cbb0fd3cfd
Rather than specialcasing handling of the '*' character, use fnmatch() to get normal shell wildcard syntax, as described in 'man glob(7)'. To get an indication of the performance impact of using globs instead of plain string matches, a test program was written. The list of all 260 log categories was extracted from the source. Then a typical log filters setup was picked by creating an array of the strings "qemu", "security", "util", "cgroup", "event", "object". Every filter string was matched against every log category. Timing information showed that using strstr() this took 8 microseconds, while fnmatch() took 114 microseconds. IOW, fnmatch is 14 times slower than our existing strstr check. These numbers show a worst case scenario that will never be hit, because it is rare that every log category would have data output. The log category matches are cached, so each category is only checked once no matter how many log statements are emitted. IOW despite being slower, this will be lost in the noise and have no consequence on real world logging performance. Reviewed-by: John Ferlan <jferlan@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@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: