about summary refs log tree commit diff
path: root/perl/lib/Nix/CopyClosure.pm
blob: cba365aa1745e6ed74e39b5898a2e6bb04a93d96 (plain) (blame)
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
package Nix::CopyClosure;

use strict;
use Nix::Config;
use Nix::Store;
use List::Util qw(sum);
use IPC::Open2;


sub readInt {
    my ($from) = @_;
    my $resp;
    sysread($from, $resp, 8) == 8 or die "did not receive valid reply from remote host\n";
    return unpack("L<x4", $resp);
}


sub copyTo {
    my ($sshHost, $sshOpts, $storePaths, $compressor, $decompressor,
        $includeOutputs, $dryRun, $sign, $progressViewer, $useSubstitutes) = @_;

    # Get the closure of this path.
    my @closure = reverse(topoSortPaths(computeFSClosure(0, $includeOutputs,
        map { followLinksToStorePath $_ } @{$storePaths})));

    # Optionally use substitutes on the remote host.
    if (!$dryRun && $useSubstitutes) {
        system "ssh $sshHost @{$sshOpts} nix-store -r --ignore-unknown @closure";
        # Ignore exit status because this is just an optimisation.
    }

    # Start ‘nix-store --serve’ on the remote host.
    my ($from, $to);
    my $pid = open2($from, $to, "ssh $sshHost @{$sshOpts} nix-store --serve --write");

    # Do the handshake.
    eval {
        my $SERVE_MAGIC_1 = 0x390c9deb; # FIXME
        my $clientVersion = 0x200;
        syswrite($to, pack("L<x4L<x4", $SERVE_MAGIC_1, $clientVersion)) or die;
        die "did not get valid handshake from remote host\n" if readInt($from) != 0x5452eecb;
        my $serverVersion = readInt($from);
        die "unsupported server version\n" if $serverVersion < 0x200 || $serverVersion >= 0x300;
    };
    if ($@) {
        chomp $@;
        warn "$@; falling back to old closure copying method\n";
        return oldCopyTo(\@closure, @_);
    }

    # Send the "query valid paths" command with the "lock" option
    # enabled. This prevens a race where the remote host
    # garbage-collect paths that are already there.
    my $req = pack("L<x4L<x4L<x4", 1, 1, scalar @closure);
    for my $s (@closure) {
        my $len = length $s;
        $req .= pack("L<x4", $len);
        $req .= $s;
        $req .= "\000" x (8 - $len % 8) if $len % 8;
    }
    syswrite($to, $req) or die;

    # Get back the set of paths that are already valid on the remote host.
    my %present;
    my $n = readInt($from);
    while ($n--) {
        my $len = readInt($from);
        my $s;
        sysread($from, $s, $len) == $len or die;
        $present{$s} = 1;
        sysread($from, $s, 8 - $len % 8) if $len % 8; # skip padding
    }

    my @missing = grep { !$present{$_} } @closure;
    return if !@missing;

    # Send the "import paths" command.
    syswrite($to, pack("L<x4", 4)) or die;
    exportPaths(fileno($to), $sign, @missing);
    readInt($from) == 1 or die;

    # Shut down the server process.
    close $to;
    waitpid $pid, 0;
}


# For backwards compatibility with Nix <= 1.7. Will be removed
# eventually.
sub oldCopyTo {
    my ($closure, $sshHost, $sshOpts, $storePaths, $compressor, $decompressor,
        $includeOutputs, $dryRun, $sign, $progressViewer, $useSubstitutes) = @_;

    # Ask the remote host which paths are invalid.  Because of limits
    # to the command line length, do this in chunks.  Eventually,
    # we'll want to use ‘--from-stdin’, but we can't rely on the
    # target having this option yet.
    my @missing;
    my $missingSize = 0;
    while (scalar(@$closure) > 0) {
        my @ps = splice(@$closure, 0, 1500);
        open(READ, "set -f; ssh $sshHost @{$sshOpts} nix-store --check-validity --print-invalid @ps|");
        while (<READ>) {
            chomp;
            push @missing, $_;
            my ($deriver, $narHash, $time, $narSize, $refs) = queryPathInfo($_, 1);
            $missingSize += $narSize;
        }
        close READ or die;
    }

    $compressor = "$compressor |" if $compressor ne "";
    $decompressor = "$decompressor |" if $decompressor ne "";
    $progressViewer = "$progressViewer -s $missingSize |" if $progressViewer ne "";

    # Export the store paths and import them on the remote machine.
    if (scalar @missing > 0) {
        print STDERR "copying ", scalar @missing, " missing paths to ‘$sshHost’...\n";
        unless ($dryRun) {
            open SSH, "| $progressViewer $compressor ssh $sshHost @{$sshOpts} '$decompressor nix-store --import' > /dev/null" or die;
            exportPaths(fileno(SSH), $sign, @missing);
            close SSH or die "copying store paths to remote machine `$sshHost' failed: $?";
        }
    }
}


1;