-# Copyright (C) 2014-2018 all contributors <meta@public-inbox.org>
+# Copyright (C) 2014-2021 all contributors <meta@public-inbox.org>
# License: GPLv2 or later <https://www.gnu.org/licenses/gpl-2.0.txt>
#
# Used to read files from a git repository without excessive forking.
# There are also API changes to simplify our usage and data set.
package PublicInbox::Git;
use strict;
-use warnings;
-use POSIX qw(dup2);
-require IO::Handle;
-use PublicInbox::Spawn qw(spawn popen_rd);
-use base qw(Exporter);
+use v5.10.1;
+use parent qw(Exporter);
+use POSIX ();
+use IO::Handle; # ->autoflush
+use Errno qw(EINTR EAGAIN);
+use File::Glob qw(bsd_glob GLOB_NOSORT);
+use File::Spec ();
+use Time::HiRes qw(stat);
+use PublicInbox::Spawn qw(popen_rd);
+use PublicInbox::Tmpfile;
+use IO::Poll qw(POLLIN);
+use Carp qw(croak);
+use Digest::SHA ();
+use PublicInbox::DS qw(dwaitpid);
our @EXPORT_OK = qw(git_unquote git_quote);
+our $PIPE_BUFSIZ = 65536; # Linux default
+our $in_cleanup;
+our $RDTIMEO = 60_000; # milliseconds
+
+use constant MAX_INFLIGHT =>
+ (($^O eq 'linux' ? 4096 : POSIX::_POSIX_PIPE_BUF()) * 3)
+ /
+ 65; # SHA-256 hex size + "\n" in preparation for git using non-SHA1
my %GIT_ESC = (
a => "\a",
sub new {
my ($class, $git_dir) = @_;
- my @st;
- $st[7] = $st[10] = 0;
# may contain {-tmp} field for File::Temp::Dir
- bless { git_dir => $git_dir, st => \@st, -git_path => {} }, $class
+ bless { git_dir => $git_dir, alt_st => '', -git_path => {} }, $class
}
sub git_path ($$) {
my ($self) = @_;
my $alt = git_path($self, 'objects/info/alternates');
my @st = stat($alt) or return 0;
- my $old_st = $self->{st};
- # 10 - ctime, 7 - size
- return 0 if ($st[10] == $old_st->[10] && $st[7] == $old_st->[7]);
- $self->{st} = \@st;
+
+ # can't rely on 'q' on some 32-bit builds, but `d' works
+ my $st = pack('dd', $st[10], $st[7]); # 10: ctime, 7: size
+ return 0 if $self->{alt_st} eq $st;
+ $self->{alt_st} = $st; # always a true value
}
sub last_check_err {
my ($self) = @_;
my $fh = $self->{err_c} or return;
- sysseek($fh, 0, 0) or fail($self, "sysseek failed: $!");
+ sysseek($fh, 0, 0) or $self->fail("sysseek failed: $!");
defined(sysread($fh, my $buf, -s $fh)) or
- fail($self, "sysread failed: $!");
+ $self->fail("sysread failed: $!");
$buf;
}
if ($self->{$pid}) {
if (defined $err) { # "err_c"
my $fh = $self->{$err};
- sysseek($fh, 0, 0) or fail($self, "sysseek failed: $!");
- truncate($fh, 0) or fail($self, "truncate failed: $!");
+ sysseek($fh, 0, 0) or $self->fail("sysseek failed: $!");
+ truncate($fh, 0) or $self->fail("truncate failed: $!");
}
return;
}
- my ($in_r, $in_w, $out_r, $out_w);
-
- pipe($in_r, $in_w) or fail($self, "pipe failed: $!");
- pipe($out_r, $out_w) or fail($self, "pipe failed: $!");
- if ($^O eq 'linux') { # 1031: F_SETPIPE_SZ
- fcntl($out_w, 1031, 4096);
- fcntl($in_w, 1031, 4096) if $batch eq '--batch-check';
