Am 30.08.2012 08:23, schrieb Joe Darcy:
On 8/29/2012 7:07 PM, Stuart Marks wrote:
On 8/29/12 4:56 PM, Joe Darcy wrote:
On 8/29/2012 4:20 PM, Stuart Marks wrote:
The various SecurityConstants being used here are Strings.
Note that this is doing String comparisons using == which is usually a bug.
But this code is relying on String interning to provide object identity for
equal string literals, in order to provide a fast path optimization for these
common cases.
Oops, didn't notice that the code is a fastpath in advance.
Changing this code to use switch-over-strings would be
semantically equivalent, but it would probably slow things down, since switch
provides equals() semantics instead of == semantics.
For that reason in project coin I always voted for == semantics as default for switch-on-strings and
optionally using
case .equals("foo") :
syntax for equals() semantics.
But anyway, equals() always first checks ==, and in fail switch-on-strings compares the hashes in
2nd step, so performance should not matter such heavy, compared to the processing which follows, and
additionally the following code must not slowly process the, I guess also frequent, case of normal
equality.
Anyway the following code could be faster, if first upper-casing the the actions string instead
comparing each char against upper AND lower case. A // FIXME tag would be nice for that, to not
forget the possible tuning in future.
I recommend explicitly mentioning interning "Using identity comparison against known-interned
strings for performance benefit."
I would additionally prefix with: "First using ..." or "Fastpath, using ..."
-Ulf
