nix-super/scripts/nix-collect-garbage.in
2004-04-22 14:17:57 +00:00

100 lines
2.2 KiB
Text
Executable file

#! @perl@ -w
use strict;
use IPC::Open2;
my $rootsDir = "@localstatedir@/nix/gcroots";
my $storeDir = "@storedir@";
my %alive;
my $keepSuccessors = 1;
my $invert = 0;
my @roots = ();
# Parse the command line.
foreach my $arg (@ARGV) {
if ($arg eq "--no-successors") { $keepSuccessors = 0; }
elsif ($arg eq "--invert") { $invert = 1; }
else { die "unknown argument `$arg'" };
}
# Read all GC roots from the given file.
sub readRoots {
my $fileName = shift;
open ROOT, "<$fileName" or die "cannot open `$fileName': $!";
while (<ROOT>) {
chomp;
foreach my $root (split ' ') {
die "bad root `$root' in file `$fileName'"
unless $root =~ /^\S+$/;
push @roots, $root;
}
}
close ROOT;
}
# Recursively finds all *.gcroot files in the given directory.
sub findRoots;
sub findRoots {
my $followSymlinks = shift;
my $dir = shift;
opendir(DIR, $dir) or die "cannot open directory `$dir': $!";
my @names = readdir DIR or die "cannot read directory `$dir': $!";
closedir DIR;
foreach my $name (@names) {
next if $name eq "." || $name eq "..";
$name = $dir . "/" . $name;
if ($name =~ /.gcroot$/ && -f $name) {
readRoots $name;
}
elsif (-d $name) {
if ($followSymlinks || !-l $name) {
findRoots 0, $name;
}
}
}
}
# Find GC roots, starting at $rootsDir.
findRoots 1, $rootsDir;
# Determine all store paths reachable from the roots.
my $extraarg = "";
if ($keepSuccessors) { $extraarg = "--include-successors"; };
my $pid = open2(\*READ, \*WRITE, "@bindir@/nix-store --query --requisites $extraarg @roots")
or die "determining live paths";
close WRITE;
while (<READ>) {
chomp;
$alive{$_} = 1;
if ($invert) { print "$_\n"; };
}
close READ;
waitpid $pid, 0;
$? == 0 or die "determining live paths";
exit 0 if ($invert);
# Using that information, find all store paths *not* reachable from
# the roots.
opendir(DIR, $storeDir) or die "cannot open directory $storeDir: $!";
foreach my $name (readdir DIR) {
next if ($name eq "." || $name eq "..");
$name = "$storeDir/$name";
if (!$alive{$name}) {
print "$name\n";
}
}
closedir DIR;