Collect historical network stats.
Periodically records delta network traffic into historical buckets to
support other services, such NetworkPolicyManager and Settings UI.
Introduces NetworkStatsHistory structure which contains sparse, uniform
buckets of data usage defined by timestamps. Service periodically
polls NetworkStats and records changes into buckets. It only persists
to disk when substantial changes have occured. Current parameters
create 4 buckets each day, and persist for 90 days, resulting in about
8kB of data per network.
Only records stats for "well known" network interfaces that have been
claimed by Telephony or Wi-Fi subsystems. Historical stats are also
keyed off identity (such as IMSI) to support SIM swapping.
Change-Id: Ia27d1289556a2bf9545fbc4f3b789425a01be53a
diff --git a/core/java/android/content/Context.java b/core/java/android/content/Context.java
index a660bd7..aecec66 100644
--- a/core/java/android/content/Context.java
+++ b/core/java/android/content/Context.java
@@ -1545,6 +1545,8 @@
public static final String NETWORKMANAGEMENT_SERVICE = "network_management";
/** {@hide} */
+ public static final String NETWORK_STATS_SERVICE = "netstats";
+ /** {@hide} */
public static final String NETWORK_POLICY_SERVICE = "netpolicy";
/**
diff --git a/core/java/android/net/INetworkStatsService.aidl b/core/java/android/net/INetworkStatsService.aidl
new file mode 100644
index 0000000..6d57036
--- /dev/null
+++ b/core/java/android/net/INetworkStatsService.aidl
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.net;
+
+import android.net.NetworkStatsHistory;
+
+/** {@hide} */
+interface INetworkStatsService {
+
+ NetworkStatsHistory[] getNetworkStatsSummary(int networkType);
+ NetworkStatsHistory getNetworkStatsUid(int uid);
+
+}
diff --git a/core/java/android/net/NetworkStats.java b/core/java/android/net/NetworkStats.java
index 0f207bc..588bf64 100644
--- a/core/java/android/net/NetworkStats.java
+++ b/core/java/android/net/NetworkStats.java
@@ -22,19 +22,22 @@
import java.io.CharArrayWriter;
import java.io.PrintWriter;
+import java.util.HashSet;
/**
- * Collection of network statistics. Can contain summary details across all
- * interfaces, or details with per-UID granularity. Designed to parcel quickly
- * across process boundaries.
+ * Collection of active network statistics. Can contain summary details across
+ * all interfaces, or details with per-UID granularity. Internally stores data
+ * as a large table, closely matching {@code /proc/} data format. This structure
+ * optimizes for rapid in-memory comparison, but consider using
+ * {@link NetworkStatsHistory} when persisting.
*
* @hide
*/
public class NetworkStats implements Parcelable {
- /** {@link #iface} value when entry is summarized over all interfaces. */
+ /** {@link #iface} value when interface details unavailable. */
public static final String IFACE_ALL = null;
- /** {@link #uid} value when entry is summarized over all UIDs. */
- public static final int UID_ALL = 0;
+ /** {@link #uid} value when UID details unavailable. */
+ public static final int UID_ALL = -1;
// NOTE: data should only be accounted for once in this structure; if data
// is broken out, the summarized version should not be included.
@@ -49,7 +52,7 @@
public final long[] rx;
public final long[] tx;
- // TODO: add fg/bg stats and tag granularity
+ // TODO: add fg/bg stats once reported by kernel
private NetworkStats(long elapsedRealtime, String[] iface, int[] uid, long[] rx, long[] tx) {
this.elapsedRealtime = elapsedRealtime;
@@ -120,15 +123,35 @@
}
/**
+ * Return list of unique interfaces known by this data structure.
+ */
+ public String[] getKnownIfaces() {
+ final HashSet<String> ifaces = new HashSet<String>();
+ for (String iface : this.iface) {
+ if (iface != IFACE_ALL) {
+ ifaces.add(iface);
+ }
+ }
+ return ifaces.toArray(new String[ifaces.size()]);
+ }
+
+ /**
* Subtract the given {@link NetworkStats}, effectively leaving the delta
* between two snapshots in time. Assumes that statistics rows collect over
* time, and that none of them have disappeared.
+ *
+ * @param enforceMonotonic Validate that incoming value is strictly
+ * monotonic compared to this object.
