Merge changes from topic "ms07-movestats" am: 942c713c9d am: cbc9da2aa2 am: ebca794eef am: ace650c0b2

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1895044

Change-Id: Ie8b9eefca78493204ae2d83c1e051f4c2788b5c5

1 files changed, 881 insertions, 0 deletions

diff --git a/framework-t/src/android/net/NetworkStatsHistory.java b/framework-t/src/android/net/NetworkStatsHistory.java
new file mode 100644
index 0000000000..a875e1ad45
--- /dev/null
+++ b/framework-t/src/android/net/NetworkStatsHistory.java
@@ -0,0 +1,881 @@
+/*
+ * 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.NetworkStats.IFACE_ALL;
+import static android.net.NetworkStats.SET_DEFAULT;
+import static android.net.NetworkStats.TAG_NONE;
+import static android.net.NetworkStats.UID_ALL;
+import static android.net.NetworkStatsHistory.DataStreamUtils.readFullLongArray;
+import static android.net.NetworkStatsHistory.DataStreamUtils.readVarLongArray;
+import static android.net.NetworkStatsHistory.DataStreamUtils.writeVarLongArray;
+import static android.net.NetworkStatsHistory.Entry.UNKNOWN;
+import static android.net.NetworkStatsHistory.ParcelUtils.readLongArray;
+import static android.net.NetworkStatsHistory.ParcelUtils.writeLongArray;
+import static android.text.format.DateUtils.SECOND_IN_MILLIS;
+
+import static com.android.internal.net.NetworkUtilsInternal.multiplySafeByRational;
+import static com.android.internal.util.ArrayUtils.total;
+
+import android.compat.annotation.UnsupportedAppUsage;
+import android.os.Build;
+import android.os.Parcel;
+import android.os.Parcelable;
+import android.service.NetworkStatsHistoryBucketProto;
+import android.service.NetworkStatsHistoryProto;
+import android.util.MathUtils;
+import android.util.proto.ProtoOutputStream;
+
+import com.android.internal.util.IndentingPrintWriter;
+
+import libcore.util.EmptyArray;
+
+import java.io.CharArrayWriter;
+import java.io.DataInput;
+import java.io.DataOutput;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.net.ProtocolException;
+import java.util.Arrays;
+import java.util.Random;
+
+/**
+ * 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_INIT = 1;
+    private static final int VERSION_ADD_PACKETS = 2;
+    private static final int VERSION_ADD_ACTIVE = 3;
+
+    public static final int FIELD_ACTIVE_TIME = 0x01;
+    public static final int FIELD_RX_BYTES = 0x02;
+    public static final int FIELD_RX_PACKETS = 0x04;
+    public static final int FIELD_TX_BYTES = 0x08;
+    public static final int FIELD_TX_PACKETS = 0x10;
+    public static final int FIELD_OPERATIONS = 0x20;
+
+    public static final int FIELD_ALL = 0xFFFFFFFF;
+
+    private long bucketDuration;
+    private int bucketCount;
+    private long[] bucketStart;
+    private long[] activeTime;
+    private long[] rxBytes;
+    private long[] rxPackets;
+    private long[] txBytes;
+    private long[] txPackets;
+    private long[] operations;
+    private long totalBytes;
+
+    public static class Entry {
+        public static final long UNKNOWN = -1;
+
+        @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
+        public long bucketDuration;
+        @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
+        public long bucketStart;
+        public long activeTime;
+        @UnsupportedAppUsage
+        public long rxBytes;
+        @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
+        public long rxPackets;
+        @UnsupportedAppUsage
+        public long txBytes;
+        @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
+        public long txPackets;
+        public long operations;
+    }
+
+    @UnsupportedAppUsage
+    public NetworkStatsHistory(long bucketDuration) {
+        this(bucketDuration, 10, FIELD_ALL);
+    }
+
+    public NetworkStatsHistory(long bucketDuration, int initialSize) {
+        this(bucketDuration, initialSize, FIELD_ALL);
+    }
+
+    public NetworkStatsHistory(long bucketDuration, int initialSize, int fields) {
+        this.bucketDuration = bucketDuration;
+        bucketStart = new long[initialSize];
+        if ((fields & FIELD_ACTIVE_TIME) != 0) activeTime = new long[initialSize];
+        if ((fields & FIELD_RX_BYTES) != 0) rxBytes = new long[initialSize];
+        if ((fields & FIELD_RX_PACKETS) != 0) rxPackets = new long[initialSize];
+        if ((fields & FIELD_TX_BYTES) != 0) txBytes = new long[initialSize];
+        if ((fields & FIELD_TX_PACKETS) != 0) txPackets = new long[initialSize];
+        if ((fields & FIELD_OPERATIONS) != 0) operations = new long[initialSize];
