public-inbox.git  about / heads / tags
an "archives first" approach to mailing lists
blob 74a9e1df1d410f5de4587e59eaa3a46a641afc8e 3961 bytes (raw)
$ git show fuse3:lib/PublicInbox/MultiGit.pm	# shows this blob on the CLI

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
 
# Copyright (C) all contributors <meta@public-inbox.org>
# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>

# common git alternates + all.git||ALL.git management code
package PublicInbox::MultiGit;
use strict;
use v5.10.1;
use PublicInbox::Spawn qw(run_die popen_rd);
use PublicInbox::Import;
use File::Temp 0.19;
use List::Util qw(max);

sub new {
	my ($cls, $topdir, $all, $epfx) = @_;
	bless {
		topdir => $topdir, # inboxdir || extindex.*.topdir
		all => $all, # all.git or ALL.git
		epfx => $epfx, # "git" (inbox) or "local" (lei/store)
	}, $cls;
}

sub read_alternates {
	my ($self, $moderef, $prune) = @_;
	my $objpfx = "$self->{topdir}/$self->{all}/objects/";
	my $f = "${objpfx}info/alternates";
	my %alt; # line => score
	my %seen; # $st_dev\0$st_ino => count
	my $other = 0;
	if (open(my $fh, '<', $f)) {
		my $is_edir = defined($self->{epfx}) ?
			qr!\A\Q../../$self->{epfx}\E/([0-9]+)\.git/objects\z! :
			undef;
		$$moderef = (stat($fh))[2] & 07777;
		for my $rel (split(/^/m, do { local $/; <$fh> })) {
			chomp(my $dir = $rel);
			my $score;
			if (defined($is_edir) && $dir =~ $is_edir) {
				$score = $1 + 0;
				substr($dir, 0, 0) = $objpfx;
			} else { # absolute paths, if any (extindex)
				$score = --$other;
			}
			if (my @st = stat($dir)) {
				next if $seen{"$st[0]\0$st[1]"}++;
				$alt{$rel} = $score;
			} else {
				warn "W: stat($dir) failed: $! ($f)";
				if ($prune) {
					++$$prune;
				} else {
					$alt{$rel} = $score;
				}
			}
		}
	} elsif (!$!{ENOENT}) {
		die "E: open($f): $!";
	}
	(\%alt, \%seen);
}

sub epoch_dir { "$_[0]->{topdir}/$_[0]->{epfx}" }

sub write_alternates {
	my ($self, $mode, $alt, @new) = @_;
	my $all_dir = "$self->{topdir}/$self->{all}";
	PublicInbox::Import::init_bare($all_dir);
	my $out = join('', sort { $alt->{$b} <=> $alt->{$a} } keys %$alt);
	my $info_dir = "$all_dir/objects/info";
	my $fh = File::Temp->new(TEMPLATE => 'alt-XXXX', DIR => $info_dir);
	my $f = $fh->filename;
	print $fh $out, @new or die "print($f): $!";
	chmod($mode, $fh) or die "fchmod($f): $!";
	close $fh or die "close($f): $!";
	my $fn = "$info_dir/alternates";
	rename($f, $fn) or die "rename($f, $fn): $!";
	$fh->unlink_on_destroy(0);
}

# returns true if new epochs exist
sub merge_epochs {
	my ($self, $alt, $seen) = @_;
	my $epoch_dir = epoch_dir($self);
	if (opendir my $dh, $epoch_dir) {
		my $has_new;
		for my $bn (grep(/\A[0-9]+\.git\z/, readdir($dh))) {
			my $rel = "../../$self->{epfx}/$bn/objects\n";
			next if exists($alt->{$rel});
			if (my @st = stat("$epoch_dir/$bn/objects")) {
				next if $seen->{"$st[0]\0$st[1]"}++;
				$alt->{$rel} = substr($bn, 0, -4) + 0;
				$has_new = 1;
			} else {
				warn "E: stat($epoch_dir/$bn/objects): $!";
			}
		}
		$has_new;
	} else {
		$!{ENOENT} ? undef : die "opendir($epoch_dir): $!";
	}
}

sub fill_alternates {
	my ($self) = @_;
	my ($alt, $seen) = read_alternates($self, \(my $mode = 0644));
	merge_epochs($self, $alt, $seen) and
		write_alternates($self, $mode, $alt);
}

sub epoch_cfg_set {
	my ($self, $epoch_nr) = @_;
	my $f = epoch_dir($self)."/$epoch_nr.git/config";
	my $v = "../../$self->{all}/config";
	if (-r $f) {
		my $rd = popen_rd([qw(git config -f), $f, 'include.path']);
		chomp(my $have = <$rd> // '');
		return if $have eq $v;
	}
	run_die([qw(git config -f), $f, 'include.path', $v ]);
}

sub add_epoch {
	my ($self, $epoch_nr) = @_;
	my $git_dir = epoch_dir($self)."/$epoch_nr.git";
	my $f = "$git_dir/config";
	my $existing = -f $f;
	PublicInbox::Import::init_bare($git_dir);
	epoch_cfg_set($self, $epoch_nr) unless $existing;
	fill_alternates($self);
	$git_dir;
}

sub git_epochs  {
	my ($self) = @_;
	if (opendir(my $dh, epoch_dir($self))) {
		my @epochs = map {
			substr($_, 0, -4) + 0; # drop ".git" suffix
		} grep(/\A[0-9]+\.git\z/, readdir($dh));
		wantarray ? sort { $b <=> $a } @epochs : (max(@epochs) // 0);
	} elsif ($!{ENOENT}) {
		wantarray ? () : 0;
	} else {
		die(epoch_dir($self).": $!");
	}
}

1;

git clone https://public-inbox.org/public-inbox.git
git clone http://7fh6tueqddpjyxjmgtdiueylzoqt6pt7hec3pukyptlmohoowvhde4yd.onion/public-inbox.git