*/
- public NetworkStats subtract(NetworkStats value) {
- // result will have our rows, but no meaningful timestamp
- final int length = length();
- final NetworkStats.Builder result = new NetworkStats.Builder(-1, length);
+ public NetworkStats subtract(NetworkStats value, boolean enforceMonotonic) {
+ final long deltaRealtime = this.elapsedRealtime - value.elapsedRealtime;
+ if (enforceMonotonic && deltaRealtime < 0) {
+ throw new IllegalArgumentException("found non-monotonic realtime");
+ }
+ // result will have our rows, and elapsed time between snapshots
+ final int length = length();
+ final NetworkStats.Builder result = new NetworkStats.Builder(deltaRealtime, length);
for (int i = 0; i < length; i++) {
final String iface = this.iface[i];
final int uid = this.uid[i];
@@ -142,6 +165,9 @@
// existing row, subtract remote value
final long rx = this.rx[i] - value.rx[j];
final long tx = this.tx[i] - value.tx[j];
+ if (enforceMonotonic && (rx < 0 || tx < 0)) {
+ throw new IllegalArgumentException("found non-monotonic values");
+ }
result.addEntry(iface, uid, rx, tx);
}
}
diff --git a/core/java/android/net/NetworkStatsHistory.aidl b/core/java/android/net/NetworkStatsHistory.aidl
new file mode 100644
index 0000000..8b9069f
--- /dev/null
+++ b/core/java/android/net/NetworkStatsHistory.aidl
@@ -0,0 +1,19 @@
+/**
+ * Copyright (c) 2011, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.net;
+
+parcelable NetworkStatsHistory;
diff --git a/core/java/android/net/NetworkStatsHistory.java b/core/java/android/net/NetworkStatsHistory.java
new file mode 100644
index 0000000..b16101f
--- /dev/null
+++ b/core/java/android/net/NetworkStatsHistory.java
@@ -0,0 +1,285 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.net;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+import java.io.CharArrayWriter;
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.util.Arrays;
+
+/**
+ * Collection of historical network statistics, recorded into equally-sized
+ * "buckets" in time. Internally it stores data in {@code long} series for more
+ * efficient persistence.
+ * <p>
+ * Each bucket is defined by a {@link #bucketStart} timestamp, and lasts for
+ * {@link #bucketDuration}. Internally assumes that {@link #bucketStart} is
+ * sorted at all times.
+ *
+ * @hide
+ */
+public class NetworkStatsHistory implements Parcelable {
+ private static final int VERSION = 1;
+
+ /** {@link #uid} value when UID details unavailable. */
+ public static final int UID_ALL = -1;
+
+ // TODO: teach about zigzag encoding to use less disk space
+ // TODO: teach how to convert between bucket sizes
+
+ public final int networkType;
+ public final String identity;
+ public final int uid;
+ public final long bucketDuration;
+
+ int bucketCount;
+ long[] bucketStart;
+ long[] rx;
+ long[] tx;
+
+ public NetworkStatsHistory(int networkType, String identity, int uid, long bucketDuration) {
+ this.networkType = networkType;
+ this.identity = identity;
+ this.uid = uid;
+ this.bucketDuration = bucketDuration;
+ bucketStart = new long[0];
+ rx = new long[0];
+ tx = new long[0];
+ bucketCount = bucketStart.length;
+ }
+
+ public NetworkStatsHistory(Parcel in) {
+ networkType = in.readInt();
+ identity = in.readString();
+ uid = in.readInt();
+ bucketDuration = in.readLong();
+ bucketStart = readLongArray(in);
+ rx = in.createLongArray();
+ tx = in.createLongArray();
+ bucketCount = bucketStart.length;
+ }
+
+ /** {@inheritDoc} */
+ public void writeToParcel(Parcel out, int flags) {
+ out.writeInt(networkType);
+ out.writeString(identity);
+ out.writeInt(uid);
+ out.writeLong(bucketDuration);
+ writeLongArray(out, bucketStart, bucketCount);
+ writeLongArray(out, rx, bucketCount);
+ writeLongArray(out, tx, bucketCount);
+ }
+
+ public NetworkStatsHistory(DataInputStream in) throws IOException {
+ final int version = in.readInt();
+ networkType = in.readInt();
+ identity = in.readUTF();
+ uid = in.readInt();
+ bucketDuration = in.readLong();
+ bucketStart = readLongArray(in);
+ rx = readLongArray(in);
+ tx = readLongArray(in);
+ bucketCount = bucketStart.length;
+ }
+
+ public void writeToStream(DataOutputStream out) throws IOException {
+ out.writeInt(VERSION);
+ out.writeInt(networkType);
+ out.writeUTF(identity);
+ out.writeInt(uid);
+ out.writeLong(bucketDuration);
+ writeLongArray(out, bucketStart, bucketCount);
+ writeLongArray(out, rx, bucketCount);
+ writeLongArray(out, tx, bucketCount);
+ }
+
+ /** {@inheritDoc} */
+ public int describeContents() {
+ return 0;
+ }
+
+ /**
+ * Record that data traffic occurred in the given time range. Will
+ * distribute across internal buckets, creating new buckets as needed.