- }
-
+ my ($out_r, $out_w);
+ pipe($out_r, $out_w) or $self->fail("pipe failed: $!");
my @cmd = (qw(git), "--git-dir=$self->{git_dir}",
qw(-c core.abbrev=40 cat-file), $batch);
- my $redir = { 0 => fileno($out_r), 1 => fileno($in_w) };
+ my $redir = { 0 => $out_r };
if ($err) {
- open(my $fh, '+>', undef) or fail($self, "open.err failed: $!");
+ my $id = "git.$self->{git_dir}$batch.err";
+ my $fh = tmpfile($id) or $self->fail("tmpfile($id): $!");
$self->{$err} = $fh;
- $redir->{2} = fileno($fh);
+ $redir->{2} = $fh;
}
- my $p = spawn(\@cmd, undef, $redir);
- defined $p or fail($self, "spawn failed: $!");
+ my ($in_r, $p) = popen_rd(\@cmd, undef, $redir);
$self->{$pid} = $p;
+ $self->{"$pid.owner"} = $$;
$out_w->autoflush(1);
+ if ($^O eq 'linux') { # 1031: F_SETPIPE_SZ
+ fcntl($out_w, 1031, 4096);
+ fcntl($in_r, 1031, 4096) if $batch eq '--batch-check';
+ }
$self->{$out} = $out_w;
$self->{$in} = $in_r;
}
-sub cat_file {
- my ($self, $obj, $ref) = @_;
- my ($retried, $in, $head);
+sub poll_in ($) { IO::Poll::_poll($RDTIMEO, fileno($_[0]), my $ev = POLLIN) }
-again:
- batch_prepare($self);
- $self->{out}->print($obj, "\n") or fail($self, "write error: $!");
+sub my_read ($$$) {
+ my ($fh, $rbuf, $len) = @_;
+ my $left = $len - length($$rbuf);
+ my $r;
+ while ($left > 0) {
+ $r = sysread($fh, $$rbuf, $PIPE_BUFSIZ, length($$rbuf));
+ if ($r) {
+ $left -= $r;
+ } elsif (defined($r)) { # EOF
+ return 0;
+ } else {
+ next if ($! == EAGAIN and poll_in($fh));
+ next if $! == EINTR; # may be set by sysread or poll_in
+ return; # unrecoverable error
+ }
+ }
+ \substr($$rbuf, 0, $len, '');
+}
- $in = $self->{in};
- local $/ = "\n";
- $head = $in->getline;
- if ($head =~ / missing$/) {
- if (!$retried && alternates_changed($self)) {
- $retried = 1;
- cleanup($self);
- goto again;
+sub my_readline ($$) {
+ my ($fh, $rbuf) = @_;
+ while (1) {
+ if ((my $n = index($$rbuf, "\n")) >= 0) {
+ return substr($$rbuf, 0, $n + 1, '');
}
- return;
+ my $r = sysread($fh, $$rbuf, $PIPE_BUFSIZ, length($$rbuf))
+ and next;
+
+ # return whatever's left on EOF
+ return substr($$rbuf, 0, length($$rbuf)+1, '') if defined($r);
+
+ next if ($! == EAGAIN and poll_in($fh));
+ next if $! == EINTR; # may be set by sysread or poll_in
+ return; # unrecoverable error
}
- $head =~ /^[0-9a-f]{40} \S+ (\d+)$/ or
- fail($self, "Unexpected result from git cat-file: $head");
-
- my $size = $1;
- my $ref_type = $ref ? ref($ref) : '';
-
- my $rv;
- my $left = $size;
- $$ref = $size if ($ref_type eq 'SCALAR');
- my $cb_err;
-
- if ($ref_type eq 'CODE') {
- $rv = eval { $ref->($in, \$left) };
- $cb_err = $@;
- # drain the rest
- my $max = 8192;
- while ($left > 0) {
- my $r = read($in, my $x, $left > $max ? $max : $left);
- defined($r) or fail($self, "read failed: $!");
- $r == 0 and fail($self, 'exited unexpectedly');
- $left -= $r;
+}
+
+sub cat_async_retry ($$$$$) {
