RFR: JDK-8293776 : Adds CSS 4 and 8 digits hex coded Color [v15]

[ScientificWare]

On Thu, 17 Aug 2023 18:02:01 GMT, Phil Race <prr at openjdk.org> wrote:

>> ScientificWare has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 30 commits:
>> 
>>  - Merge branch 'openjdk:master' into scientificware-patch-003-CSS-add_4_8_digits_hex_coded_color
>>  - Merge branch 'master'
>>    
>>    CSS.java :
>>    Removes assigning values inside the if-condition
>>    Extracts the assignments into separate line.
>>    
>>    Hex3468DigitsColor.java :
>>    Adds a message to result in case of failure only
>>  - Updates copyright date.
>>    
>>    Updates copyright date to 2023.
>>  - Updates copyright date.
>>    
>>    Updates copyright date to 2023.
>>  - Update imports
>>    
>>    Remove java.util.Pattern and add java.util.Map imports
>>  - Performance improvement
>>    
>>    Performance results came from my repository I mentioned in the header.
>>    
>>        The code before this PR ran in 230ms.
>>        Our previous codes ran in 1 200ms to 1800 ms with String + formatted + %n$s usage.
>>        They ran in 350ms to 380ms with String + formatted + %s usage.
>>        And in 100ms to 110ms if we replace String + format with a string concatenation.
>>        Now the code below gives the same results in 36ms and with all our expected behaviors. Since we control notation length we
>>            can bypass some controls,
>>            directly generate the color value,
>>            without generate a new string,
>>            and reject a wrong number format without generate any exception.
>>  - Corrects a value in a message.
>>    
>>    A message is added to the result in case of failure only. The updated code does not output the actual value. The tested color is #f12a instead of #f00a.
>>  - Simplifications of the test.
>>    
>>    Removes individual color tests and only compares the RGB value.
>>  - Renames an identifier.
>>    
>>    Suggested change, not to use `l` as an identifier because it could be confused with `1`.
>>    This part of code could change and be replaced by bits right rotation after  performance tests.
>>  - Corrects Licence Header.
>>    
>>    Removes Classpath exception.
>>  - ... and 20 more: https://git.openjdk.org/jdk/compare/b80001de...0dbd8f0f
>
> Back in Feb I wrote 
>> As noted there, this PR likely needs to be withdrawn and absorbed into https://github.com/openjdk/jdk/pull/9825
> 
> Nothing has changed on that front, so I don't know why you re-opened this.

@prrace Before withdraw it, I wanted to push all @aivanov-jdk's requested changes in this branch.

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PR Comment: https://git.openjdk.org/jdk/pull/10317#issuecomment-1682792735