From 2a717d13f10fcdc69921d80cf94c47a694a175d4 Mon Sep 17 00:00:00 2001
From: Eric Wong <e@80x24.org>
Date: Thu, 11 Jun 2020 00:57:53 +0000
Subject: nntpd+imapd: detect replaced over.sqlite3

For v1 inboxes (and possibly v2 in the future, for VACUUM),
public-inbox-compact replaces over.sqlite3 with a new file.

This currently doesn't need an extra inotify watch descriptor
(or FD for kevent) at the moment, so it can coexist nicely for
systems w/o IO::KQueue or Linux::Inotify2.
---
 lib/PublicInbox/Inbox.pm | 14 +++++++++++---
 lib/PublicInbox/NNTP.pm  |  4 +++-
 lib/PublicInbox/NNTPD.pm | 12 ++++++++++--
 lib/PublicInbox/Over.pm  | 36 +++++++++++++++++++++++++++++-------
 4 files changed, 53 insertions(+), 13 deletions(-)

(limited to 'lib/PublicInbox')

diff --git a/lib/PublicInbox/Inbox.pm b/lib/PublicInbox/Inbox.pm
index b2b0b56f..7d5e0483 100644
--- a/lib/PublicInbox/Inbox.pm
+++ b/lib/PublicInbox/Inbox.pm
@@ -31,7 +31,7 @@ sub cleanup_task () {
 	for my $ibx (values %$CLEANUP) {
 		my $again;
 		if ($have_devel_peek) {
-			foreach my $f (qw(mm search over)) {
+			foreach my $f (qw(mm search)) {
 				# we bump refcnt by assigning tmp, here:
 				my $tmp = $ibx->{$f} or next;
 				next if Devel::Peek::SvREFCNT($tmp) > 2;
@@ -45,9 +45,9 @@ sub cleanup_task () {
 				$again = 1 if $git->cleanup;
 			}
 		}
+		check_inodes($ibx);
 		if ($have_devel_peek) {
-			$again ||= !!($ibx->{over} || $ibx->{mm} ||
-			              $ibx->{search});
+			$again ||= !!($ibx->{mm} || $ibx->{search});
 		}
 		$next->{"$ibx"} = $ibx if $again;
 	}
@@ -407,9 +407,17 @@ sub unsubscribe_unlock {
 	delete $self->{unlock_subs}->{$ident};
 }
 
+sub check_inodes ($) {
+	my ($self) = @_;
+	for (qw(over)) { # TODO: search, mm
+		$self->{$_}->check_inodes if $self->{$_};
+	}
+}
+
 # called by inotify
 sub on_unlock {
 	my ($self) = @_;
+	check_inodes($self);
 	my $subs = $self->{unlock_subs} or return;
 	for (values %$subs) {
 		eval { $_->on_inbox_unlock($self) };
diff --git a/lib/PublicInbox/NNTP.pm b/lib/PublicInbox/NNTP.pm
index ac13c7df..bffd773c 100644
--- a/lib/PublicInbox/NNTP.pm
+++ b/lib/PublicInbox/NNTP.pm
@@ -334,7 +334,9 @@ sub cmd_newnews ($$$$;$$) {
 sub cmd_group ($$) {
 	my ($self, $group) = @_;
 	my $no_such = '411 no such news group';
-	my $ng = $self->{nntpd}->{groups}->{$group} or return $no_such;
+	my $nntpd = $self->{nntpd};
+	my $ng = $nntpd->{groups}->{$group} or return $no_such;
+	$nntpd->idler_start;
 
