On 3/20/19 1:40 AM, Eric Blake wrote:
Rather than allowing a leaky abstraction where multiple drivers have to open-code operations that update the relations in a virDomainSnapshotObjList, it is better to add accessor functions so that updates to relations are maintained closer to the internals. The goal here is to avoid access to, nchildren, first_child, or sibling outside of the lowest level functions, making it easier to refactor later on. While many of the conversions are fairly straightforward, the MoveChildren refactoring can be a bit interesting to follow.
Understatement ;-) Some black magic occurs The qemuDomainSnapshotReparentChildren "snap->parent = rep->parent" gets replaced by the new for loop... Tough to see without watching really closely.
Signed-off-by: Eric Blake <eblake@redhat.com> --- src/conf/virdomainsnapshotobj.h | 5 ++++ src/conf/virdomainsnapshotobjlist.h | 2 ++ src/conf/virdomainsnapshotobj.c | 42 +++++++++++++++++++++++++++++ src/conf/virdomainsnapshotobjlist.c | 42 ++++++++++++++++++----------- src/libvirt_private.syms | 3 +++ src/qemu/qemu_driver.c | 19 +++---------- src/test/test_driver.c | 18 +++---------- 7 files changed, 85 insertions(+), 46 deletions(-)
[...]
diff --git a/src/conf/virdomainsnapshotobj.c b/src/conf/virdomainsnapshotobj.c index 7f92ac21d9..d6b216c7b2 100644 --- a/src/conf/virdomainsnapshotobj.c +++ b/src/conf/virdomainsnapshotobj.c
[...]
+/* Take all children of @from and convert them into children of @to. */ +void +virDomainSnapshotMoveChildren(virDomainSnapshotObjPtr from, + virDomainSnapshotObjPtr to) +{ + virDomainSnapshotObjPtr child; + virDomainSnapshotObjPtr last; + + for (child = from->first_child; child; child = child->sibling) { + child->parent = to; + if (!child->sibling) + last = child; + } + to->nchildren += from->nchildren; + last->sibling = to->first_child;
Silly Coverity compiler gets quite confused thinking that @last couldn't be set while not considering the above loop couldn't end without it unless of course from->first_child == NULL I suppose, which would be a different issue. Still if before the for loop we check "if (!from->first_child) return;", then coverity is happy.
+ to->first_child = from->first_child; + from->nchildren = 0; + from->first_child = NULL;
Or virDomainSnapshotDropChildren... Still makes sense, albeit new. Seems to make VIR_DOMAIN_SNAPSHOT_DELETE_CHILDREN_ONLY processing unnecessary. It's not a problem but perhaps worthy of a mention.
+} diff --git a/src/conf/virdomainsnapshotobjlist.c b/src/conf/virdomainsnapshotobjlist.c index 1eecb89a5d..9538521ab3 100644 --- a/src/conf/virdomainsnapshotobjlist.c +++ b/src/conf/virdomainsnapshotobjlist.c @@ -72,7 +72,7 @@ virDomainSnapshotObjListParse(const char *xmlStr, _("incorrect flags for bulk parse")); return -1; } - if (snapshots->metaroot.nchildren || snapshots->current) { + if (virDomainSnapshotObjListSize(snapshots)) {
The only way the call could return < 0 from virHashSize is if @snapshots == NULL... Just noting it - no problem.
virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", _("bulk define of snapshots only possible with " "no existing snapshot"));
Reviewed-by: John Ferlan <jferlan@redhat.com> John BTW: There could have been 3 patches out of this, but I'm fine with 1.