Read data from the ringbuffer.
@param rb a pointer to the ringbuffer structure. @param dest a pointer to a buffer where data read from the ringbuffer will go. @param cnt the number of bytes to read.
@return the number of bytes read, which may range from 0 to cnt.
See Implementation
Read data from the ringbuffer.
@param rb a pointer to the ringbuffer structure. @param dest a pointer to a buffer where data read from the ringbuffer will go. @param cnt the number of bytes to read.
@return the number of bytes read, which may range from 0 to cnt.