+ */
+ public void recordData(long start, long end, long rx, long tx) {
+ // create any buckets needed by this range
+ ensureBuckets(start, end);
+
+ // distribute data usage into buckets
+ final long duration = end - start;
+ for (int i = bucketCount - 1; i >= 0; i--) {
+ final long curStart = bucketStart[i];
+ final long curEnd = curStart + bucketDuration;
+
+ // bucket is older than record; we're finished
+ if (curEnd < start) break;
+ // bucket is newer than record; keep looking
+ if (curStart > end) continue;
+
+ final long overlap = Math.min(curEnd, end) - Math.max(curStart, start);
+ if (overlap > 0) {
+ this.rx[i] += rx * overlap / duration;
+ this.tx[i] += tx * overlap / duration;
+ }
+ }
+ }
+
+ /**
+ * Ensure that buckets exist for given time range, creating as needed.
+ */
+ private void ensureBuckets(long start, long end) {
+ // normalize incoming range to bucket boundaries
+ start -= start % bucketDuration;
+ end += (bucketDuration - (end % bucketDuration)) % bucketDuration;
+
+ for (long now = start; now < end; now += bucketDuration) {
+ // try finding existing bucket
+ final int index = Arrays.binarySearch(bucketStart, 0, bucketCount, now);
+ if (index < 0) {
+ // bucket missing, create and insert
+ insertBucket(~index, now);
+ }
+ }
+ }
+
+ /**
+ * Insert new bucket at requested index and starting time.
+ */
+ private void insertBucket(int index, long start) {
+ // create more buckets when needed
+ if (bucketCount + 1 > bucketStart.length) {
+ final int newLength = bucketStart.length + 10;
+ bucketStart = Arrays.copyOf(bucketStart, newLength);
+ rx = Arrays.copyOf(rx, newLength);
+ tx = Arrays.copyOf(tx, newLength);
+ }
+
+ // create gap when inserting bucket in middle
+ if (index < bucketCount) {
+ final int dstPos = index + 1;
+ final int length = bucketCount - index;
+
+ System.arraycopy(bucketStart, index, bucketStart, dstPos, length);
+ System.arraycopy(rx, index, rx, dstPos, length);
+ System.arraycopy(tx, index, tx, dstPos, length);
+ }
+
+ bucketStart[index] = start;
+ rx[index] = 0;
+ tx[index] = 0;
+ bucketCount++;
+ }
+
+ /**
+ * Remove buckets older than requested cutoff.
+ */
+ public void removeBucketsBefore(long cutoff) {
+ int i;
+ for (i = 0; i < bucketCount; i++) {
+ final long curStart = bucketStart[i];
+ final long curEnd = curStart + bucketDuration;
+
+ // cutoff happens before or during this bucket; everything before
+ // this bucket should be removed.
