show_unexpected_close_warning(),
+            [];
+        eof ->
+            [];
+        {Cont, Logs} ->
+            lists:reverse(maybe_drop_header(Logs) ++ read_full_log(Name, Cont))
+    end.
+
+read_full_log(Name, Cont) ->
+    case disk_log:chunk(Name, Cont) of
+        {error, no_such_log} ->
+            show_unexpected_close_warning(),
+            [];
+        eof ->
+            [];
+        {NextCont, Logs} ->
+            maybe_drop_header(Logs) ++ read_full_log(Name, NextCont)
+    end.
+
+maybe_drop_header([{vsn, _} | Rest]) -> Rest;
+maybe_drop_header(Logs) -> Logs.
+
+-spec handle_open_error(_) -> ok.
+handle_open_error({arg_mismatch, OptName, CurrentVal, NewVal}) ->
+    show('$#erlang-history-arg-mismatch',
+         "Log file argument ~p changed value from ~p to ~p "
+         "and cannot be automatically updated. Please clear the "
+         "history files and try again.~n",
+         [OptName, CurrentVal, NewVal]);
+handle_open_error({not_a_log_file, FileName}) ->
+    show_invalid_file_warning(FileName);
+handle_open_error({invalid_index_file, FileName}) ->
+    show_invalid_file_warning(FileName);
+handle_open_error({invalid_header, Term}) ->
+    show('$#erlang-history-invalid-header',
+         "Shell history expects to be able to use the log files "
+         "which currently have unknown headers (~p) and may belong to "
+         "another mechanism. History logging will be "
+         "disabled.~n",
+         [Term]);
+handle_open_error({file_error, FileName, Reason}) ->
+    show('$#erlang-history-file-error',
+         "Error handling File ~s. Reason: ~p~n"
+         "History logging will be disabled.~n",
+         [FileName, Reason]);
+handle_open_error(Err) ->
+    show_unexpected_warning({disk_log, open, 1}, Err).
+
+find_wrap_values() ->
+    ConfSize = case application:get_env(kernel, shell_history_file_bytes) of
+        undefined -> ?DEFAULT_SIZE;
+        {ok, S} -> S
+    end,
+    SizePerFile = max(?MIN_HISTORY_SIZE, ConfSize div ?MAX_HISTORY_FILES),
+    FileCount = if SizePerFile > ?MIN_HISTORY_SIZE ->
+                       ?MAX_HISTORY_FILES
+                 ; SizePerFile =< ?MIN_HISTORY_SIZE ->
+                       max(1, ConfSize div SizePerFile)
+                end,
+    {SizePerFile, FileCount}.
+
+report_repairs(_, _, 0) ->
+    %% just a regular close repair
+    ok;
+report_repairs(_, Good, Bad) ->
+    show('$#erlang-history-report-repairs',
+         "The shell history log file was corrupted and was repaired. "
+         "~p bytes were recovered and ~p were lost.~n", [Good, Bad]).
+
+resize_log(Name, _OldSize, NewSize) ->
+    show('$#erlang-history-resize-attempt',
+         "Attempting to resize the log history file to ~p...", [NewSize]),
+    Opts = lists:keydelete(size, 1, log_options()),
+    _ = case disk_log:open(Opts) of
+        {error, {need_repair, _}} ->
+            _ = repair_log(Name),
+            disk_log:open(Opts);
+        _ ->
+            ok
+    end,
+    case disk_log:change_size(Name, NewSize) of
+        ok ->
+            show('$#erlang-history-resize-result',
+                 "ok~n", []);
+        {error, {new_size_too_small, _}} ->
+            show('$#erlang-history-resize-result',
+                 "failed (new size is too small)~n", []),
+            disable_history();
+        {error, Reason} ->
+            show('$#erlang-history-resize-result',
+                 "failed (~p)~n", [Reason]),
+            disable_history()
+    end.
+
