RFR: 8167002: JAXP schema validator: Use HashSet instead of ArrayList for tracking XML IDs
Martin Buchholz
martinrb at google.com
Sat Oct 1 16:54:39 UTC 2016
On Sat, Oct 1, 2016 at 5:45 AM, Claes Redestad <claes.redestad at oracle.com>
wrote:
>
> On 2016-10-01 02:41, Martin Buchholz wrote:
>
>> https://bugs.openjdk.java.net/browse/JDK-8167002
>> http://cr.openjdk.java.net/~martin/webrevs/openjdk9/xml-id-v
>> alidation-by-hash/
>>
>>
> +1, but I have to ask what the intended benefit of writing:
>
> ((fIds != null) ? fIds : (fIds = new HashSet<>())).add(name);
>
> rather than keeping the pre-existing pattern:
>
> if (fIds == null) fIds = new HashSet<>();
> fIds.add(name);
>
> If this is about bytecode optimization to help with inlining or such,
> the latter actually generate a more compact method (14 vs 16 bytecodes).
The intent was (by instinct) to not code a re-read of a field, but ... yeah
.... that wasn't achieved.
That could be done correctly using
public void addId(String name) {
HashSet<String> x;
if ((x = fIds) == null) fIds = x = new HashSet<>();
x.add(name);
}
but I'll just revert to
if (fIds == null) fIds = new HashSet<>();
fIds.add(name);
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