[pacman-dev] [PATCH v2] Remove "total download" callback in favor of generic event callback

[Andrew Gregory]

On 03/07/21 at 08:48pm, Anatol Pomozov wrote:
> Total download callback called right before packages start downloaded.
> But we already have an event for such event (ALPM_EVENT_PKG_RETRIEVE_START)
> and it is naturally to use the event to pass information about expected
> download size.
> 
> Signed-off-by: Anatol Pomozov <anatol.pomozov at gmail.com>
> ---

WRT this specific patch, it looks like we should do the same for
packages downloaded with -U.  We weren't calling totaldcb for that
before and we won't have a size to pass, but we can still at least
pass the count.

At a higher level though, I would like to start providing front-ends
the full list of payload data.  The existing setup, and this patch,
just provide enough information for pacman's display.  I think
something like the following callback API would be ideal:

/* all_progress - list of all payloads in the transaction
 * changed      - payloads changed since the last cb call
 * ctx          - caller-defined context
 */
int dlprogresscb(alpm_list_t *all_progress, alpm_list_t *changed, void *ctx)

I think we should split the current payload structure into a download
structure and a progress structure.  The full list of download
structures can then be passed to the fetchcb (and event cb), allowing
it to behave much more intelligently than it can now.  The list given
to the progress callback would be the list of progress structures,
which would probably then have a pointer back to the underlying
download structure.