+ if (curEnd > cutoff) break;
+ }
+
+ if (i > 0) {
+ final int length = bucketStart.length;
+ bucketStart = Arrays.copyOfRange(bucketStart, i, length);
+ rx = Arrays.copyOfRange(rx, i, length);
+ tx = Arrays.copyOfRange(tx, i, length);
+ bucketCount -= i;
+ }
+ }
+
+ public void dump(String prefix, PrintWriter pw) {
+ // TODO: consider stripping identity when dumping
+ pw.print(prefix);
+ pw.print("NetworkStatsHistory: networkType="); pw.print(networkType);
+ pw.print(" identity="); pw.print(identity);
+ pw.print(" uid="); pw.println(uid);
+ for (int i = 0; i < bucketCount; i++) {
+ pw.print(prefix);
+ pw.print(" timestamp="); pw.print(bucketStart[i]);
+ pw.print(" rx="); pw.print(rx[i]);
+ pw.print(" tx="); pw.println(tx[i]);
+ }
+ }
+
+ @Override
+ public String toString() {
+ final CharArrayWriter writer = new CharArrayWriter();
+ dump("", new PrintWriter(writer));
+ return writer.toString();
+ }
+
+ public static final Creator<NetworkStatsHistory> CREATOR = new Creator<NetworkStatsHistory>() {
+ public NetworkStatsHistory createFromParcel(Parcel in) {
+ return new NetworkStatsHistory(in);
+ }
+
+ public NetworkStatsHistory[] newArray(int size) {
+ return new NetworkStatsHistory[size];
+ }
+ };
+
+ private static long[] readLongArray(DataInputStream in) throws IOException {
+ final int size = in.readInt();
+ final long[] values = new long[size];
+ for (int i = 0; i < values.length; i++) {
+ values[i] = in.readLong();
+ }
+ return values;
+ }
+
+ private static void writeLongArray(DataOutputStream out, long[] values, int size) throws IOException {
+ if (size > values.length) {
+ throw new IllegalArgumentException("size larger than length");
+ }
+ out.writeInt(size);
+ for (int i = 0; i < size; i++) {
+ out.writeLong(values[i]);
+ }
+ }
+
+ private static long[] readLongArray(Parcel in) {
+ final int size = in.readInt();
+ final long[] values = new long[size];
+ for (int i = 0; i < values.length; i++) {
+ values[i] = in.readLong();
+ }
+ return values;
+ }
+
+ private static void writeLongArray(Parcel out, long[] values, int size) {
+ if (size > values.length) {
+ throw new IllegalArgumentException("size larger than length");
+ }
+ out.writeInt(size);
+ for (int i = 0; i < size; i++) {
+ out.writeLong(values[i]);
+ }
+ }
+
+}
diff --git a/core/java/android/net/TrafficStats.java b/core/java/android/net/TrafficStats.java
index c0ff734..8ab64fa 100644
--- a/core/java/android/net/TrafficStats.java
+++ b/core/java/android/net/TrafficStats.java
@@ -141,7 +141,8 @@
// subtract starting values and return delta
final NetworkStats profilingStop = getNetworkStatsForUid(context);
- final NetworkStats profilingDelta = profilingStop.subtract(sActiveProfilingStart);
+ final NetworkStats profilingDelta = profilingStop.subtract(
+ sActiveProfilingStart, false);
sActiveProfilingStart = null;
return profilingDelta;
}
diff --git a/core/java/android/os/INetStatService.aidl b/core/java/android/os/INetStatService.aidl
deleted file mode 100644
index a8f3de0..0000000
--- a/core/java/android/os/INetStatService.aidl
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * Copyright (C) 2008 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.os;
-
-/**
- * Retrieves packet and byte counts for the phone data interface,
- * and for all interfaces.
- * Used for the data activity icon and the phone status in Settings.
- *
- * {@hide}
- */
-interface INetStatService {
- long getMobileTxPackets();
- long getMobileRxPackets();
- long getMobileTxBytes();
- long getMobileRxBytes();
- long getTotalTxPackets();
- long getTotalRxPackets();
- long getTotalTxBytes();
- long getTotalRxBytes();
-}
diff --git a/core/tests/coretests/src/android/net/NetworkStatsHistoryTest.java b/core/tests/coretests/src/android/net/NetworkStatsHistoryTest.java
new file mode 100644
index 0000000..eb63c0d
--- /dev/null
+++ b/core/tests/coretests/src/android/net/NetworkStatsHistoryTest.java
@@ -0,0 +1,210 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.net;
