RFR: 8292914: Drop the counter from lambda class names [v6]

[David M. Lloyd]

On Thu, 16 Feb 2023 19:37:18 GMT, ExE Boss <duke at openjdk.org> wrote:

>> David M. Lloyd has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Use a unique index for the dumped lambda class instead of a time stamp
>
> src/java.base/share/classes/java/lang/invoke/InnerClassLambdaMetafactory.java line 208:
> 
>> 206:             name = name.replace('/', '_');
>> 207:         }
>> 208:         return name.replace('.', '/') + "$$Lambda$";
> 
> Using `String::concat` uses the same code path as indy‑based String concatenation[^1].
> Suggestion:
> 
>         return name.replace('.', '/').concat("$$Lambda");
> 
> 
> [^1]: The JDK uses `StringBuilder`‑based String concatenation:
> https://github.com/openjdk/jdk/blob/a39cf2e3b242298fbf5fafdb8aa9b5d4562061ef/make/modules/java.base/Java.gmk#L28

The original code used `+` so I assume it's not a problem here... but if I'm wrong, wouldn't it be better to migrate from `+` to `concat` in a separate change?

> src/java.base/share/classes/java/lang/invoke/ProxyClassesDumper.java line 103:
> 
>> 101:         final int len = className.length();
>> 102:         // add some padding to `len` for the index
>> 103:         StringBuilder sb = new StringBuilder(len + 5);
> 
> Suggestion:
> 
>         StringBuilder sb = new StringBuilder(len + 6);

The index is unlikely to be more than 5 digits (pulled out of a hat really) for most applications I would think; is there something I overlooked here?

> src/java.base/share/classes/java/lang/invoke/ProxyClassesDumper.java line 124:
> 
>> 122:             }
>> 123:         }
>> 124:         sb.append(counter.incrementAndGet());
> 
> Suggestion:
> 
>         sb.append('$').append(counter.incrementAndGet());

The Lamdba class name already ends in `$` - is there a reason we'd need a second one when dumping?

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PR: https://git.openjdk.org/jdk/pull/12579