[PATCH pve-cluster 7/9] cluster: add helpers module with version comparison functions

[David Riley <d.riley@proxmox.com>]

Move 'version_cmp' and 'pvecfg_min_version' over from qemu-server, to
make them more accessible.

Originally-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
Originally-by: Alexandre Derumier <aderumier@odiso.com>
Signed-off-by: David Riley <d.riley@proxmox.com>
---
 debian/pve-cluster.install |  1 +
 src/PVE/Cluster/Helpers.pm | 51 ++++++++++++++++++++++++++++++++++++++
 src/PVE/Cluster/Makefile   |  2 +-
 3 files changed, 53 insertions(+), 1 deletion(-)
 create mode 100644 src/PVE/Cluster/Helpers.pm

diff --git a/debian/pve-cluster.install b/debian/pve-cluster.install
index f66cd06..46d40c4 100644
--- a/debian/pve-cluster.install
+++ b/debian/pve-cluster.install
@@ -5,4 +5,5 @@ usr/lib/
 usr/share/man/man8/pmxcfs.8
 usr/share/perl5/PVE/Cluster.pm
 usr/share/perl5/PVE/Cluster/IPCConst.pm
+usr/share/perl5/PVE/Cluster/Helpers.pm
 usr/share/perl5/PVE/IPCC.pm
diff --git a/src/PVE/Cluster/Helpers.pm b/src/PVE/Cluster/Helpers.pm
new file mode 100644
index 0000000..a4b41c9
--- /dev/null
+++ b/src/PVE/Cluster/Helpers.pm
@@ -0,0 +1,51 @@
+package PVE::Cluster::Helpers;
+
+use strict;
+use warnings;
+
+use JSON;
+
+use base 'Exporter';
+our @EXPORT_OK = qw(pvecfg_min_version assert_min_cluster_version version_cmp);
+
+sub pvecfg_min_version {
+    my ($verstr, $major, $minor, $release) = @_;
+
+    return 0 if !$verstr;
+
+    if ($verstr =~ m/^(\d+)\.(\d+)(?:[.-](\d+))?/) {
+        return 1 if version_cmp($1, $major, $2, $minor, $3 // 0, $release) >= 0;
+        return 0;
+    }
+
+    die "internal error: cannot check version of invalid string '$verstr'";
+}
+
+# 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 < $right;
+    }
+    return 0;
+}
+
+1;
+
diff --git a/src/PVE/Cluster/Makefile b/src/PVE/Cluster/Makefile
index 3f920cb..db685bc 100644
--- a/src/PVE/Cluster/Makefile
+++ b/src/PVE/Cluster/Makefile
@@ -1,6 +1,6 @@
 PVEDIR=$(DESTDIR)/usr/share/perl5/PVE
 
-SOURCES=IPCConst.pm Setup.pm
+SOURCES=Helpers.pm IPCConst.pm Setup.pm
 
 .PHONY: install
 install: $(SOURCES)
-- 
2.47.3