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%% This Source Code Form is subject to the terms of the Mozilla Public
%% License, v. 2.0. If a copy of the MPL was not distributed with this
%% file, You can obtain one at https://mozilla.org/MPL/2.0/.
%%
%% Copyright (c) 2011-2020 VMware, Inc. or its affiliates. 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]).
-export([read_file_info/1]).
-export([filename_as_a_directory/1]).
-import(file_handle_cache, [with_handle/1, with_handle/2]).
-define(TMP_EXT, ".tmp").
%%----------------------------------------------------------------------------
-type ok_or_error() :: rabbit_types:ok_or_error(any()).
%%----------------------------------------------------------------------------
-spec is_file((file:filename())) -> boolean().
is_file(File) ->
case read_file_info(File) of
{ok, #file_info{type=regular}} -> true;
{ok, #file_info{type=directory}} -> true;
_ -> false
end.
-spec is_dir((file:filename())) -> boolean().
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.
-spec file_size((file:filename())) -> non_neg_integer().
file_size(File) ->
case read_file_info(File) of
{ok, #file_info{size=Size}} -> Size;
_ -> 0
end.
-spec ensure_dir((file:filename())) -> ok_or_error().
ensure_dir(File) -> with_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.
-spec wildcard(string(), file:filename()) -> [file:filename()].
wildcard(Pattern, Dir) ->
case list_dir(Dir) of
{ok, Files} -> {ok, RE} = re:compile(Pattern, [anchored]),
[File || File <- Files,
match =:= re:run(File, RE, [{capture, none}])];
{error, _} -> []
end.
-spec list_dir(file:filename()) ->
rabbit_types:ok_or_error2([file:filename()], any()).
list_dir(Dir) -> with_handle(fun () -> prim_file:list_dir(Dir) end).
read_file_info(File) ->
with_handle(fun () -> prim_file:read_file_info(File) end).
-spec read_term_file
(file:filename()) -> {'ok', [any()]} | rabbit_types:error(any()).
read_term_file(File) ->
try
{ok, Data} = with_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(G) || G <- group_tokens([], Ts)].
group_tokens([], []) -> [];
group_tokens(Cur, []) -> [Cur];
group_tokens(Cur, [T = {dot, _} | Ts]) -> [[T | Cur] | group_tokens([], Ts)];
group_tokens(Cur, [T | Ts]) -> group_tokens([T | Cur], Ts).
-spec write_term_file(file:filename(), [any()]) -> ok_or_error().
write_term_file(File, Terms) ->
write_file(File, list_to_binary([io_lib:format("~w.~n", [Term]) ||
Term <- Terms])).
-spec write_file(file:filename(), iodata()) -> ok_or_error().
write_file(Path, Data) -> write_file(Path, Data, []).
-spec write_file(file:filename(), iodata(), [any()]) -> ok_or_error().
write_file(Path, Data, Modes) ->
Modes1 = [binary, write | (Modes -- [binary, write])],
case make_binary(Data) of
Bin when is_binary(Bin) -> write_file1(Path, Bin, Modes1);
{error, _} = E -> E
end.
%% make_binary/1 is based on the corresponding function in the
%% kernel/file.erl module of the Erlang R14B02 release, which is
%% licensed under the EPL.
make_binary(Bin) when is_binary(Bin) ->
Bin;
make_binary(List) ->
try
iolist_to_binary(List)
catch error:Reason ->
{error, Reason}
end.
write_file1(Path, Bin, Modes) ->
try
with_synced_copy(Path, Modes,
fun (Hdl) ->
ok = prim_file:write(Hdl, Bin)
end)
catch
error:{badmatch, Error} -> Error;
_:{error, Error} -> {error, Error}
end.
with_synced_copy(Path, Modes, Fun) ->
case lists:member(append, Modes) of
true ->
{error, append_not_supported, Path};
false ->
with_handle(
fun () ->
Bak = Path ++ ?TMP_EXT,
case prim_file:open(Bak, Modes) of
{ok, Hdl} ->
try
Result = Fun(Hdl),
ok = prim_file:sync(Hdl),
ok = prim_file:rename(Bak, Path),
Result
after
prim_file:close(Hdl)
end;
{error, _} = E -> E
end
end)
end.
%% TODO the semantics of this function are rather odd. But see bug 25021.
-spec append_file(file:filename(), string()) -> ok_or_error().
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_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_handle(2, fun () ->
file:copy(File, {[File, Suffix], [append]})
end) of
{ok, _BytesCopied} -> ok;
Error -> Error
end.
-spec ensure_parent_dirs_exist(string()) -> 'ok'.
ensure_parent_dirs_exist(Filename) ->
case ensure_dir(Filename) of
ok -> ok;
{error, Reason} ->
throw({error, {cannot_create_parent_dirs, Filename, Reason}})
end.
-spec rename(file:filename(), file:filename()) -> ok_or_error().
rename(Old, New) -> with_handle(fun () -> prim_file:rename(Old, New) end).
-spec delete([file:filename()]) -> ok_or_error().
delete(File) -> with_handle(fun () -> prim_file:delete(File) end).
-spec recursive_delete([file:filename()]) ->
rabbit_types:ok_or_error({file:filename(), any()}).
recursive_delete(Files) ->
with_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.
-spec recursive_copy(file:filename(), file:filename()) ->
rabbit_types:ok_or_error({file:filename(), file:filename(), any()}).
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]
-spec lock_file(file:filename()) -> rabbit_types:ok_or_error('eexist').
lock_file(Path) ->
case is_file(Path) of
true -> {error, eexist};
false -> with_handle(
fun () -> {ok, Lock} = prim_file:open(Path, [write]),
ok = prim_file:close(Lock)
end)
end.
-spec filename_as_a_directory(file:filename()) -> file:filename().
filename_as_a_directory(FileName) ->
case lists:last(FileName) of
"/" ->
FileName;
_ ->
FileName ++ "/"
end.
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