Mares Darwin compatible devices support a nitrox mode. The nitrogen
percentage should only be taken into account when the dive mode is set
to nitrox, because the last used value remains in place for air dives.
Errors reported by system calls are now converted to the corresponding
libdivecomputer status code. This results in a more descriptive and
meaningfull return value.
The low level serial and IrDA functions are modified to:
- Use the libdivecomputer namespace prefix.
- Return a more detailed status code instead of the zero on success and
negative on error return value. This will allow to return more
fine-grained error codes.
- The read and write functions have an additional output parameter to
return the actual number of bytes transferred. Since these functions
are not atomic, some data might still be transferred successfully if
an error occurs.
The dive computer backends are updated to use the new api.
The devinfo event with the device serial number is required for the
fingerprint feature. Without this event, applications won't be able to
load (or save) the correct fingerprint. All necessary information is
already available in the initial handshake packet.
A new buffer is allocated for each dive, but only the last one is freed.
Since the code is already prepared to simply re-use the same buffer,
there is no need to allocate those extra buffers.
Just like the D4i and D6i, the new header is a few bytes larger. The
correct variant can again be detected by means of the logbook id tag at
the start of the header.
The Shearwater devices support adding, removing or editing gas mixes
during the dive. The pre-defined gas mixes available in the opening and
closing block are only a snapshot of the configuration at the start and
at the end of the dive. Thus by editing the gas mixes during the dive
it's possible to switch to a gas mix that is not present in the opening
(or even the closing block). The parser doesn't support that.
To avoid this problem, we now collect the available gas mixes from the
sample data. As a side effect we only return those gas mixes that are
effectively used during the dive.
One of the newer D4i and D6i firmware versions (for example v1.5.9),
introduces a new variant of the data format. The new dive header is 8
bytes larger. The correct variant can be detected by means of the
logbook id tag at the start of the header.
By reading the hardware descriptor immediately after entering download
or service mode, we can identify the specific model and adapt to minor
differences in the communication protocol.
For the OSTC3 compatible devices, a missing initial gas mix (e.g. no gas
marked as the first gas) leaves the initial gas mix index at its default
value of zero. This is different from the OSTC2 compatible devices,
where a missing initial gas is stored as the value 0xFF.
By initializing the index with the value 0xFF, the existing detection
works for both variants.
Unlike the other socket functions, the WSAStartup() function returns the
extended error code directly. A call to the WSAGetLastError() function
is not needed and should not be used.
In freedive mode, samples are only 2 or 4 bytes large, thus a sample
containing all 0x00 bytes represents a zero depth value and not some
invalid data that should be ignored.
I originally assumed the second byte contains the hour, but that turns
out to be wrong. At least some of the bits have a different meaning.
With only seconds and minutes, the maximum divetime is limited to at
most 99 minutes and 59 seconds. That shouldn't be a problem for
freedives.
The Oceanic and Aeris F11 have a configurable sample rate. The possible
sample intervals are 2, 1, 0.5 and 0.25 seconds. Since our smallest unit
of time is one second, we can't represent the last two, and the extra
samples will get dropped for now.
Both the allocation and initialization of the object data structure is
now moved to a single function. The corresponding deallocation function
is intended to free objects that have been allocated, but are not fully
initialized yet. The public cleanup function shouldn't be used in such
case, because it may try to release resources that haven't been
initialized yet.
Instead of freeing the object data structure in the backend specific
cleanup function, the memory is now freed automatically in the base
class function. This reduces the amount of boilerplate code in the
backends. Backends that don't allocate any additional resources, do no
longer require a cleanup function at all.
When the close function returns, all resources should be freed,
regardless of whether an error has occured or not. The error code is
purely informative.
However, in order to return the first error code, which is usually the
most interesting one, the current implementation is unnecessary
complicated. If an error occurs, there is no need to exit immediately.
Simply store the error code unless there is already a previous one, and
then continue.
To store the day (range 1 to 31) as a binary encoded value, only 5 bits
are required. The extra 6th bit is part of the year. The year is also
not BCD encoded. This happened to work by accident, because for a single
nibble, the current implementation of the bcd2dec() function returns the
binary value.
The new gasmix sample contains the index of the active gas mix.
This new sample is intended as a replacement for the existing gas change
events (SAMPLE_EVENT_GASCHANGE and SAMPLE_EVENT_GASCHANGE2). To maintain
backwards compatibility, the legacy events are marked as deprecated but
not removed yet.
In CC mode, only the diluents are stored in the header. The list with
the OC gas mixes, which are used for bailout, are not stored in the
header. In order to retrieve the bailout mixes too, we need to parse the
profile and add them to the manual gas mixes.
