# Copyright (C) 2020 all contributors <meta@public-inbox.org>
# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
#
-# internal class used by PublicInbox::Git + Danga::Socket
+# internal class used by PublicInbox::Git + PublicInbox::DS
# This parses the output pipe of "git cat-file --batch"
-#
-# Note: this does NOT set the non-blocking flag, we expect `git cat-file'
-# to be a local process, and git won't start writing a blob until it's
-# fully read. So minimize context switching and read as much as possible
-# and avoid holding a buffer in our heap any longer than it has to live.
package PublicInbox::GitAsyncCat;
use strict;
use parent qw(PublicInbox::DS Exporter);
-use fields qw(git);
+use POSIX qw(WNOHANG);
use PublicInbox::Syscall qw(EPOLLIN EPOLLET);
-our @EXPORT = qw(git_async_msg);
-
-sub new {
- my ($class, $git) = @_;
- my $self = fields::new($class);
- $git->batch_prepare;
- $self->SUPER::new($git->{in}, EPOLLIN|EPOLLET);
- $self->{git} = $git;
- $self;
+our @EXPORT = qw(git_async_cat git_async_prefetch);
+use PublicInbox::Git ();
+
+our $GCF2C; # singleton PublicInbox::Gcf2Client
+
+sub close {
+ my ($self) = @_;
+
+ if (my $gitish = delete $self->{gitish}) {
+ PublicInbox::Git::cat_async_abort($gitish);
+ }
+ $self->SUPER::close; # PublicInbox::DS::close
}
sub event_step {
my ($self) = @_;
- my $git = $self->{git} or return; # ->close-ed
- my $inflight = $git->{inflight};
- if (@$inflight) {
- $git->cat_async_step($inflight);
- $self->requeue if @$inflight || exists $git->{cat_rbuf};
+ my $gitish = $self->{gitish} or return;
+ return $self->close if ($gitish->{in} // 0) != ($self->{sock} // 1);
+ my $inflight = $gitish->{inflight};
+ if ($inflight && @$inflight) {
+ $gitish->cat_async_step($inflight);
+
+ # child death?
+ if (($gitish->{in} // 0) != ($self->{sock} // 1)) {
+ $self->close;
+ } elsif (@$inflight || exists $gitish->{cat_rbuf}) {
+ # ok, more to do, requeue for fairness
+ $self->requeue;
+ }
+ } elsif ((my $pid = waitpid($gitish->{pid}, WNOHANG)) > 0) {
+ # May happen if the child process is killed by a BOFH
+ # (or segfaults)
+ delete $gitish->{pid};
+ warn "E: gitish $pid exited with \$?=$?\n";
+ $self->close;
}
}
-sub close {
- my ($self) = @_;
- delete $self->{git};
- $self->SUPER::close; # PublicInbox::DS::close
+sub git_async_cat ($$$$) {
+ my ($git, $oid, $cb, $arg) = @_;
+ my $gitish = $GCF2C //= eval {
+ require PublicInbox::Gcf2;
+ require PublicInbox::Gcf2Client;
+ PublicInbox::Gcf2Client::new();
+ } // 0; # 0: do not retry if libgit2 or Inline::C are missing
+ if ($gitish) { # Gcf2 active, {inflight} may be unset due to errors
+ $GCF2C->{inflight} or
+ $gitish = $GCF2C = PublicInbox::Gcf2Client::new();
+ $oid .= " $git->{git_dir}";
+ } else {
+ $gitish = $git;
+ }
+ $gitish->cat_async($oid, $cb, $arg);
+ $gitish->{async_cat} //= do {
+ # read-only end of pipe (Gcf2Client is write-only end)
+ my $self = bless { gitish => $gitish }, __PACKAGE__;
+ $gitish->{in}->blocking(0);
+ $self->SUPER::new($gitish->{in}, EPOLLIN|EPOLLET);
+ \undef; # this is a true ref()
+ };
}
-sub git_async_msg ($$$$) {
- my ($ibx, $smsg, $cb, $arg) = @_;
- $ibx->git->cat_async($smsg->{blob}, $cb, $arg);
- $ibx->{async_cat} //= new(__PACKAGE__, $ibx->{git});
+# this is safe to call inside $cb, but not guaranteed to enqueue
+# returns true if successful, undef if not.
+sub git_async_prefetch {
+ my ($git, $oid, $cb, $arg) = @_;
+ if ($GCF2C) {
+ if ($GCF2C->{async_cat} && !$GCF2C->{wbuf}) {
+ $oid .= " $git->{git_dir}";
+ return $GCF2C->cat_async($oid, $cb, $arg);
+ }
+ } elsif ($git->{async_cat} && (my $inflight = $git->{inflight})) {
+ # we could use MAX_INFLIGHT here w/o the halving,
+ # but lets not allow one client to monopolize a git process
+ if (@$inflight < int(PublicInbox::Git::MAX_INFLIGHT/2)) {
+ print { $git->{out} } $oid, "\n" or
+ $git->fail("write error: $!");
+ return push(@$inflight, $oid, $cb, $arg);
+ }
+ }
+ undef;
}
1;