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Diffstat (limited to 'src/mochiweb/mochitemp.erl')
-rw-r--r-- | src/mochiweb/mochitemp.erl | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/src/mochiweb/mochitemp.erl b/src/mochiweb/mochitemp.erl new file mode 100644 index 00000000..bb23d2a6 --- /dev/null +++ b/src/mochiweb/mochitemp.erl @@ -0,0 +1,310 @@ +%% @author Bob Ippolito <bob@mochimedia.com> +%% @copyright 2010 Mochi Media, Inc. + +%% @doc Create temporary files and directories. Requires crypto to be started. + +-module(mochitemp). +-export([gettempdir/0]). +-export([mkdtemp/0, mkdtemp/3]). +-export([rmtempdir/1]). +%% -export([mkstemp/4]). +-define(SAFE_CHARS, {$a, $b, $c, $d, $e, $f, $g, $h, $i, $j, $k, $l, $m, + $n, $o, $p, $q, $r, $s, $t, $u, $v, $w, $x, $y, $z, + $A, $B, $C, $D, $E, $F, $G, $H, $I, $J, $K, $L, $M, + $N, $O, $P, $Q, $R, $S, $T, $U, $V, $W, $X, $Y, $Z, + $0, $1, $2, $3, $4, $5, $6, $7, $8, $9, $_}). +-define(TMP_MAX, 10000). + +-include_lib("kernel/include/file.hrl"). + +%% TODO: An ugly wrapper over the mktemp tool with open_port and sadness? +%% We can't implement this race-free in Erlang without the ability +%% to issue O_CREAT|O_EXCL. I suppose we could hack something with +%% mkdtemp, del_dir, open. +%% mkstemp(Suffix, Prefix, Dir, Options) -> +%% ok. + +rmtempdir(Dir) -> + case file:del_dir(Dir) of + {error, eexist} -> + ok = rmtempdirfiles(Dir), + ok = file:del_dir(Dir); + ok -> + ok + end. + +rmtempdirfiles(Dir) -> + {ok, Files} = file:list_dir(Dir), + ok = rmtempdirfiles(Dir, Files). + +rmtempdirfiles(_Dir, []) -> + ok; +rmtempdirfiles(Dir, [Basename | Rest]) -> + Path = filename:join([Dir, Basename]), + case filelib:is_dir(Path) of + true -> + ok = rmtempdir(Path); + false -> + ok = file:delete(Path) + end, + rmtempdirfiles(Dir, Rest). + +mkdtemp() -> + mkdtemp("", "tmp", gettempdir()). + +mkdtemp(Suffix, Prefix, Dir) -> + mkdtemp_n(rngpath_fun(Suffix, Prefix, Dir), ?TMP_MAX). + + + +mkdtemp_n(RngPath, 1) -> + make_dir(RngPath()); +mkdtemp_n(RngPath, N) -> + try make_dir(RngPath()) + catch throw:{error, eexist} -> + mkdtemp_n(RngPath, N - 1) + end. + +make_dir(Path) -> + case file:make_dir(Path) of + ok -> + ok; + E={error, eexist} -> + throw(E) + end, + %% Small window for a race condition here because dir is created 777 + ok = file:write_file_info(Path, #file_info{mode=8#0700}), + Path. + +rngpath_fun(Prefix, Suffix, Dir) -> + fun () -> + filename:join([Dir, Prefix ++ rngchars(6) ++ Suffix]) + end. + +rngchars(0) -> + ""; +rngchars(N) -> + [rngchar() | rngchars(N - 1)]. + +rngchar() -> + rngchar(crypto:rand_uniform(0, tuple_size(?SAFE_CHARS))). + +rngchar(C) -> + element(1 + C, ?SAFE_CHARS). + +%% @spec gettempdir() -> string() +%% @doc Get a usable temporary directory using the first of these that is a directory: +%% $TMPDIR, $TMP, $TEMP, "/tmp", "/var/tmp", "/usr/tmp", ".". +gettempdir() -> + gettempdir(gettempdir_checks(), fun normalize_dir/1). + +gettempdir_checks() -> + [{fun os:getenv/1, ["TMPDIR", "TMP", "TEMP"]}, + {fun gettempdir_identity/1, ["/tmp", "/var/tmp", "/usr/tmp"]}, + {fun gettempdir_cwd/1, [cwd]}]. + +gettempdir_identity(L) -> + L. + +gettempdir_cwd(cwd) -> + {ok, L} = file:get_cwd(), + L. + +gettempdir([{_F, []} | RestF], Normalize) -> + gettempdir(RestF, Normalize); +gettempdir([{F, [L | RestL]} | RestF], Normalize) -> + case Normalize(F(L)) of + false -> + gettempdir([{F, RestL} | RestF], Normalize); + Dir -> + Dir + end. + +normalize_dir(False) when False =:= false orelse