simple ringbuffer with possibility to get all data and/or only updates
the idea is to provide a ring buffer that can be queried for all inserted data, reset the read pointer and get incremental updates. I've used this approach in a system monitoring application where in the background the free memory is queried every second and put into the ringbuffer (put). When the reporting tool is started I get the total number of values inserted into the buffer (totalAvailableNumberElements and totalGet), reset the pointer after I've got all values (resetReadPosition) and afterwards can make live-reports with incremental updates (availableNumberElements and get) of the values instead of updating all values every updatestep.
the following sequence should explain well how the buffer works:
- ringbuffer(size 10) has 0 elements(totalAvailable and available elements return 0)
- put 1,2,3,4,5 into the ringbuffer
- totalAvailable and available elements return 5
- get 2 values (return the 1 and 2)
- totalAvailable will return 5, available elements return 3
- call resetReadPosition
- totalAvailable will return 5, available elements return 0
- put 6,7,8,9,10 into the ringbuffer
- totalAvailable will return 9, available elements return 5 (a ringbuffer of size n can save at most n-1 elements!)
- put 11,12,13,14,15,16,17,18,19 into the ringbuffer
- totalAvailable and available elements will return 9
no error detection is done, for example don't insert more values than the size of the ringbuffer-1 and don't get more elements than inserted and stuff like that.
MIT License
Copyright (C) 2013 questor(KaiJ)
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