+ my ($self, $inflight, $req, $cb, $arg) = @_;
+
+ # {inflight} may be non-existent, but if it isn't we delete it
+ # here to prevent cleanup() from waiting:
+ delete $self->{inflight};
+ cleanup($self);
+
+ $self->{inflight} = $inflight;
+ batch_prepare($self);
+ my $buf = "$req\n";
+ for (my $i = 0; $i < @$inflight; $i += 3) {
+ $buf .= "$inflight->[$i]\n";
+ }
+ print { $self->{out} } $buf or $self->fail("write error: $!");
+ unshift(@$inflight, \$req, $cb, $arg); # \$ref to indicate retried
+
+ cat_async_step($self, $inflight); # take one step
+}
+
+sub cat_async_step ($$) {
+ 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}, $rbuf);
+ # ->fail may be called via Gcf2Client.pm
+ if ($head =~ /^([0-9a-f]{40,}) (\S+) ([0-9]+)$/) {
+ ($oid, $type, $size) = ($1, $2, $3 + 0);
+ $bref = my_read($self->{in}, $rbuf, $size + 1) or
+ $self->fail(defined($bref) ? 'read EOF' : "read: $!");
+ chop($$bref) eq "\n" or $self->fail('LF missing after blob');
+ } elsif ($head =~ s/ missing\n//s) {
+ $oid = $head;
+ # ref($req) indicates it's already been retried
+ # -gcf2 retries internally, so it never hits this path:
+ if (!ref($req) && !$in_cleanup && $self->alternates_changed) {
+ return cat_async_retry($self, $inflight,
+ $req, $cb, $arg);
}
+ $type = 'missing';
+ $oid = ref($req) ? $$req : $req if $oid eq '';
} else {
- my $offset = 0;
- my $buf = '';
- while ($left > 0) {
- my $r = read($in, $buf, $left, $offset);
- defined($r) or fail($self, "read failed: $!");
- $r == 0 and fail($self, 'exited unexpectedly');
- $left -= $r;
- $offset += $r;
- }
- $rv = \$buf;
+ my $err = $! ? " ($!)" : '';
+ $self->fail("bad result from async cat-file: $head$err");
}
+ $self->{cat_rbuf} = $rbuf if $$rbuf ne '';
+ eval { $cb->($bref, $oid, $type, $size, $arg) };
+ warn "E: $oid: $@\n" if $@;
+}
- my $r = read($in, my $buf, 1);
- defined($r) or fail($self, "read failed: $!");
- fail($self, 'newline missing after blob') if ($r != 1 || $buf ne "\n");
- die $cb_err if $cb_err;
+sub cat_async_wait ($) {
+ my ($self) = @_;
+ my $inflight = $self->{inflight} or return;
+ while (scalar(@$inflight)) {
+ cat_async_step($self, $inflight);
+ }
+}
- $rv;
+sub batch_prepare ($) {
+ _bidi_pipe($_[0], qw(--batch in out pid));
}
-sub batch_prepare ($) { _bidi_pipe($_[0], qw(--batch in out pid)) }
+sub _cat_file_cb {
+ my ($bref, undef, undef, $size, $result) = @_;
+ @$result = ($bref, $size);
+}
-sub check {
- my ($self, $obj) = @_;
- _bidi_pipe($self, qw(--batch-check in_c out_c pid_c err_c));
- $self->{out_c}->print($obj, "\n") or fail($self, "write error: $!");
- local $/ = "\n";
- chomp(my $line = $self->{in_c}->getline);
- my ($hex, $type, $size) = split(' ', $line);
+sub cat_file {
+ my ($self, $oid, $sizeref) = @_;
+ my $result = [];
+ cat_async($self, $oid, \&_cat_file_cb, $result);
+ cat_async_wait($self);
+ $$sizeref = $result->[1] if $sizeref;
