From 68f83ca5236078128a0ccf47a1e54bd955777120 Mon Sep 17 00:00:00 2001
From: Eric Wong <e@80x24.org>
Date: Sat, 31 Dec 2016 11:16:47 +0000
Subject: initial git async work

This will allow us to handle network operations while waiting
on "git cat-file" to seek and unpack things.
---
 lib/PublicInbox/Git.pm | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)

(limited to 'lib/PublicInbox/Git.pm')

diff --git a/lib/PublicInbox/Git.pm b/lib/PublicInbox/Git.pm
index 4dfc4099..0b482c7e 100644
--- a/lib/PublicInbox/Git.pm
+++ b/lib/PublicInbox/Git.pm
@@ -13,6 +13,10 @@ use POSIX qw(dup2);
 require IO::Handle;
 use PublicInbox::Spawn qw(spawn popen_rd);
 use Fcntl qw(:seek);
+my $have_async = eval {
+	require PublicInbox::EvCleanup;
+	require PublicInbox::GitAsyncRd;
+};
 
 # Documentation/SubmittingPatches recommends 12 (Linux v4.4)
 my $abbrev = `git config core.abbrev` || 12;
@@ -64,6 +68,7 @@ sub _bidi_pipe {
 	$self->{$in} = $in_r;
 }
 
+# legacy synchronous API
 sub cat_file_begin {
 	my ($self, $obj) = @_;
 	$self->_bidi_pipe(qw(--batch in out pid));
@@ -79,6 +84,7 @@ sub cat_file_begin {
 	($in, $1, $2, $3);
 }
 
+# legacy synchronous API
 sub cat_file_finish {
 	my ($self, $left) = @_;
 	my $max = 8192;
@@ -96,6 +102,7 @@ sub cat_file_finish {
 	fail($self, 'newline missing after blob') if ($r != 1 || $buf ne "\n");
 }
 
+# legacy synchronous API
 sub cat_file {
 	my ($self, $obj, $ref) = @_;
 
@@ -131,6 +138,7 @@ sub cat_file {
 
 sub batch_prepare ($) { _bidi_pipe($_[0], qw(--batch in out pid)) }
 
+# legacy synchronous API
 sub check {
 	my ($self, $obj) = @_;
 	$self->_bidi_pipe(qw(--batch-check in_c out_c pid_c));
@@ -185,10 +193,91 @@ sub cleanup {
 	my ($self) = @_;
 	_destroy($self, qw(in out pid));
 	_destroy($self, qw(in_c out_c pid_c));
+
+	if ($have_async) {
+		my %h = %$self; # yup, copy ourselves
+		%$self = ();
+		my $ds_closed;
+
+		# schedule closing with Danga::Socket::close:
+		foreach (qw(async async_c)) {
+			my $ds = delete $h{$_} or next;
+			$ds->close;
+			$ds_closed = 1;
+		}
+
+		# can't do waitpid in _destroy() until next tick,
+		# since D::S defers closing until end of current event loop
+		$ds_closed and PublicInbox::EvCleanup::next_tick(sub {
+			_destroy(\%h, qw(in_a out_a pid_a));
+			_destroy(\%h, qw(in_ac out_ac pid_ac));
+		});
+	}
 }
 
 sub DESTROY { cleanup(@_) }
 
+# modern async API
+sub check_async_ds ($$$) {
+	my ($self, $obj, $cb) = @_;
+	($self->{async_c} ||= do {
+		_bidi_pipe($self, qw(--batch-check in_ac out_ac pid_ac));
+		PublicInbox::GitAsyncRd->new($self->{in_ac}, $self->{out_ac}, 1)
+	})->cat_file_async($obj, $cb);
+}
+
+sub cat_async_ds ($$$) {
+	my ($self, $obj, $cb) = @_;
+	($self->{async} ||= do {
+		_bidi_pipe($self, qw(--batch in_a out_a pid_a));
+		PublicInbox::GitAsyncRd->new($self->{in_a}, $self->{out_a});
+	})->cat_file_async($obj, $cb);
+}
+
+sub async_info_compat ($) {
+	local $/ = "\n";
+	chomp(my $line = $_[0]->getline);
+	[ split(/ /, $line) ];
+}
+
+sub check_async_compat ($$$) {
+	my ($self, $obj, $cb) = @_;
+	$self->_bidi_pipe(qw(--batch-check in_c out_c pid_c));
+	$self->{out_c}->print($obj."\n") or fail($self, "write error: $!");
+	my $info = async_info_compat($self->{in_c});
+	$cb->($info);
+}
+
+sub cat_async_compat ($$$) {
+	my ($self, $obj, $cb) = @_;
+	$self->_bidi_pipe(qw(--batch in out pid));
+	$self->{out}->print($obj."\n") or fail($self, "write error: $!");
+	my $in = $self->{in};
+	my $info = async_info_compat($in);
+	$cb->($info);
+	return if scalar(@$info) != 3; # missing
+	my $max = 8192;
+	my $left = $info->[2];
+	my ($buf, $r);
+	while ($left > 0) {
+		$r = read($in, $buf, $left > $max ? $max : $left);
+		return $cb->($r) unless $r; # undef or 0
+		$left -= $r;
+		$cb->(\$buf);
+	}
+	$r = read($in, $buf, 1);
+	defined($r) or fail($self, "read failed: $!");
+	fail($self, 'newline missing after blob') if ($r != 1 || $buf ne "\n");
+}
+
+if ($have_async) {
+	*check_async = *check_async_ds;
+	*cat_async = *cat_async_ds;
+} else {
+	*check_async = *check_async_compat;
+	*cat_async = *cat_async_compat;
+}
+
 1;
 __END__
 =pod
-- 
cgit v1.2.3-24-ge0c7