git: allow async_cat to pass arg to callback

This allows callers to avoid allocating several KB for for every
call to ->async_cat.

1 files changed, 8 insertions, 6 deletions

diff --git a/lib/PublicInbox/Git.pm b/lib/PublicInbox/Git.pm
index 90595840..af3a5712 100644
--- a/lib/PublicInbox/Git.pm
+++ b/lib/PublicInbox/Git.pm
@@ -148,16 +148,18 @@ sub read_cat_in_full ($$$) {
 
 sub _cat_async_step ($$$) {
         my ($self, $inflight, $in) = @_;
-        my $cb = shift @$inflight or die 'BUG: inflight empty';
+        my $pair = shift @$inflight or die 'BUG: inflight empty';
+        my ($cb, $arg) = @$pair;
         local $/ = "\n";
         my $head = $in->getline;
-        return eval { $cb->(undef) } if $head =~ / missing$/;
+        $head =~ / missing$/ and return
+                eval { $cb->(undef, undef, undef, undef, $arg) };
 
         $head =~ /^([0-9a-f]{40}) (\S+) ([0-9]+)$/ or
                 fail($self, "Unexpected result from async git cat-file: $head");
         my ($oid_hex, $type, $size) = ($1, $2, $3 + 0);
         my $bref = read_cat_in_full($self, $in, $size);
-        eval { $cb->($bref, $oid_hex, $type, $size) };
+        eval { $cb->($bref, $oid_hex, $type, $size, $arg) };
 }
 
 sub cat_async_wait ($) {
@@ -319,15 +321,15 @@ sub cat_async_begin {
         $self->{inflight} = [];
 }
 
-sub cat_async ($$$) {
-        my ($self, $oid, $cb) = @_;
+sub cat_async ($$$;$) {
+        my ($self, $oid, $cb, $arg) = @_;
         my $inflight = $self->{inflight} or die 'BUG: not in async';
         if (scalar(@$inflight) >= MAX_INFLIGHT) {
                 _cat_async_step($self, $inflight, $self->{in});
         }
 
         $self->{out}->print($oid, "\n") or fail($self, "write error: $!");
-        push @$inflight, $cb;
+        push(@$inflight, [ $cb, $arg ]);
 }
 
 sub commit_title ($$) {