Adds a method called `reserve()`, that will take a ByteBuffer::IoVec
array of at least two elements, and return the number of elements
filled out. 0 will be returned if `len` is over the total space of
the buffer; 1 will be returned if there's enough contiguous bytes in
the buffer; 2 will be returned if there are two non-contiguous blocks
of memory.
This method is suitable to be used with POSIX system calls such as
readv(), and is an optimization to not require temporary memory copies
while reading from a file descriptor.
Also modify the write() method to use reserve(), so that similar checks
are performed only in one place.
Modify ByteBuffer class to have a `peekiovec()` method, that takes in a
`struct IoVec` array (similar to `struct iovec` from POSIX), and a
number of bytes, and returns the number of elements from this array
that have been filled out. It is either 0 (buffer is empty), 1
(there's enough contiguous bytes to read that amount) or 2 (ring buffer
is wrapping around).
This enables using scatter-gather I/O (i.e. writev()), removing calls
to memcpy(). That's one call when no wrap-around is happening, and
two calls if it is.
Also, rewrite `ByteBuffer::peekbytes()` to use `peekiovec()`, so that
some of the checks performed by the former are not replicated in the
latter.
this adds TKOFF_NAV_ALT which controls the altitude above takeoff that
navigation can begin. It is meant for unstable vehicles such as helis
to prevent blade strike during initial takeoff.
This also adds a new parameter class ParametersG2 which can hold 64
parameters. This is to avoid running out of parameters in the first
256 block
- Correctly sort includes and add missing AP_Math.h
- Use anonymous struct for trim_registers in _load_trim_values,
renaming its members so they don't start with underscore
- Don't change _dig* values when we failed to read from sensor
- Add some blank lines
- Make _dig_* members be inside a _dig struct
- Use constrain_int32 instead of if/else chain
- s/time_us/time_usec/
- Construct raw_field with a single constructor in _update()
- Add missing copyright notice
- Group methods together in declaration
