-# Copyright (C) 2014-2020 all contributors <meta@public-inbox.org>
+# Copyright (C) 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.
use parent qw(Exporter);
use POSIX ();
use IO::Handle; # ->autoflush
-use Errno qw(EINTR);
+use Errno qw(EINTR EAGAIN ENOENT);
use File::Glob qw(bsd_glob GLOB_NOSORT);
use File::Spec ();
use Time::HiRes qw(stat);
-use PublicInbox::Spawn qw(popen_rd);
+use PublicInbox::Spawn qw(popen_rd spawn);
use PublicInbox::Tmpfile;
-use Carp qw(croak);
+use IO::Poll qw(POLLIN);
+use Carp qw(croak carp);
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
+our $async_warn; # true in read-only daemons
-use constant MAX_INFLIGHT =>
- (($^O eq 'linux' ? 4096 : POSIX::_POSIX_PIPE_BUF()) * 3)
- /
+use constant MAX_INFLIGHT => (POSIX::PIPE_BUF * 3) /
65; # SHA-256 hex size + "\n" in preparation for git using non-SHA1
my %GIT_ESC = (
sub git_unquote ($) {
return $_[0] unless ($_[0] =~ /\A"(.*)"\z/);
$_[0] = $1;
- $_[0] =~ s/\\([\\"abfnrtv])/$GIT_ESC{$1}/g;
- $_[0] =~ s/\\([0-7]{1,3})/chr(oct($1))/ge;
+ $_[0] =~ s!\\([\\"abfnrtv]|[0-3][0-7]{2})!$GIT_ESC{$1}//chr(oct($1))!ge;
$_[0];
}
sub git_quote ($) {
if ($_[0] =~ s/([\\"\a\b\f\n\r\t\013]|[^[:print:]])/
- '\\'.($ESC_GIT{$1}||sprintf("%0o",ord($1)))/egs) {
+ '\\'.($ESC_GIT{$1}||sprintf("%03o",ord($1)))/egs) {
return qq{"$_[0]"};
}
$_[0];
sub new {
my ($class, $git_dir) = @_;
+ $git_dir =~ tr!/!/!s;
+ $git_dir =~ s!/*\z!!s;
# may contain {-tmp} field for File::Temp::Dir
bless { git_dir => $git_dir, alt_st => '', -git_path => {} }, $class
}
sub git_path ($$) {
my ($self, $path) = @_;
- $self->{-git_path}->{$path} ||= do {
+ $self->{-git_path}->{$path} //= do {
local $/ = "\n";
chomp(my $str = $self->qx(qw(rev-parse --git-path), $path));
$self->{alt_st} = $st; # always a true value
}
+sub object_format {
+ $_[0]->{object_format} //= do {
+ my $fmt = $_[0]->qx(qw(config extensions.objectformat));
+ $fmt eq "sha256\n" ? \'sha256' : \undef;
+ }
+}
+
sub last_check_err {
my ($self) = @_;
my $fh = $self->{err_c} or return;
- sysseek($fh, 0, 0) or fail($self, "sysseek failed: $!");
+ sysseek($fh, 0, 0) or $self->fail("sysseek failed: $!");
defined(sysread($fh, my $buf, -s $fh)) or
- fail($self, "sysread failed: $!");
+ $self->fail("sysread failed: $!");
$buf;
}
if ($self->{$pid}) {
if (defined $err) { # "err_c"
my $fh = $self->{$err};
- sysseek($fh, 0, 0) or fail($self, "sysseek failed: $!");
- truncate($fh, 0) or fail($self, "truncate failed: $!");
+ sysseek($fh, 0, 0) or $self->fail("sysseek failed: $!");
+ truncate($fh, 0) or $self->fail("truncate failed: $!");
}
return;
}
- my ($out_r, $out_w);
- pipe($out_r, $out_w) or fail($self, "pipe failed: $!");
- my @cmd = (qw(git), "--git-dir=$self->{git_dir}",
+ pipe(my ($out_r, $out_w)) or $self->fail("pipe failed: $!");
+ my $rdr = { 0 => $out_r, pgid => 0 };
+ my $gd = $self->{git_dir};
+ if ($gd =~ s!/([^/]+/[^/]+)\z!/!) {
+ $rdr->{-C} = $gd;
+ $gd = $1;
+ }
+ my @cmd = (qw(git), "--git-dir=$gd",
qw(-c core.abbrev=40 cat-file), $batch);
- my $redir = { 0 => $out_r };
if ($err) {
my $id = "git.$self->{git_dir}$batch.err";
- my $fh = tmpfile($id) or fail($self, "tmpfile($id): $!");
+ my $fh = tmpfile($id) or $self->fail("tmpfile($id): $!");
$self->{$err} = $fh;
- $redir->{2} = $fh;
+ $rdr->{2} = $fh;
}
- my ($in_r, $p) = popen_rd(\@cmd, undef, $redir);
