Re: [Engine-devel] Guid improvements

Great news. Allon - please note that GUID is being recreated from String by both DB calls and by data received from VDSM. It is VERY useful to cache Guid String-->Guid, and not just Empty GUID. However, as the Guid class runs in GWT as well, you can't use Infinispan and you're limited in the HashMap implementations you can use. Personally, I don't think it's a memory leak, as GUID number in the system are finite and not too large.

On Jun 30, 2013, at 11:13 AM, Yair Zaslavsky wrote: > 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... >> > _______________________________________________ > Engine-devel mailing list > Engine-devel(a)ovirt.org > http://lists.ovirt.org/mailman/listinfo/engine-devel _______________________________________________ Engine-devel mailing list Engine-devel(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel