Extremely slow Petrel import + crash when saving

[Jef Driesen]

> On Tue, Sep 17, 2013 at 10:52 PM, Jef Driesen <jefdriesen at telenet.be> 
> wrote:
> If you try downloading with the libdivecomputer universal tool, is the
> download equally slow? The generated logfile will contain detailed 
> timing
> info.
> 
> ./universal -l output.log -d output.xml -v -n "Shearwater Petrel"
> <portname>
> 
> Yup, still about one minute per dive.  I cancelled the the transfer 
> after
> two dives, and here are the logs:
> 
> https://dl.dropboxusercontent.com/u/1087529/output.log
> https://dl.dropboxusercontent.com/u/1087529/output.xml

When I analyze the logfile, I see a repeating pattern. There is always a 
number of write's (to send a request to the device) followed by a number 
of read's (the receive the response packet). The read sequence is always 
very fast, in the order of just a few milliseconds for the entire 
packet. But writing appears to be terrible slow, with about 1.5 seconds 
for just a few bytes.

Look for example at the first dive (lines 3594 to 7560). It has a 
(compressed) size of only 3460 bytes but takes approximately 47 seconds 
to download. Since the data is send in packets of 144 bytes, there are 
24 data packets (and two more for the init/quit packets). Thus of those 
47 seconds, roughly 39 seconds (26 times 1.5s) are spend sending 
requests!

I wonder if this is some platform or driver related issue. Can you try 
the download on another platform (Windows or Linux) to check?

Jef