commit 78a7a626aa135d9cd7414e7610b4713a67b83266 Author: Karsten Loesing karsten.loesing@gmx.net Date: Sun Jun 15 10:37:30 2014 +0200
Don't compress weights values with missing values.
When compressing weights status lines, we simply combined adjacent intervals by calculating arithmetic means. But we did not consider missing values, which were encoded as 0.0. As a result the result was lower than it should really have been. Now that missing values are encoded as -1.0, it becomes even more apparent that this approach was wrong with negative weights values of, e.g., -0.127320915201. As a fix, avoid compressing intervals with missing values for certain weights.
Example of an old combined line:
2008-08-20 20:00:00 2008-08-29 00:00:00 0.000261225507 -0.127320915201 -1.000000000000 -1.000000000000 -1.000000000000 76374.857142857120 65.306122448979
The -0.127320915201 part is wrong there.
Example of the same data, not combined:
2008-08-20 20:00:00 2008-08-21 21:00:00 0.000245451671 -1.000000000000 -1.000000000000 -1.000000000000 -1.000000000000 73466.880000000000 -1.000000000000 2008-08-21 21:00:00 2008-08-29 00:00:00 0.000263531623 0.000263746320 -1.000000000000 -1.000000000000 -1.000000000000 76800.000000000000 75.000000000000
Found in the context of implementing #11388. --- src/org/torproject/onionoo/WeightsStatusUpdater.java | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/src/org/torproject/onionoo/WeightsStatusUpdater.java b/src/org/torproject/onionoo/WeightsStatusUpdater.java index 24c98ff..5932da6 100644 --- a/src/org/torproject/onionoo/WeightsStatusUpdater.java +++ b/src/org/torproject/onionoo/WeightsStatusUpdater.java @@ -257,6 +257,7 @@ public class WeightsStatusUpdater implements DescriptorListener, long lastStartMillis = 0L, lastEndMillis = 0L; double[] lastWeights = null; String lastMonthString = "1970-01"; + int lastMissingValues = -1; for (Map.Entry<long[], double[]> e : history.entrySet()) { long startMillis = e.getKey()[0], endMillis = e.getKey()[1]; double[] weights = e.getValue(); @@ -277,10 +278,17 @@ public class WeightsStatusUpdater implements DescriptorListener, } String monthString = DateTimeHelper.format(startMillis, DateTimeHelper.ISO_YEARMONTH_FORMAT); + int missingValues = 0; + for (int i = 0; i < weights.length; i++) { + if (weights[i] < -0.5) { + missingValues += 1 << i; + } + } if (lastEndMillis == startMillis && ((lastEndMillis - 1L) / intervalLengthMillis) == ((endMillis - 1L) / intervalLengthMillis) && - lastMonthString.equals(monthString)) { + lastMonthString.equals(monthString) && + lastMissingValues == missingValues) { double lastIntervalInHours = (double) ((lastEndMillis - lastStartMillis) / DateTimeHelper.ONE_HOUR); double currentIntervalInHours = (double) ((endMillis @@ -303,6 +311,7 @@ public class WeightsStatusUpdater implements DescriptorListener, lastWeights = weights; } lastMonthString = monthString; + lastMissingValues = missingValues; } if (lastStartMillis > 0L) { compressedHistory.put(new long[] { lastStartMillis, lastEndMillis },