Most of the gains were from replacing endl with '\n', which avoids
unnecessary flushing. But there were a few hot functions whose
inefficiency ended up having a significan impact.
DreamStation ramp time and mask resistance "off" settings are now also imported.
Ventilator alarms are not yet parsed reliably enough to import at this time.
Previously it was reporting spurious information when the humidifier was
disconnected. Now it only reports settings details when the humidifier is
connected (the only time they're valid.)
It also now reports the humidification mode (fixed, adaptive, or heated
tube), and the heated tube temperature when appropriate.
The last statistics events in each slice are now correctly imported.
Previously, in the surprising edge case where two statistic periods are
reported with the same end-of-slice timestamp, they were both being duplicated
when marking the end of the slice.
Also, there were scattered instances where the final statistics in a slice
weren't being imported at all or were being imported incorrectly. These are
now fixed as well.
If there are no mask-on slices of nonzero duration, then there's not any
meaningful event or waveform data for the session. There is occasionally some
fragmentary data, but it's always less than 1 second.
When such fragmentary waveform data is present, it only contains 1-3 nonzero
samples, corresponding to 0.2s - 0.6s of data, which suggests that the
mask-on slice was really that long rather than precisely 0. As a result,
it appears that the timestamps of the mask-on/mask-off slices are just the
current value of the machine's internal clock, which only has 1-second
resolution.
But rather than embark on herculean efforts to derive a sub-second slice
duration from (only occasionally present) event or waveform data, we just
treat the session as having no detailed data.
Because summaries used to be parsed incorrectly, there was a bunch of ugly
logic that was designed to infer the session start & end times from other data.
Now that the summary parsers work, that can all go away. The only change to
imported data is that sessions ending with the mask off are now longer, to
reflect that extra time before the machine was turned off.
Also clean up unused PRS1 channels and fix a regression from
9a25647c that broke unintentional leak calculation for CPAP/APAP.
Also add PRS1PressureAverageEvent to F0V4 list of supported events.
Right now this results in slightly confusing graphs, since sometimes
the IPAP/EPAP data for a machine is primarily reported by its settings
events, and for other machines by its statistics events. Also, the
"average" pressure on F0 looks like it might be effectivley EPAP in
single-pressure mode rather than the true average in bi-level mode.
Once we decide on the best presentation, we can either update the importer
or the display to show the most helpful channels for a given session.
This one's slice 8 is shorter than anything else we've seen before!
Also add support for a new slice type and noted possible values
for other data, including a possible lead on the CPAP mode.
Remarkably, this resulted in nearly no changes to the test output.
Only one session with 0 duration had its start/end times reset to 0,
since it will no longer get imported.
This has already exposed many limitations, and possibly some memory trampling. Before this will work as
a true regression test, we'll need to address both of those, so that this produces reliable, reproducible
output.