+ $result->[0];
+}
- # Future versions of git.git may show 'ambiguous', but for now,
+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->{chk_rbuf}) // \(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/
- return if $type eq 'missing' || $type eq 'ambiguous';
-
if ($hex eq 'dangling' || $hex eq 'notdir' || $hex eq 'loop') {
- $size = $type + length("\n");
- my $r = read($self->{in_c}, my $buf, $size);
- defined($r) or fail($self, "read failed: $!");
- return;
+ my $ret = my_read($self->{in_c}, $rbuf, $type + 1);
+ $self->fail(defined($ret) ? 'read EOF' : "read: $!") if !$ret;
+ }
+ $self->{chk_rbuf} = $rbuf if $$rbuf ne '';
+ eval { $cb->($hex, $type, $size, $arg, $self) };
+ warn "E: check($req) $@\n" if $@;
+}
+
+sub check_async_wait ($) {
+ my ($self) = @_;
+ my $inflight_c = $self->{inflight_c} or return;
+ while (scalar(@$inflight_c)) {
+ check_async_step($self, $inflight_c);
}
+}
+sub check_async_begin ($) {
+ my ($self) = @_;
+ cleanup($self) if alternates_changed($self);
+ _bidi_pipe($self, qw(--batch-check in_c out_c pid_c err_c));
+ die 'BUG: already in async check' if $self->{inflight_c};
+ $self->{inflight_c} = [];
+}
+
+sub check_async ($$$$) {
+ my ($self, $oid, $cb, $arg) = @_;
+ my $inflight_c = $self->{inflight_c} // check_async_begin($self);
+ while (scalar(@$inflight_c) >= MAX_INFLIGHT) {
+ check_async_step($self, $inflight_c);
+ }
+ print { $self->{out_c} } $oid, "\n" or $self->fail("write error: $!");
+ push(@$inflight_c, $oid, $cb, $arg);
+}
+
+sub _check_cb { # check_async callback
+ my ($hex, $type, $size, $result) = @_;
+ @$result = ($hex, $type, $size);
+}
+
+sub check {
+ my ($self, $oid) = @_;
+ my $result = [];
+ check_async($self, $oid, \&_check_cb, $result);
+ check_async_wait($self);
+ my ($hex, $type, $size) = @$result;
+
+ # Future versions of git.git may show 'ambiguous', but for now,
+ # we must handle 'dangling' below (and maybe some other oddball
+ # stuff):
+ # https://public-inbox.org/git/20190118033845.s2vlrb3wd3m2jfzu@dcvr/T/
+ return if $type eq 'missing' || $type eq 'ambiguous';
+ return if $hex eq 'dangling' || $hex eq 'notdir' || $hex eq 'loop';
($hex, $type, $size);
}
sub _destroy {
- my ($self, $in, $out, $pid) = @_;
+ my ($self, $rbuf, $in, $out, $pid, $err) = @_;
+ delete @$self{($rbuf, $in, $out)};
+ delete $self->{$err} if $err; # `err_c'
+
+ # GitAsyncCat::event_step may delete {pid}
my $p = delete $self->{$pid} or return;
- delete @$self{($in, $out)};
- waitpid $p, 0;
+ dwaitpid($p) if $$ == $self->{"$pid.owner"};
}
-sub fail {
- my ($self, $msg) = @_;
+sub cat_async_abort ($) {
+ my ($self) = @_;
+ if (my $inflight = $self->{inflight}) {
+ while (@$inflight) {
+ my ($req, $cb, $arg) = splice(@$inflight, 0, 3);
+ $req =~ s/ .*//; # drop git_dir for Gcf2Client
+ eval { $cb->(undef, $req, undef, undef, $arg) };
+ warn "E: $req: $@ (in abort)\n" if $@;
+ }