+ my ($in_r, $p) = popen_rd(\@cmd, undef, $rdr);
$self->{$pid} = $p;
+ $self->{"$pid.owner"} = $$;
$out_w->autoflush(1);
if ($^O eq 'linux') { # 1031: F_SETPIPE_SZ
fcntl($out_w, 1031, 4096);
$self->{$in} = $in_r;
}
+sub poll_in ($) { IO::Poll::_poll($RDTIMEO, fileno($_[0]), my $ev = POLLIN) }
+
sub my_read ($$$) {
my ($fh, $rbuf, $len) = @_;
my $left = $len - length($$rbuf);
$r = sysread($fh, $$rbuf, $PIPE_BUFSIZ, length($$rbuf));
if ($r) {
$left -= $r;
+ } elsif (defined($r)) { # EOF
+ return 0;
} else {
- next if (!defined($r) && $! == EINTR);
- return $r;
+ next if ($! == EAGAIN and poll_in($fh));
+ next if $! == EINTR; # may be set by sysread or poll_in
+ return; # unrecoverable error
}
}
- \substr($$rbuf, 0, $len, '');
+ my $no_pad = substr($$rbuf, 0, $len, '');
+ \$no_pad;
}
sub my_readline ($$) {
if ((my $n = index($$rbuf, "\n")) >= 0) {
return substr($$rbuf, 0, $n + 1, '');
}
- my $r = sysread($fh, $$rbuf, $PIPE_BUFSIZ, length($$rbuf));
- next if $r || (!defined($r) && $! == EINTR);
- return defined($r) ? '' : undef; # EOF or error
+ my $r = sysread($fh, $$rbuf, $PIPE_BUFSIZ, length($$rbuf))
+ and next;
+
+ # return whatever's left on EOF
+ return substr($$rbuf, 0, length($$rbuf)+1, '') if defined($r);
+
+ next if ($! == EAGAIN and poll_in($fh));
+ next if $! == EINTR; # may be set by sysread or poll_in
+ return; # unrecoverable error
}
}
-sub cat_async_retry ($$$$$) {
- my ($self, $inflight, $req, $cb, $arg) = @_;
+sub cat_async_retry ($$) {
+ my ($self, $inflight) = @_;
# {inflight} may be non-existent, but if it isn't we delete it
# here to prevent cleanup() from waiting:
$self->{inflight} = $inflight;
batch_prepare($self);
- my $buf = "$req\n";
+ my $buf = '';
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
+ print { $self->{out} } $buf or $self->fail("write error: $!");
+ my $req = shift @$inflight;
+ unshift(@$inflight, \$req); # \$ref to indicate retried
cat_async_step($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 $new = '');
+ my ($req, $cb, $arg) = @$inflight[0, 1, 2];
+ my $rbuf = delete($self->{rbuf}) // \(my $new = '');
my ($bref, $oid, $type, $size);
my $head = my_readline($self->{in}, $rbuf);
# ->fail may be called via Gcf2Client.pm
# ref($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, $arg);
+ return cat_async_retry($self, $inflight);
}
$type = 'missing';
$oid = ref($req) ? $$req : $req if $oid eq '';
} else {
- $self->fail("Unexpected result from async git cat-file: $head");
+ my $err = $! ? " ($!)" : '';
+ $self->fail("bad result from async cat-file: $head$err");
}
- $self->{cat_rbuf} = $rbuf if $$rbuf ne '';
+ $self->{rbuf} = $rbuf if $$rbuf ne '';
+ splice(@$inflight, 0, 3); # don't retry $cb on ->fail
eval { $cb->($bref, $oid, $type, $size, $arg) };
- warn "E: $oid: $@\n" if $@;
+ async_err($self, $req, $oid, $@, 'cat') if $@;
}
sub cat_async_wait ($) {
}
sub _cat_file_cb {
- my ($bref, undef, undef, $size, $result) = @_;
- @$result = ($bref, $size);
+ my ($bref, $oid, $type, $size, $result) = @_;
+ @$result = ($bref, $oid, $type, $size);
}
sub cat_file {
- my ($self, $oid, $sizeref) = @_;
+ my ($self, $oid) = @_;
my $result = [];
cat_async($self, $oid, \&_cat_file_cb, $result);
cat_async_wait($self);
- $$sizeref = $result->[1] if $sizeref;
- $result->[0];
+ wantarray ? @$result : $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->{chk_rbuf}) // \(my $new = '');
