On 11/07/2014 08:51 AM, Brian Dolbec wrote: > On Fri, 7 Nov 2014 00:45:55 -0800 > Zac Medico <zmed...@gentoo.org> wrote: > >> This adds add support to generate a vdb_metadata_delta.json file >> which tracks package merges / unmerges that occur between updates to >> vdb_metadata.pickle. IndexedVardb can use the delta together with >> vdb_metadata.pickle to reconstruct a complete view of /var/db/pkg, >> so that it can avoid expensive listdir calls in /var/db/pkg/*. >> Note that vdb_metadata.pickle is only updated periodically, in >> order to avoid excessive re-writes of a large file. >> >> In order to test the performance gains from this patch, you need to >> generate /var/cache/edb/vdb_metadata_delta.json first, which will >> happen automatically if you run 'emerge -p anything' with root >> privileges. >> --- > > The following code I would like to see either as an independant class > and file if possible, then just instantiated here in the main vardbapi. > Looking over the code, I didn't see much use of other class functions. > This class is already too large in many ways.
Yeah, I definitely want to split it out. > Also is there a > possibility this code could be re-used as a generic delta cache > anywhere else? Maybe. For example, the PreservedLibsRegistry and WorldSelectedSet classes both have similarities in the way that encapsulate an on-disk data store and manage concurrency. Maybe I'll create a helper class that can be utilized by these classes to manage concurrency with on-disk data stores. > Another possibility is moving this code and the aux_cache code to > another class that the vardbapi class also subclasses. This would move > all the cache code to a small class easily viewed, edited, maintained. In this case, I think a helper class will work just fine, so there will be no need for inheritance. -- Thanks, Zac
