A bulk transfer of more than 8K of data takes about one second with the
Cobalt. Because we use a one second timeout combined with a 10K buffer,
such a transfer can easily exceed the timeout. Normally this shouldn't
be a problem because the leftover data is supposed to be received with
the next transfer. However to break out of the loop we check the actual
number of bytes received, and ignore the libusb LIBUSB_ERROR_TIMEOUT
return code.
To fix this problem, the internal buffer is reduced to 8K, and the
timeout is increased to 2 seconds. This should avoid hitting the timeout
and allows to consider LIBUSB_ERROR_TIMEOUT a fatal error.
Adding the "dc_" namespace prefix (which is of course an abbreviation
for libdivecomputer) should avoid conflicts with other libraries. For
the time being, only the high-level device and parser layers are
changed.
The public header files are moved to a new subdirectory, to separate
the definition of the public interface from the actual implementation.
Using an identical directory layout as the final installation has the
advantage that the example code can be build outside the project tree
without any modifications to the #include statements.
Some of the older firmware versions contain a critical bug that can
possibly crash the device when trying to download dives, and also a bug
in the checksum calculation. To avoid these problems we simply refuse to
download when an old firmware is detected and require the user to
upgrade the firmware first.
The detection is performed by means of a new version command which
allows to retrieve the device information prior to downloading the
dives, but is only supported by recent firmware versions.
As a side effect, we gain access to the current firmware version, which
may be different from the one recorded during the last dive. And we can
get the info even if there are no dives present.
