turnersoftware / pingalot Goto Github PK

Found a possible stats bug whilst creating a unit test to verify statistics.
Test setup:
10 pings - 8 successful and 2 timed out
6 Pings with 10ms RT, 2 with 5ms RT and 2 time out so RT is 0.

Formula used for calculating AverageRoundtrip = totalRoundtrip / PacketsReceived

For our test case - calculating manually:
totalRoundtrip = 70
PacketsReceived = 8
AverageRoundtrip = 70 / 8 = 8.75

I am thinking that our result to two or maybe three decimal places, rounded up, would suffice?
Or should we more explicitly round this off to an integer?

Currently the application comes up with the AverageRoundtrip as 8 - no decimal places.

This appears to be because we use implicit typing to declare totalRoundtrip and assign a value of 0 as a long.
var totalRoundtrip = 0L;
PacketsReceived is an int
AverageRoundtrip is a double

double = long / int
This is truncating decimal places before being stored in the double
Explicitly setting totalRoundtrip to a double resolves the issue.

However we need to test further for results with more decimal places and maybe look to round to either 2 or 3 decimal places.

To replicate the issue:
Command Line Arguments: -t --layout 2 --export test.csv 56.56.56.56
This IP fails to respond to ping - for all requests

PingSession.cs:line 65
AverageRoundtrip = totalRoundtrip / PacketsReceived;
On the first ping PacketsReceived will be zero - triggering the DivideByZeroException

Picked this up when creating unit tests for PingSession

Possibly we just need to wrap line 65 with a conditional statement that sets AverageRoundtrip to 0 if PacketsReceived is 0.

Will add a unit test for this specific scenario

Based on the same concept in this: https://en.wikipedia.org/wiki/MTR_(software)

Effectively trace the hops between two targets, then ping each of the hops to see where the packet loss might be happening.

PacketsLostPercentage is a double.
Good idea to round this to two decimal places?

Currently it stores a list for final export but that isn't ideal for memory allocations. Instead, if the code was setup to write to the file every ping, if the application crashes the data isn't lost.

The core library does the heavy lifting of pinging. It is mostly a utility wrapper but might prove useful to those that want to embed pinging into their own applications.

Further research needs to be done on the applicability of this and how best to do it.