vrb_space_len
returns the total length of space available in the given
virtual ring buffer.
This is the maximum space the caller may store into the buffer
from the pointer returned by
vrb_space_ptr(3).
ARGUMENTS
vrb_p vrb
specifies the virtual ring buffer to obtain the length of available
space in.
If a NULL or invalid pointer is given, results are unpredictable
and are likely to be disasterous.
RETURN VALUE
size_t
The length of available space in the virtual ring buffer is returned.