Re: realloc() - frequency, conditions, or experiences about relocation?

On 18/06/2024 11:19, Malcolm McLean wrote:

On 18/06/2024 08:09, Tim Rentsch wrote:

Anton Shepelev <anton.txt@g{oogle}mail.com> writes:
>

Ben Bacarisse to Malcolm McLean:
>

[next is a comment from Malcolm]
>

Your strategy for avoiding these extremes is exponential
growth.

>
It's odd to call it mine.  It's very widely know and used.
"The one I mentioned" might be less confusing description.

>
I think it is a modern English idiom, which I dislike as
well.  StackOverflow is full of questions starting like:
"How do you do this?" and "How do I do that?"  They are
informal ways of the more literary "How does one do this?"
or "What is the way to do that?"

>
I have a different take here.  First the "your" of "your
strategy" reads as a definite pronoun, meaning it refers
specifically to Ben and not to some unknown other party.
(And incidentally is subtly insulting because of that,
whether it was meant that way or not.)
>
Second the use of "you" to mean an unspecified other person
is not idiom but standard usage.  The word "you" is both a
definite pronoun and an indefinite pronoun, depending on
context.  The word "they" also has this property.  Consider
these two examples:
>
    The bank downtown was robbed.  They haven't been caught
    yet.
>
    They say the sheriff isn't going to run for re-election.
>
In the first example "they" is a definite pronoun, referring
to the people who robbed the bank.  In the second example,
"they" is an indefinite pronoun, referring to unspecified
people in general (perhaps but not necessarily everyone).
The word "you" is similar:  it can mean specifically the
listener, or it can mean generically anyone in a broader
audience, even those who never hear or read the statement
with "you" in it.
>
The word "one" used as a pronoun is more formal, and to me
at least often sounds stilted.  In US English "one" is most
often an indefinite pronoun, either second person or third
person.  But "one" can also be used as a first person
definite pronoun (referring to the speaker), which an online
reference tells me is chiefly British English.  (I would
guess that this usage predominates in "the Queen's English"
dialect of English, but I have very little experience in
such things.)
>
Finally I would normally read "I" as a first person definite
pronoun, and not an indefinite pronoun.  So I don't have any
problem with someone saying "how should I ..." when asking
for advice.  They aren't asking how someone else should ...
but how they should ..., and what advice I might give could
very well depend on who is doing the asking.

 Ben said
 > Restore snipped Ben upthread
"In practice, the cost is usually
moderate and can be very effectively managed by using an exponential
allocation scheme: at every reallocation multiply the storage space by
some factor greater than 1 (I often use 3/2, but doubling is often used
as well)."
 So it's open and shut, and no two ways about it. Ben's strategy is exponential growth. And to be fair I use that strategy myself in functions like fslutp(). It's only not Ben's strategy if we mean to imply that Ben was the first person to use expoential growth, or the first to understand the mathematical implications, and of course that's not the case. It was all worked out by Euler long before any of us were born.
 The question is whether we can be a bit more rigorous than "we need exonential growth, let's double on each reallocation. Actually, that looks a bit greedy. Try 3/2". And we can do that. We can put it on a sounder statistical footing. Whether it actually worth it or not is a different matter.
 

Here are some real stats on file sizes, in case anone is interested.
Data set, / OS Log-normal median & mean, Arithmetic mean, 50% occupied by
(< mean)
whole data set,   9.0 KB,   730 KB, 1.5 MB < 5.4 KB
Mac OS            8.0 KB,   533 KB, 1.4 MB < 4.9 KB
Windows           11.5 KB,  1.0 MB, 1.7 MB < 8.3 KB
GNU/Linux         10.8 KB,  1.7MB,  2.2 MB < 4.8 KB
https://www.researchgate.net/publication/353066615_How_Big_Are_Peoples%27_Computer_Files_File_Size_Distributions_Among_User-managed_Collections
--
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