+ delete $self->{cat_rbuf};
+ delete $self->{inflight};
+ }
cleanup($self);
- die $msg;
+}
+
+sub fail { # may be augmented in subclasses
+ my ($self, $msg) = @_;
+ cat_async_abort($self);
+ croak(ref($self) . ' ' . ($self->{git_dir} // '') . ": $msg");
}
sub popen {
sub qx {
my ($self, @cmd) = @_;
my $fh = $self->popen(@cmd);
- defined $fh or return;
- local $/ = "\n";
- return <$fh> if wantarray;
- local $/;
- <$fh>
+ local $/ = wantarray ? "\n" : undef;
+ <$fh>;
+}
+
+# check_async and cat_async may trigger the other, so ensure they're
+# both completely done by using this:
+sub async_wait_all ($) {
+ my ($self) = @_;
+ while (scalar(@{$self->{inflight_c} // []}) ||
+ scalar(@{$self->{inflight} // []})) {
+ $self->check_async_wait;
+ $self->cat_async_wait;
+ }
}
# returns true if there are pending "git cat-file" processes
sub cleanup {
my ($self) = @_;
- _destroy($self, qw(in out pid));
- _destroy($self, qw(in_c out_c pid_c));
+ local $in_cleanup = 1;
+ delete $self->{async_cat};
+ async_wait_all($self);
+ delete $self->{inflight};
+ delete $self->{inflight_c};
+ _destroy($self, qw(cat_rbuf in out pid));
+ _destroy($self, qw(chk_rbuf in_c out_c pid_c err_c));
!!($self->{pid} || $self->{pid_c});
}
+
# assuming a well-maintained repo, this should be a somewhat
# accurate estimation of its size
# TODO: show this in the WWW UI as a hint to potential cloners
my ($self) = @_;
my $n = 0;
my $pack_dir = git_path($self, 'objects/pack');
- foreach my $p (glob("$pack_dir/*.pack")) {
+ foreach my $p (bsd_glob("$pack_dir/*.pack", GLOB_NOSORT)) {
$n += -s $p;
}
$n
wantarray ? ($ret) : $ret;
}
-# show the blob URL for cgit/gitweb/whatever
-sub src_blob_url {
- my ($self, $oid) = @_;
- # blob_url_format = "https://example.com/foo.git/blob/%s"
- if (my $bfu = $self->{blob_url_format}) {
- return map { sprintf($_, $oid) } @$bfu if wantarray;
- return sprintf($bfu->[0], $oid);
- }
- local_nick($self);
-}
-
sub host_prefix_url ($$) {
my ($env, $url) = @_;
return $url if index($url, '//') >= 0;
my $scheme = $env->{'psgi.url_scheme'};
- my $host_port = $env->{HTTP_HOST} ||
+ my $host_port = $env->{HTTP_HOST} //
"$env->{SERVER_NAME}:$env->{SERVER_PORT}";
"$scheme://$host_port". ($env->{SCRIPT_NAME} || '/') . $url;
}
local_nick($self);
}
-sub commit_title ($$) {
- my ($self, $oid) = @_; # PublicInbox::Git, $sha1hex
- my $buf = cat_file($self, $oid) or return;
- utf8::decode($$buf);
- ($$buf =~ /\r?\n\r?\n([^\r\n]+)\r?\n?/)[0]
+sub cat_async_begin {
+ my ($self) = @_;
+ cleanup($self) if $self->alternates_changed;
+ $self->batch_prepare;
+ die 'BUG: already in async' if $self->{inflight};
+ $self->{inflight} = [];
+}
+
+sub cat_async ($$$;$) {
+ my ($self, $oid, $cb, $arg) = @_;
+ my $inflight = $self->{inflight} // cat_async_begin($self);
+ while (scalar(@$inflight) >= MAX_INFLIGHT) {
+ cat_async_step($self, $inflight);
+ }
