This adds the infrastructure for the "field cache", which is just
various helpers for the dc_get_field() interface.
This includes the 'dc_field_cache_t' structure that a libdivecomputer
backend can just add to its parser data structure, and a few macros to
make it very easy to initialize the fields and then return them in the
'get_field()' callback.
And part of it is the infrastructure support for the 'dc_field_string_t'
type, which adds the support for string fields. That will be used to
return various string-formatted data from the dive computer, like deco
models, serial numbers, etc.
And no, a serial number is most definitely not a "number". It's a string.
Right now there are no users of this yet, that comes next.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a new type to distinguish between closed circuit (CCR) and
semi-closed circuit (SCR) diving. Some dive computers from HW and
DiveSystem/Ratio support this.
Because the CCR/SCR abbreviations are more commonly used, let's take the
opportunity to also rename the existing DC_DIVEMODE_CC. To preserve
backwards compatibility, a macro is added to map the old name to the new
one.
Reported-by: Jan Mulder <jlmulder@xs4all.nl>
Allthough most dive computers always use local time and don't support
timezones at all, there are a few exceptions. There are two different
sources of timezone information:
- Some of the newer Uwatec/Scubapro devices use UTC internally and also
support a timezone setting. This UTC offset is currently taken into
account to obtain the dive date/time, but the UTC offset itself is
lost.
- Uwatec/Scubapro and Reefnet devices rely on the clock of the host
system to synchronize the internal device clock and calculate the
dive date/time. The consequence is that the resulting date/time is
always in the timezone of the host system.
In order to preserve this timezone information, the dc_datetime_t
structure is extended with a new "timezone" field, containing the UTC
offset in seconds. Devices without timezone support will set the field
to the special value DC_TIMEZONE_NONE.
The dc_datetime_localtime() and dc_datetime_gmtime() functions will
automatically populate the new field with respectively the local
timezone offset and zero. The dc_datetime_mktime() function will take
into account the new timezone field for the conversion to UTC. The
special value DC_TIMEZONE_NONE is interpreted as zero.
Libdivecomputer always uses metric units internally. But when reverse
engineering a device that stores everything using imperial units, it's
very convenient to be able to switch the output to imperial units too.
