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src/cfg.erl
%%% ------------------------------------------------------------------------------------------------
%%% "cfg" is available for use under the following license, commonly known as the 3-clause
%%% (or "modified") BSD license:
%%%
%%% Copyright (c) 2017-2018, Pouriya Jahanbakhsh
%%% (pouriya.jahanbakhsh@gmail.com)
%%% All rights reserved.
%%%
%%% Redistribution and use in source and binary forms, with or without modification, are permitted
%%% provided that the following conditions are met:
%%%
%%% 1. Redistributions of source code must retain the above copyright notice, this list of
%%% conditions and the following disclaimer.
%%%
%%% 2. Redistributions in binary form must reproduce the above copyright notice, this list of
%%% conditions and the following disclaimer in the documentation and/or other materials provided
%%% with the distribution.
%%%
%%% 3. Neither the name of the copyright holder nor the names of its contributors may be used to
%%% endorse or promote products derived from this software without specific prior written
%%% permission.
%%%
%%% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
%%% IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
%%% FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
%%% CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
%%% CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
%%% SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
%%% THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
%%% OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
%%% POSSIBILITY OF SUCH DAMAGE.
%%% ------------------------------------------------------------------------------------------------
%% @author Pouriya Jahanbakhsh <pouriya.jahanbakhsh@gmail.com>
%% @version 17.10.4
%% @doc
%% Simple and modern config parser.
%% @end
%% -------------------------------------------------------------------------------------------------
-module(cfg).
-author("pouriya.jahanbakhsh@gmail.com").
%% -------------------------------------------------------------------------------------------------
%% Exports:
%% API:
-export([parse/1
,parse/2
,format_error/1]).
%% -------------------------------------------------------------------------------------------------
%% Records & Macros & Includes:
-define(is_filename(Arg), (erlang:is_list(Arg) orelse erlang:is_binary(Arg))).
-define(DEF_TAB_OPTS, [named_table]).
%% -------------------------------------------------------------------------------------------------
%% API:
-spec
parse(file:filename()) ->
{'ok', []} | {'ok', [{atom(), term()}]} | {'error', any()}.
%% @doc
%% Reads file File and returns containing data as erlang terms.
%% @end
parse(File) when ?is_filename(File) ->
case cfg_parser:parse_file(File) of
{ok, Data} ->
{ok, [{Key, Val} || {Key, Val, _} <- Data]};
{error, _}=Err ->
Err
end.
-spec
parse(file:filename(), Opts) ->
'ok' | {'error', any()}
when
Opts :: [] | [Opt],
Opt :: {'ets', atom()}
| {'app', atom()}
| {'ets', atom(), TabOpts::list()}
| {'app', atom(), SetEnvOpts::list()}
| {'callback', {module(), Func::atom()}}
| {'callback', fun((Key::atom()
,Val::term()
,LineNumber::pos_integer()) -> {'error', any()} | any())}.
%% @doc
%% Reads file File and inserts containing data in ETS table or sets as application environment
%% variable or calls callback with them.
%% @end
parse(File, {ets, Tab}=TabArg) when ?is_filename(File) andalso erlang:is_atom(Tab) ->
case create_table(Tab, ?DEF_TAB_OPTS) of
ok ->
do_parse(File, TabArg);
{error, _}=Err ->
Err
end;
parse(File, {app, App}=AppArg) when ?is_filename(File) andalso erlang:is_atom(App) ->
do_parse(File, AppArg);
parse(File, {ets, Tab, TabOpts}) when ?is_filename(File) andalso
erlang:is_atom(Tab) andalso
erlang:is_list(TabOpts) ->
case create_table(Tab, ?DEF_TAB_OPTS ++ TabOpts) of
ok ->
do_parse(File, {ets, Tab});
{error, _}=Err ->
Err
end;
parse(File, {app, App, SetEnvOpts}=AppArg) when ?is_filename(File) andalso
erlang:is_atom(App) andalso
erlang:is_list(SetEnvOpts) ->
do_parse(File, AppArg);
parse(File, {callback, Mod, Func}=CallbackArg) when ?is_filename(File) andalso
erlang:is_atom(Mod) andalso
erlang:is_atom(Func) ->
do_parse(File, CallbackArg);
parse(File, {callback, Func}=CallbackArg) when ?is_filename(File) andalso
erlang:is_function(Func, 3) ->
do_parse(File, CallbackArg).
-spec
format_error({atom(), [] | [{atom(), term()}]}) ->
binary().
%% @doc
%% Formats returned error of parse/1 and parse/2 binary for making it more human-readable.
