lix/perl/lib/Nix/CopyClosure.pm
2014-08-20 18:03:48 +02:00

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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, $sign, $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), $sign, @missing);
readInt($from) == 1 or die "remote machine $sshHost failed to import closure\n";
}
sub copyTo {
my ($sshHost, $sshOpts, $storePaths, $includeOutputs, $dryRun, $sign, $useSubstitutes) = @_;
# Connect to the remote host.
my ($from, $to);
eval {
($from, $to) = connectToRemoteNix($sshHost, $sshOpts);
};
if ($@) {
chomp $@;
warn "$@; falling back to old closure copying method\n";
return oldCopyTo(@_);
}
copyToOpen($from, $to, $sshHost, $storePaths, $includeOutputs, $dryRun, $sign, $useSubstitutes);
close $to;
}
# For backwards compatibility with Nix <= 1.7. Will be removed
# eventually.
sub oldCopyTo {
my ($sshHost, $sshOpts, $storePaths, $includeOutputs, $dryRun, $sign, $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} @globalSshOpts nix-store -r --ignore-unknown @closure";
# Ignore exit status because this is just an optimisation.
}
# 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} @globalSshOpts 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;
}
# Export the store paths and import them on the remote machine.
if (scalar @missing > 0) {
print STDERR "copying ", scalar @missing, " missing paths to $sshHost...\n";
print STDERR "@missing\n";
unless ($dryRun) {
open SSH, "| ssh $sshHost @{$sshOpts} @globalSshOpts '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;