+        bucketCount = 0;
+        totalBytes = 0;
+    }
+
+    public NetworkStatsHistory(NetworkStatsHistory existing, long bucketDuration) {
+        this(bucketDuration, existing.estimateResizeBuckets(bucketDuration));
+        recordEntireHistory(existing);
+    }
+
+    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
+    public NetworkStatsHistory(Parcel in) {
+        bucketDuration = in.readLong();
+        bucketStart = readLongArray(in);
+        activeTime = readLongArray(in);
+        rxBytes = readLongArray(in);
+        rxPackets = readLongArray(in);
+        txBytes = readLongArray(in);
+        txPackets = readLongArray(in);
+        operations = readLongArray(in);
+        bucketCount = bucketStart.length;
+        totalBytes = in.readLong();
+    }
+
+    @Override
+    public void writeToParcel(Parcel out, int flags) {
+        out.writeLong(bucketDuration);
+        writeLongArray(out, bucketStart, bucketCount);
+        writeLongArray(out, activeTime, bucketCount);
+        writeLongArray(out, rxBytes, bucketCount);
+        writeLongArray(out, rxPackets, bucketCount);
+        writeLongArray(out, txBytes, bucketCount);
+        writeLongArray(out, txPackets, bucketCount);
+        writeLongArray(out, operations, bucketCount);
+        out.writeLong(totalBytes);
+    }
+
+    public NetworkStatsHistory(DataInput in) throws IOException {
+        final int version = in.readInt();
+        switch (version) {
+            case VERSION_INIT: {
+                bucketDuration = in.readLong();
+                bucketStart = readFullLongArray(in);
+                rxBytes = readFullLongArray(in);
+                rxPackets = new long[bucketStart.length];
+                txBytes = readFullLongArray(in);
+                txPackets = new long[bucketStart.length];
+                operations = new long[bucketStart.length];
+                bucketCount = bucketStart.length;
+                totalBytes = total(rxBytes) + total(txBytes);
+                break;
+            }
+            case VERSION_ADD_PACKETS:
+            case VERSION_ADD_ACTIVE: {
+                bucketDuration = in.readLong();
+                bucketStart = readVarLongArray(in);
+                activeTime = (version >= VERSION_ADD_ACTIVE) ? readVarLongArray(in)
+                        : new long[bucketStart.length];
+                rxBytes = readVarLongArray(in);
+                rxPackets = readVarLongArray(in);
+                txBytes = readVarLongArray(in);
+                txPackets = readVarLongArray(in);
+                operations = readVarLongArray(in);
+                bucketCount = bucketStart.length;
+                totalBytes = total(rxBytes) + total(txBytes);
+                break;
+            }
+            default: {
+                throw new ProtocolException("unexpected version: " + version);
+            }
+        }
+
+        if (bucketStart.length != bucketCount || rxBytes.length != bucketCount
+                || rxPackets.length != bucketCount || txBytes.length != bucketCount
+                || txPackets.length != bucketCount || operations.length != bucketCount) {
+            throw new ProtocolException("Mismatched history lengths");
+        }
+    }
+
+    public void writeToStream(DataOutput out) throws IOException {
+        out.writeInt(VERSION_ADD_ACTIVE);
+        out.writeLong(bucketDuration);
+        writeVarLongArray(out, bucketStart, bucketCount);
+        writeVarLongArray(out, activeTime, bucketCount);
+        writeVarLongArray(out, rxBytes, bucketCount);
+        writeVarLongArray(out, rxPackets, bucketCount);
+        writeVarLongArray(out, txBytes, bucketCount);
+        writeVarLongArray(out, txPackets, bucketCount);
+        writeVarLongArray(out, operations, bucketCount);
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
+    public int size() {
+        return bucketCount;
+    }
+
+    public long getBucketDuration() {
+        return bucketDuration;
+    }
+
+    @UnsupportedAppUsage
+    public long getStart() {
+        if (bucketCount > 0) {
+            return bucketStart[0];
+        } else {
+            return Long.MAX_VALUE;
+        }
+    }
+
+    @UnsupportedAppUsage
+    public long getEnd() {
+        if (bucketCount > 0) {
+            return bucketStart[bucketCount - 1] + bucketDuration;
+        } else {
+            return Long.MIN_VALUE;
+        }
+    }
+
+    /**
+     * Return total bytes represented by this history.
