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.
The existing output code is removed and replaced with the new XML and
RAW output formats. The desired output format can be selected with a new
command-line option. The XML format remains the default output format.
The RAW output format exports each dive to a raw (binary) file. To
output multiple files, the filename is interpreted as a template and
should contain one or more placeholders.
The new output interface provides the necessary infrastructure to add
support for multiple output formats. Due to the abstract interface, each
new format will require only minimal changes in the application itself.
On BSD based operating systems (which includes Mac OS X), the getopt()
function is posix compliant and thus the option processing stops when
the first non-option is found. But the getopt_long() function permutes
the argument vector, just like the GNU implementation.
Using a leading '+' character in the option string disables the
permutation again.
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.
The universal application works well, but is quite difficult to extend
with more functionality. Therefore a new and more modular application is
needed. The new dctool application will support multiple sub-commands,
to carry out specific actions. Extending the application will be as easy
as adding new commands.
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.
