1 files changed, 67 insertions, 22 deletions

diff --git a/lib/PublicInbox/Git.pm b/lib/PublicInbox/Git.pm
index 59c27470..dee027a3 100644
--- a/lib/PublicInbox/Git.pm
+++ b/lib/PublicInbox/Git.pm
@@ -12,10 +12,35 @@ use warnings;
 use POSIX qw(dup2);
 require IO::Handle;
 use PublicInbox::Spawn qw(spawn popen_rd);
+use IO::File;
+use Fcntl qw(:seek);
+
+# Documentation/SubmittingPatches recommends 12 (Linux v4.4)
+my $abbrev = `git config core.abbrev` || 12;
+
+sub abbrev { "--abbrev=$abbrev" }
 
 sub new {
         my ($class, $git_dir) = @_;
-        bless { git_dir => $git_dir }, $class
+        bless { git_dir => $git_dir, err => IO::File->new_tmpfile }, $class
+}
+
+sub err_begin ($) {
+        my $err = $_[0]->{err};
+        sysseek($err, 0, SEEK_SET) or die "sysseek failed: $!";
+        truncate($err, 0) or die "truncate failed: $!";
+        my $ret = fileno($err);
+        defined $ret or die "fileno failed: $!";
+        $ret;
+}
+
+sub err ($) {
+        my $err = $_[0]->{err};
+        sysseek($err, 0, SEEK_SET) or die "sysseek failed: $!";
+        defined(sysread($err, my $buf, -s $err)) or die "sysread failed: $!";
+        sysseek($err, 0, SEEK_SET) or die "sysseek failed: $!";
+        truncate($err, 0) or die "truncate failed: $!";
+        $buf;
 }
 
 sub _bidi_pipe {
@@ -36,20 +61,43 @@ sub _bidi_pipe {
         $self->{$in} = $in_r;
 }
 
-sub cat_file {
-        my ($self, $obj, $ref) = @_;
-
-        batch_prepare($self);
+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: $!");
 
         my $in = $self->{in};
         local $/ = "\n";
         my $head = $in->getline;
         $head =~ / missing$/ and return undef;
-        $head =~ /^[0-9a-f]{40} \S+ (\d+)$/ or
+        $head =~ /^([0-9a-f]{40}) (\S+) (\d+)$/ or
                 fail($self, "Unexpected result from git cat-file: $head");
 
-        my $size = $1;
+        ($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;
@@ -58,16 +106,8 @@ sub cat_file {
         my $cb_err;
 
         if ($ref_type eq 'CODE') {
-                $rv = eval { $ref->($in, \$left) };
+                $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 = '';
@@ -80,10 +120,7 @@ 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;
@@ -119,8 +156,16 @@ sub fail {
 
 sub popen {
         my ($self, @cmd) = @_;
-        @cmd = ('git', "--git-dir=$self->{git_dir}", @cmd);
-        popen_rd(\@cmd);
+        my $cmd = [ 'git', "--git-dir=$self->{git_dir}" ];
+        my ($env, $opt);
+        if (ref $cmd[0]) {
+                push @$cmd, @{$cmd[0]};
+                $env = $cmd[1];
+                $opt = $cmd[2];
+        } else {
+                push @$cmd, @cmd;
+        }
+        popen_rd($cmd, $env, $opt);
 }
 
 sub qx {