The dc_parser_set_data() function allows to re-use a parser object for
multiple dives. The advantages of this feature are actually very limited
in practice. The reduction in memory consumption is almost negligible,
because the amount of internal state in the parser is typically very
small. But the implementation requires some additional complexity
because each backend needs code to reset its internal state. Therefore,
the function is removed and the data and size needs to be passed
directly to the dc_parser_new() and dc_parser_new2() functions instead.
Because keeping a reference to the data has also caused issues in the
past, especially for applications implemented in a garbage collected
language, the data will now also get copied internally.
Because the sample struct is passed by value, the size of the structure
can't be changed without also changing the function signature and
breaking backwards compatibility. This prevents adding new fields in the
future, to support some new features.
When passing the sample struct by reference using a pointer, the size of
the pointer does always remains the same.
Rebreathers typically support multiple ppO2 sensors as a safety measure
in case a sensor fails during the dive. The current api can already
report multiple ppO2 values per sample, but it does not provide any
information about which sensor the measurement is from.
The new sensor index provides this info, and can also be used to
distinguish between the average/voted ppO2 value using the special value
DC_SENSOR_NONE.
Some dive computers, especially freediving computers, supports multiple
samples per second. Since our smallest unit of time is one second, we
can't represent this, and the extra samples are dropped. Therefore, the
units are changed to milliseconds to prepare supporting this extra
resolution.
For dive computers where the reference time (epoch) of the device is
unknown, libdivecomputer uses the current time of the device (devtime)
and the host system (systime) to synchronize both clocks.
Currently, both timestamps are passed directly to the constructor of the
parser. With the new public function, the application can adjust the
timestamps afterwards.
Some dive computers store the depth as an absolute pressure value (in
bar). To convert to a depth value (in meters), the atmospheric pressure
and water density are required. For dive computers that do not have
those values available, libdivecomputer uses a default value. With the
new public api functions, applications can adjust those default values.
Some dive computers already provided a backend specific calibration
function. Those functions are now deprecated. They are kept around to
maintain backwards compatibility for now, but they will be removed in
the next version.
