Don't re-encode byte[] values in SortValues transform

[clairemcginty]

A small optimization for SortValues transform to avoid doubly roundtrip encoding values that are already byte[]s -- they can be passed directly to the Sorter.

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Reminder, please take a look at this pr: @Abacn

[Abacn]

thanks, will take a look

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Reminder, please take a look at this pr: @Abacn

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Reminder, please take a look at this pr: @damondouglas

[clairemcginty]

Thank you for contributing this! The following three proposals go together and made more sense to provide in one comment, rather than separately. May we consider instead of the new custom class:

1. two private static methods as shown below:

private static <T> T elementOf(Coder<T> coder, byte[] bytes) throws CoderException {
    if (coder instanceof ByteArrayCoder) {
      return (T) bytes;
    }
    return CoderUtils.decodeFromByteArray(coder, bytes);
  }

  private static <T> byte[] bytesOf(Coder<T> coder, T element) throws CoderException {
    if (element instanceof byte[]) {
      return (byte[]) element;
    }
    return CoderUtils.encodeToByteArray(coder, element);
  }

2. Refactoring the SortValuesDoFn's processElement method with:

for (KV<SecondaryKeyT, ValueT> record : records) {
    sorter.add(KV.of(
        bytesOf(keyCoder, record.getKey()),
        bytesOf(valueCoder, record.getValue()))
    );
}

3. Refactoring DecodingIterator's next with:

SecondaryKeyT secondaryKey = elementOf(keyCoder, next.getKey());
ValueT value = elementOf(valueCoder, next.getValue());
return KV.of(secondaryKey, value);

Thanks for the review @damondouglas ! Sorry for the late reply, I've been out of office, but will apply these suggestions today or tomorrow 👍

[clairemcginty]

Thanks for the review @damondouglas ! Sorry for the late reply, I've been out of office, but will apply these suggestions today or tomorrow 👍

Updated! your suggestions are much clearer -- my original approach constructed the custom functions up-front so that we wouldn't have to do the type-checking on every individual element, but I think the readability/clarity was just not worth it.

[github-actions[bot]]

Reminder, please take a look at this pr: @damondouglas

[damondouglas]

@clairemcginty

Updated! your suggestions are much clearer -- my original approach constructed the custom functions up-front so that we wouldn't have to do the type-checking on every individual element, but I think the readability/clarity was just not worth it.

Thank you so much for listening! Apologies as I was taking a week off last week and will review now.