Re: [PATCH v3 1/3] string-list: add string_list initialiser helper functions

From: Torsten Bögershausen <tboegi@web.de>
Date: Jun 23, 2014, 12:36 UTC
Message-ID: <53A81F45.70802@web.de>
In-Reply-To: <1403518300-23053-2-git-send-email-tanayabh@gmail.com>

On 2014-06-23 12.11, Tanay Abhra wrote:

Show 29 quoted lines

> The string-list API has STRING_LIST_INIT_* macros to be used
> to define variables with initialisers, but lacks functions
> to initialise an uninitialised piece of memory to be used as
> a string-list at the run-time.
> Introduce string_list_init_{dup,nodup}() functions for that.
> 
> Signed-off-by: Tanay Abhra <tanayabh@gmail.com>
> ---
>  string-list.c | 18 ++++++++++++++++++
>  string-list.h |  3 +++
>  2 files changed, 21 insertions(+)
> 
> diff --git a/string-list.c b/string-list.c
> index aabb25e..8c3a4eb 100644
> --- a/string-list.c
> +++ b/string-list.c
> @@ -1,6 +1,24 @@
>  #include "cache.h"
>  #include "string-list.h"
>  
> +void string_list_init_nodup(struct string_list *list)
> +{
> +	list->items = NULL;
> +	list->nr = 0;
> +	list->alloc = 0;
> +	list->strdup_strings = 0;
> +	list->cmp = NULL;
> +}
> +

If we look at the definition below:
struct string_list {
	struct string_list_item *items;
	unsigned int nr, alloc;
	unsigned int strdup_strings:1;
	compare_strings_fn cmp; /* NULL uses strcmp() */
I think a simple memset() will be easier to read,
and it will be more future proof:
In case elements are added, the will have 0 or NULL automatically:

void string_list_init_nodup(struct string_list *list)
{
	memset (list, 0, sizeof(*list));
}
(But then I wonder if we need the function at all ?)

Or does it make sense to have a common function similar to this, which covers both cases:

void string_list_init(struct string_list *list, int strdup_strings)
{
	memset (list, 0, sizeof(*list));
	list->strdup_strings = strdup_strings;
}