On Fri, 28 Oct 2005 17:07:17 Lawrence Sanbourne <email@hidden> wrote:
> On Oct 28, 2005, at 4:54 PM, Laurence Harris wrote:
>
>> No. You're going to have to allocate memory somehow as you add more
>> items to
>> the array anyway.
>
> But with a C array I have to reallocate the entire array, rather than
> just being able to add entries to the end of it as I go, as with a
> linked list.
True, but see below.
>>> Do you think it's worth it to make my own simple linked list
>>> struct?
>>
>> I wouldn't, not if I wanted the advantages of an array. A linked
>> list is a very different beast and is best for different operations
>> than those at which an array excels.
>> ...
>> You get the advantages of contiguous memory, the easy of use of vectors,
Why do you think there is an advantage of using continuous memory and
vectors in this case (iterating directory structure)? I don't see the
need for random access here. Yes, arrays are typically considered
easier than linked lists, but there are cons as well.
> Since I'm just iterating straight through this collection, a linked
> list would be fine.
Yes, but see below.
> I didn't know about PtrAndHand! Very cool. Do you think it would be
> more efficient to use a linked list since this will never require
> relocating allocated memory (no doubt a costly operation)?
WinAPI's FindFirst just allocate the whole directory structure in one
handle making a "snapshot" and the subsequent FindNexts just read from
this handle. This has the advantage of atomic (consistent) result: you
won't get inconsistent result if the directory changing while you
iterating over it. You may try doing the same by allocating memory for
all items and making a single GetBulkInfo call, thus eliminating the
need for reallocate or using linked list structures. Though, the
problem with this is that the number of files in the directory might
change after you've called FSGetCatalogInfo on the parent (to know
its valence = number of sub items in it) and before you call
FSGetCatalogInfoBulk to grab that many items.
Mike
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