+     */
+    public long getTotalBytes() {
+        return totalBytes;
+    }
+
+    /**
+     * Return index of bucket that contains or is immediately before the
+     * requested time.
+     */
+    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
+    public int getIndexBefore(long time) {
+        int index = Arrays.binarySearch(bucketStart, 0, bucketCount, time);
+        if (index < 0) {
+            index = (~index) - 1;
+        } else {
+            index -= 1;
+        }
+        return MathUtils.constrain(index, 0, bucketCount - 1);
+    }
+
+    /**
+     * Return index of bucket that contains or is immediately after the
+     * requested time.
+     */
+    public int getIndexAfter(long time) {
+        int index = Arrays.binarySearch(bucketStart, 0, bucketCount, time);
+        if (index < 0) {
+            index = ~index;
+        } else {
+            index += 1;
+        }
+        return MathUtils.constrain(index, 0, bucketCount - 1);
+    }
+
+    /**
+     * Return specific stats entry.
+     */
+    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
+    public Entry getValues(int i, Entry recycle) {
+        final Entry entry = recycle != null ? recycle : new Entry();
+        entry.bucketStart = bucketStart[i];
+        entry.bucketDuration = bucketDuration;
+        entry.activeTime = getLong(activeTime, i, UNKNOWN);
+        entry.rxBytes = getLong(rxBytes, i, UNKNOWN);
+        entry.rxPackets = getLong(rxPackets, i, UNKNOWN);
+        entry.txBytes = getLong(txBytes, i, UNKNOWN);
+        entry.txPackets = getLong(txPackets, i, UNKNOWN);
+        entry.operations = getLong(operations, i, UNKNOWN);
+        return entry;
+    }
+
+    public void setValues(int i, Entry entry) {
+        // Unwind old values
+        if (rxBytes != null) totalBytes -= rxBytes[i];
+        if (txBytes != null) totalBytes -= txBytes[i];
+
+        bucketStart[i] = entry.bucketStart;
+        setLong(activeTime, i, entry.activeTime);
+        setLong(rxBytes, i, entry.rxBytes);
+        setLong(rxPackets, i, entry.rxPackets);
+        setLong(txBytes, i, entry.txBytes);
+        setLong(txPackets, i, entry.txPackets);
+        setLong(operations, i, entry.operations);
+
+        // Apply new values
+        if (rxBytes != null) totalBytes += rxBytes[i];
+        if (txBytes != null) totalBytes += txBytes[i];
+    }
+
+    /**
+     * Record that data traffic occurred in the given time range. Will
+     * distribute across internal buckets, creating new buckets as needed.
+     */
+    @Deprecated
+    public void recordData(long start, long end, long rxBytes, long txBytes) {
+        recordData(start, end, new NetworkStats.Entry(
+                IFACE_ALL, UID_ALL, SET_DEFAULT, TAG_NONE, rxBytes, 0L, txBytes, 0L, 0L));
+    }
+
+    /**
+     * 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, NetworkStats.Entry entry) {
+        long rxBytes = entry.rxBytes;
+        long rxPackets = entry.rxPackets;
+        long txBytes = entry.txBytes;
+        long txPackets = entry.txPackets;
+        long operations = entry.operations;
+
+        if (entry.isNegative()) {
+            throw new IllegalArgumentException("tried recording negative data");
+        }
+        if (entry.isEmpty()) {
+            return;
+        }
+
+        // create any buckets needed by this range
+        ensureBuckets(start, end);
+
+        // distribute data usage into buckets
+        long duration = end - start;
+        final int startIndex = getIndexAfter(end);
+        for (int i = startIndex; 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) continue;
+
+            // integer math each time is faster than floating point
+            final long fracRxBytes = multiplySafeByRational(rxBytes, overlap, duration);
+            final long fracRxPackets = multiplySafeByRational(rxPackets, overlap, duration);
+            final long fracTxBytes = multiplySafeByRational(txBytes, overlap, duration);
+            final long fracTxPackets = multiplySafeByRational(txPackets, overlap, duration);
+            final long fracOperations = multiplySafeByRational(operations, overlap, duration);
+
+
+            addLong(activeTime, i, overlap);
+            addLong(this.rxBytes, i, fracRxBytes); rxBytes -= fracRxBytes;
+            addLong(this.rxPackets, i, fracRxPackets); rxPackets -= fracRxPackets;
+            addLong(this.txBytes, i, fracTxBytes); txBytes -= fracTxBytes;
+            addLong(this.txPackets, i, fracTxPackets); txPackets -= fracTxPackets;
+            addLong(this.operations, i, fracOperations); operations -= fracOperations;
+
+            duration -= overlap;
+        }
+
+        totalBytes += entry.rxBytes + entry.txBytes;
+    }
+
+    /**
+     * Record an entire {@link NetworkStatsHistory} into this history. Usually
+     * for combining together stats for external reporting.
