git: factor out cat_file_begin and cat_file_finish

Unfortunately, it seems being able to handle callbacks is
insufficient; and these methods will allow us to avoid making
an extra $git->check call.

diff --git a/lib/PublicInbox/Git.pm b/lib/PublicInbox/Git.pm
index 4bc879ffd9b6b497bd7fda818fdf1e91a1590b30..aec2db0b3c8ebd36d079c7047c916e9ed38fc8a8 100644 (file)
--- a/lib/PublicInbox/Git.pm
+++ b/lib/PublicInbox/Git.pm
@@ -34,9 +34,8 @@ sub _bidi_pipe {
        $self->{$in} = $in_r;
 }
 
-sub cat_file {
-       my ($self, $obj, $ref) = @_;
-
+sub cat_file_begin {
+       my ($self, $obj) = @_;
        $self->_bidi_pipe(qw(--batch in out pid));
        $self->{out}->print($obj, "\n") or fail($self, "write error: $!");
 
@@ -46,7 +45,31 @@ sub cat_file {
        $head =~ /^([0-9a-f]{40}) (\S+) (\d+)$/ or
                fail($self, "Unexpected result from git cat-file: $head");
 
-       my ($hex, $type, $size) = ($1, $2, $3);
+       ($in, $1, $2, $3);
+}
+
+sub cat_file_finish {
+       my ($self, $left) = @_;
+       my $max = 8192;
+       my $in = $self->{in};
+       my $buf;
+       while ($left > 0) {
+               my $r = read($in, $buf, $left > $max ? $max : $left);
+               defined($r) or fail($self, "read failed: $!");
+               $r == 0 and fail($self, 'exited unexpectedly');
+               $left -= $r;
+       }
+
+       my $r = read($in, $buf, 1);
+       defined($r) or fail($self, "read failed: $!");
+       fail($self, 'newline missing after blob') if ($r != 1 || $buf ne "\n");
+}
+
+sub cat_file {
+       my ($self, $obj, $ref) = @_;
+
+       my ($in, $hex, $type, $size) = $self->cat_file_begin($obj);
+       return unless $in;
        my $ref_type = $ref ? ref($ref) : '';
 
        my $rv;
@@ -57,14 +80,6 @@ sub cat_file {
        if ($ref_type eq 'CODE') {
                $rv = eval { $ref->($in, \$left, $type, $hex) };
                $cb_err = $@;
-               # drain the rest
-               my $max = 8192;
-               while ($left > 0) {
-                       my $r = read($in, my $x, $left > $max ? $max : $left);
-                       defined($r) or fail($self, "read failed: $!");
-                       $r == 0 and fail($self, 'exited unexpectedly');
-                       $left -= $r;
-               }
        } else {
                my $offset = 0;
                my $buf = '';
@@ -77,10 +92,7 @@ sub cat_file {
                }
                $rv = \$buf;
        }
-
-       my $r = read($in, my $buf, 1);
-       defined($r) or fail($self, "read failed: $!");
-       fail($self, 'newline missing after blob') if ($r != 1 || $buf ne "\n");
+       $self->cat_file_finish($left);
        die $cb_err if $cb_err;
 
        $rv;