False =:= "" -> + %% Erlang doesn't have an unsetenv, wtf. + false; +normalize_dir(L) -> + Dir = filename:absname(L), + case filelib:is_dir(Dir) of + false -> + false; + true -> + Dir + end. + +%% +%% Tests +%% +-include_lib("eunit/include/eunit.hrl"). +-ifdef(TEST). +pushenv(L) -> + [{K, os:getenv(K)} || K <- L]. +popenv(L) -> + F = fun ({K, false}) -> + %% Erlang doesn't have an unsetenv, wtf. + os:putenv(K, ""); + ({K, V}) -> + os:putenv(K, V) + end, + lists:foreach(F, L). + +gettempdir_fallback_test() -> + ?assertEqual( + "/", + gettempdir([{fun gettempdir_identity/1, ["/--not-here--/"]}, + {fun gettempdir_identity/1, ["/"]}], + fun normalize_dir/1)), + ?assertEqual( + "/", + %% simulate a true os:getenv unset env + gettempdir([{fun gettempdir_identity/1, [false]}, + {fun gettempdir_identity/1, ["/"]}], + fun normalize_dir/1)), + ok. + +gettempdir_identity_test() -> + ?assertEqual( + "/", + gettempdir([{fun gettempdir_identity/1, ["/"]}], fun normalize_dir/1)), + ok. + +gettempdir_cwd_test() -> + {ok, Cwd} = file:get_cwd(), + ?assertEqual( + normalize_dir(Cwd), + gettempdir([{fun gettempdir_cwd/1, [cwd]}], fun normalize_dir/1)), + ok. + +rngchars_test() -> + crypto:start(), + ?assertEqual( + "", + rngchars(0)), + ?assertEqual( + 10, + length(rngchars(10))), + ok. + +rngchar_test() -> + ?assertEqual( + $a, + rngchar(0)), + ?assertEqual( + $A, + rngchar(26)), + ?assertEqual( + $_, + rngchar(62)), + ok. + +mkdtemp_n_failonce_test() -> + crypto:start(), + D = mkdtemp(), + Path = filename:join([D, "testdir"]), + %% Toggle the existence of a dir so that it fails + %% the first time and succeeds the second. + F = fun () -> + case filelib:is_dir(Path) of + true -> + file:del_dir(Path); + false -> + file:make_dir(Path) + end, + Path + end, + try + %% Fails the first time + ?assertThrow( + {error, eexist}, + mkdtemp_n(F, 1)), + %% Reset state + file:del_dir(Path), + %% Succeeds the second time + ?assertEqual( + Path, + mkdtemp_n(F, 2)) + after rmtempdir(D) + end, + ok. + +mkdtemp_n_fail_test() -> + {ok, Cwd} = file:get_cwd(), + ?assertThrow( + {error, eexist}, + mkdtemp_n(fun () -> Cwd end, 1)), + ?assertThrow( + {error, eexist}, + mkdtemp_n(fun () -> Cwd end, 2)), + ok. + +make_dir_fail_test() -> + {ok, Cwd} = file:get_cwd(), + ?assertThrow( + {error, eexist}, + make_dir(Cwd)), + ok. + +mkdtemp_test() -> + crypto:start(), + D = mkdtemp(), + ?assertEqual( + true, + filelib:is_dir(D)), + ?assertEqual( + ok, + file:del_dir(D)), + ok. + +rmtempdir_test() -> + crypto:start(), + D1 = mkdtemp(), + ?assertEqual( + true, + filelib:is_dir(D1)), + ?assertEqual( + ok, + rmtempdir(D1)), + D2 = mkdtemp(), + ?assertEqual( + true, + filelib:is_dir(D2)), + ok = file:write_file(filename:join([D2, "foo"]), <<"bytes">>), + D3 = mkdtemp("suffix", "prefix", D2), + ?assertEqual( + true, + filelib:is_dir(D3)), + ok = file:write_file(filename:join([D3, "foo"]), <<"bytes">>), + ?assertEqual( + ok, + rmtempdir(D2)), + ?assertEqual( + {error, enoent}, + file:consult(D3)), + ?assertEqual( + {error, enoent}, + file:consult(D2)), + ok. + +gettempdir_env_test() -> + Env = pushenv(["TMPDIR", "TEMP", "TMP"]), + FalseEnv = [{"TMPDIR", false}, {"TEMP", false}, {"TMP", false}], + try + popenv(FalseEnv), + popenv([{"TMPDIR", "/"}]), + ?assertEqual( + "/", + os:getenv("TMPDIR")), + ?assertEqual( + "/", + gettempdir()), + {ok, Cwd} = file:get_cwd(), + popenv(FalseEnv), + popenv([{"TMP", Cwd}]), + ?assertEqual( + normalize_dir(Cwd), + gettempdir()) + after popenv(Env) + end, + ok. + +-endif. |