Good catch. Closed it as duplicate - also surprised myself that I didn't
find this one when I did a cursory search in JBS for pre-existing
issues.
/Claes
On 2020-04-06 07:24, Anirvan Sarkar wrote:
JDK-8189375 <https://bugs.openjdk.java.net/browse/JDK-8189375> should be
closed as duplicate.
On Thu, 26 Mar 2020 at 18:06, Claes Redestad <claes.redes...@oracle.com
<mailto:claes.redes...@oracle.com>> wrote:
Filed and pushed: https://bugs.openjdk.java.net/browse/JDK-8241649
/Claes
On 2020-03-26 00:12, Roger Riggs wrote:
> Agreed, +1
>
> On 3/25/20 5:53 PM, Claes Redestad wrote:
>> Looks good and trivial, including the drive-by cleanups.
>>
>> I can sponsor.
>>
>> /Claes
>>
>> On 2020-03-25 22:18, Сергей Цыпанов wrote:
>>> Hello,
>>>
>>> I think we can reduce allocation rate for
j.l.Character.toString() by
>>> calling String.valueOf(char) instead of String.valueOf(char[]).
>>>
>>> Current implementation creates char[] with one char which is later
>>> decoded into byte[].
>>>
>>> Instead String.valueOf(char) decodes char directly consuming less
>>> memory. I've used benchmark [1]
>>> and on my machine got those results (JDK 14):
>>>
>>> Benchmark Mode Score Error Units
>>>
>>> CharacterToStringBenchmark.toString_utf8 avgt 14.723 ±
1.354 ns/op
>>> CharacterToStringBenchmark.valueOf_utf8 avgt 7.678 ±
0.601 ns/op
>>>
>>> CharacterToStringBenchmark.toString_latin avgt 10.992 ±
1.371 ns/op
>>> CharacterToStringBenchmark.valueOf_latin avgt 7.844 ±
1.044 ns/op
>>>
>>> CharacterToStringBenchmark.toString_utf8:·gc.alloc.rate.norm avgt
>>> 96.003 ± 0.001 B/op
>>> CharacterToStringBenchmark.valueOf_utf8:·gc.alloc.rate.norm avgt
>>> 48.002 ± 0.001 B/op
>>>
>>> CharacterToStringBenchmark.toString_latin:·gc.alloc.rate.norm avgt
>>> 72.003 ± 0.001 B/op
>>> CharacterToStringBenchmark.valueOf_latin:·gc.alloc.rate.norm avgt
>>> 48.002 ± 0.001 B/op
>>>
>>>
>>> Patch is below.
>>>
>>> With best regards,
>>> Sergey Tsypanov
>>>
>>> [1]
>>>
https://github.com/stsypanov/strings/blob/master/src/jmh/java/tsypanov/strings/character/CharacterToStringBenchmark.java
>>>
>>>
>>> diff --git a/src/java.base/share/classes/java/lang/Character.java
>>> b/src/java.base/share/classes/java/lang/Character.java
>>> --- a/src/java.base/share/classes/java/lang/Character.java
>>> +++ b/src/java.base/share/classes/java/lang/Character.java
>>> @@ -3285,7 +3285,7 @@
>>> "SYMBOLS AND PICTOGRAPHS
EXTENDED-A",
>>> "SYMBOLSANDPICTOGRAPHSEXTENDED-A");
>>> - private static final int blockStarts[] = {
>>> + private static final int[] blockStarts = {
>>> 0x0000, // 0000..007F; Basic Latin
>>> 0x0080, // 0080..00FF; Latin-1 Supplement
>>> 0x0100, // 0100..017F; Latin Extended-A
>>> @@ -8068,7 +8068,7 @@
>>> UNKNOWN, // E01F0..10FFFF
>>> };
>>> - private static HashMap<String, Character.UnicodeScript>
>>> aliases;
>>> + private static final HashMap<String,
>>> Character.UnicodeScript> aliases;
>>> static {
>>> aliases = new HashMap<>((int)(153 / 0.75f + 1.0f));
>>> aliases.put("ADLM", ADLAM);
>>> @@ -8421,8 +8421,7 @@
>>> * @return a string representation of this object.
>>> */
>>> public String toString() {
>>> - char buf[] = {value};
>>> - return String.valueOf(buf);
>>> + return toString(value);
>>> }
>>> /**
>>>
>
--
Anirvan
