nix-gh/perl/lib/Nix/CopyClosure.pm

62 lines
1.8 KiB
Perl

package Nix::CopyClosure;
use utf8;
use strict;
use Nix::Config;
use Nix::Store;
use Nix::SSH;
use List::Util qw(sum);
use IPC::Open2;
sub copyToOpen {
my ($from, $to, $sshHost, $storePaths, $includeOutputs, $dryRun, $useSubstitutes) = @_;
$useSubstitutes = 0 if $dryRun || !defined $useSubstitutes;
# Get the closure of this path.
my @closure = reverse(topoSortPaths(computeFSClosure(0, $includeOutputs,
map { followLinksToStorePath $_ } @{$storePaths})));
# Send the "query valid paths" command with the "lock" option
# enabled. This prevents a race where the remote host
# garbage-collect paths that are already there. Optionally, ask
# the remote host to substitute missing paths.
syswrite($to, pack("L<x4L<x4L<x4", 1, 1, $useSubstitutes)) or die;
writeStrings(\@closure, $to);
# Get back the set of paths that are already valid on the remote host.
my %present;
$present{$_} = 1 foreach readStrings($from);
my @missing = grep { !$present{$_} } @closure;
return if !@missing;
my $missingSize = 0;
$missingSize += (queryPathInfo($_, 1))[3] foreach @missing;
printf STDERR "copying %d missing paths (%.2f MiB) to '$sshHost'...\n",
scalar(@missing), $missingSize / (1024**2);
return if $dryRun;
# Send the "import paths" command.
syswrite($to, pack("L<x4", 4)) or die;
exportPaths(fileno($to), @missing);
readInt($from) == 1 or die "remote machine '$sshHost' failed to import closure\n";
}
sub copyTo {
my ($sshHost, $storePaths, $includeOutputs, $dryRun, $useSubstitutes) = @_;
# Connect to the remote host.
my ($from, $to) = connectToRemoteNix($sshHost, []);
copyToOpen($from, $to, $sshHost, $storePaths, $includeOutputs, $dryRun, $useSubstitutes);
close $to;
}
1;