File 3281-shell-history-allow-configurable-history-m... of Package erlang

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File 3281-shell-history-allow-configurable-history-module.patch of Package erlang

From b78f444e56815adc4865134ccaa70a5a4b7e68da Mon Sep 17 00:00:00 2001
From: Maxim Fedorov <dane@whatsapp.com>
Date: Mon, 21 Dec 2020 16:22:35 -0800
Subject: [PATCH] shell history: allow configurable history module

In addition to 'enabled' or 'disabled' setting, kernel
shell_history variable may be an atom that allows to use
any module as callback module for shell history.
This enabled to fetch shell history from different sources,
for example, cloud-based environment, or other nodes of
a cluster.
This commit also fixes test case that was using -kernel
shell_history 'true' instead of 'enabled'.
---
 lib/kernel/doc/src/kernel_app.xml           | 10 +++++--
 lib/kernel/src/group_history.erl            | 16 +++++++-----
 lib/kernel/test/interactive_shell_SUITE.erl | 29 ++++++++++++++++++---
 3 files changed, 44 insertions(+), 11 deletions(-)

diff --git a/lib/kernel/doc/src/kernel_app.xml b/lib/kernel/doc/src/kernel_app.xml
index d4f707951d..74cf089918 100644
--- a/lib/kernel/doc/src/kernel_app.xml
+++ b/lib/kernel/doc/src/kernel_app.xml
@@ -446,10 +446,16 @@ MaxT = TickTime + TickTime / 4</code>
 	 using this service.
 Defaults to <c>false</c>.
 </item>
- <tag><c>shell_history = enabled | disabled </c></tag>
+ <tag><c>shell_history = enabled | disabled | module()</c></tag>
 <item>
 Specifies whether shell history should be logged to disk
- between usages of <c>erl</c>.
+ between usages of <c>erl</c> (<c>enabled</c>), not logged
+ at all (<c>disabled</c>), or a user-specified module will
+ be used to log shell history. This module should export
+ <c>load() -> [string()]</c> returning a list of strings to
+ load in the shell when it starts, and <c>add(iodata()) -> ok.</c>
+ called every time new line is entered in the shell. By default
+ logging is disabled.
 </item>
 <tag><c>shell_history_drop = [string()]</c></tag>
 <item>
diff --git a/lib/kernel/src/group_history.erl b/lib/kernel/src/group_history.erl
index bbe5a8077e..c196b0c1a9 100644
--- a/lib/kernel/src/group_history.erl
+++ b/lib/kernel/src/group_history.erl
@@ -73,8 +73,10 @@ load() ->
 % the node is shutting down. Ignore it.
 exit:_ -> []
 end;
- _ ->
- []
+ disabled ->
+ [];
+ Provider ->
+ Provider:load()
 end.
 
 %% @doc adds a log line to the erlang history log, if configured to do so.
@@ -98,7 +100,9 @@ add(Line, enabled) ->
 ok
 end;
 add(_Line, disabled) ->
- ok.
+ ok;
+add(Line, Provider) ->
+ lists:member(Line, to_drop()) orelse Provider:add(Line).
 
 %%%%%%%%%%%%%%%
 %%% PRIVATE %%%
@@ -129,13 +133,13 @@ repair_log(Name) ->
 load().
 
 %% Return whether the shell history is enabled or not
--spec history_status() -> enabled | disabled.
+-spec history_status() -> enabled | disabled | module().
 history_status() ->
 %% Don't run for user proc or if the emulator's tearing down
 Skip = is_user() orelse not init_running(),
 case application:get_env(kernel, shell_history) of
- {ok, enabled} when not Skip ->
- enabled;
+ {ok, Atom} when not Skip, is_atom(Atom) ->
+ Atom;
 undefined when not Skip ->
 ?DEFAULT_STATUS;
 _ ->
diff --git a/lib/kernel/test/interactive_shell_SUITE.erl b/lib/kernel/test/interactive_shell_SUITE.erl
index f058b53497..b4ca502dc4 100644
--- a/lib/kernel/test/interactive_shell_SUITE.erl
+++ b/lib/kernel/test/interactive_shell_SUITE.erl
@@ -22,7 +22,7 @@
 -export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1, 
 	 init_per_group/2,end_per_group/2, 
 	 get_columns_and_rows/1, exit_initial/1, job_control_local/1, 
-	 job_control_remote/1,stop_during_init/1,
+	 job_control_remote/1,stop_during_init/1, custom_shell_history/1,
 	 job_control_remote_noshell/1,ctrl_keys/1]).
 
 -export([init_per_testcase/2, end_per_testcase/2]).
@@ -28,6 +28,8 @@
 -export([init_per_testcase/2, end_per_testcase/2]).
 %% For spawn
 -export([toerl_server/3]).
+%% Exports for custom shell history module
+-export([load/0, add/1]).
 
 init_per_testcase(_Func, Config) ->
 Config.
@@ -42,7 +44,7 @@
 all() -> 
 [get_columns_and_rows, exit_initial, job_control_local,
 job_control_remote, job_control_remote_noshell,
- ctrl_keys, stop_during_init].
+ ctrl_keys, stop_during_init, custom_shell_history].
 
 groups() -> 
 [].
@@ -158,13 +160,34 @@ stop_during_init(Config) when is_list(Config) ->
 		{error, Reason2} ->
 		 {skip, Reason2};
 		Tempdir ->
-		 XArg = " -kernel shell_history true -s init stop",
+		 XArg = " -kernel shell_history enabled -s init stop",
 		 start_runerl_command(RunErl, Tempdir, "\\\""++Erl++"\\\""++XArg),
 		 {ok, Binary} = file:read_file(filename:join(Tempdir, "erlang.log.1")),
 		 nomatch = binary:match(Binary, <<"*** ERROR: Shell process terminated! ***">>)
 	 end
 end.
 
+custom_shell_history(Config) when is_list(Config) ->
+ case proplists:get_value(default_shell, Config) of
+ old -> {skip, "Not supported in old shell"};
+ new ->%% Up key: Ctrl + P = Cp=[$\^p]
+ rtnode([
+ {putline, ""},
+ {putline, [$\^p]},
+ {putline_raw, ""},
+ {getline, "0"},
+ {putline, "echo."},
+ {getline, "!echo"} %% exclamation sign is printed by custom history module
+ ], [], [], " -kernel shell_history " ++ atom_to_list(?MODULE) ++
+ " -pz " ++ filename:dirname(code:which(?MODULE)))
+ end.
+
+load() ->
+ ["0.\n\n"].
+
+add(_Line) ->
+ io:format("!", []).
+
 %% Tests that local shell can be started by means of job control.
 job_control_local(Config) when is_list(Config) ->
 case proplists:get_value(default_shell,Config) of
-- 
2.26.2

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File 3281-shell-history-allow-configurable-history-module.patch of Package erlang

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