[pve-devel] [PATCH guest-common 1/3] reformat code for snapshot tree into GuestHelpers

[Oguz Bektas]

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 at proxmox.com>
---
 PVE/GuestHelpers.pm | 54 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/PVE/GuestHelpers.pm b/PVE/GuestHelpers.pm
index ebe2781..64e26c9 100644
--- 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;
-- 
2.20.1