From: Linus Torvalds torvalds@linux-foundation.org Date: Sat, 3 Jan 2015 17:21:05 -0800 Subject: [PATCH] Extend SAMPLE_EVENT_GASCHANGE2 to have cylinder index in 'flags' field

A value of zero (which is the normal legacy one) remains "unknown", but the divecomputer backend can now give both gasmix and cylinder number this way.

Currently only the EON Steel backend does that, but it should be easy enough to extend others too.

Also, fix the user-visible cylinder numbering in the cylinder change tooltip to use a human-friendlier one-based numbering (ie first cylinder is "cyl 1", not "cyl 0")

Signed-off-by: Linus Torvalds torvalds@linux-foundation.org ---

This is the subsurface side to take advantage of the gas index in the "flags" field of SAMPLE_EVENT_GASCHANGE2.

The main downside is that nobody historically looked at the "flag" field before, it is possible that some libdivecomputer backend doesn't fill it with zero. But a quick check seems to imply that all backends properly clear it (most with an explicit "flag = 0" right around that SAMPLE_EVENT_GASCHANGE2, and the Suunto D9 parser that doesn't do that has a

dc_sample_value_t sample = {0};

to initialize the whole sample with zero, so it all looks fine.

NOTE! In subsurface itself, when we then *save* the data, it looks like we don't save a cylinder index of 0 in the git save state. So we lose the explicit cylinder value for the first cylinder. I'll take a look at that later, but it's independent of this particular patch.

It's also not clear that subsurface should necessarily bother to save the cylinder index at all if it's unambiguous and can be calculated from the gas mix. None of this code has really gotten much testing, since the whole "explicit cylinder index" is all new, and basically nobody has data with it (since libdivecomputer imports haven't had the data).

The fact that we showed the cylinder index zero-based in the newly added tooltip text is very much an example of that kind of lack of data leading to lack of test coverage. This fixes that too (we internally number our gas indexes from 0..7 because they are C array indexes, and "unknown" is thus -1. But obviously from a human readability we should call the first cylinder "cyl 1" rather than "cyl 0".

Ho humm. We probably have tons of small issues like this in this area.

dive.c | 7 ++++++- qt-ui/profile/diveeventitem.cpp | 2 +- 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/dive.c b/dive.c index 32ac25e2ae83..711392c5adc1 100644 --- a/dive.c +++ b/dive.c @@ -57,6 +57,7 @@ int event_gasmix_redundant(struct event *ev)

struct event *add_event(struct divecomputer *dc, int time, int type, int flags, int value, const char *name) { + int gas_index = -1; struct event *ev, **p; unsigned int size, len = strlen(name);

@@ -79,11 +80,15 @@ struct event *add_event(struct divecomputer *dc, int time, int type, int flags, case SAMPLE_EVENT_GASCHANGE2: /* High 16 bits are He percentage */ ev->gas.mix.he.permille = (value >> 16) * 10; + + /* Extension to the GASCHANGE2 format: cylinder index in 'flags' */ + if (flags > 0 && flags <= MAX_CYLINDERS) + gas_index = flags-1; /* Fallthrough */ case SAMPLE_EVENT_GASCHANGE: /* Low 16 bits are O2 percentage */ ev->gas.mix.o2.permille = (value & 0xffff) * 10; - ev->gas.index = -1; + ev->gas.index = gas_index; break; }

diff --git a/qt-ui/profile/diveeventitem.cpp b/qt-ui/profile/diveeventitem.cpp index 4294dfb29589..1a5e29dda1ee 100644 --- a/qt-ui/profile/diveeventitem.cpp +++ b/qt-ui/profile/diveeventitem.cpp @@ -106,7 +106,7 @@ void DiveEventItem::setupToolTipString()

/* Do we have an explicit cylinder index? Show it. */ if (internalEvent->gas.index >= 0) - name += QString(" (cyl %1)").arg(internalEvent->gas.index); + name += QString(" (cyl %1)").arg(internalEvent->gas.index+1); } else if (type == SAMPLE_EVENT_PO2 && name == "SP change") { name += QString(":%1").arg((double)value / 1000); } else {