+
+import static android.net.ConnectivityManager.TYPE_MOBILE;
+import static android.net.NetworkStatsHistory.UID_ALL;
+import static android.text.format.DateUtils.DAY_IN_MILLIS;
+import static android.text.format.DateUtils.HOUR_IN_MILLIS;
+import static android.text.format.DateUtils.MINUTE_IN_MILLIS;
+import static android.text.format.DateUtils.SECOND_IN_MILLIS;
+import static android.text.format.DateUtils.WEEK_IN_MILLIS;
+import static android.text.format.DateUtils.YEAR_IN_MILLIS;
+
+import android.test.suitebuilder.annotation.SmallTest;
+import android.test.suitebuilder.annotation.Suppress;
+import android.util.Log;
+
+import junit.framework.TestCase;
+
+import java.util.Random;
+
+@SmallTest
+public class NetworkStatsHistoryTest extends TestCase {
+ private static final String TAG = "NetworkStatsHistoryTest";
+
+ private static final long TEST_START = 1194220800000L;
+
+ private NetworkStatsHistory stats;
+
+ @Override
+ protected void tearDown() throws Exception {
+ super.tearDown();
+ if (stats != null) {
+ assertConsistent(stats);
+ }
+ }
+
+ public void testRecordSingleBucket() throws Exception {
+ final long BUCKET_SIZE = HOUR_IN_MILLIS;
+ stats = buildStats(BUCKET_SIZE);
+
+ // record data into narrow window to get single bucket
+ stats.recordData(TEST_START, TEST_START + SECOND_IN_MILLIS, 1024L, 2048L);
+
+ assertEquals(1, stats.bucketCount);
+ assertBucket(stats, 0, 1024L, 2048L);
+ }
+
+ public void testRecordEqualBuckets() throws Exception {
+ final long bucketDuration = HOUR_IN_MILLIS;
+ stats = buildStats(bucketDuration);
+
+ // split equally across two buckets
+ final long recordStart = TEST_START + (bucketDuration / 2);
+ stats.recordData(recordStart, recordStart + bucketDuration, 1024L, 128L);
+
+ assertEquals(2, stats.bucketCount);
+ assertBucket(stats, 0, 512L, 64L);
+ assertBucket(stats, 1, 512L, 64L);
+ }
+
+ public void testRecordTouchingBuckets() throws Exception {
+ final long BUCKET_SIZE = 15 * MINUTE_IN_MILLIS;
+ stats = buildStats(BUCKET_SIZE);
+
+ // split almost completely into middle bucket, but with a few minutes
+ // overlap into neighboring buckets. total record is 20 minutes.
+ final long recordStart = (TEST_START + BUCKET_SIZE) - MINUTE_IN_MILLIS;
+ final long recordEnd = (TEST_START + (BUCKET_SIZE * 2)) + (MINUTE_IN_MILLIS * 4);
+ stats.recordData(recordStart, recordEnd, 1000L, 5000L);
+
+ assertEquals(3, stats.bucketCount);
+ // first bucket should have (1/20 of value)
+ assertBucket(stats, 0, 50L, 250L);
+ // second bucket should have (15/20 of value)
+ assertBucket(stats, 1, 750L, 3750L);
+ // final bucket should have (4/20 of value)
+ assertBucket(stats, 2, 200L, 1000L);
+ }
+
+ public void testRecordGapBuckets() throws Exception {
+ final long BUCKET_SIZE = HOUR_IN_MILLIS;
+ stats = buildStats(BUCKET_SIZE);
+
+ // record some data today and next week with large gap
+ final long firstStart = TEST_START;
+ final long lastStart = TEST_START + WEEK_IN_MILLIS;
+ stats.recordData(firstStart, firstStart + SECOND_IN_MILLIS, 128L, 256L);
+ stats.recordData(lastStart, lastStart + SECOND_IN_MILLIS, 64L, 512L);
+
+ // we should have two buckets, far apart from each other
+ assertEquals(2, stats.bucketCount);
+ assertBucket(stats, 0, 128L, 256L);
+ assertBucket(stats, 1, 64L, 512L);
+
+ // now record something in middle, spread across two buckets
+ final long middleStart = TEST_START + DAY_IN_MILLIS;
+ final long middleEnd = middleStart + (HOUR_IN_MILLIS * 2);
+ stats.recordData(middleStart, middleEnd, 2048L, 2048L);
+
+ // now should have four buckets, with new record in middle two buckets
+ assertEquals(4, stats.bucketCount);
+ assertBucket(stats, 0, 128L, 256L);
+ assertBucket(stats, 1, 1024L, 1024L);
+ assertBucket(stats, 2, 1024L, 1024L);
+ assertBucket(stats, 3, 64L, 512L);
+ }
+
+ public void testRecordOverlapBuckets() throws Exception {
+ final long BUCKET_SIZE = HOUR_IN_MILLIS;
+ stats = buildStats(BUCKET_SIZE);
+
