RFR 15: 8243010: Test support: Customizable Hex Printer

[Pavel Rappo]

Hi Roger,

First of all, many thanks for doing this. After skimming through that webrev I have two comments.

1. It might make sense to beef this up with more retrofitted tests, so people could more clearly see how applicable this API is. If you'd like I could help you with looking for those across the OpenJDK codebase.

2. Correct me if I'm wrong, but I couldn't find the complementary functionality of parsing in a hexdump in that webrev. I'm not sure how prevalent this is, but I can attest that there is an occasional need for it. For instance, when implementing the HPACK format I coded the tests from that RFC which use a two-byte hexadecimal representation. For example,

   1008 7061 7373 776f 7264 0673 6563 7265 | ..password.secre
   74                                      | t

I'm sure that's not the only case where hex parsing might be needed.

Regardless of whether or not this functionality is already included in that webrev (I might've missed it), the hex printing in and of itself is valuable.

-Pavel

> On 16 Apr 2020, at 20:17, Roger Riggs <Roger.Riggs at oracle.com> wrote:
> 
> Please review[2] and comment on a new Hex printing utility to support OpenJDK tests.
> The usefulness of a hex printing has been discussed from time to time with
> many suggestions as to the API shape and features.
> 
> To get an idea of the API and features, take a look at the javadoc[1].
> It covers the basic formatting of offset, and values, and extends the
> descriptive part beyond simple ASCII or printable so that a custom formatter
> can interpret the byte stream in parallel to the bytes.
> 
> The webrev includes changes to existing tests that currently
> use HexDumpEncoder to use HexPrinter.
> 
> Comments appreciated, Roger
> 
> [1]Javadoc:
> http://cr.openjdk.java.net/~rriggs/webrev-hexprinter-8243010/javadoc
> 
> [2] Webrev:
>   http://cr.openjdk.java.net/~rriggs/webrev-hexprinter-8243010/
> 
> [3] Issue:
>   https://bugs.openjdk.java.net/browse/JDK-8243010