 	$self->{ng} = $ng;
 	my ($min, $max) = $ng->mm->minmax;
diff --git a/lib/PublicInbox/NNTPD.pm b/lib/PublicInbox/NNTPD.pm
index ed5cf7cc..6b762d89 100644
--- a/lib/PublicInbox/NNTPD.pm
+++ b/lib/PublicInbox/NNTPD.pm
@@ -8,6 +8,7 @@ use strict;
 use warnings;
 use Sys::Hostname;
 use PublicInbox::Config;
+use PublicInbox::InboxIdle;
 
 sub new {
 	my ($class) = @_;
@@ -24,15 +25,17 @@ sub new {
 		err => \*STDERR,
 		out => \*STDOUT,
 		grouplist => [],
+		pi_config => $pi_config,
 		servername => $name,
 		greet => \"201 $name ready - post via email\r\n",
 		# accept_tls => { SSL_server => 1, ..., SSL_reuse_ctx => ... }
+		# idler => PublicInbox::InboxIdle
 	}, $class;
 }
 
 sub refresh_groups {
-	my ($self, $pi_config) = @_;
-	$pi_config //= PublicInbox::Config->new;
+	my ($self, $sig) = @_;
+	my $pi_config = $sig ? PublicInbox::Config->new : $self->{pi_config};
 	my $new = {};
 	my @list;
 	$pi_config->each_inbox(sub {
@@ -59,8 +62,13 @@ sub refresh_groups {
 	});
 	@list =	sort { $a->{newsgroup} cmp $b->{newsgroup} } @list;
 	$self->{grouplist} = \@list;
+	$self->{pi_config} = $pi_config;
 	# this will destroy old groups that got deleted
 	%{$self->{groups}} = %$new;
 }
 
+sub idler_start {
+	$_[0]->{idler} //= PublicInbox::InboxIdle->new($_[0]->{pi_config});
+}
+
 1;
diff --git a/lib/PublicInbox/Over.pm b/lib/PublicInbox/Over.pm
index e32104f0..74c8fb86 100644
--- a/lib/PublicInbox/Over.pm
+++ b/lib/PublicInbox/Over.pm
@@ -19,13 +19,23 @@ sub dbh_new {
 	if ($rw && !-f $f) { # SQLite defaults mode to 0644, we want 0666
 		open my $fh, '+>>', $f or die "failed to open $f: $!";
 	}
-	my $dbh = DBI->connect("dbi:SQLite:dbname=$f",'','', {
-		AutoCommit => 1,
-		RaiseError => 1,
-		PrintError => 0,
-		ReadOnly => !$rw,
-		sqlite_use_immediate_transaction => 1,
-	});
+	my (@st, $st, $dbh);
+	my $tries = 0;
+	do {
+		@st = stat($f) or die "failed to stat $f: $!";
+		$st = pack('dd', $st[0], $st[1]); # 0: dev, 1: inode
+		$dbh = DBI->connect("dbi:SQLite:dbname=$f",'','', {
+			AutoCommit => 1,
+			RaiseError => 1,
+			PrintError => 0,
+			ReadOnly => !$rw,
+			sqlite_use_immediate_transaction => 1,
+		});
+		$self->{st} = $st;
+		@st = stat($f) or die "failed to stat $f: $!";
+		$st = pack('dd', $st[0], $st[1]);
+	} while ($st ne $self->{st} && $tries++ < 3);
+	warn "W: $f: .st_dev, .st_ino unstable\n" if $st ne $self->{st};
 	$dbh->{sqlite_unicode} = 1;
 	$dbh;
 }
@@ -259,4 +269,16 @@ SELECT MAX(num) FROM over WHERE num > 0
 	($exists, $uidnext, $sth->fetchrow_array // 0);
 }
 
+sub check_inodes {
+	my ($self) = @_;
+	if (my @st = stat($self->{filename})) { # did st_dev, st_ino change?
+		my $st = pack('dd', $st[0], $st[1]);
+
+		# don't actually reopen, just let {dbh} be recreated later
+		delete($self->{dbh}) if ($st ne ($self->{st} // $st));
+	} else {
+		warn "W: stat $self->{filename}: $!\n";
+	}
+}
+
 1;
-- 
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