+ // record some data in one bucket, and another overlapping buckets
+ stats.recordData(TEST_START, TEST_START + SECOND_IN_MILLIS, 256L, 256L);
+ final long midStart = TEST_START + (HOUR_IN_MILLIS / 2);
+ stats.recordData(midStart, midStart + HOUR_IN_MILLIS, 1024L, 1024L);
+
+ // should have two buckets, with some data mixed together
+ assertEquals(2, stats.bucketCount);
+ assertBucket(stats, 0, 768L, 768L);
+ assertBucket(stats, 1, 512L, 512L);
+ }
+
+ public void testRemove() throws Exception {
+ final long BUCKET_SIZE = HOUR_IN_MILLIS;
+ stats = buildStats(BUCKET_SIZE);
+
+ // record some data across 24 buckets
+ stats.recordData(TEST_START, TEST_START + DAY_IN_MILLIS, 24L, 24L);
+ assertEquals(24, stats.bucketCount);
+
+ // try removing far before buckets; should be no change
+ stats.removeBucketsBefore(TEST_START - YEAR_IN_MILLIS);
+ assertEquals(24, stats.bucketCount);
+
+ // try removing just moments into first bucket; should be no change
+ // since that bucket contains data beyond the cutoff
+ stats.removeBucketsBefore(TEST_START + SECOND_IN_MILLIS);
+ assertEquals(24, stats.bucketCount);
+
+ // try removing single bucket
+ stats.removeBucketsBefore(TEST_START + HOUR_IN_MILLIS);
+ assertEquals(23, stats.bucketCount);
+
+ // try removing multiple buckets
+ stats.removeBucketsBefore(TEST_START + (4 * HOUR_IN_MILLIS));
+ assertEquals(20, stats.bucketCount);
+
+ // try removing all buckets
+ stats.removeBucketsBefore(TEST_START + YEAR_IN_MILLIS);
+ assertEquals(0, stats.bucketCount);
+ }
+
+ @Suppress
+ public void testFuzzing() throws Exception {
+ try {
+ // fuzzing with random events, looking for crashes
+ final Random r = new Random();
+ for (int i = 0; i < 500; i++) {
+ stats = buildStats(r.nextLong());
+ for (int j = 0; j < 10000; j++) {
+ if (r.nextBoolean()) {
+ // add range
+ final long start = r.nextLong();
+ final long end = start + r.nextInt();
+ stats.recordData(start, end, r.nextLong(), r.nextLong());
+ } else {
+ // trim something
+ stats.removeBucketsBefore(r.nextLong());
+ }
+ }
+ assertConsistent(stats);
+ }
+ } catch (Throwable e) {
+ Log.e(TAG, String.valueOf(stats));
+ throw new RuntimeException(e);
+ }
+ }
+
+ private static NetworkStatsHistory buildStats(long bucketSize) {
+ return new NetworkStatsHistory(TYPE_MOBILE, null, UID_ALL, bucketSize);
+ }
+
+ private static void assertConsistent(NetworkStatsHistory stats) {
+ // verify timestamps are monotonic
+ for (int i = 1; i < stats.bucketCount; i++) {
+ assertTrue(stats.bucketStart[i - 1] < stats.bucketStart[i]);
+ }
+ }
+
+ private static void assertBucket(NetworkStatsHistory stats, int index, long rx, long tx) {
+ assertEquals("unexpected rx", rx, stats.rx[index]);
+ assertEquals("unexpected tx", tx, stats.tx[index]);
+ }
+
+}
diff --git a/core/tests/coretests/src/android/net/NetworkStatsTest.java b/core/tests/coretests/src/android/net/NetworkStatsTest.java
index 45719c2..23eb9cf 100644
--- a/core/tests/coretests/src/android/net/NetworkStatsTest.java
+++ b/core/tests/coretests/src/android/net/NetworkStatsTest.java
@@ -47,8 +47,9 @@
.addEntry(TEST_IFACE, 100, 1024, 0)
.addEntry(TEST_IFACE, 101, 0, 1024).build();
- final NetworkStats result = after.subtract(before);
+ final NetworkStats result = after.subtract(before, true);
+ // identical data should result in zero delta
assertEquals(0, result.rx[0]);
assertEquals(0, result.tx[0]);
assertEquals(0, result.rx[1]);
@@ -64,7 +65,7 @@
.addEntry(TEST_IFACE, 100, 1025, 2)
.addEntry(TEST_IFACE, 101, 3, 1028).build();
- final NetworkStats result = after.subtract(before);
+ final NetworkStats result = after.subtract(before, true);
// expect delta between measurements
assertEquals(1, result.rx[0]);
@@ -83,7 +84,7 @@
.addEntry(TEST_IFACE, 101, 0, 1024)
.addEntry(TEST_IFACE, 102, 1024, 1024).build();
- final NetworkStats result = after.subtract(before);
+ final NetworkStats result = after.subtract(before, true);
// its okay to have new rows
assertEquals(0, result.rx[0]);