+upgrade_version(_Name, Unsupported) ->
+    %% We only know of one version and can't support a newer one
+    show('$#erlang-history-upgrade',
+         "The version for the shell logs found on disk (~p) is "
+         "not supported by the current version (~p)~n",
+         [Unsupported, ?VSN]),
+    disable_history().
+
+disable_history() ->
+    show('$#erlang-history-disable', "Disabling shell history logging.~n", []),
+    application:set_env(kernel, shell_history, force_disabled).
+
+home() ->
+    case init:get_argument(home) of
+        {ok, [[Home]]} ->
+            Home;
+        _ ->
+            error_logger:error_msg("No home directory found"),
+            error(badarg)
+    end.
+
+to_drop() ->
+    case application:get_env(kernel, shell_history_drop) of
+        undefined ->
+            application:set_env(kernel, shell_history_drop, ?DEFAULT_DROP),
+            ?DEFAULT_DROP;
+        {ok, V} when is_list(V) -> [Ln++"\n" || Ln <- V];
+        {ok, _} -> ?DEFAULT_DROP
+    end.
+
+%%%%%%%%%%%%%%%%%%%%%%%%
+%%% Output functions %%%
+%%%%%%%%%%%%%%%%%%%%%%%%
+show_rename_warning() ->
+    show('$#erlang-history-rename-warn',
+         "A history file with a different path has already "
+         "been started for the shell of this node. The old "
+         "name will keep being used for this session.~n",
+         []).
+
+show_invalid_file_warning(FileName) ->
+    show('$#erlang-history-invalid-file',
+         "Shell history expects to be able to use the file ~s "
+         "which currently exists and is not a file usable for "
+         "history logging purposes. History logging will be "
+         "disabled.~n", [FileName]).
+
+show_unexpected_warning({M,F,A}, Term) ->
+    show('$#erlang-history-unexpected-return',
+         "unexpected return value from ~p:~p/~p: ~p~n"
+         "shell history will be disabled for this session.~n",
+         [M,F,A,Term]).
+
+show_unexpected_close_warning() ->
+    show('$#erlang-history-unexpected-close',
+         "The shell log file has mysteriousy closed. Ignoring "
+         "currently unread history.~n", []).
+
+show_size_warning(_Current, _New) ->
+    show('$#erlang-history-size',
+         "The configured log history file size is different from "
+         "the size of the log file on disk.~n", []).
+
+show(Key, Format, Args) ->
+    case get(Key) of
+        undefined ->
+            io:format(standard_error, Format, Args),
+            put(Key, true),
+            ok;
+        true ->
+            ok
+    end.
diff -Ndurp otp_src_19.3.4/lib/kernel/src/kernel.app.src otp_src_19.3.4-shell-history/lib/kernel/src/kernel.app.src
--- otp_src_19.3.4/lib/kernel/src/kernel.app.src	2017-05-11 18:41:34.000000000 +0300
+++ otp_src_19.3.4-shell-history/lib/kernel/src/kernel.app.src	2017-05-22 17:09:02.362965449 +0300
@@ -43,6 +43,7 @@
 	     global_group,
 	     global_search,
 	     group,
+	     group_history,
 	     heart,
 	     hipe_unified_loader,
 	     inet6_tcp,
diff -Ndurp otp_src_19.3.4/lib/kernel/src/Makefile otp_src_19.3.4-shell-history/lib/kernel/src/Makefile
--- otp_src_19.3.4/lib/kernel/src/Makefile	2017-05-11 18:41:34.000000000 +0300
+++ otp_src_19.3.4-shell-history/lib/kernel/src/Makefile	2017-05-22 15:40:16.315601143 +0300
@@ -84,6 +84,7 @@ MODULES = \
 	global_group \
 	global_search \
 	group \
+	group_history \
 	heart \
 	hipe_unified_loader \
 	inet \

Places

File otp_src_19.3.4-shell-history.patch of Package erlang (Revision 67b0bdcb550035a7d2b35b4c93c007f7)

Places