[FFmpeg-devel] [PATCH] avutil/mem: add av_memdup()

[Paul B Mahol]

On 4/30/13, Michael Niedermayer <michaelni at gmx.at> wrote:
> On Sun, Apr 28, 2013 at 02:52:30PM +0200, Nicolas George wrote:
>> Le nonidi 9 floreal, an CCXXI, Michael Niedermayer a ecrit :
>> >  /**
>> > + * Duplicate the buffer p.
>> > + * @param p buffer to be duplicated
>> > + * @return Pointer to a newly allocated buffer containing a
>> > + * copy of p or NULL if the buffer cannot be allocated.
>> > + */
>> > +void *av_memdup(const void *p, size_t size);
>>
>> I like the idea. Possibly slightly more practical API:
>>
>> int av_memdup(void **dst, const void *src, size_t size);
>>
>> Returns 0 or AVERROR(ENOMEM) -> avoids "ret = AVERROR(ENOMEM);" before
>> "goto
>> fail;".
>>
>> dst is unchanged if allocation failed -> avoids using a temp variable.
>>
>> Optionally: free *dst before overwriting it.
>
> the cases where i want to use this copy a structure and then
> duplicate fields that where allocated so the whole struct becomes a
> clone.
> code that leaves dst in case of failure as well as code to free
> it are quite inconvenient for that (both would need to be worked
> around)

I like original simple code which is "clone" of av_strdup.

>
>
>>
>> Second option: "if (size == (size_t)-1) size = strlen(src) + 1;".
>>
>> Regards,
>>
>> --
>>   Nicolas George
>
>