* Move root finding from `nix-collect-garbage' to `nix-store --gc'.

  This was necessary becase root finding must be done after
  acquisition of the global GC lock.

  This makes `nix-collect-garbage' obsolete; it is now just a wrapper
  around `nix-store --gc'.

* Automatically remove stale GC roots (i.e., indirect GC roots that
  point to non-existent paths).

1 files changed, 2 insertions, 83 deletions

diff --git a/scripts/nix-collect-garbage.in b/scripts/nix-collect-garbage.in
index c92737f25c..7ec9f349b1 100644
--- a/scripts/nix-collect-garbage.in
+++ b/scripts/nix-collect-garbage.in
@@ -1,83 +1,2 @@
-#! @perl@ -w
-
-use strict;
-use IPC::Open2;
-
-my $rootsDir = "@localstatedir@/nix/gcroots";
-my $storeDir = "@storedir@";
-
-my %alive;
-
-my $gcOper = "--delete";
-my $extraArgs = "";
-
-my @roots = ();
-
-
-# Parse the command line.
-for (my $i = 0; $i < scalar @ARGV; $i++) {
-    my $arg = $ARGV[$i];
-    if ($arg eq "--delete" || $arg eq "--print-live" || $arg eq "--print-dead") {
-        $gcOper = $arg;
-    }
-    elsif ($arg =~ /^-v+$/) {
-        $extraArgs = "$extraArgs $arg";
-    }
-    else { die "unknown argument `$arg'" };
-}
-
-
-# Recursively finds all symlinks to the store 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 "..";
-        my $path = $dir . "/" . $name;
-
-        if (-l $path) {
-            my $target = readlink $path
-                or die "cannot read symlink `$path': $!";
-            
-            if (substr($target, 0, length $storeDir) eq $storeDir) {
-                # We're only interested in the store-level part.
-                $target = substr($target, length $storeDir);
-                $target = "$storeDir/$target";
-                push @roots, $target;
-            }
-
-            elsif ($followSymlinks && -d $path) {
-                findRoots 0, $path;
-            }
-        }
-        
-        elsif (-d $path) {
-            findRoots $followSymlinks, $path;
-        }
-    }
-    
-}
-
-
-# Find GC roots, starting at $rootsDir.
-findRoots 1, $rootsDir;
-
-
-# Run the collector with the roots we found.
-my $pid = open2(">&1", \*WRITE, "@bindir@/nix-store --gc $gcOper $extraArgs")
-    or die "cannot run `nix-store --gc'";
-
-foreach my $root (@roots) {
-    print WRITE "$root\n";
-}
-
-close WRITE;
-
-waitpid $pid, 0;
-$? == 0 or die "`nix-store --gc' failed";
+#! @shell@ -e
+exec @bindir@/nix-store --gc "$@"