v2writable: recount partitions after acquiring lock

The partition count can change if public-inbox-compact runs
while public-inbox-watch or public-inbox-index is running.

diff --git a/lib/PublicInbox/V2Writable.pm b/lib/PublicInbox/V2Writable.pm
index 74953d347b92cc0f32ffdda3b351a08454a31ae6..e0c8ac37916f629b6f028d8edfd8222d00086c23 100644 (file)
--- a/lib/PublicInbox/V2Writable.pm
+++ b/lib/PublicInbox/V2Writable.pm
@@ -26,22 +26,14 @@ sub nproc () {
        int($ENV{NPROC} || `nproc 2>/dev/null` || 2);
 }
 
-sub new {
-       my ($class, $v2ibx, $creat) = @_;
-       my $dir = $v2ibx->{mainrepo} or die "no mainrepo in inbox\n";
-       unless (-d $dir) {
-               if ($creat) {
-                       require File::Path;
-                       File::Path::mkpath($dir);
-               } else {
-                       die "$dir does not exist\n";
-               }
-       }
-
+sub count_partitions ($) {
+       my ($self) = @_;
        my $nparts = 0;
-       my $xpfx = "$dir/xap" . PublicInbox::Search::SCHEMA_VERSION;
+       my $xpfx = $self->{xpfx};
 
        # always load existing partitions in case core count changes:
+       # Also, partition count may change while -watch is running
+       # due to -compact
        if (-d $xpfx) {
                foreach my $part (<$xpfx/*>) {
                        -d $part && $part =~ m!/\d+\z! or next;
@@ -51,21 +43,37 @@ sub new {
                        };
                }
        }
-       $nparts = nproc() if ($nparts == 0);
+       $nparts;
+}
+
+sub new {
+       my ($class, $v2ibx, $creat) = @_;
+       my $dir = $v2ibx->{mainrepo} or die "no mainrepo in inbox\n";
+       unless (-d $dir) {
+               if ($creat) {
+                       require File::Path;
+                       File::Path::mkpath($dir);
+               } else {
+                       die "$dir does not exist\n";
+               }
+       }
 
        $v2ibx = PublicInbox::InboxWritable->new($v2ibx);
+
+       my $xpfx = "$dir/xap" . PublicInbox::Search::SCHEMA_VERSION;
        my $self = {
                -inbox => $v2ibx,
                im => undef, #  PublicInbox::Import
-               partitions => $nparts,
                parallel => 1,
                transact_bytes => 0,
+               xpfx => $xpfx,
                over => PublicInbox::OverIdxFork->new("$xpfx/over.sqlite3"),
                lock_path => "$dir/inbox.lock",
                # limit each repo to 1GB or so
                rotate_bytes => int((1024 * 1024 * 1024) / $PACKING_FACTOR),
                last_commit => [],
        };
+       $self->{partitions} = count_partitions($self) || nproc();
        bless $self, $class;
 }
 
@@ -206,6 +214,12 @@ sub idx_init {
                $self->lock_acquire;
                $over->create($self);
 
+               # -compact can change partition count while -watch is idle
+               my $nparts = count_partitions($self);
+               if ($nparts && $nparts != $self->{partitions}) {
+                       $self->{partitions} = $nparts;
+               }
+
                # need to create all parts before initializing msgmap FD
                my $max = $self->{partitions} - 1;