xqerl

%% -------------------------------------------------------------------
%%
%% xqerl - XQuery processor
%%
%% Copyright (c) 2018-2020 Zachary N. Dean  All Rights Reserved.
%%
%% This file is provided to you 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.
%%
%% -------------------------------------------------------------------

-module(xqldb_file).

-define(TIMEOUT, 90000).

%% ====================================================================
%% API functions
%% ====================================================================
-export([pmap/4]).

pmap(Dir, Pattern, Recursive, Fun) ->
    Self = self(),
    Fun2 = fun(Filename, Acc) ->
        Pid = spawn(fun() -> Self ! {self(), catch (Fun(Filename))} end),
        [Pid | Acc]
    end,
    Pids = filelib:fold_files(Dir, Pattern, Recursive, Fun2, []),
    receive_pids(lists:reverse(Pids)).

%% ====================================================================
%% Internal functions
%% ====================================================================

receive_pids(Pids) -> receive_pids(Pids, []).

receive_pids([H | T], Acc) ->
    receive
        {H, V} ->
            receive_pids(T, [V | Acc])
    after ?TIMEOUT -> timeout
    end;
receive_pids([], Acc) ->
    Acc.

%% -record(file_info,
%%         {size   :: non_neg_integer() | 'undefined',  % Size of file in bytes.
%%          type   :: 'device' | 'directory' | 'other' | 'regular' | 'symlink'
%%                  | 'undefined',
%%          access :: 'read' | 'write' | 'read_write' | 'none' | 'undefined',
%%          mtime  :: file:date_time() | non_neg_integer() | 'undefined',% The local time the file was last written.