reformat code for snapshot tree into GuestHelpers

qm/pct listsnapshot lack feature parity w.r.t. showing snapshots in a
tree ordered by the date. by moving this code into GuestHelpers, it can
be shared.

Signed-off-by: Oguz Bektas <o.bektas@proxmox.com>

diff --git a/PVE/GuestHelpers.pm b/PVE/GuestHelpers.pm
index ebe278111b5aee5a10023697f96cb9682ceddd08..64e26c96652f260d2adc76412e9c21792af299e6 100644 (file)
--- a/PVE/GuestHelpers.pm
+++ b/PVE/GuestHelpers.pm
@@ -6,6 +6,8 @@ use warnings;
 use PVE::Tools;
 use PVE::Storage;
 
+use POSIX qw(strftime);
+
 # We use a separate lock to block migration while a replication job
 # is running.
 
@@ -60,4 +62,56 @@ sub exec_hookscript {
     }
 }
 
+sub snapshot_tree {
+    my ($res) = @_;
+
+    my $snapshots = { map { $_->{name} => $_ } @$res };
+
+    my @roots;
+    foreach my $e (@$res) {
+       my $parent;
+       if (($parent = $e->{parent}) && defined $snapshots->{$parent}) {
+           push @{$snapshots->{$parent}->{children}}, $e->{name};
+       } else {
+           push @roots, $e->{name};
+       }
+    }
+
+    # sort the elements by snaptime - with "current" (no snaptime) highest
+    my $snaptimesort = sub {
+       return +1 if !defined $snapshots->{$a}->{snaptime};
+       return -1 if !defined $snapshots->{$b}->{snaptime};
+       return $snapshots->{$a}->{snaptime} <=> $snapshots->{$b}->{snaptime};
+    };
+
+    # recursion function for displaying the tree
+    my $snapshottree;
+    $snapshottree = sub {
+       my ($prefix, $root, $snapshots) = @_;
+       my $e = $snapshots->{$root};
+
+       my $description = $e->{description} || 'no-description';
+       ($description) = $description =~ m/(.*)$/m;
+
+       my $timestring = "";
+       if (defined $e->{snaptime}) {
+           $timestring = strftime("%F %H:%M:%S", localtime($e->{snaptime}));
+       }
+
+       my $len = 30 - length($prefix); # for aligning the description
+       printf("%s %-${len}s %-23s %s\n", $prefix, $root, $timestring, $description);
+
+       if ($e->{children}) {
+           $prefix = "    $prefix";
+           foreach my $child (sort $snaptimesort @{$e->{children}}) {
+               $snapshottree->($prefix, $child, $snapshots);
+           }
+       }
+    };
+
+    foreach my $root (sort $snaptimesort @roots) {
+       $snapshottree->('`->', $root, $snapshots);
+    }
+}
+
 1;