On ti, 06 huhti 2021, Juliette Tux via FreeIPA-devel wrote:
Hello,
My name is Julia Dronova, I do Russian translations. Could some of you,
gentlemen, kindly clarify the meaning of the following:
"With those two attributes a range object can reserve the Posix IDs starting
with base-id up to but not including base-id+range-size exclusively"
I'm particularly confused by the meaning of "up to but not including"
followed by "exclusively". Does "exclusively" duplicate here the
"not
including" part or what..? Please help (:
Hi Julia,
"starting with base-id up to but not including" and "exclusively"
apply
to different parts of the sentence.
An ID range occupies some space and ID ranges cannot overlap. This is
what "exclusively" means here.
That space is "starting with base-id up to but not including base-id +
range-size". E.g. if base-id is 1000000 and size is 500000, then space
[1000000, 1500000) is what belongs to that ID range and no other ID
range can occupy it. I use '[' and ')' here in a traditional
mathematical sense -- '[' means including the starting point (e.g.
1000000) and ')' means excluding the final point (e.g. 1500000).
This means we can have two ranges:
- range A: [1000000, 1500000), size 500000
- range B: [1500000, 1700000), size 200000
They are not overlapping as ID 1500000 does not belong to range A.
We cannot have
- range C: [1400000, 1500001), size 100001
because this range would overlap with eihter range A and range B. Thus,
exclusivity rule makes range C incorrect.
Does it make sense now?
--
/ Alexander Bokovoy
Sr. Principal Software Engineer
Security / Identity Management Engineering
Red Hat Limited, Finland