On Tue, Dec 19, 2006 at 02:05:32PM -0500, Daniel Veillard wrote: > On Tue, Dec 19, 2006 at 06:48:16PM +0000, Daniel P. Berrange wrote: > > The code for managing config files in /etc/xen assumed that the filename of > > the config matched the name of the guest defined inside. One might thing > > this a reasonable assumption, but in the wild I've had reports from users > > whom have various config files for the same guest, but with different > > settings. This caused some really wierd behaviour in the current code base. > > virt-manager display would alternate displaying each config upon refresh! > > > > Now, our API requires that there is only one config per name, so we can't > > expose this to the UI. The attached patch, thus simply detects when we > > have more than one config with same named guest, and hides the duplicates. > > > > The way it does this is to change the way we cache configs. Previously we > > had a single hash table mapping relative filenames to virConfPtr objects, > > with the implicit assumption that relative filename == guest name. With > > the attached patch we now maintain two hash tables. The first maps fully > > qualified pathnames to virConfPtr objects, the second maps guest names > > to the first filename found for that name. Thus when querying details for > > a guest, we first resolve the guest name to its filename, and then lookup > > the virConfPtr object associated with this filename. > > > > This isn't perfect, but its a hell of alot better than current code, so > > I want to commit it as is and figure out more improvement later. There is > > no ABI issue here, so we can iterate over impl at will. > > okay sounds fine to me... Ok, will commit. > > + value = malloc(sizeof(virConfValue)); > > + value->str = strdup(filename); > > + free(value); > > + return (-1); > > This makes me think about an idea I had to swicth all allocations in > libvirt to reuse xmlMalloc/xmlFree/xmlStrdup . The reasons are the following: > - libxml2 is a mandatory module > - libxml2 memory debug allow to track easilly memory allocations > and check we never leak, this can be really useful > - libxml2 memory routines can also be overiden by the library client > to use a different allocator which in some circumstances can be really > useful > > My prime motivation is debug but reuse of libxml2 facilities is not neglectible. Sounds reasonble. I'm not familiar with libxml2 debug stuff though - does it give more info that we can get from valgrind ? Dan. -- |=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=| |=- Perl modules: http://search.cpan.org/~danberr/ -=| |=- Projects: http://freshmeat.net/~danielpb/ -=| |=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=|