[pve-devel] [PATCH storage v3 1/4] introduce helpers for content type assertions of storages and volumes

[Daniel Kral]

Add subroutines for asserting the content types of storages and volumes
to reduce code duplication, e.g. when implementing preconditions in an
API handler before calling vdisk_alloc().

Signed-off-by: Daniel Kral <d.kral at proxmox.com>
---
changes since v2:
  * split documentation back to be above each helper
  * changed names of helpers from *_supported to *_available
  * made both helpers also assert whether storage is enabled

 src/PVE/Storage.pm | 47 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/src/PVE/Storage.pm b/src/PVE/Storage.pm
index d0a696a..b5a2c8a 100755
--- a/src/PVE/Storage.pm
+++ b/src/PVE/Storage.pm
@@ -537,6 +537,53 @@ sub parse_volume_id {
     return PVE::Storage::Plugin::parse_volume_id($volid, $noerr);
 }
 
+=head3 assert_content_type_available($cfg, $storeid, $content_type [, $node])
+
+Asserts whether the storage with the identifier C<$storeid>, which is defined
+in C<$cfg>, is available and supports the content type C<$content_type>.
+
+If C<$node> is set, the assertion is made for the specified C<$node>, else for
+the current node.
+
+If the check fails, the subroutine will C<die> with an error message for either
+the storage being unavailable or the storage not supporting the specified
+content type.
+
+=cut
+
+sub assert_content_type_available : prototype($$$;$) {
+    my ($cfg, $storeid, $content_type, $node) = @_;
+
+    my $scfg = storage_check_enabled($cfg, $storeid, $node);
+
+    die "storage '$storeid' does not support content type '$content_type'\n"
+	if !$scfg->{content}->{$content_type};
+}
+
+=head3 assert_volume_type_available($cfg, $volid [, $node])
+
+Asserts whether the volume with the identifier C<$volid>, which is on a storage
+defined in C<$cfg>, is available and supports the volume's content type
+determined by C<L<< parse_volname()|/parse_volname($cfg, $volid) >>>.
+
+If C<$node> is set, the assertion is made for the specified C<$node>, else for
+the current node.
+
+If the check fails, the subroutine will C<die> with an error message for either
+the volume's storage being unavailable or the storage not supporting the
+volume's content type.
+
+=cut
+
+sub assert_volume_type_available : prototype($$;$) {
+    my ($cfg, $volid, $node) = @_;
+
+    my ($storeid) = parse_volume_id($volid);
+    my ($vtype) = parse_volname($cfg, $volid);
+
+    assert_content_type_available($cfg, $storeid, $vtype, $node);
+}
+
 # test if we have read access to volid
 sub check_volume_access {
     my ($rpcenv, $user, $cfg, $vmid, $volid, $type) = @_;
-- 
2.39.5