Am 26.02.2010 13:58, schrieb Alan Bateman:
Jason Mehrens wrote:
Alan,
Shouldn't the loading of 'this.count' into 'len' be only performed if
'h' is zero? Otherwise, when hash is not zero we perform a little
unnecessary work every time hashCode is called.
Jason
That's a good suggestion although it might be hard to measure any
difference.
In case of HotSpot compiled code, I guess, len will not be filled by
this.count before it is actually needed, but in interpreted code Jason
may be right.
So optimum could be:
public int hashCode() {
int h = hash;
if (h == 0) {
int len = count;
if (len> 0) {
char[] val = value;
for (int i = 0, off = offset; i< len; i++)
h = 31*h + val[off++];
hash = h;
}
}
return h;
}
- Ulf
