Uwatec Smart Z data download takes 1.5 hours for only 4 dives

Linus Torvalds torvalds at linux-foundation.org
Mon Dec 23 16:29:37 UTC 2013

On Mon, Dec 23, 2013 at 1:25 PM, Dirk Hohndel <dirk at hohndel.org> wrote:
> Linus - I don't remember why we did not use the fingerprint based
> implementation... can you remind me?

The fingerprint was too much random crud to actually bother saving
without a sane format (it's just a byte blob). We do use it (to
generate the dive ID), but we have turned it into something much more
easily used for our needs.

Also, it's useless for all the cases we had actually seen, so there
was very little reason to even worry about it.

But I guess we could save it off for specific dive computers, and then
in libdivecomputer.c:event_cb(), we cowhen we've calculated the
deviceid, we could do something like

    /* We don't have this right now, it would walk dives
     * starting from the most recent to the oldest */
    for_each_dive_reverse(dive, i) {
        for_each_dc(dive, dc) {
            if (dc->deviceid == devdata->deviceid && dc->fingerprint) {
                dc_device_set_fingerprint(device, dc->fingerprint);
                return 0;

or similar (the above is pseudo-code and the fingerprint isn't a
string, it would have to be a blob with length etc).

But this seems to be the first device to actually need it, and the
1.5h download seems to really be due to some independent problem (ie
something is much too slow regardless).


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