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. This patch starts the task with a single new function: virDomainSnapshotMoveChildren(). The logic might not be immediately obvious [okay, that's an understatement - the existing code uses black magic ;-)], so here's an overview: The old code has an implicit for loop around each call to qemuDomainSnapshotReparentChildren() by using virDomainSnapshotForEachChild() (you'll need a wider context than git's default of 3 lines to see that); the new code has a more visible for loop. Then it helps if you realize that the code is making two separate changes to each child object: STRDUP of the new parent name prior to writing XML files (unchanged), and touching up the pointer to the parent object (refactored); the end result is the same whether a single pass made both changes (both in driver code), or whether it is split into two passes making one change each (one in driver code, the other in the new accessor). Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Ferlan <jferlan@redhat.com>
Libvirt API for virtualization
Libvirt provides a portable, long term stable C API for managing the virtualization technologies provided by many operating systems. It includes support for QEMU, KVM, Xen, LXC, bhyve, Virtuozzo, VMware vCenter and ESX, VMware Desktop, Hyper-V, VirtualBox and the POWER Hypervisor.
For some of these hypervisors, it provides a stateful management daemon which runs on the virtualization host allowing access to the API both by non-privileged local users and remote users.
Layered packages provide bindings of the libvirt C API into other languages including Python, Perl, PHP, Go, Java, OCaml, as well as mappings into object systems such as GObject, CIM and SNMP.
Further information about the libvirt project can be found on the website:
License
The libvirt C API is distributed under the terms of GNU Lesser General
Public License, version 2.1 (or later). Some parts of the code that are
not part of the C library may have the more restrictive GNU General
Public License, version 2.1 (or later). See the files COPYING.LESSER
and COPYING
for full license terms & conditions.
Installation
Libvirt uses the GNU Autotools build system, so in general can be built and installed with the usual commands. For example, to build in a manner that is suitable for installing as root, use:
$ ./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var
$ make
$ sudo make install
While to build & install as an unprivileged user
$ ./configure --prefix=$HOME/usr
$ make
$ make install
The libvirt code relies on a large number of 3rd party libraries. These will
be detected during execution of the configure
script and a summary printed
which lists any missing (optional) dependencies.
Contributing
The libvirt project welcomes contributions in many ways. For most components the best way to contribute is to send patches to the primary development mailing list. Further guidance on this can be found on the website:
https://libvirt.org/contribute.html
Contact
The libvirt project has two primary mailing lists:
- libvirt-users@redhat.com (for user discussions)
- libvir-list@redhat.com (for development only)
Further details on contacting the project are available on the website: