[Mesa-dev] [PATCH v2 27/64] gallium/util: add new util_dynarray_{shrink, delete} helpers

[Samuel Pitoiset]

On 06/07/2017 06:21 PM, Nicolai Hähnle wrote:
> On 30.05.2017 22:35, Samuel Pitoiset wrote:
>> These helpers will be used for handling dynamic arrays of resident
>> texture/image handles.
>>
>> Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
>> ---
>>   src/gallium/auxiliary/util/u_dynarray.h | 20 ++++++++++++++++++++
>>   1 file changed, 20 insertions(+)
>>
>> diff --git a/src/gallium/auxiliary/util/u_dynarray.h 
>> b/src/gallium/auxiliary/util/u_dynarray.h
>> index 7b7a093d82..d6f3d5c901 100644
>> --- a/src/gallium/auxiliary/util/u_dynarray.h
>> +++ b/src/gallium/auxiliary/util/u_dynarray.h
>> @@ -109,6 +109,26 @@ util_dynarray_trim(struct util_dynarray *buf)
>>   #define util_dynarray_element(buf, type, idx) ((type*)(buf)->data + 
>> (idx))
>>   #define util_dynarray_begin(buf) ((buf)->data)
>>   #define util_dynarray_end(buf) ((void*)util_dynarray_element((buf), 
>> char, (buf)->size))
>> +#define util_dynarray_shrink(buf, type, begin, 
>> end)                        \
>> +   do 
>> {                                                                    \
>> +      void *__begin = util_dynarray_element((buf), type, 
>> (begin));         \
>> +      void *__end = util_dynarray_element((buf), type, 
>> (end));             \
>> +      if ((end) * sizeof(type) < 
>> (buf)->size)                              \
>> +         memmove(__begin, __end, (buf)->size - ((end) * 
>> sizeof(type)));    \
>> +      (buf)->size = (buf)->size - ((end) - (begin)) * 
>> sizeof(type);        \
>> +   } while (0)
>> +#define util_dynarray_delete(buf, type, v)                           \
>> +   do {                                                              \
>> +      unsigned num_elements = (buf)->size / sizeof(type);            \
>> +      unsigned i;                                                    \
>> +      for (i = 0; i < num_elements; i++) {                           \
>> +         type __v = *util_dynarray_element((buf), type, (i));        \
>> +         if (v == __v) {                                             \
>> +            util_dynarray_shrink((buf), type, i, i + 1);             \
>> +            break;                                                   \
>> +         }                                                           \
>> +      }                                                              \
>> +   } while (0)
> 
> Does the order of elements matter? If not, it would be better to just 
> copy the last element into the gap that is left by the deleted element.

It doesn't matter, at least not for bindless handles.

> 
> Might be wise to rename the macro to util_dynarray_delete_unordered to 
> avoid future confusion.

Fixed locally.

Samuel.

> 
> Cheers,
> Nicolai
> 
> 
>>   #endif /* U_DYNARRAY_H */
>>
> 
>