nix-super/scripts/copy-from-other-stores.pl.in
Eelco Dolstra 3c92ea399d * Make nix-env --dry-run print the paths to be substituted correctly
again.  (After the previous substituter mechanism refactoring I
  didn't update the code that obtains the references of substitutable
  paths.)  This required some refactoring: the substituter programs
  are now kept running and receive/respond to info requests via
  stdin/stdout.
2008-08-02 12:54:35 +00:00

94 lines
2.7 KiB
Perl

#! @perl@ -w
use strict;
use File::Basename;
use IO::Handle;
STDOUT->autoflush(1);
my @remoteStoresAll = split ':', ($ENV{"NIX_OTHER_STORES"} or "");
my @remoteStores;
foreach my $dir (@remoteStoresAll) {
push @remoteStores, glob($dir);
}
sub findStorePath {
my $storePath = shift;
my $storePathName = basename $storePath;
foreach my $store (@remoteStores) {
# Determine whether $storePath exists by looking for the
# existence of the info file, and if so, get store path info
# from that file. This rather breaks abstraction: we should
# be using `nix-store' for that. But right now there is no
# good way to tell nix-store to access a store mounted under a
# different location (there's $NIX_STORE, but that only works
# if the remote store is mounted under its "real" location).
my $infoFile = "$store/var/nix/db/info/$storePathName";
my $storePath2 = "$store/store/$storePathName";
if (-f $infoFile && -e $storePath2) {
return ($infoFile, $storePath2);
}
}
}
if ($ARGV[0] eq "--query") {
while (<STDIN>) {
my $cmd = $_; chomp $cmd;
if ($cmd eq "have") {
my $storePath = <STDIN>; chomp $storePath;
(my $infoFile) = findStorePath $storePath;
print STDOUT ($infoFile ? "1\n" : "0\n");
}
elsif ($cmd eq "info") {
my $storePath = <STDIN>; chomp $storePath;
(my $infoFile) = findStorePath $storePath;
if (!$infoFile) {
print "0\n";
next; # not an error
}
print "1\n";
my $deriver = "";
my @references = ();
open INFO, "<$infoFile" or die "cannot read info file $infoFile\n";
while (<INFO>) {
chomp;
/^([\w-]+): (.*)$/ or die "bad info file";
my $key = $1;
my $value = $2;
if ($key eq "Deriver") { $deriver = $value; }
elsif ($key eq "References") { @references = split ' ', $value; }
}
close INFO;
print "$deriver\n";
print scalar @references, "\n";
print "$_\n" foreach @references;
}
else { die "unknown command `$cmd'"; }
}
}
elsif ($ARGV[0] eq "--substitute") {
die unless scalar @ARGV == 2;
my $storePath = $ARGV[1];
(my $infoFile, my $sourcePath) = findStorePath $storePath;
die unless $infoFile;
print "\n*** Copying `$storePath' from `$sourcePath'\n\n";
system("@bindir@/nix-store --dump $sourcePath | @bindir@/nix-store --restore $storePath") == 0
or die "cannot copy `$sourcePath' to `$storePath'";
}
else { die; }