feat: add support for query operators

[vasa-develop]

Supported Conditional Operators

• $lt
• $gt
• $lte
• $gte

Supported Logical Operators

• $and
• $or

Observations

1. The benchmark seems to have taken a big hit.

461 queries per second, 17695 queries in 40 seconds (Oplog: 5000)
488 queries per second, 18183 queries in 41 seconds (Oplog: 5000)
562 queries per second, 18745 queries in 42 seconds (Oplog: 5000)
652 queries per second, 19397 queries in 43 seconds (Oplog: 5000)
578 queries per second, 19975 queries in 44 seconds (Oplog: 5000)
611 queries per second, 20586 queries in 45 seconds (Oplog: 5000)
541 queries per second, 21127 queries in 46 seconds (Oplog: 5000)
457 queries per second, 21584 queries in 47 seconds (Oplog: 5000)
544 queries per second, 22128 queries in 48 seconds (Oplog: 5000)
561 queries per second, 22689 queries in 49 seconds (Oplog: 5000)
--> Average of 535 q/s in the last 10 seconds

2. The benchmarks have the same results, irrespective of how complex is the query.

License: MIT
Signed-off-by: Vaibhav Saini vasa@dappkit.io

[vasa-develop]

@vaultec81 I will try to optimize the query algorithm in the future releases. Let me know if you can suggest some optimizations in QueryOperators.js

Also, the implementation is a bit messy. I will clean it up going forward.

[vaultec81]

Possible issue here. How does this affect when we want to use an on disk index or other optimized index?

[vasa-develop]

I'm not aware of that. How should this be written? Should I add another param for supplying a custom index?

[vaultec81]

I am not sure at the moment. We don't have any formal API for index/store. I think for now its alright.

[vasa-develop]

I got a few ideas to make this efficient: Short-circuit evaluation

UPDATE: Applied all optimizations that I could think of. The performance improved for some specific conditions.
But for worst cases (in which it has to loop through all the query conditions), we can't do much better.