Am 20.09.2013 18:38, schrieb Peter Levart:
[...]
As I understand the Thread.firstCaller() does exactly that.
"findFirstCallerMatchingPredicate". Choosen name abbreviation is maybe
not making the semantic immediately obvious.
then sorry, I overlooked that in the link
though the usage of this is not that nice:
Class getCallerClass(final int nonSkippedFramesDepth) {
return findCaller(new Predicate<StackFrameInfo>() {
int depth = 0;
boolean test(StackFrameInfo info) {
if (haveToSkip(info.getDeclaringClass())) return
false;
depth++;
if (depth>=nonSkippedFramesDepth) return
info.getDeclaringClass();
}
}, StackFrameInfo::getDeclaringClass());
}
But the API is making it possible without walking entire stack or making
N partial walks with lengths 1..N, which is O(N^2)...
You know the trouble with the O-notation. For once, there are constants
in this, that are not mentioned and for second O(N^2) is only always
better than any O(N^3) if N is big enough. Otherwise even an O(2^N) can
be less effort. And the lengths we are talking here about are not big Ns
More compact, using lambda:
Class getCallerClass(int nonSkippedFramesDepth) {
int[] depth = new int[1];
return Thread.fistCaller(
info -> !haveToSkip(info.getDeclaringClass()) && (++depth[0] >
nonSkippedFramesDepth),
StackFrameInfo::getDeclaringClass
);
}
silly me... of course... why do I return the class when I need to return
a boolean.. its been a long day already... ok, your version is accepted
;) using an array instead is quite the hack for me, but we are used to
that for Java AIC
bye blackdrag
--
Jochen "blackdrag" Theodorou - Groovy Project Tech Lead
blog: http://blackdragsview.blogspot.com/
german groovy discussion newsgroup: de.comp.lang.misc
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