X-Git-Url: http://www.git.stargrave.org/?a=blobdiff_plain;f=lib%2FPublicInbox%2FGit.pm;h=181026c7bc1b726ff562e1b488f3256a0bf98c87;hb=b80dccff433cc529040e3c11604d76f669570511;hp=54c163e8c2f5151b0122c998936c94f72507e801;hpb=6d2fad2c3f6eaf7334b1e805de607e1d5b24ff9e;p=public-inbox.git

diff --git a/lib/PublicInbox/Git.pm b/lib/PublicInbox/Git.pm
index 54c163e8..181026c7 100644
--- a/lib/PublicInbox/Git.pm
+++ b/lib/PublicInbox/Git.pm
@@ -8,19 +8,22 @@
 # There are also API changes to simplify our usage and data set.
 package PublicInbox::Git;
 use strict;
-use warnings;
+use v5.10.1;
+use parent qw(Exporter);
 use POSIX ();
 use IO::Handle; # ->autoflush
+use Errno qw(EINTR);
 use File::Glob qw(bsd_glob GLOB_NOSORT);
+use Time::HiRes qw(stat);
 use PublicInbox::Spawn qw(popen_rd);
 use PublicInbox::Tmpfile;
-use base qw(Exporter);
+use Carp qw(croak);
 our @EXPORT_OK = qw(git_unquote git_quote);
-use Errno qw(EINTR);
 our $PIPE_BUFSIZ = 65536; # Linux default
+our $in_cleanup;
 
 use constant MAX_INFLIGHT =>
-	(($^O eq 'linux' ? 4096 : POSIX::_POSIX_PIPE_BUF()) * 2)
+	(($^O eq 'linux' ? 4096 : POSIX::_POSIX_PIPE_BUF()) * 3)
 	/
 	65; # SHA-256 hex size + "\n" in preparation for git using non-SHA1
 
@@ -123,7 +126,6 @@ sub _bidi_pipe {
 		fcntl($out_w, 1031, 4096);
 		fcntl($in_r, 1031, 4096) if $batch eq '--batch-check';
 	}
-	$self->{$batch} = \(my $rbuf = '');
 	$self->{$out} = $out_w;
 	$self->{$in} = $in_r;
 }
@@ -156,29 +158,59 @@ sub my_readline ($$) {
 	}
 }
 
-sub _cat_async_step ($$) {
-	my ($self, $inflight) = @_;
-	die 'BUG: inflight empty or odd' if scalar(@$inflight) < 2;
-	my ($cb, $arg) = splice(@$inflight, 0, 2);
-	my $head = my_readline($self->{in}, $self->{'--batch'});
-	$head =~ / missing$/ and return
-		eval { $cb->(undef, undef, undef, undef, $arg) };
+sub cat_async_retry ($$$$$) {
+	my ($self, $inflight, $req, $cb, $arg) = @_;
+
+	# {inflight} may be non-existent, but if it isn't we delete it
+	# here to prevent cleanup() from waiting:
+	delete $self->{inflight};
+	cleanup($self);
+
+	$self->{inflight} = $inflight;
+	batch_prepare($self);
+	my $buf = "$req\n";
+	for (my $i = 0; $i < @$inflight; $i += 3) {
+		$buf .= "$inflight->[$i]\n";
+	}
+	print { $self->{out} } $buf or fail($self, "write error: $!");
+	unshift(@$inflight, \$req, $cb, $arg); # \$ref to indicate retried
+
+	cat_async_step($self, $inflight); # take one step
+}
 
-	$head =~ /^([0-9a-f]{40}) (\S+) ([0-9]+)$/ or
+sub cat_async_step ($$) {
+	my ($self, $inflight) = @_;
+	die 'BUG: inflight empty or odd' if scalar(@$inflight) < 3;
+	my ($req, $cb, $arg) = splice(@$inflight, 0, 3);
+	my $rbuf = delete($self->{cat_rbuf}) // \(my $new = '');
+	my ($bref, $oid, $type, $size);
+	my $head = my_readline($self->{in}, $rbuf);
+	if ($head =~ /^([0-9a-f]{40}) (\S+) ([0-9]+)$/) {
+		($oid, $type, $size) = ($1, $2, $3 + 0);
+		$bref = my_read($self->{in}, $rbuf, $size + 1) or
+			fail($self, defined($bref) ? 'read EOF' : "read: $!");
+		chop($$bref) eq "\n" or fail($self, 'LF missing after blob');
+	} elsif ($head =~ / missing$/) {
+		# ref($req) indicates it's already been retried
+		if (!ref($req) && !$in_cleanup && alternates_changed($self)) {
+			return cat_async_retry($self, $inflight,
+						$req, $cb, $arg);
+		}
+		$type = 'missing';
+		$oid = ref($req) ? $$req : $req;
+	} else {
 		fail($self, "Unexpected result from async git cat-file: $head");
-	my ($oid_hex, $type, $size) = ($1, $2, $3 + 0);
-	my $ret = my_read($self->{in}, $self->{'--batch'}, $size + 1);
-	fail($self, defined($ret) ? 'read EOF' : "read: $!") if !$ret;
-	chop($$ret) eq "\n" or fail($self, 'newline missing after blob');
-	eval { $cb->($ret, $oid_hex, $type, $size, $arg) };
-	warn "E: $oid_hex $@\n" if $@;
+	}
+	eval { $cb->($bref, $oid, $type, $size, $arg) };
+	$self->{cat_rbuf} = $rbuf if $$rbuf ne '';
+	warn "E: $oid: $@\n" if $@;
 }
 