%% @end
format_error({Reason, ErrParams}) when erlang:is_atom(Reason) andalso erlang:is_list(ErrParams) ->
AtomToBin =
fun(Atom) ->
binary:replace(<<(erlang:atom_to_binary(Atom, utf8))/bits>>
,<<"_">>
,<<" ">>
,[global])
end,
Fold =
fun
({Key, Val}, Acc) when erlang:is_atom(Val) ->
<<Acc/bits, "\t"
,(AtomToBin(Key))/bits
,": "
,(AtomToBin(Val))/bits
,"\n">>;
({Key, Val}, Acc) ->
<<Acc/bits, "\t"
,(AtomToBin(Key))/bits
,": "
,(erlang:list_to_binary(io_lib:print(Val)))/bits
,"\n">>
end,
lists:foldl(Fold, <<"Error: ", (AtomToBin(Reason))/bits, "\nDetails:\n">>, ErrParams).
%% -------------------------------------------------------------------------------------------------
%% Internal functions:
create_table(Tab, Opts) ->
case lists:member(Tab, ets:all()) of
true ->
Self = erlang:self(),
case {ets:info(Tab, protection), ets:info(Tab, owner)} of
{public, _} ->
ok;
{_, Self} ->
ok;
{Protection, Owner} ->
{error, {table_protection_or_ownership, [{protection, Protection}
,{owner, Owner}
,{table, Tab}
,{self, Self}]}}
end;
false ->
try
_ = ets:new(Tab, Opts),
ok
catch
_ErrType:Reason ->
{error, {create_table, [{reason, Reason}
,{stacktrace, erlang:get_stacktrace()}]}}
end
end.
do_parse(File, InsertMode) ->
case cfg_parser:parse_file(File) of
{ok, Data} ->
insert(Data, File, InsertMode);
{error, _}=Err ->
Err
end.
insert(Data, File, InsertMode) ->
Func =
case InsertMode of
{ets, Tab} ->
fun({Key, Val, LineNumber}) ->
try
ets:insert(Tab, {Key, Val})
catch
_:Reason ->
{error, {insert, [{reason, Reason}
,{key, Key}
,{value, Val}
,{line, LineNumber}
,{table, Tab}
,{file, File}
,{stacktrace, erlang:get_stacktrace()}]}}
end
end;
{app, AppName} ->
fun({Key, Val, LineNumber}) ->
try
application:set_env(AppName, Key, Val)
catch
_:Reason ->
{error, {insert, [{reason, Reason}
,{key, Key}
,{value, Val}
,{line, LineNumber}
,{application, AppName}
,{file, File}
,{stacktrace, erlang:get_stacktrace()}]}}
end
end;
{app, AppName, SetEnvOpts} ->
fun({Key, Val, LineNumber}) ->
try
application:set_env(AppName, Key, Val, SetEnvOpts)
catch
_:Reason ->
{error, {insert, [{reason, Reason}
,{key, Key}
,{value, Val}
,{line, LineNumber}
,{application, AppName}
,{set_environment_options, SetEnvOpts}
,{file, File}
,{stacktrace, erlang:get_stacktrace()}]}}
end
end;
{callback, Mod, Func2} ->
fun({Key, Val, LineNumber}) ->
try
case Mod:Func2(Key, Val, LineNumber) of
{error, Reason} ->
{error, {insert, [{reason, Reason}
,{key, Key}
,{value, Val}
,{line, LineNumber}
,{module, Mod}
,{function, Func2}
,{file, File}]}};
_ ->
ok
end
catch
_:Reason2 ->
{error, {insert, [{reason, Reason2}
,{key, Key}
,{value, Val}
,{line, LineNumber}
,{module, Mod}
,{function, Func2}
,{file, File}
,{stacktrace, erlang:get_stacktrace()}]}}
end
end;
{callback, Func2} ->
fun({Key, Val, LineNumber}) ->
try
case Func2(Key, Val, LineNumber) of
{error, Reason} ->
{error, {insert, [{reason, Reason}
,{key, Key}
,{value, Val}
,{line, LineNumber}
,{function, Func2}
,{file, File}]}};
_ ->
ok
end
catch
_:Reason2 ->
{error, {insert, [{reason, Reason2}
,{key, Key}
,{value, Val}
,{line, LineNumber}
,{function, Func2}
,{file, File}
,{stacktrace, erlang:get_stacktrace()}]}}
end
end
end,
do_insert(Data, Func).
do_insert([Data|Rest], Func) ->
case Func(Data) of
{error, _}=Err ->
Err;
_ ->
do_insert(Rest, Func)
end;
do_insert([], _) ->
ok.