fail early in RInChIGeneratorFactory when there is an issue with the native RInChI lib?

[uli-f]

I left a TODO for us in RInChIGeneratorFactory.

RInChIGeneratorFactory declared a CDKException in its private constructor and stated in the documentation that this exception is thrown when the native library cannot be loaded. However, the native library wasn't loaded when RInChIGeneratorFactory was instantiated.

InChIGeneratorFactory does the same thing: declaring a CDKException in its private constructor and stating in the documentation that this exception is thrown when the native library cannot be loaded. So my guess is that this is where this originates from.

The code in RInChIGeneratorFactory is now changed due to my refactoring of the singleton pattern. However, the question remains: Shouldn't RInChIGeneratorFactory fail as early as possible if there is an issue with the loading of the native library?

The following code loads the native library by explicitly loading the class io.github.dan2097.jnarinchi.JnaRinchi thereby making sure that there is an exception as soon as the the method getInstance() of RInChIGeneratorFactory is called:

private static class SingletonInstanceHolder {
  public final static RInChIGeneratorFactory INSTANCE;

  static {
    INSTANCE = new RInChIGeneratorFactory();
    // TODO do we want to load the rinchi native library at this point so that we get an exception early on?
    try {
      RInChIGeneratorFactory.class.getClassLoader().loadClass("io.github.dan2097.jnarinchi.JnaRinchi");
    } catch (ClassNotFoundException e) {
      throw new RuntimeException(e);
    }
  }
}

However, the main drawback is that the thrown exception must be a RuntimeException (or subclass thereof) as this happens in a static block.

@ntk73 Any thoughts?

[vedina]

@uli-f I agree with your proposal, it's better to fail early. I am not sure why RuntimeException should be a concern, we are not implementing interface requiring CDKException to worry about it.

Tests might need to be updated to throw RuntimeException .

[uli-f]

Okay. I made a PR for this change: PR #21

@ntk73 Would you please merge this one as well? Thanks.

Whether to fail early - and if so, how - might be something that I will discuss with the CDK developers once we open a PR to merge the rinchi code.

As a reminder for myself I would like to leave this open for now.

[ntk73]

PR #21 is already merged.