IPFM Timestamps

A little explanation on right timestamps:

When I measure a value over time, I obtain, say 42 from 10:00 to 10:15. To store the value, you have multiple choices:

interval	left timestamp	right timestamp
10:00 -> 10:15 - 42	10:00 - 42	10:15 - 42
10:15 -> 10:30 - 43	10:15 - 43	10:30 - 43
10:30 -> 10:45 - 44	10:30 - 44	10:45 - 44
10:45 -> 11:00 - 43	10:45 - 43	11:00 - 43
...	...	...

Most of the time, the period of time over which you are mesuring is known, so you don't store the interval.

In energy production, the usage is to store production plans left stamped (at 10:00, produce 42MW power) and measures right stamped (at 10:15, you produced 42MW average power)

Actual IPFM behaviour (trunk since [117])

• IPFM uses a customisable timestamp (link/right dump/clear) for the output file name
• IPFM lists current time, link and left timestamp for dump and clear in the output file.
• IPFM does not care about the real time for the name of the output file (it could be different because of a SIGINT, SIGUSR1, and so on).

Wishlist

• have a look how IPFM handels an interface that does not output packets. I think it hangs and would produce its dump to late. See Ticket #10