Merge "Revert "Account for interpolation loss in cumulative network stats"" into main (ce7e0227) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/stats/pull/netstats/NetworkStatsAccumulator.java

+4 −20

Original line number	Diff line number	Diff line
		@@ -19,7 +19,6 @@ package com.android.server.stats.pull.netstats;
		import android.annotation.NonNull;
		import android.net.NetworkStats;
		import android.net.NetworkTemplate;
		import android.util.Log;

		import java.util.Objects;

		@@ -34,7 +33,6 @@ import java.util.Objects;
		*/
		public class NetworkStatsAccumulator {

		private static final String TAG = "NetworkStatsAccumulator";
		private final NetworkTemplate mTemplate;
		private final boolean mWithTags;
		private final long mBucketDurationMillis;
		@@ -59,9 +57,8 @@ public class NetworkStatsAccumulator {
		@NonNull
		public NetworkStats queryStats(long currentTimeMillis,
		@NonNull StatsQueryFunction queryFunction) {
		NetworkStats completeStats = snapshotPlusFollowingStats(currentTimeMillis, queryFunction);
		maybeExpandSnapshot(currentTimeMillis, completeStats, queryFunction);
		return completeStats;
		maybeExpandSnapshot(currentTimeMillis, queryFunction);
		return snapshotPlusFollowingStats(currentTimeMillis, queryFunction);
		}

		/**
		@@ -75,28 +72,15 @@ public class NetworkStatsAccumulator {
		* Expands the internal cumulative stats snapshot, if possible, by querying NetworkStats.
		*/
		private void maybeExpandSnapshot(long currentTimeMillis,
		NetworkStats completeStatsUntilCurrentTime,
		@NonNull StatsQueryFunction queryFunction) {
		// Update snapshot only if it is possible to expand it by at least one full bucket, and only
		// if the new snapshot's end is not in the active bucket.
		long newEndTimeMillis = currentTimeMillis - mBucketDurationMillis;
		if (newEndTimeMillis - mSnapshotEndTimeMillis > mBucketDurationMillis) {
		Log.v(TAG,
		"Expanding snapshot (mTemplate=" + mTemplate + ", mWithTags=" + mWithTags
		+ ") from " + mSnapshotEndTimeMillis + " to " + newEndTimeMillis
		+ " at " + currentTimeMillis);
		NetworkStats extraStats = queryFunction.queryNetworkStats(
		mTemplate, mWithTags, mSnapshotEndTimeMillis, newEndTimeMillis);
		NetworkStats extraStats = queryFunction.queryNetworkStats(mTemplate, mWithTags,
		mSnapshotEndTimeMillis, newEndTimeMillis);
		mSnapshot = mSnapshot.add(extraStats);
		mSnapshotEndTimeMillis = newEndTimeMillis;

		// NetworkStats queries interpolate historical data using integers maths, which makes
		// queries non-transitive: Query(t0, t1) + Query(t1, t2) <= Query(t0, t2).
		// Compute interpolation data loss from moving the snapshot's end-point, and add it to
		// the snapshot to avoid under-counting.
		NetworkStats newStats = snapshotPlusFollowingStats(currentTimeMillis, queryFunction);
		NetworkStats interpolationLoss = completeStatsUntilCurrentTime.subtract(newStats);
		mSnapshot = mSnapshot.add(interpolationLoss);
		}
		}