[PATCH common v3 01/21] tools: move version_cmp() helper from qemu-server

[Fiona Ebner <f.ebner@proxmox.com>]

To be re-used from pve-cluster for node version checking.

This helper seems generic enough to warrant inclusion in the
PVE::Tools module. There is no module like PVE::Version or similar yet
and a module for the single helper seems overkill.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
---

New in v3.

 src/PVE/Tools.pm | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/src/PVE/Tools.pm b/src/PVE/Tools.pm
index 8e7646d..18e1dd2 100644
--- a/src/PVE/Tools.pm
+++ b/src/PVE/Tools.pm
@@ -1647,4 +1647,30 @@ sub is_deeply {
     return 1;
 }
 
+# gets in pairs the versions you want to compares, i.e.:
+# ($a-major, $b-major, $a-minor, $b-minor, $a-extra, $b-extra, ...)
+# returns 0 if same, -1 if $a is older than $b, +1 if $a is newer than $b
+sub version_cmp {
+    my @versions = @_;
+
+    my $size = scalar(@versions);
+
+    return 0 if $size == 0;
+
+    if ($size & 1) {
+        my (undef, $fn, $line) = caller(0);
+        die "cannot compare odd count of versions, called from $fn:$line\n";
+    }
+
+    for (my $i = 0; $i < $size; $i += 2) {
+        my ($left, $right) = splice(@versions, 0, 2);
+        $left //= 0;
+        $right //= 0;
+
+        return 1 if $left > $right;
+        return -1 if $left < $right;
+    }
+    return 0;
+}
+
 1;
-- 
2.47.3