On Fri, 22 Dec 2023 13:00:11 GMT, Sergey Tsypanov <stsypa...@openjdk.org> wrote:

>> Currently if we create a record it's fields are compared in their 
>> declaration order. This might be ineffective in cases when two objects have 
>> "heavy" fields equals to each other, but different "lightweight" fields 
>> (heavy and lightweight in terms of comparison) e.g. primitives, enums, 
>> nullable/non-nulls etc.
>> 
>> If we have declared a record like
>> 
>> public record MyRecord(String field1, int field2) {}
>> 
>> It's equals() looks like:
>> 
>>   public final equals(Ljava/lang/Object;)Z
>>    L0
>>     LINENUMBER 3 L0
>>     ALOAD 0
>>     ALOAD 1
>>     INVOKEDYNAMIC 
>> equals(Lcom/caspianone/openbanking/productservice/controller/MyRecord;Ljava/lang/Object;)Z
>>  [
>>       // handle kind 0x6 : INVOKESTATIC
>>       
>> java/lang/runtime/ObjectMethods.bootstrap(Ljava/lang/invoke/MethodHandles$Lookup;Ljava/lang/String;Ljava/lang/invoke/TypeDescriptor;Ljava/lang/Class;Ljava/lang/String;[Ljava/lang/invoke/MethodHandle;)Ljava/lang/Object;
>>       // arguments:
>>       com.caspianone.openbanking.productservice.controller.MyRecord.class,
>>       "field1;field2",
>>       // handle kind 0x1 : GETFIELD
>>       
>> com/caspianone/openbanking/productservice/controller/MyRecord.field1(Ljava/lang/String;),
>>       // handle kind 0x1 : GETFIELD
>>       com/caspianone/openbanking/productservice/controller/MyRecord.field2(I)
>>     ]
>>     IRETURN
>>    L1
>>     LOCALVARIABLE this 
>> Lcom/caspianone/openbanking/productservice/controller/MyRecord; L0 L1 0
>>     LOCALVARIABLE o Ljava/lang/Object; L0 L1 1
>>     MAXSTACK = 2
>>     MAXLOCALS = 2
>> 
>> This can be improved by rearranging the comparison order of the fields 
>> moving enums and primitives upper, and collections/arrays lower.
>
> Sergey Tsypanov has updated the pull request incrementally with two 
> additional commits since the last revision:
> 
>  - Merge remote-tracking branch 'origin/record-equals' into record-equals
>  - 8322292: Add test case

Anything else I can do about it?

-------------

PR Comment: https://git.openjdk.org/jdk/pull/17143#issuecomment-1902184686

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