array_intersect: allow passing list of references for convenience

[pve-common.git] / src / PVE / Tools.pm

diff --git a/src/PVE/Tools.pm b/src/PVE/Tools.pm
index accf6539da94d2b5d5b6f4539310fe5c4d526c7e..676647eefb375d8d1ad00e9d06ab404baab9c906 100644 (file)
--- a/src/PVE/Tools.pm
+++ b/src/PVE/Tools.pm
@@ -1384,6 +1384,11 @@ sub parse_host_and_port {
     return; # nothing
 }
 
+sub setresuid($$$) {
+    my ($ruid, $euid, $suid) = @_;
+    return 0 == syscall(PVE::Syscall::setresuid, $ruid, $euid, $suid);
+}
+
 sub unshare($) {
     my ($flags) = @_;
     return 0 == syscall(PVE::Syscall::unshare, $flags);
@@ -1399,6 +1404,11 @@ sub syncfs($) {
     return 0 == syscall(PVE::Syscall::syncfs, $fileno);
 }
 
+sub fsync($) {
+    my ($fileno) = @_;
+    return 0 == syscall(PVE::Syscall::fsync, $fileno);
+}
+
 sub sync_mountpoint {
     my ($path) = @_;
     sysopen my $fd, $path, O_PATH or die "failed to open $path: $!\n";
@@ -1627,4 +1637,55 @@ sub get_host_arch {
     }
 }
 
+# Devices are: [ (12 bits minor) (12 bits major) (8 bits minor) ]
+sub dev_t_major($) {
+    my ($dev_t) = @_;
+    return (int($dev_t) & 0xfff00) >> 8;
+}
+
+sub dev_t_minor($) {
+    my ($dev_t) = @_;
+    $dev_t = int($dev_t);
+    return (($dev_t >> 12) & 0xfff00) | ($dev_t & 0xff);
+}
+
+# Given an array of array refs [ \[a b c], \[a b b], \[e b a] ]
+# Returns the intersection of elements as a single array [a b]
+sub array_intersect {
+    my ($arrays) = @_;
+
+    if (!ref($arrays->[0])) {
+       $arrays = [ grep { ref($_) eq 'ARRAY' } @_ ];
+    }
+
+    return [] if scalar(@$arrays) == 0;
+    return $arrays->[0] if scalar(@$arrays) == 1;
+
+    my $array_unique = sub {
+       my %seen = ();
+       return grep { ! $seen{ $_ }++ } @_;
+    };
+
+    # base idea is to get all unique members from the first array, then
+    # check the common elements with the next (uniquely made) one, only keep
+    # those. Repeat for every array and at the end we only have those left
+    # which exist in all arrays
+    my $return_arr = [ $array_unique->(@{$arrays->[0]}) ];
+    for my $i (1 .. $#$arrays) {
+       my %count = ();
+       # $return_arr is already unique, explicit at before the loop, implicit below.
+       foreach my $element (@$return_arr, $array_unique->(@{$arrays->[$i]})) {
+           $count{$element}++;
+       }
+       $return_arr = [];
+       foreach my $element (keys %count) {
+           push @$return_arr, $element if $count{$element} > 1;
+       }
+       last if scalar(@$return_arr) == 0; # empty intersection, early exit
+    }
+
+    return $return_arr;
+}
+
+
 1;