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+%% The contents of this file are subject to the Mozilla Public License
+%% Version 1.1 (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.mozilla.org/MPL/
+%%
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and
+%% limitations under the License.
+%%
+%% The Original Code is RabbitMQ.
+%%
+%% The Initial Developer of the Original Code is VMware, Inc.
+%% Copyright (c) 2011 VMware, Inc. All rights reserved.
+%%
+
+-module(rabbit_file).
+
+-include_lib("kernel/include/file.hrl").
+
+-export([is_file/1, is_dir/1, file_size/1, ensure_dir/1, wildcard/2, list_dir/1]).
+-export([read_term_file/1, write_term_file/2, write_file/2, write_file/3]).
+-export([append_file/2, ensure_parent_dirs_exist/1]).
+-export([rename/2, delete/1, recursive_delete/1, recursive_copy/2]).
+-export([lock_file/1]).
+
+%%----------------------------------------------------------------------------
+
+-ifdef(use_specs).
+
+-type(ok_or_error() :: rabbit_types:ok_or_error(any())).
+
+-spec(is_file/1 :: ((file:filename())) -> boolean()).
+-spec(is_dir/1 :: ((file:filename())) -> boolean()).
+-spec(file_size/1 :: ((file:filename())) -> non_neg_integer()).
+-spec(ensure_dir/1 :: ((file:filename())) -> ok_or_error()).
+-spec(wildcard/2 :: (string(), file:filename()) -> [file:filename()]).
+-spec(list_dir/1 :: (file:filename()) -> rabbit_types:ok_or_error2(
+ [file:filename()], any())).
+-spec(read_term_file/1 ::
+ (file:filename()) -> {'ok', [any()]} | rabbit_types:error(any())).
+-spec(write_term_file/2 :: (file:filename(), [any()]) -> ok_or_error()).
+-spec(write_file/2 :: (file:filename(), iodata()) -> ok_or_error()).
+-spec(write_file/3 :: (file:filename(), iodata(), [any()]) -> ok_or_error()).
+-spec(append_file/2 :: (file:filename(), string()) -> ok_or_error()).
+-spec(ensure_parent_dirs_exist/1 :: (string()) -> 'ok').
+-spec(rename/2 ::
+ (file:filename(), file:filename()) -> ok_or_error()).
+-spec(delete/1 :: ([file:filename()]) -> ok_or_error()).
+-spec(recursive_delete/1 ::
+ ([file:filename()])
+ -> rabbit_types:ok_or_error({file:filename(), any()})).
+-spec(recursive_copy/2 ::
+ (file:filename(), file:filename())
+ -> rabbit_types:ok_or_error({file:filename(), file:filename(), any()})).
+-spec(lock_file/1 :: (file:filename()) -> rabbit_types:ok_or_error('eexist')).
+
+-endif.
+
+%%----------------------------------------------------------------------------
+
+is_file(File) ->
+ case read_file_info(File) of
+ {ok, #file_info{type=regular}} -> true;
+ {ok, #file_info{type=directory}} -> true;
+ _ -> false
+ end.
+
+is_dir(Dir) -> is_dir_internal(read_file_info(Dir)).
+
+is_dir_no_handle(Dir) -> is_dir_internal(prim_file:read_file_info(Dir)).
+
+is_dir_internal({ok, #file_info{type=directory}}) -> true;
+is_dir_internal(_) -> false.
+
+file_size(File) ->
+ case read_file_info(File) of
+ {ok, #file_info{size=Size}} -> Size;
+ _ -> 0
+ end.
+
+ensure_dir(File) -> with_fhc_handle(fun () -> ensure_dir_internal(File) end).
+
+ensure_dir_internal("/") ->
+ ok;
+ensure_dir_internal(File) ->
+ Dir = filename:dirname(File),
+ case is_dir_no_handle(Dir) of
+ true -> ok;
+ false -> ensure_dir_internal(Dir),
+ prim_file:make_dir(Dir)
+ end.
+
+wildcard(Pattern, Dir) ->
+ {ok, Files} = list_dir(Dir),
+ {ok, RE} = re:compile(Pattern, [anchored]),
+ [File || File <- Files, match =:= re:run(File, RE, [{capture, none}])].
+
+list_dir(Dir) -> with_fhc_handle(fun () -> prim_file:list_dir(Dir) end).
+
+read_file_info(File) ->
+ with_fhc_handle(fun () -> prim_file:read_file_info(File) end).
+
+with_fhc_handle(Fun) ->
+ ok = file_handle_cache:obtain(),
+ try Fun()
+ after ok = file_handle_cache:release()
+ end.
+
+read_term_file(File) ->
+ try
+ {ok, Data} = with_fhc_handle(fun () -> prim_file:read_file(File) end),
+ {ok, Tokens, _} = erl_scan:string(binary_to_list(Data)),
+ TokenGroups = group_tokens(Tokens),
+ {ok, [begin
+ {ok, Term} = erl_parse:parse_term(Tokens1),
+ Term
+ end || Tokens1 <- TokenGroups]}
+ catch
+ error:{badmatch, Error} -> Error
+ end.
+
+group_tokens(Ts) -> lists:reverse([lists:reverse(G) || G <- group_tokens1(Ts)]).
+
+group_tokens1([]) -> [];
+group_tokens1([{_, N, _} | _] = Tokens) -> group_tokens([], N, Tokens);
+group_tokens1([{_, N} | _] = Tokens) -> group_tokens([], N, Tokens).
