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From: Eric Wong <e@80x24.org>
To: meta@public-inbox.org
Subject: [PATCH 2/2] tmpfile: support O_APPEND and use it in DS::tmpio
Date: Thu, 12 Sep 2019 08:34:21 +0000
Message-Id: <20190912083421.12629-3-e@80x24.org>
In-Reply-To: <20190912083421.12629-1-e@80x24.org>
References: <20190912083421.12629-1-e@80x24.org>
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Might as well share some code for temporary file creation
---
 lib/PublicInbox/DS.pm      | 14 ++++----------
 lib/PublicInbox/Tmpfile.pm |  8 ++++----
 2 files changed, 8 insertions(+), 14 deletions(-)

diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index 1e51dc41..30a9641a 100644
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -26,6 +26,7 @@ use warnings;
 use 5.010_001;
 
 use PublicInbox::Syscall qw(:epoll);
+use PublicInbox::Tmpfile;
 
 use fields ('sock',              # underlying socket
             'rbuf',              # scalarref, usually undef
@@ -33,7 +34,7 @@ use fields ('sock',              # underlying socket
             'wbuf_off',  # offset into first element of wbuf to start writing at
             );
 
-use Errno  qw(EAGAIN EINVAL EEXIST);
+use Errno  qw(EAGAIN EINVAL);
 use Carp   qw(croak confess carp);
 require File::Spec;
 
@@ -488,15 +489,8 @@ sub drop {
 # PerlIO::mmap or PerlIO::scalar if needed
 sub tmpio ($$$) {
     my ($self, $bref, $off) = @_;
-    my $fh; # open(my $fh, '+>>', undef) doesn't set O_APPEND
-    do {
-        my $fn = File::Spec->tmpdir . '/wbuf-' . rand;
-        if (sysopen($fh, $fn, O_RDWR|O_CREAT|O_EXCL|O_APPEND, 0600)) { # likely
-            unlink($fn) or return drop($self, "unlink($fn) $!");
-        } elsif ($! != EEXIST) { # EMFILE/ENFILE/ENOSPC/ENOMEM
-            return drop($self, "open: $!");
-        }
-    } until (defined $fh);
+    my $fh = tmpfile('wbuf', $self->{sock}, 1) or
+        return drop($self, "tmpfile $!");
     $fh->autoflush(1);
     my $len = bytes::length($$bref) - $off;
     $fh->write($$bref, $len, $off) or return drop($self, "write ($len): $!");
diff --git a/lib/PublicInbox/Tmpfile.pm b/lib/PublicInbox/Tmpfile.pm
index 7fda100e..28e87f88 100644
--- a/lib/PublicInbox/Tmpfile.pm
+++ b/lib/PublicInbox/Tmpfile.pm
@@ -12,10 +12,9 @@ require File::Spec;
 # use tmpfile instead of open(..., '+>', undef) so we can get an
 # unlinked filename which makes sense when viewed with lsof
 # (at least on Linux)
-# TODO: O_APPEND support (this is the reason I'm not using File::Temp)
 # And if we ever stop caring to have debuggable filenames, O_TMPFILE :)
-sub tmpfile ($;$) {
-	my ($id, $sock) = @_;
+sub tmpfile ($;$$) {
+	my ($id, $sock, $append) = @_;
 	if (defined $sock) {
 		# add the socket inode number so we can figure out which
 		# socket it belongs to
@@ -25,10 +24,11 @@ sub tmpfile ($;$) {
 	$id =~ tr!/!^!;
 
 	my $fl = O_RDWR | O_CREAT | O_EXCL;
+	$fl |= O_APPEND if $append;
 	do {
 		my $fn = File::Spec->tmpdir . "/$id-".time.'-'.rand;
 		if (sysopen(my $fh, $fn, $fl, 0600)) { # likely
-			unlink($fn) or die "unlink($fn): $!"; # FS broken
+			unlink($fn) or warn "unlink($fn): $!"; # FS broken
 			return $fh; # success
 		}
 	} while ($! == EEXIST);