Subject: Re: [PATCH 1/2] add macro REALLOC_ARRAY

From: Junio C Hamano <[email-masked]>
Date: Wed, 24 Sep 2014 10:59:29 -0700

Michael Haggerty <[email-masked]> writes:

> On 09/16/2014 08:56 PM, René Scharfe wrote:
>> The macro ALLOC_GROW manages several aspects of dynamic memory
>> allocations for arrays: It performs overprovisioning in order to avoid
>> reallocations in future calls, updates the allocation size variable,
>> multiplies the item size and thus allows users to simply specify the
>> item count, performs the reallocation and updates the array pointer.
>> 
>> Sometimes this is too much.  Add the macro REALLOC_ARRAY, which only
>> takes care of the latter three points and allows users to specfiy the
>> number of items the array can store.  It can increase and also decrease
>> the size.  Using the macro avoid duplicating the variable name and
>> takes care of the item sizes automatically.
>
> Is there a reason that ALLOC_GROW and REALLOC_ARRAY are defined in two
> separate header files (cache.h and git-compat-util.h, respectively)? It
> seems to me that they are close siblings and therefore I find it
> surprising that they are not defined right next to each other.

That was my initial reaction, but on the other hand, because
REALLOC_ARRAY() should never be used on an array managed by
ALLOC_GROW() without mucking with internal implementation details of
what ALLOC_GROW() does yourself, there is not much reason for them
to be listed and live together in the same place.

Listing them together might even invite confusion and mixed use by
mistake.