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Re: [JGIT PATCH 11/12] Cleanup Config's MAGIC_EMPTY_VALUE to be more safe

From
Shawn O. Pearce <spearce@spearce.org>
Date
Jul 21, 2009, 21:54 UTC
Message-ID
<20090721215451.GU11191@spearce.org>
In-Reply-To
<200907212351.21760.robin.rosenberg@dewire.com>
Robin Rosenberg <robin.rosenberg@dewire.com> wrote:
> tisdag 21 juli 2009 22:19:29 skrev "Shawn O. Pearce" <spearce@spearce.org>:
> > The magic value "%%magic%%empty%%" is just too magic; 
...
Show 6 quoted lines
> > -	private static final String MAGIC_EMPTY_VALUE = "%%magic%%empty%%";
> > +	private static final String MAGIC_EMPTY_VALUE = new StringBuilder(0)
> > +			.toString();
> 
> Can we be sure an implementation doesn't "optimize" toString() here? But an
> explicit new String() shouldn't be..?
*sigh*

I used this form because FindBugs dislikes new String(""). But yea, at least with new String() we know its a new string object and there is no pooling of the empty string going on under the covers.

I can't imagine it being a common enough case to convert a StringBuilder to an empty string that a runtime implementation would waste instructions over checking for it and reusing a pooled copy, but eh, yea, maybe this should be new String("") and include a FindBugs entry to disable the warning here.

-- 
Shawn.
Previous: Robin RosenbergNext: Constantine Plotnikov
Message 15 of 18 in “Cleanup Config class”
  1. 00/12 Cleanup Config classShawn O. Pearce, Jul 21, 2009
  2. 01/12 Use NB.readFully(File) to slurp complete file contentsShawn O. Pearce, Jul 21, 2009
  3. 02/12 Correct name of fileRead member of Config classShawn O. Pearce, Jul 21, 2009
  4. 03/12 Add setLong to ConfigShawn O. Pearce, Jul 21, 2009
  5. 04/12 Fix Config setInt(..., 0) to store "0" not "0 g"Shawn O. Pearce, Jul 21, 2009
  6. 05/12 Rename Config.unsetString to just unset()Shawn O. Pearce, Jul 21, 2009
  7. 06/12 Remove pointless null assignments in ConfigShawn O. Pearce, Jul 21, 2009
  8. 07/12 Clarify section and subsection values in Config codeShawn O. Pearce, Jul 21, 2009
  9. 08/12 Don't subclass PrintWriter when writing the ConfigShawn O. Pearce, Jul 21, 2009
  10. 09/12 Use a Java 5 style iteration over the Config entries listShawn O. Pearce, Jul 21, 2009
  11. 10/12 Match config subsection names using case sensitive searchShawn O. Pearce, Jul 21, 2009
  12. 11/12 Cleanup Config's MAGIC_EMPTY_VALUE to be more safeShawn O. Pearce, Jul 21, 2009
  13. 12/12 Remove unreferenced REMOTE_SECTION from RepositoryConfigShawn O. Pearce, Jul 21, 2009
  14. Robin RosenbergJul 21, 2009
  15. Shawn O. PearceJul 21, 2009
  16. Constantine PlotnikovJul 22, 2009
  17. Robin RosenbergJul 22, 2009
  18. Ensure Config readers handle case insensitive names correctlyShawn O. Pearce, Jul 24, 2009

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