RFR: 8170769 Provide a simple hexdump facility for binary data

[Roger Riggs]

Hi,

I don't think this is performance sensitive and less code is better.

Use java.lang.Character.digit(ch, 16) to convert the char to an int.

Roger

On 12/07/2018 01:49 PM, Kasper Nielsen wrote:
> Hi,
>
> I don't know if performance is an issue. But if it is, I think it world
> make sense to use a precompute array. And replace
>
> private static int hexToBinary(char ch) {
>      if ('0' <= ch && ch <= '9') {
>          return ch - '0';
>      }
>      if ('A' <= ch && ch <= 'F') {
>          return ch - 'A' + 10;
>      }
>      if ('a' <= ch && ch <= 'f') {
>          return ch - 'a' + 10;
>      }
>      return -1;
> }
>
> with
>
> private static int hexToBinary(char ch) {
>      return ch <= 'f' ? staticPrecomputedArray[ch] : -1;
> }
>
> where int[] staticPrecomputedArray is computed in a static initializer
> block.
>
> /Kasper
>
> On Fri, 23 Nov 2018 at 14:51, Vincent Ryan <vincent.x.ryan at oracle.com>
> wrote:
>
>> Hello,
>>
>> Please review this proposal for a new API to conveniently generate and
>> display binary data using hexadecimal string representation.
>> It supports both bulk and stream operations and it can also generate the
>> well-known hexdump format [1].
>>
>> This latest revision addresses review comments provided earlier.
>> These include adding methods to support for data supplied in a
>> ByteBuffer, exposing the default formatter implementation as a public
>> static and dropping the superfluous 'Hex' term from several method names.
>>
>> Thanks
>>
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8170769
>> API:
>>
>> http://cr.openjdk.java.net/~vinnie/8170769/javadoc.06/api/java.base/java/util/Hex.html
>> Webrev: http://cr.openjdk.java.net/~vinnie/8170769/webrev.06/
>>
>>
>> ____
>> [1] https://docs.oracle.com/cd/E88353_01/html/E37839/hexdump-1.html
>>