From e5631087d3862823d0d4854a8dfc1258f91cb115 Mon Sep 17 00:00:00 2001 From: Eric Wong Date: Thu, 12 Sep 2019 08:34:20 +0000 Subject: tmpfile: give temporary files meaningful names Although we always unlink temporary files, give them a meaningful name so that we can we can still make sense of the pre-unlink name when using lsof(8) or similar tools on Linux. --- lib/PublicInbox/Tmpfile.pm | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) create mode 100644 lib/PublicInbox/Tmpfile.pm (limited to 'lib/PublicInbox/Tmpfile.pm') diff --git a/lib/PublicInbox/Tmpfile.pm b/lib/PublicInbox/Tmpfile.pm new file mode 100644 index 00000000..7fda100e --- /dev/null +++ b/lib/PublicInbox/Tmpfile.pm @@ -0,0 +1,38 @@ +# Copyright (C) 2019 all contributors +# License: AGPL-3.0+ +package PublicInbox::Tmpfile; +use strict; +use warnings; +use base qw(Exporter); +our @EXPORT = qw(tmpfile); +use Fcntl qw(:DEFAULT); +use Errno qw(EEXIST); +require File::Spec; + +# use tmpfile instead of open(..., '+>', undef) so we can get an +# unlinked filename which makes sense when viewed with lsof +# (at least on Linux) +# TODO: O_APPEND support (this is the reason I'm not using File::Temp) +# And if we ever stop caring to have debuggable filenames, O_TMPFILE :) +sub tmpfile ($;$) { + my ($id, $sock) = @_; + if (defined $sock) { + # add the socket inode number so we can figure out which + # socket it belongs to + my @st = stat($sock); + $id .= '-ino:'.$st[1]; + } + $id =~ tr!/!^!; + + my $fl = O_RDWR | O_CREAT | O_EXCL; + do { + my $fn = File::Spec->tmpdir . "/$id-".time.'-'.rand; + if (sysopen(my $fh, $fn, $fl, 0600)) { # likely + unlink($fn) or die "unlink($fn): $!"; # FS broken + return $fh; # success + } + } while ($! == EEXIST); + undef # EMFILE/ENFILE/ENOSPC/ENOMEM +} + +1; -- cgit v1.2.3-24-ge0c7