[FFmpeg-devel] [PATCH 1/6] lavu/mem: add av_realloc_reuse() as a replacement for av_fast_realloc()

[Tomas Härdin]

ons 2022-09-28 klockan 12:48 +0200 skrev Anton Khirnov:
> 
> +/**
> + * Reallocate a data buffer, reusing the existing one if it is large
> enough.
> + *
> + * This function is similar to av_realloc(), but optimized for cases
> where the
> + * buffer may grow significantly and is not expected to shrink.
> + *
> + * @param[in] ptr Previously allocated buffer, or `NULL`. If `ptr`
> is `NULL`, a
> + * new uninitialized buffer is allocated. `ptr` is invalidated when
> this
> + * function returns non-`NULL` and must be replaced with its return
> value.
> + *
> + * @param[in,out] size Pointer to the allocated size of buffer
> `ptr`. This
> + * function updates `*size` to the new allocated size (which may be
> larger than
> + * `min_size`). `*size` is set to 0 on failure.
> + *
> + * @param[in] min_size Minimum size in bytes of the returned buffer.
> + *
> + * @return
> + * - An allocated buffer (to be freed with `av_free()`) that is
> large enough to
> + *   hold at least `min_size` bytes. The first `*size` (value on
> entry to this
> + *   function) bytes of the buffer remain the same as the data in
> `ptr`, the
> + *   rest is uninitialized.
> + * - `NULL` on failure, then `*size` is set to 0 and ptr remains
> untouched.
> + *
> + * @see av_realloc()
> + * @see av_fast_malloc()
> + */
> +void *av_realloc_reuse(void *ptr, size_t *size, size_t min_size);

Isn't it better to return int like av_realloc_array_reuse() and leave
*ptr and *size untouched on error just as it does? If we're in the
business of straightening this all out then having all functions work
the same is less mental load down the line.

/Tomas