Re: [gentoo-portage-dev] [PATCH] rsync metadata cache patch (obsoletes metadata transfer on sync)

[Brian Harring]

On Sat, Jan 28, 2006 at 02:39:42AM -0800, Zac Medico wrote:
> 	def _delitem(self, cpv):
> 		try:
> 			del self.db_rw[cpv]
> 		except KeyError, ke:
> 			if not self.db_ro.has_key(cpv):
> 				raise ke

You need white outs here (lifting a unionfs term); this won't actually 
change state in any way if you're trying to delete a bad entry from 
the underlying metadata cache.

>
> 	def has_key(self, cpv):
> 		return self.db_rw.has_key(cpv) or self.db_ro.has_key(cpv)
>
> 	def iterkeys(self):
> 		s = set()
> 		for db in (self.db_rw, self.db_ro):
> 			for cpv in db.iterkeys():
> 				if cpv not in s:
> 					yield cpv
> 					s.add(cpv)
Should just do 
s=set()
for cpv in self.db_rw:
	yield cpv
	s.add(cpv)
for cpv in self.db_ro:
	if cpv not in s:
		yield cpv


Slightly faster (1us per yield for the set lookup), but mainly less 
memory usage.

Aside from that, the label trick is icky. ;)