[pulseaudio-discuss] [PATCH] hashmap: Allow freeing of keys in addition to values

[Arun Raghavan]

On Tue, 2013-08-06 at 12:55 +0200, David Henningsson wrote:
> On 08/06/2013 11:02 AM, Arun Raghavan wrote:
> > This is handy for cases where we want to have the key freed at entry
> > removal or hashmap free'ing time. For example, this is useful when
> > creating a hashmap based on non-static strings.
> 
> I agree about the problem about string keys, but I think the
> implementation could be more elegant:
> 
> 1) The free_cb functions could be supplied with pa_hashmap_new and
> stored inside the hashmap, rather than being supplied in several places.

I did want to go this way originally, but it's a lot of non-scriptable
changes (~80 call sites). Tanu also had the same preference. Let me try
to rework the patch to do this, though not sure when I'll be able to do
that.

> 2) This applies mostly to strings. Could we perhaps make a convenience
> layer for string-key hashmaps, like this:
> 
> pa_hashmap_put_strkey(const char *strkey, void *value) {
>   void *key = pa_strdup(strkey);
>   pa_hashmap_put(key, value);
> }
> 
> ...and similar for other functions, when necessary?

I think it might be easier to read explicit pa_xstrdup() in the
pa_hashmap_put than to hide away this detail in a call.

Thanks,
Arun