+ my ($req, $cb, $arg) = @$inflight_c[0, 1, 2];
+ my $rbuf = delete($self->{rbuf_c}) // \(my $new = '');
chomp(my $line = my_readline($self->{in_c}, $rbuf));
my ($hex, $type, $size) = split(/ /, $line);
# https://public-inbox.org/git/20190118033845.s2vlrb3wd3m2jfzu@dcvr/T/
if ($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;
+ $self->fail(defined($ret) ? 'read EOF' : "read: $!") if !$ret;
}
- $self->{chk_rbuf} = $rbuf if $$rbuf ne '';
+ $self->{rbuf_c} = $rbuf if $$rbuf ne '';
+ splice(@$inflight_c, 0, 3); # don't retry $cb on ->fail
eval { $cb->($hex, $type, $size, $arg, $self) };
- warn "E: check($req) $@\n" if $@;
+ async_err($self, $req, $hex, $@, 'check') if $@;
}
sub check_async_wait ($) {
while (scalar(@$inflight_c) >= MAX_INFLIGHT) {
check_async_step($self, $inflight_c);
}
- print { $self->{out_c} } $oid, "\n" or fail($self, "write error: $!");
+ print { $self->{out_c} } $oid, "\n" or $self->fail("write error: $!");
push(@$inflight_c, $oid, $cb, $arg);
}
# GitAsyncCat::event_step may delete {pid}
my $p = delete $self->{$pid} or return;
-
- # PublicInbox::DS may not be loaded
- eval { PublicInbox::DS::dwaitpid($p, undef, undef) };
- waitpid($p, 0) if $@; # wait synchronously if not in event loop
+ dwaitpid($p) if $$ == $self->{"$pid.owner"};
}
-sub cat_async_abort ($) {
+sub async_abort ($) {
my ($self) = @_;
- if (my $inflight = $self->{inflight}) {
- while (@$inflight) {
- my ($req, $cb, $arg) = splice(@$inflight, 0, 3);
- $req =~ s/ .*//; # drop git_dir for Gcf2Client
- eval { $cb->(undef, $req, undef, undef, $arg) };
- warn "E: $req: $@ (in abort)\n" if $@;
+ while (scalar(@{$self->{inflight_c} // []}) ||
+ scalar(@{$self->{inflight} // []})) {
+ for my $c ('', '_c') {
+ my $q = $self->{"inflight$c"} or next;
+ while (@$q) {
+ my ($req, $cb, $arg) = splice(@$q, 0, 3);
+ $req = $$req if ref($req);
+ $req =~ s/ .*//; # drop git_dir for Gcf2Client
+ eval { $cb->(undef, $req, undef, undef, $arg) };
+ warn "E: (in abort) $req: $@" if $@;
+ }
+ delete $self->{"inflight$c"};
+ delete $self->{"rbuf$c"};
}
- delete $self->{cat_rbuf};
- delete $self->{inflight};
}
cleanup($self);
}
-sub fail {
+sub fail { # may be augmented in subclasses
my ($self, $msg) = @_;
- cat_async_abort($self);
+ async_abort($self);
croak(ref($self) . ' ' . ($self->{git_dir} // '') . ": $msg");
}
+sub async_err ($$$$$) {
+ my ($self, $req, $oid, $err, $action) = @_;
+ $req = $$req if ref($req); # retried
+ my $msg = "E: $action $req ($oid): $err";
+ $async_warn ? carp($msg) : $self->fail($msg);
+}
+
+# $git->popen(qw(show f00)); # or
+# $git->popen(qw(show f00), { GIT_CONFIG => ... }, { 2 => ... });
sub popen {
- my ($self, @cmd) = @_;
- @cmd = ('git', "--git-dir=$self->{git_dir}", @cmd);
- popen_rd(\@cmd);
+ my ($self, $cmd) = splice(@_, 0, 2);
+ $cmd = [ 'git', "--git-dir=$self->{git_dir}",
+ ref($cmd) ? @$cmd : ($cmd, grep { defined && !ref } @_) ];
+ popen_rd($cmd, grep { !defined || ref } @_); # env and opt
}
+# same args as popen above
sub qx {
- my ($self, @cmd) = @_;
- my $fh = $self->popen(@cmd);
- local $/ = "\n";
- return <$fh> if wantarray;
- local $/;
- <$fh>
+ my $fh = popen(@_);
+ if (wantarray) {
+ my @ret = <$fh>;
+ close $fh; # caller should check $?
+ @ret;
+ } else {
+ local $/;
+ my $ret = <$fh>;
+ close $fh; # caller should check $?
