Re: [Engine-devel] Guid improvements

Well done, should have been done ages ago :) Now, for the painful rebase of async_task_mgr changes :)

----- Original Message ----- > From: "Allon Mureinik" <amureini(a)redhat.com&gt; > To: "engine-devel" <engine-devel(a)ovirt.org&gt;, "Barak Azulay" <bazulay(a)redhat.com&gt; > Cc: "Yair Zaslavsky" <yzaslavs(a)redhat.com&gt;, "Michael Pasternak" <mpastern(a)redhat.com&gt;, "Tal Nisan" > <tnisan(a)redhat.com&gt;, "Ayal Baron" <abaron(a)redhat.com&gt; > Sent: Sunday, June 30, 2013 11:11:30 AM > Subject: Guid improvements > > Hi all, > > I just merged a couple of improvements to the [N]Guid class [1] to improve > it's performance both CPU-wise and memory-wise, based on a set of benchmarks > presented by Liran. > > What this patchset achieves: > 1. Clean up the code, so it's easier to understand and use > 2. Eliminate the inflation in the memory foot print caused by the getValue() > method > 3. Eliminate all the heavy calls to UUID.fromString when creating a new/empty > Guid instance as a default value > 4. Note that the cleanups proposed in (1) will have minor performance > benefits (e.g., eliminating useless conditional statements), but I doubt > this would be anything to write home about. > > From a developer's perspective, here's what changed: > 1. No more NGuid, just Guid. Both static methods to create a Guid from String > still exist, and are named createGuidFromString and > createGuidFromStringDefaultEmpty. > 2. [N]Guid.getValue() was removed, it's no longer needed after (1) was > implemented > 3. The Guid() constructor was made private, as it forced a redundant call to > UUID.fromString(String). If you need an empty Guid instance, just use > Guid.Empty > 4. The Guid.EMPTY_GUID_VALUE string constant was removed, as it was used for > redundant calls to UUID.fromString. If you really, REALLY, need it, just > call Guid.Empty.getValue() for a UUID or Guid.Empty.toString() for a String. > 5. All sorts of ways to transform Strings to Guids were removed. If you have > a literal you trust, just use new Guid(String). If you suspect it may be > null, use Guid.createGuidFromString[DefaultEmpty] > 6. NewGuid is now called newGuid. We're in Java, not C# :-) > > > Many thanks to everyone who reviewed this patchset. > You guys rock! > > > Regards, > Allon > > > [1] > http://gerrit.ovirt.org/#/q/project:ovirt-engine+branch:master+topic:guid... >