rand: add uuid_v7(), session function, simplify uuid_v4()

[kbkpbot]

Feature request #24311

[huly-for-github]

Connected to Huly®: V_0.6-22689

[spytheman]

Good work.
What is the performance of the new uuid_v4 implementation compared to the old one?

[kbkpbot]

Good work. What is the performance of the new uuid_v4 implementation compared to the old one?

A simple benchmark:

module main
import rand
import benchmark

fn main() {
        mut b := benchmark.start()

        for _ in 0..10000000 {
                rand.uuid_v4()
        }
        b.measure('uuid_v4')
}

old version:

$ ./r
 SPENT  3146.729 ms in uuid_v4

new version:

$ ./r
 SPENT   925.424 ms in uuid_v4

This is mainly because old version uuid_v4() generate a single uuid will use 4 calls of rand.u64() , but the new version only use 2 calls of rand.u64().

[JalonSolov]

Ooo... gotta love it. Add feature AND increase performance at the same time? Nice...