Basic search

[dranikpg]

Implements brute force search

Basic redis search interface:

• FT.CREATE with a single index
• FT.SEARCH

[royjacobson]

We can have some contention here when pushing to the vectors... We have this pattern also in other places in the code as well, but this one is a bit worse because you're pushing to the vector in a loop during the search :)

[dranikpg]

Do you mean that we push in a loop without a resize ahead? We don't have any estimation for the number of docs 🤷🏻 I don't think that's as issue for now (MVP is brute force search, no performance goals)

[royjacobson]

No, sorry that I've been unclear. We're pushing to docs[0] and docs[1] from different threads, but since they're allocated continuously inside docs they're probably on the same cache line. And since each push_back changes the vector's size member, you're going to get contention between the threads.

I agree it's not the end of the world, just wanted to point it out :)

[dranikpg]

Ah, I see, you mean cache padding. Agree, we need a general solution for this for all other places as well:

• a CachePadded<T> wrapper
• and possibly use an inlined vector for small thread counts

Transaction currently does all of this with its shard data, but its not re-usable.

[chakaz]

Usually there's no need for static-private class members, we can just declare them in an anonymous namespace in the .cc file. Looks like we've already done this in bitops_family:

dragonfly/src/server/bitops_family.h

Lines 20 to 28 in 79da3e6

	class BitOpsFamily {
	public:
	/// @brief Register the function that would be called to operate on user commands.
	/// @param registry The location to which the handling functions would be registered.
	///
	/// We are assuming that this would have a valid registry to work on (i.e this do not point to
	/// null!).
	static void Register(CommandRegistry* registry);
	};

[dranikpg]

We do it very inconsistently, they're present mostly on the older files. I like when you have a quick overview over the command handlers from the header. Anyways I can remove them

[chakaz]

100% your call, just a suggestion. As always, feel free to overrule :)

[chakaz]

Very rapid progress, good job! :)

[chakaz]

100% your call, just a suggestion. As always, feel free to overrule :)

[dranikpg]

Fixed comments