Re: [PATCH 3/9] hashmap: Call user supplied value free function in insert

[Denis Kenzior <denkenz@gmail.com>]

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Hi Patrik,

On 02/11/2015 03:27 AM, Patrik Flykt wrote:
> On Tue, 2015-02-10 at 13:18 -0600, Denis Kenzior wrote:
>> With the current implementation, the item inserted first is
>> returned.  I don't think enforcement of unique keys is required at the
>> hashmap_insert level.
>
> As long as there is no function to read out more than one of the values
> from the hashmap, the hashmap should definitely require keys to be
> unique. It's way much simpler to require unique keys as the opposite
> situation with multiple values per key  as it is really uncommon and
> shows that the upper level data structure needs a rethought.
>

The point is, you can't just add a 'value destroy' function when we 
already provide l_hashmap_destroy_func_t as an argument.  That is just 
wrong, no ifs or buts about it.  If you want to do that, then you need 
to fix a ton of existing code to handle the new usage model.  Not just 
hack stuff in.

Duplicate key detection is just overhead, if the programmer knows that 
no duplicate keys are possible.  This is about 99% of how we do things. 
  If you need guaranteed enforcement, then just implement 
l_hashmap_replace like I suggested.

Regards,
-Denis