Re: [PATCH 1/2] add macro REALLOC_ARRAY

Michael Haggerty [off-list ref] writes:

On 09/16/2014 08:56 PM, René Scharfe wrote:

quoted

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.