import: avoid needless git update-server-info

We don't need to update-server-info (or read-tree) if fast
import was spawned for removals and no changes were made.

diff --git a/lib/PublicInbox/Import.pm b/lib/PublicInbox/Import.pm
index 1db2a0b858701051f0c03e2e01b19e05b1518da5..1afcf5d252407adc8d9189a9a4bb9f06bc24978b 100644 (file)
--- a/lib/PublicInbox/Import.pm
+++ b/lib/PublicInbox/Import.pm
@@ -51,6 +51,7 @@ sub gfi_start {
        $self->{out} = $out_w;
        $self->{lockfh} = $lockfh;
        $self->{pid} = $pid;
+       $self->{nchg} = 0;
        ($in_r, $out_w);
 }
 
@@ -131,6 +132,7 @@ sub remove {
                "data 3\nrm\n\n",
                'from ', ($parent ? $parent : $tip), "\n" or wfail;
        print $w "D $path\n\n" or wfail;
+       $self->{nchg}++;
        (($self->{tip} = ":$commit"), $cur);
 }
 
@@ -191,6 +193,7 @@ sub add {
                print $w 'from ', ($parent ? $parent : $tip), "\n" or wfail;
        }
        print $w "M 100644 :$blob $path\n\n" or wfail;
+       $self->{nchg}++;
        $self->{tip} = ":$commit";
 }
 
@@ -202,14 +205,15 @@ sub done {
        my $pid = delete $self->{pid} or die 'BUG: missing {pid} when done';
        waitpid($pid, 0) == $pid or die 'fast-import did not finish';
        $? == 0 or die "fast-import failed: $?";
+       my $nchg = delete $self->{nchg};
 
        # for compatibility with existing ssoma installations
        # we can probably remove this entirely by 2020
        my $git_dir = $self->{git}->{git_dir};
-       my $index = "$git_dir/ssoma.index";
        # XXX: change the following scope to: if (-e $index) # in 2018 or so..
        my @cmd = ('git', "--git-dir=$git_dir");
-       unless ($ENV{FAST}) {
+       if ($nchg && !$ENV{FAST}) {
+               my $index = "$git_dir/ssoma.index";
                my $env = { GIT_INDEX_FILE => $index };
                my @rt = (@cmd, qw(read-tree -m -v -i), $self->{ref});
                $pid = spawn(\@rt, $env, undef);
@@ -217,11 +221,13 @@ sub done {
                waitpid($pid, 0) == $pid or die 'read-tree did not finish';
                $? == 0 or die "failed to update $git_dir/ssoma.index: $?\n";
        }
-
-       $pid = spawn([@cmd, 'update-server-info'], undef, undef);
-       defined $pid or die "spawn update-server-info failed: $!\n";
-       waitpid($pid, 0) == $pid or die 'update-server-info did not finish';
-       $? == 0 or die "failed to update-server-info: $?\n";
+       if ($nchg) {
+               $pid = spawn([@cmd, 'update-server-info'], undef, undef);
+               defined $pid or die "spawn update-server-info failed: $!\n";
+               waitpid($pid, 0) == $pid or
+                       die 'update-server-info did not finish';
+               $? == 0 or die "failed to update-server-info: $?\n";
+       }
 
        my $lockfh = delete $self->{lockfh} or die "BUG: not locked: $!";
        flock($lockfh, LOCK_UN) or die "unlock failed: $!";