 sub cat_async_wait ($) {
 	my ($self) = @_;
 	my $inflight = delete $self->{inflight} or return;
 	while (scalar(@$inflight)) {
-		_cat_async_step($self, $inflight);
+		cat_async_step($self, $inflight);
 	}
 }
 
@@ -186,60 +218,92 @@ sub batch_prepare ($) {
 	_bidi_pipe($_[0], qw(--batch in out pid));
 }
 
+sub _cat_file_cb {
+	my ($bref, undef, undef, $size, $result) = @_;
+	@$result = ($bref, $size);
+}
+
 sub cat_file {
-	my ($self, $obj, $sizeref) = @_;
-	my ($retried, $head);
+	my ($self, $oid, $sizeref) = @_;
+	my $result = [];
+	cat_async($self, $oid, \&_cat_file_cb, $result);
 	cat_async_wait($self);
-again:
-	batch_prepare($self);
-	print { $self->{out} } $obj, "\n" or fail($self, "write error: $!");
-	$head = my_readline($self->{in}, $self->{'--batch'});
-	if ($head =~ / missing$/) {
-		if (!$retried && alternates_changed($self)) {
-			$retried = 1;
-			cleanup($self);
-			goto again;
-		}
-		return;
+	$$sizeref = $result->[1] if $sizeref;
+	$result->[0];
+}
+
+sub check_async_step ($$) {
+	my ($self, $inflight_c) = @_;
+	die 'BUG: inflight empty or odd' if scalar(@$inflight_c) < 3;
+	my ($req, $cb, $arg) = splice(@$inflight_c, 0, 3);
+	my $rbuf = delete($self->{rbuf_c}) // \(my $new = '');
+	chomp(my $line = my_readline($self->{in_c}, $rbuf));
+	my ($hex, $type, $size) = split(/ /, $line);
+
+	# Future versions of git.git may have type=ambiguous, but for now,
+	# we must handle 'dangling' below (and maybe some other oddball
+	# stuff):
+	# https://public-inbox.org/git/20190118033845.s2vlrb3wd3m2jfzu@dcvr/T/
+	if ($hex eq 'dangling' || $hex eq 'notdir' || $hex eq 'loop') {
+		my $ret = my_read($self->{in_c}, $rbuf, $type + 1);
+		fail($self, defined($ret) ? 'read EOF' : "read: $!") if !$ret;
+	}
+	eval { $cb->($hex, $type, $size, $arg, $self) };
+	warn "E: check($req) $@\n" if $@;
+	$self->{rbuf_c} = $rbuf if $$rbuf ne '';
+}
+
+sub check_async_wait ($) {
+	my ($self) = @_;
+	my $inflight_c = delete $self->{inflight_c} or return;
+	while (scalar(@$inflight_c)) {
+		check_async_step($self, $inflight_c);
+	}
+}
+
+sub check_async_begin ($) {
+	my ($self) = @_;
+	cleanup($self) if alternates_changed($self);
+	_bidi_pipe($self, qw(--batch-check in_c out_c pid_c err_c));
+	die 'BUG: already in async check' if $self->{inflight_c};
+	$self->{inflight_c} = [];
+}
+
+sub check_async ($$$$) {
+	my ($self, $oid, $cb, $arg) = @_;
+	my $inflight_c = $self->{inflight_c} // check_async_begin($self);
+	if (scalar(@$inflight_c) >= MAX_INFLIGHT) {
+		check_async_step($self, $inflight_c);
 	}
-	$head =~ /^[0-9a-f]{40} \S+ ([0-9]+)$/ or
-		fail($self, "Unexpected result from git cat-file: $head");
+	print { $self->{out_c} } $oid, "\n" or fail($self, "write error: $!");
+	push(@$inflight_c, $oid, $cb, $arg);
+}
 