+ $ret;
+ }
+}
+
+sub date_parse {
+ my $self = shift;
+ map {
+ substr($_, length('--max-age='), -1)
+ } $self->qx('rev-parse', map { "--since=$_" } @_);
}
# check_async and cat_async may trigger the other, so ensure they're
my ($self) = @_;
while (scalar(@{$self->{inflight_c} // []}) ||
scalar(@{$self->{inflight} // []})) {
- $self->check_async_wait;
- $self->cat_async_wait;
+ check_async_wait($self);
+ cat_async_wait($self);
}
}
# returns true if there are pending "git cat-file" processes
sub cleanup {
- my ($self) = @_;
+ my ($self, $lazy) = @_;
+ return 1 if $lazy && (scalar(@{$self->{inflight_c} // []}) ||
+ scalar(@{$self->{inflight} // []}));
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} || $self->{pid_c});
+ _destroy($self, qw(rbuf in out pid));
+ _destroy($self, qw(rbuf_c in_c out_c pid_c err_c));
+ undef;
}
-
# assuming a well-maintained repo, this should be a somewhat
# accurate estimation of its size
# TODO: show this in the WWW UI as a hint to potential cloners
sub DESTROY { cleanup(@_) }
sub local_nick ($) {
- my ($self) = @_;
- my $ret = '???';
# don't show full FS path, basename should be OK:
- if ($self->{git_dir} =~ m!/([^/]+)(?:/\.git)?\z!) {
- $ret = "/path/to/$1";
- }
- wantarray ? ($ret) : $ret;
+ $_[0]->{git_dir} =~ m!/([^/]+?)(?:/*\.git/*)?\z! ? "$1.git" : '???';
}
sub host_prefix_url ($$) {
if (my $urls = $self->{cgit_url}) {
return map { host_prefix_url($env, $_) } @$urls;
}
- local_nick($self);
+ (local_nick($self));
}
sub cat_async_begin {
while (scalar(@$inflight) >= MAX_INFLIGHT) {
cat_async_step($self, $inflight);
}
- print { $self->{out} } $oid, "\n" or fail($self, "write error: $!");
+ print { $self->{out} } $oid, "\n" or $self->fail("write error: $!");
push(@$inflight, $oid, $cb, $arg);
}
-sub async_prefetch {
- my ($self, $oid, $cb, $arg) = @_;
- if (my $inflight = $self->{inflight}) {
- # we could use MAX_INFLIGHT here w/o the halving,
- # but lets not allow one client to monopolize a git process
- if (scalar(@$inflight) < int(MAX_INFLIGHT/2)) {
- print { $self->{out} } $oid, "\n" or
- fail($self, "write error: $!");
- return push(@$inflight, $oid, $cb, $arg);
- }
- }
- undef;
-}
-
-sub extract_cmt_time {
- my ($bref, undef, undef, undef, $modified) = @_;
-
- if ($$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
# of a grokmirror manifest
sub modified ($) {
- my ($self) = @_;
- my $modified = 0;
- my $fh = popen($self, qw(rev-parse --branches));
- local $/ = "\n";
- while (my $oid = <$fh>) {
- chomp $oid;
- cat_async($self, $oid, \&extract_cmt_time, \$modified);
- }
- cat_async_wait($self);
- $modified || time;
+ # committerdate:unix is git 2.9.4+ (2017-05-05), so using raw instead
+ my $fh = popen($_[0], qw[for-each-ref --sort=-committerdate
+ --format=%(committerdate:raw) --count=1]);
+ (split(/ /, <$fh> // time))[0] + 0; # integerize for JSON
}
# for grokmirror, which doesn't read gitweb.description
# templates/this--description in git.git
sub manifest_entry {
my ($self, $epoch, $default_desc) = @_;
- my ($fh, $pid) = $self->popen('show-ref');
+ my $fh = $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
+ close $fh or return; # empty, uninitialized git repo
+ undef $fh; # for open, below
my $git_dir = $self->{git_dir};
my $ent = {
fingerprint => $dig->hexdigest,
$ent;
}
+# returns true if there are pending cat-file processes
+sub cleanup_if_unlinked {
+ my ($self) = @_;
+ return cleanup($self, 1) if $^O ne 'linux';
+ # Linux-specific /proc/$PID/maps access
+ # TODO: support this inside git.git
+ my $ret = 0;
+ for my $fld (qw(pid pid_c)) {
+ my $pid = $self->{$fld} // next;
+ open my $fh, '<', "/proc/$pid/maps" or return cleanup($self, 1);
+ while (<$fh>) {
+ # n.b. we do not restart for unlinked multi-pack-index
+ # since it's not too huge, and the startup cost may
+ # be higher.
+ /\.(?:idx|pack) \(deleted\)$/ and
+ return cleanup($self, 1);
+ }
+ ++$ret;
+ }
+ $ret;
+}
+
1;
__END__
=pod