Cache time representation.

[cheatfate]

According to my benchmarks this gives 18% performance boost on Linux.
Latest version gives over 100% performance boost on Linux.

[cheatfate]

I have improved algorithm and using this example i have benchmarked original and improved version in Linux VM using redirection to file (to avoid terminal performance problems).

import chronicles, std/monotimes

const TestsCount = 6000000

proc testFoo() =
  let start = getMonoTime()
  for i in 0 ..< TestsCount:
    info "Performance check", index = i
  echo "It takes ", getMonoTime() - start

when isMainModule:
  testFoo()

Original version

It takes (seconds: 47, nanosecond: 561114303) = 47.561 = 126153 lines/sec
It takes (seconds: 47, nanosecond: 945328972) = 47.945 = 125143 lines/sec
It takes (seconds: 47, nanosecond: 265613714) = 47.265 = 126943 lines/sec
It takes (seconds: 49, nanosecond: 303206524) = 49.303 = 121696 lines/sec
It takes (seconds: 48, nanosecond: 444603490) = 48.444 = 123854 lines/sec

Average performance = 124757 lines/sec

Improved version

It takes (seconds: 21, nanosecond: 419377659) = 21.419 = 280125 lines/sec
It takes (seconds: 20, nanosecond: 913452058) = 20.913 = 286902 lines/sec
It takes (seconds: 19, nanosecond: 751597292) = 19.751 = 303782 lines/sec
It takes (seconds: 18, nanosecond: 108224670) = 18.108 = 331345 lines/sec
It takes (seconds: 22, nanosecond: 91658474) = 22.916 = 261825 lines/sec

Average performance = 292795 lines/sec

Performance boost 134.69%

[arnetheduck]

Suggested change

	let tmp = $sec
	res[1] = tmp[0]
	res[1] = '0' + char(sec)

etc .. can avoid the memory allocations here