diff options
Diffstat (limited to 'lib/kernel')
| -rw-r--r-- | lib/kernel/doc/src/kernel_app.xml | 23 | ||||
| -rw-r--r-- | lib/kernel/src/Makefile | 1 | ||||
| -rw-r--r-- | lib/kernel/src/group.erl | 3 | ||||
| -rw-r--r-- | lib/kernel/src/group_history.erl | 341 | ||||
| -rw-r--r-- | lib/kernel/src/kernel.app.src | 1 |
5 files changed, 368 insertions, 1 deletions
diff --git a/lib/kernel/doc/src/kernel_app.xml b/lib/kernel/doc/src/kernel_app.xml index 28af155493..9fccb4c7ac 100644 --- a/lib/kernel/doc/src/kernel_app.xml +++ b/lib/kernel/doc/src/kernel_app.xml @@ -419,6 +419,29 @@ MaxT = TickTime + TickTime / 4</code> using this service.</p> <p>Defaults to <c>false</c>.</p> </item> + <tag><c>shell_history = enabled | disabled </c></tag> + <item> + <p>Specifies whether shell history should be logged to disk + between usages of <c>erl</c>.</p> + </item> + <tag><c>shell_history_drop = [string()]</c></tag> + <item> + <p>Specific log lines that should not be persisted. For + example <c>["q().", "init:stop()."]</c> will allow to + ignore commands that shut the node down. Defaults to + <c>[]</c>.</p> + </item> + <tag><c>shell_history_file_bytes = integer()</c></tag> + <item> + <p>how many bytes the shell should remember. By default, the + value is set to 512kb, and the minimal value is 50kb.</p> + </item> + <tag><c>shell_history_path = string()</c></tag> + <item> + <p>Specifies where the shell history files will be stored. + defaults to the user's cache directory as returned by + <c>filename:basedir(user_cache, "erlang-history")</c>.</p> + </item> <tag><c>shutdown_func = {Mod, Func}</c></tag> <item> <p>Where:</p> diff --git a/lib/kernel/src/Makefile b/lib/kernel/src/Makefile index 2a89faaf13..78aa6192a9 100644 --- a/lib/kernel/src/Makefile +++ b/lib/kernel/src/Makefile @@ -85,6 +85,7 @@ MODULES = \ global_group \ global_search \ group \ + group_history \ heart \ hipe_unified_loader \ inet \ diff --git a/lib/kernel/src/group.erl b/lib/kernel/src/group.erl index b5e73117dd..0eeaaad8d2 100644 --- a/lib/kernel/src/group.erl +++ b/lib/kernel/src/group.erl @@ -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 --git a/lib/kernel/src/group_history.erl b/lib/kernel/src/group_history.erl new file mode 100644 index 0000000000..5ca5e2d1dd --- /dev/null +++ b/lib/kernel/src/group_history.erl @@ -0,0 +1,341 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2017. All Rights Reserved. +%% +%% Licensed under the Apache License, Version 2.0 (the "License"); +%% you may not use this file except in compliance with the License. +%% You may obtain a copy of the License at +%% +%% http://www.apache.org/licenses/LICENSE-2.0 +%% +%% Unless required by applicable law or agreed to in writing, software +%% distributed under the License is distributed on an "AS IS" BASIS, +%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +%% See the License for the specific language governing permissions and +%% limitations under the License. +%% +%% %CopyrightEnd% +%% +-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-shell-log"). +-define(MAX_HISTORY_FILES, 10). +-define(DEFAULT_SIZE, 1024*512). % 512 kb total default +-define(DEFAULT_STATUS, disabled). +-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. + +%% Repair the log out of band +repair_log(Name) -> + Opts = lists:keydelete(size, 1, log_options()), + 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), + load(). + +%% Return whether the shell history is enabled or not +-spec history_status() -> enabled | disabled. +history_status() -> + case is_user() orelse application:get_env(kernel, shell_history) of + true -> disabled; % don't run for user proc + {ok, enabled} -> enabled; + undefined -> ?DEFAULT_STATUS; + _ -> disabled + end. + +%% Return whether the user process is running this +-spec is_user() -> boolean(). +is_user() -> + case process_info(self(), registered_name) of + {registered_name, user} -> true; + _ -> false + 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 +log_options() -> + Path = find_path(), + File = filename:join([Path, ?DEFAULT_HISTORY_FILE]), + Size = find_wrap_values(), + [{name, ?LOG_NAME}, + {file, File}, + {repair, true}, + {format, internal}, + {type, wrap}, + {size, Size}, + {distributed, []}, + {notify, false}, + {head, {vsn, ?VSN}}, + {quiet, true}, + {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('$#erlang-history-disable', "Disabling shell history logging.~n", []), + application:set_env(kernel, shell_history, force_disabled). + +find_path() -> + case application:get_env(kernel, shell_history_path) of + undefined -> filename:basedir(user_cache, "erlang-history"); + {ok, Path} -> Path + end. + +to_drop() -> + case application:get_env(kernel, shell_history_drop) of + undefined -> + application:set_env(kernel, shell_history_drop, ?DEFAULT_DROP), + ?DEFAULT_DROP; + {ok, V} when is_list(V) -> [Ln++"\n" || Ln <- V]; + {ok, _} -> ?DEFAULT_DROP + end. + +%%%%%%%%%%%%%%%%%%%%%%%% +%%% Output functions %%% +%%%%%%%%%%%%%%%%%%%%%%%% +show_rename_warning() -> + show('$#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 --git a/lib/kernel/src/kernel.app.src b/lib/kernel/src/kernel.app.src index 25e4ddd95c..1128ee3ec5 100644 --- a/lib/kernel/src/kernel.app.src +++ b/lib/kernel/src/kernel.app.src @@ -44,6 +44,7 @@ global_group, global_search, group, + group_history, heart, hipe_unified_loader, inet6_tcp, |