-	my $size = $1 + 0;
-	$$sizeref = $size if $sizeref;
-	my $ret = my_read($self->{in}, $self->{'--batch'}, $size + 1);
-	fail($self, defined($ret) ? 'read EOF' : "read: $!") if !$ret;
-	chop($$ret) eq "\n" or fail($self, 'newline missing after blob');
-	$ret;
+sub _check_cb { # check_async callback
+	my ($hex, $type, $size, $result) = @_;
+	@$result = ($hex, $type, $size);
 }
 
 sub check {
-	my ($self, $obj) = @_;
-	_bidi_pipe($self, qw(--batch-check in_c out_c pid_c err_c));
-	print { $self->{out_c} } $obj, "\n" or fail($self, "write error: $!");
-	chomp(my $line = my_readline($self->{in_c}, $self->{'--batch-check'}));
-	my ($hex, $type, $size) = split(' ', $line);
+	my ($self, $oid) = @_;
+	my $result = [];
+	check_async($self, $oid, \&_check_cb, $result);
+	check_async_wait($self);
+	my ($hex, $type, $size) = @$result;
 
 	# Future versions of git.git may show 'ambiguous', but for now,
 	# we must handle 'dangling' below (and maybe some other oddball
 	# stuff):
 	# https://public-inbox.org/git/20190118033845.s2vlrb3wd3m2jfzu@dcvr/T/
 	return if $type eq 'missing' || $type eq 'ambiguous';
-
-	if ($hex eq 'dangling' || $hex eq 'notdir' || $hex eq 'loop') {
-		my $ret = my_read($self->{in_c}, $self->{'--batch-check'},
-				$type + 1);
-		fail($self, defined($ret) ? 'read EOF' : "read: $!") if !$ret;
-		return;
-	}
-
+	return if $hex eq 'dangling' || $hex eq 'notdir' || $hex eq 'loop';
 	($hex, $type, $size);
 }
 
 sub _destroy {
-	my ($self, $batch, $in, $out, $pid, $err) = @_;
+	my ($self, $rbuf, $in, $out, $pid, $err) = @_;
 	my $p = delete $self->{$pid} or return;
-	delete @$self{($batch, $in, $out)};
+	delete @$self{($rbuf, $in, $out)};
 	delete $self->{$err} if $err; # `err_c'
 
 	# PublicInbox::DS may not be loaded
@@ -256,7 +320,7 @@ sub cat_async_abort ($) {
 sub fail {
 	my ($self, $msg) = @_;
 	$self->{inflight} ? cat_async_abort($self) : cleanup($self);
-	die $msg;
+	croak("git $self->{git_dir}: $msg");
 }
 
 sub popen {
@@ -277,8 +341,12 @@ sub qx {
 # returns true if there are pending "git cat-file" processes
 sub cleanup {
 	my ($self) = @_;
-	_destroy($self, qw(--batch in out pid));
-	_destroy($self, qw(--batch-check in_c out_c pid_c err_c));
+	local $in_cleanup = 1;
+	delete $self->{async_cat};
+	check_async_wait($self);
+	cat_async_wait($self);
+	_destroy($self, qw(cat_rbuf in out pid));
+	_destroy($self, qw(chk_rbuf in_c out_c pid_c err_c));
 	!!($self->{pid} || $self->{pid_c});
 }
 
@@ -334,13 +402,29 @@ sub cat_async_begin {
 
 sub cat_async ($$$;$) {
 	my ($self, $oid, $cb, $arg) = @_;
-	my $inflight = $self->{inflight} or die 'BUG: not in async';
+	my $inflight = $self->{inflight} // cat_async_begin($self);
 	if (scalar(@$inflight) >= MAX_INFLIGHT) {
-		_cat_async_step($self, $inflight);
+		cat_async_step($self, $inflight);
 	}
 
 	print { $self->{out} } $oid, "\n" or fail($self, "write error: $!");
-	push(@$inflight, $cb, $arg);
+	push(@$inflight, $oid, $cb, $arg);
+}
+
+# this is safe to call inside $cb, but not guaranteed to enqueue
+# returns true if successful, undef if not.
+sub async_prefetch {
+	my ($self, $oid, $cb, $arg) = @_;
+	if (defined($self->{async_cat}) && (my $inflight = $self->{inflight})) {
+		# we could use MAX_INFLIGHT here w/o the halving,
+		# but lets not allow one client to monopolize a git process
+		if (scalar(@$inflight) < int(MAX_INFLIGHT/2)) {
+			print { $self->{out} } $oid, "\n" or
+						fail($self, "write error: $!");
+			return push(@$inflight, $oid, $cb, $arg);
+		}
+	}
+	undef;
 }
 
 sub extract_cmt_time {
@@ -358,7 +442,6 @@ sub modified ($) {
 	my ($self) = @_;
 	my $modified = 0;
 	my $fh = popen($self, qw(rev-parse --branches));
-	cat_async_begin($self);
 	local $/ = "\n";
 	while (my $oid = <$fh>) {
 		chomp $oid;