Take two triples in atomic way

[volovyks]

Making all operations atomic prevents race conditions, especially in multithreaded and multi-node design. It also decreases the number of Redis calls and simplifies the code, although we lose some error types.

I plan to adopt this approach in other places if we stick with it.

[ChaoticTempest]

Why not use redis::transaction or redis::pipeline for this? A lua script would imply running a lua runtime and all the overhead that brings

[volovyks]

@ChaoticTempest atomic and transaction do not allow us to have conditional logic, return errors, etc.

[volovyks]

From what I see, Lua scripts are the only thing we can use to make all these operations in a completely isolated way.
Redis should be able to execute tens of thousands of such Lua scripts per second. We are very far from it to be a bottleneck.

[ChaoticTempest]

I took a look at benchmarks and Lua scripts actually don't have a huge performance impact (around +4-5%) but that's fine in the grand scheme of things

[ChaoticTempest]

TripleId implements Copy so no need to pass by reference. It's also cheaper to pass it by value than reference here too since pointers are fat (i.e. 8 bytes in 64bit systems)

[ChaoticTempest]

same with this one

[ailisp]

Looks good!