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Subject: Re: get rid of getpwent? (Was: cygwin-1.7.28 getpwent header declaration changes ?)
From: Warren Young <warren AT etr-usa DOT com>
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On Feb 7, 2014, at 5:40 PM, Andrey Repin <anrdaemon AT yandex DOT ru> wrote:

>>> I thought the point of the programme /was/ to call getpwnam() a million
>>> times.

Precisely.

> In either case, repeatedly requesting the same record in a short amount of
> time will only test the system level cache.

If that were true, moving the requested record around in /etc/passwd wouldn’t cause a 6x spread in test results. That’s O(N) type behavior, whereas a cache approaches O(1).

If SAM uses a tree-structured DB, as I suspect, it will be some logarithmic function, like O(log2(N)).
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