+ print { $self->{out} } $oid, "\n" or $self->fail("write error: $!");
+ push(@$inflight, $oid, $cb, $arg);
+}
+
+sub async_prefetch {
+ my ($self, $oid, $cb, $arg) = @_;
+ if (my $inflight = $self->{inflight}) {
+ # we could use MAX_INFLIGHT here w/o the halving,
+ # but lets not allow one client to monopolize a git process
+ if (scalar(@$inflight) < int(MAX_INFLIGHT/2)) {
+ print { $self->{out} } $oid, "\n" or
+ $self->fail("write error: $!");
+ return push(@$inflight, $oid, $cb, $arg);
+ }
+ }
+ undef;
+}
+
+sub extract_cmt_time {
+ my ($bref, undef, undef, undef, $modified) = @_;
+
+ if ($$bref =~ /^committer .*?> ([0-9]+) [\+\-]?[0-9]+/sm) {
+ my $cmt_time = $1 + 0;
+ $$modified = $cmt_time if $cmt_time > $$modified;
+ }
}
# returns the modified time of a git repo, same as the "modified" field
my ($self) = @_;
my $modified = 0;
my $fh = popen($self, qw(rev-parse --branches));
- defined $fh or return $modified;
local $/ = "\n";
- foreach my $oid (<$fh>) {
+ while (my $oid = <$fh>) {
chomp $oid;
- my $buf = cat_file($self, $oid) or next;
- $$buf =~ /^committer .*?> (\d+) [\+\-]?\d+/sm or next;
- my $cmt_time = $1;
- $modified = $cmt_time if $cmt_time > $modified;
+ cat_async($self, $oid, \&extract_cmt_time, \$modified);
}
+ cat_async_wait($self);
$modified || time;
}
+# for grokmirror, which doesn't read gitweb.description
+# templates/hooks--update.sample and git-multimail in git.git
+# only match "Unnamed repository", not the full contents of
+# templates/this--description in git.git
+sub manifest_entry {
+ my ($self, $epoch, $default_desc) = @_;
+ my ($fh, $pid) = $self->popen('show-ref');
+ my $dig = Digest::SHA->new(1);
+ while (read($fh, my $buf, 65536)) {
+ $dig->add($buf);
+ }
+ close $fh;
+ waitpid($pid, 0);
+ return if $?; # empty, uninitialized git repo
+ my $git_dir = $self->{git_dir};
+ my $ent = {
+ fingerprint => $dig->hexdigest,
+ reference => undef,
+ modified => modified($self),
+ };
+ chomp(my $owner = $self->qx('config', 'gitweb.owner'));
+ utf8::decode($owner);
+ $ent->{owner} = $owner eq '' ? undef : $owner;
+ my $desc = '';
+ if (open($fh, '<', "$git_dir/description")) {
+ local $/ = "\n";
+ chomp($desc = <$fh>);
+ utf8::decode($desc);
+ }
+ $desc = 'Unnamed repository' if $desc eq '';
+ if (defined $epoch && $desc =~ /\AUnnamed repository/) {
+ $desc = "$default_desc [epoch $epoch]";
+ }
+ $ent->{description} = $desc;
+ if (open($fh, '<', "$git_dir/objects/info/alternates")) {
+ # n.b.: GitPython doesn't seem to handle comments or C-quoted
+ # strings like native git does; and we don't for now, either.
+ local $/ = "\n";
+ chomp(my @alt = <$fh>);
+
+ # grokmirror only supports 1 alternate for "reference",
+ if (scalar(@alt) == 1) {
+ my $objdir = "$git_dir/objects";
+ my $ref = File::Spec->rel2abs($alt[0], $objdir);
+ $ref =~ s!/[^/]+/?\z!!; # basename
+ $ent->{reference} = $ref;
+ }
+ }
+ $ent;
+}
+
1;
__END__
=pod