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>
To: "engine-devel" <engine-devel(a)ovirt.org>, "Barak Azulay"
<bazulay(a)redhat.com>
Cc: "Yair Zaslavsky" <yzaslavs(a)redhat.com>, "Michael Pasternak"
<mpastern(a)redhat.com>, "Tal Nisan"
<tnisan(a)redhat.com>, "Ayal Baron" <abaron(a)redhat.com>
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...