ARROW-7205 : [C++][Gandiva] Implement regexp_like in Gandiva

[wjones127]

Was looking for "rlike" support in Gandiva and found we had nearly implementing it. This PR revives #5860.

[github-actions]

https://issues.apache.org/jira/browse/ARROW-7205

[wjones127]

@pravindra@Praveen2112@projjal Got some time for a review? 😁

[projjal]

Hi @wjones127. Looks like creating a base holder class and two derived class for just these two functions seems overkill to me (I think thats why I closed the original pr temporarily). The only difference in logic between the two functions is that in case of "like" we convert the sql pattern to regex pattern before storing the compiled pattern. Would it make sense if we pass a flag to the holder that says if this is sql pattern or regex patttern?

[wjones127]

Projjal, that's a good point. The SQL like function is basically a wrapper around regexp_like. I don't know why I didn't see the optimizations should be the same.

I will consolidate them into a single LikeHolder.

[wjones127]

FYI This looks to be the first use of Arrow::Result in the Gandiva codebase, but this seems to be what the main arrow C++ codebase is using recently. Let me know if you object.

[wjones127]

Previously, like was using RE2::FullMatch. However, regexp_matches needs to use RE2::PartialMatch, so I've modified this method to make partial match statements. I have added a new set of tests to validate it.

I didn't see any use of this utility method outside of the like implementation, so I thought this change would be okay.

[wjones127]

This change enables using \ as an escape character in LIKE statements. For example, col like '\_%' can match anything starting with an underscore.

[wjones127]

I think we should merge #9700 before this one, since my refactor of LikeHolder would cause merge conflicts on that PR. So I'll wait for that merge and then finish this.

[nealrichardson]

I think we should merge #9700 before this one, since my refactor of LikeHolder would cause merge conflicts on that PR. So I'll wait for that merge and then finish this.

@wjones127#9700 has merged, are you planning to pick this back up?

[wjones127]

I think we should merge #9700 before this one, since my refactor of LikeHolder would cause merge conflicts on that PR. So I'll wait for that merge and then finish this.

@wjones127#9700 has merged, are you planning to pick this back up?

Yes, I'll work on it this weekend.

[wjones127]

@projjal This is now ready for review.

Since we've added ilike and special escape_char options for like, I made SQLLikeHolder inherit from RegexMatchHolder instead of sharing the same holder class. I did make sure the TryOptimize logic wasn't duplicated.