*index: more consistent graceful shutdown checks

v1 and v2 inbox indexing now supports graceful shutdown checks
just like ExtSearchIdx.  Additionally, we'll consistently
perform quit checks at the top of loops for consistency.

Interaction with the --xapian-only and --sequential-shard
options are a bit lacking, and will warn the user to use
"--reindex --xapian-only" to fix.

1 files changed, 21 insertions, 4 deletions

diff --git a/lib/PublicInbox/SearchIdx.pm b/lib/PublicInbox/SearchIdx.pm
index 18390602..d06c159b 100644
--- a/lib/PublicInbox/SearchIdx.pm
+++ b/lib/PublicInbox/SearchIdx.pm
@@ -632,10 +632,11 @@ sub index_sync {
         my ($self, $opt) = @_;
         delete $self->{lock_path} if $opt->{-skip_lock};
         $self->with_umask(\&_index_sync, $self, $opt);
-        if ($opt->{reindex}) {
+        if ($opt->{reindex} && !$opt->{quit}) {
                 my %again = %$opt;
                 delete @again{qw(rethread reindex)};
                 index_sync($self, \%again);
+                $opt->{quit} = $again{quit}; # propagate to caller
         }
 }
 
@@ -688,7 +689,7 @@ sub v1_checkpoint ($$;$) {
         if (my $pr = $sync->{-opt}->{-progress}) {
                 $pr->("indexed $nr/$sync->{ntodo}\n") if $nr;
         }
-        if (!$stk) { # more to come
+        if (!$stk && !$sync->{quit}) { # more to come
                 begin_txn_lazy($self);
                 $self->{mm}->{dbh}->begin_work;
         }
@@ -709,6 +710,7 @@ sub process_stack {
         if (my @leftovers = keys %{delete($sync->{D}) // {}}) {
                 warn('W: unindexing '.scalar(@leftovers)." leftovers\n");
                 for my $oid (@leftovers) {
+                        last if $sync->{quit};
                         $oid = unpack('H*', $oid);
                         $git->cat_async($oid, \&unindex_both, $sync);
                 }
@@ -718,6 +720,7 @@ sub process_stack {
         }
         while (my ($f, $at, $ct, $oid, $cur_cmt) = $stk->pop_rec) {
                 my $arg = { %$sync, cur_cmt => $cur_cmt };
+                last if $sync->{quit};
                 if ($f eq 'm') {
                         $arg->{autime} = $at;
                         $arg->{cotime} = $ct;
@@ -731,7 +734,7 @@ sub process_stack {
                         $git->cat_async($oid, \&unindex_both, $arg);
                 }
         }
-        v1_checkpoint($self, $sync, $stk);
+        v1_checkpoint($self, $sync, $sync->{quit} ? undef : $stk);
 }
 
 sub log2stack ($$$) {
@@ -841,6 +844,16 @@ sub reindex_from ($$) {
         ref($reindex) eq 'HASH' ? $reindex->{from} : '';
 }
 
+sub quit_cb ($) {
+        my ($sync) = @_;
+        sub {
+                # we set {-opt}->{quit} too, so ->index_sync callers
+                # can abort multi-inbox loops this way
+                $sync->{quit} = $sync->{-opt}->{quit} = 1;
+                warn "gracefully quitting\n";
+        }
+}
+
 # indexes all unindexed messages (v1 only)
 sub _index_sync {
         my ($self, $opt) = @_;
@@ -850,6 +863,10 @@ sub _index_sync {
         $ibx->git->batch_prepare;
         my $pr = $opt->{-progress};
         my $sync = { reindex => $opt->{reindex}, -opt => $opt, ibx => $ibx };
+        my $quit = quit_cb($sync);
+        local $SIG{QUIT} = $quit;
+        local $SIG{INT} = $quit;
+        local $SIG{TERM} = $quit;
         my $xdb = $self->begin_txn_lazy;
         $self->{oidx}->rethread_prepare($opt);
         my $mm = _msgmap_init($self);
@@ -870,7 +887,7 @@ sub _index_sync {
         my $stk = prepare_stack($sync, $range);
         $sync->{ntodo} = $stk ? $stk->num_records : 0;
         $pr->("$sync->{ntodo}\n") if $pr; # continue previous line
-        process_stack($self, $sync, $stk);
+        process_stack($self, $sync, $stk) if !$sync->{quit};
 }
 
 sub DESTROY {