Am 25.02.2010 23:07, schrieb Alan Bateman:
Kelly O'Hair wrote:
Yup. My eyes must be tired, I didn't see that. :^(
Too many repositories in the air at the same time. The webrev has been
refreshed. Thanks Ulf.
Another thought:
In the constructors of String we could initialize hash =
Integer.MIN_VALUE except if length == 0.
Then we could stay at the fastest version:
public int hashCode() {
int h = hash;
if (h == Integer.MIN_VALUE) {
h = 0;
char[] val = value;
for (int i = offset, limit = count + i; i != limit; )
h = 31 * h + val[i++];
hash = h;
}
return h;
}
As an alternative we could use:
private static final int UNKNOWN_HASH = 1;
Justification:
Using a small value results in little shorter byte code and machine code
footprint after compilation.
Additionally on some CPU's this likely will perform little better, but
never worse.
Please note:
Original loop causes 2 values to increment:
for (int i = 0; i < len; i++) {
h = 31*h + val[off++];
}
This is inefficient as I have proved in a little micro-benchmark.
-Ulf