+
+group_tokens(Cur, _, []) -> [Cur];
+group_tokens(Cur, N, [T = {_, N} | Ts]) -> group_tokens([T | Cur], N, Ts);
+group_tokens(Cur, _, [{_, M} | _] = Ts) -> [Cur | group_tokens([], M, Ts)];
+group_tokens(Cur, N, [T = {_, N, _} | Ts]) -> group_tokens([T | Cur], N, Ts);
+group_tokens(Cur, _, [{_, M, _} | _] = Ts) -> [Cur | group_tokens([], M, Ts)].
+
+write_term_file(File, Terms) ->
+ write_file(File, list_to_binary([io_lib:format("~w.~n", [Term]) ||
+ Term <- Terms])).
+
+write_file(Path, Data) -> write_file(Path, Data, []).
+
+%% write_file/3 and make_binary/1 are both based on corresponding
+%% functions in the kernel/file.erl module of the Erlang R14B02
+%% release, which is licensed under the EPL. That implementation of
+%% write_file/3 does not do an fsync prior to closing the file, hence
+%% the existence of this version. APIs are otherwise identical.
+write_file(Path, Data, Modes) ->
+ Modes1 = [binary, write | (Modes -- [binary, write])],
+ case make_binary(Data) of
+ Bin when is_binary(Bin) ->
+ with_fhc_handle(
+ fun () -> case prim_file:open(Path, Modes1) of
+ {ok, Hdl} -> try prim_file:write(Hdl, Bin) of
+ ok -> prim_file:sync(Hdl);
+ {error, _} = E -> E
+ after
+ prim_file:close(Hdl)
+ end;
+ {error, _} = E -> E
+ end
+ end);
+ {error, _} = E -> E
+ end.
+
+make_binary(Bin) when is_binary(Bin) ->
+ Bin;
+make_binary(List) ->
+ try
+ iolist_to_binary(List)
+ catch error:Reason ->
+ {error, Reason}
+ end.
+
+
+append_file(File, Suffix) ->
+ case read_file_info(File) of
+ {ok, FInfo} -> append_file(File, FInfo#file_info.size, Suffix);
+ {error, enoent} -> append_file(File, 0, Suffix);
+ Error -> Error
+ end.
+
+append_file(_, _, "") ->
+ ok;
+append_file(File, 0, Suffix) ->
+ with_fhc_handle(fun () ->
+ case prim_file:open([File, Suffix], [append]) of
+ {ok, Fd} -> prim_file:close(Fd);
+ Error -> Error
+ end
+ end);
+append_file(File, _, Suffix) ->
+ case with_fhc_handle(fun () -> prim_file:read_file(File) end) of
+ {ok, Data} -> write_file([File, Suffix], Data, [append]);
+ Error -> Error
+ end.
+
+ensure_parent_dirs_exist(Filename) ->
+ case ensure_dir(Filename) of
+ ok -> ok;
+ {error, Reason} ->
+ throw({error, {cannot_create_parent_dirs, Filename, Reason}})
+ end.
+
+rename(Old, New) -> with_fhc_handle(fun () -> prim_file:rename(Old, New) end).
+
+delete(File) -> with_fhc_handle(fun () -> prim_file:delete(File) end).
+
+recursive_delete(Files) ->
+ with_fhc_handle(
+ fun () -> lists:foldl(fun (Path, ok) -> recursive_delete1(Path);
+ (_Path, {error, _Err} = Error) -> Error
+ end, ok, Files)
+ end).
+
+recursive_delete1(Path) ->
+ case is_dir_no_handle(Path) and not(is_symlink_no_handle(Path)) of
+ false -> case prim_file:delete(Path) of
+ ok -> ok;
+ {error, enoent} -> ok; %% Path doesn't exist anyway
+ {error, Err} -> {error, {Path, Err}}
+ end;
+ true -> case prim_file:list_dir(Path) of
+ {ok, FileNames} ->
+ case lists:foldl(
+ fun (FileName, ok) ->
+ recursive_delete1(
+ filename:join(Path, FileName));
+ (_FileName, Error) ->
+ Error
+ end, ok, FileNames) of
+ ok ->
+ case prim_file:del_dir(Path) of
+ ok -> ok;
+ {error, Err} -> {error, {Path, Err}}
+ end;
+ {error, _Err} = Error ->
+ Error
+ end;
+ {error, Err} ->
+ {error, {Path, Err}}
+ end
+ end.
+
+is_symlink_no_handle(File) ->
+ case prim_file:read_link(File) of
+ {ok, _} -> true;
+ _ -> false
+ end.
+
+recursive_copy(Src, Dest) ->
+ %% Note that this uses the 'file' module and, hence, shouldn't be
+ %% run on many processes at once.
+ case is_dir(Src) of
+ false -> case file:copy(Src, Dest) of
+ {ok, _Bytes} -> ok;
+ {error, enoent} -> ok; %% Path doesn't exist anyway
+ {error, Err} -> {error, {Src, Dest, Err}}
+ end;
+ true -> case file:list_dir(Src) of
+ {ok, FileNames} ->
+ case file:make_dir(Dest) of
+ ok ->
+ lists:foldl(
+ fun (FileName, ok) ->
+ recursive_copy(
+ filename:join(Src, FileName),
+ filename:join(Dest, FileName));
+ (_FileName, Error) ->
+ Error
+ end, ok, FileNames);
+ {error, Err} ->
+ {error, {Src, Dest, Err}}
+ end;
+ {error, Err} ->
+ {error, {Src, Dest, Err}}
+ end
+ end.
+
+%% TODO: When we stop supporting Erlang prior to R14, this should be
+%% replaced with file:open [write, exclusive]
+lock_file(Path) ->
+ case is_file(Path) of
+ true -> {error, eexist};
+ false -> with_fhc_handle(
+ fun () -> {ok, Lock} = prim_file:open(Path, [write]),
+ ok = prim_file:close(Lock)
+ end)
+ end.
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