Jellyfish.Commands.Metrics.RollingPercentileNumber.GetBuckets C# (CSharp) Method

        internal IEnumerable<Bucket> GetBuckets(long startWindowTime = 0)
        {
            var idx = currentBucketIndex;
            if (startWindowTime == 0)
                startWindowTime = clock.EllapsedTimeInMs - (numberOfBuckets * bucketSizeInMs);
            var cx = numberOfBuckets;

            while (cx-- > 0)
            {
                var b = buckets[idx];
                if (b.bucketStartInMs < startWindowTime) break;
                yield return b;
                idx = (idx - 1);
                if (idx < 0) idx = numberOfBuckets;
            }
        }

        public void testRolling()
        {
            MockedClock time = new MockedClock();
            RollingPercentileNumber p = new RollingPercentileNumber(time, timeInMilliseconds, numberOfBuckets, bucketDataLength, DynamicProperties.Factory.AsProperty(true));
            p.AddValue(1000);
            p.AddValue(1000);
            p.AddValue(1000);
            p.AddValue(2000);

            Assert.Equal(1, p.GetBuckets().Count());

            // no bucket turnover yet so percentile not yet generated
            Assert.Equal(0, p.GetPercentile(50));

            time.Increment(6000);

            // still only 1 bucket until we touch it again
            Assert.Equal(1, p.GetBuckets().Count());

            // a bucket has been created so we have a new percentile
            Assert.Equal(1000, p.GetPercentile(50));

            // now 2 buckets since getting a percentile causes bucket retrieval
            Assert.Equal(2, p.GetBuckets().Count());

            p.AddValue(1000);
            p.AddValue(500);

            // should still be 2 buckets
            Assert.Equal(2, p.GetBuckets().Count());

            p.AddValue(200);
            p.AddValue(200);
            p.AddValue(1600);
            p.AddValue(200);
            p.AddValue(1600);
            p.AddValue(1600);

            // we haven't progressed to a new bucket so the percentile should be the same and ignore the most recent bucket
            Assert.Equal(1000, p.GetPercentile(50));

            // Increment to another bucket so we include all of the above in the PercentileSnapshot
            time.Increment(6000);

            // the rolling version should have the same data as creating a snapshot like this
            PercentileSnapshot ps = new PercentileSnapshot(1000, 1000, 1000, 2000, 1000, 500, 200, 200, 1600, 200, 1600, 1600);

            Assert.Equal(ps.GetPercentile(0.15), p.GetPercentile(0.15));
            Assert.Equal(ps.GetPercentile(0.50), p.GetPercentile(0.50));
            Assert.Equal(ps.GetPercentile(0.90), p.GetPercentile(0.90));
            Assert.Equal(ps.GetPercentile(0.995), p.GetPercentile(0.995));

            //Console.WriteLine("100th: " + ps.GetPercentile(100) + "  " + p.GetPercentile(100));
            //Console.WriteLine("99.5th: " + ps.GetPercentile(99.5) + "  " + p.GetPercentile(99.5));
            //Console.WriteLine("99th: " + ps.GetPercentile(99) + "  " + p.GetPercentile(99));
            //Console.WriteLine("90th: " + ps.GetPercentile(90) + "  " + p.GetPercentile(90));
            //Console.WriteLine("50th: " + ps.GetPercentile(50) + "  " + p.GetPercentile(50));
            //Console.WriteLine("10th: " + ps.GetPercentile(10) + "  " + p.GetPercentile(10));

            // mean = 1000+1000+1000+2000+1000+500+200+200+1600+200+1600+1600/12
            Assert.Equal(991, ps.Mean);
        }