+     */
+    @UnsupportedAppUsage
+    public void recordEntireHistory(NetworkStatsHistory input) {
+        recordHistory(input, Long.MIN_VALUE, Long.MAX_VALUE);
+    }
+
+    /**
+     * Record given {@link NetworkStatsHistory} into this history, copying only
+     * buckets that atomically occur in the inclusive time range. Doesn't
+     * interpolate across partial buckets.
+     */
+    public void recordHistory(NetworkStatsHistory input, long start, long end) {
+        final NetworkStats.Entry entry = new NetworkStats.Entry(
+                IFACE_ALL, UID_ALL, SET_DEFAULT, TAG_NONE, 0L, 0L, 0L, 0L, 0L);
+        for (int i = 0; i < input.bucketCount; i++) {
+            final long bucketStart = input.bucketStart[i];
+            final long bucketEnd = bucketStart + input.bucketDuration;
+
+            // skip when bucket is outside requested range
+            if (bucketStart < start || bucketEnd > end) continue;
+
+            entry.rxBytes = getLong(input.rxBytes, i, 0L);
+            entry.rxPackets = getLong(input.rxPackets, i, 0L);
+            entry.txBytes = getLong(input.txBytes, i, 0L);
+            entry.txPackets = getLong(input.txPackets, i, 0L);
+            entry.operations = getLong(input.operations, i, 0L);
+
+            recordData(bucketStart, bucketEnd, entry);
+        }
+    }
+
+    /**
+     * 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 >= bucketStart.length) {
+            final int newLength = Math.max(bucketStart.length, 10) * 3 / 2;
+            bucketStart = Arrays.copyOf(bucketStart, newLength);
+            if (activeTime != null) activeTime = Arrays.copyOf(activeTime, newLength);
+            if (rxBytes != null) rxBytes = Arrays.copyOf(rxBytes, newLength);
+            if (rxPackets != null) rxPackets = Arrays.copyOf(rxPackets, newLength);
+            if (txBytes != null) txBytes = Arrays.copyOf(txBytes, newLength);
+            if (txPackets != null) txPackets = Arrays.copyOf(txPackets, newLength);
+            if (operations != null) operations = Arrays.copyOf(operations, 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);
+            if (activeTime != null) System.arraycopy(activeTime, index, activeTime, dstPos, length);
+            if (rxBytes != null) System.arraycopy(rxBytes, index, rxBytes, dstPos, length);
+            if (rxPackets != null) System.arraycopy(rxPackets, index, rxPackets, dstPos, length);
+            if (txBytes != null) System.arraycopy(txBytes, index, txBytes, dstPos, length);
+            if (txPackets != null) System.arraycopy(txPackets, index, txPackets, dstPos, length);
+            if (operations != null) System.arraycopy(operations, index, operations, dstPos, length);
+        }
+
+        bucketStart[index] = start;
+        setLong(activeTime, index, 0L);
+        setLong(rxBytes, index, 0L);
+        setLong(rxPackets, index, 0L);
+        setLong(txBytes, index, 0L);
+        setLong(txPackets, index, 0L);
+        setLong(operations, index, 0L);
+        bucketCount++;
+    }
+
+    /**
+     * Clear all data stored in this object.
+     */
+    public void clear() {
+        bucketStart = EmptyArray.LONG;
+        if (activeTime != null) activeTime = EmptyArray.LONG;
+        if (rxBytes != null) rxBytes = EmptyArray.LONG;
+        if (rxPackets != null) rxPackets = EmptyArray.LONG;
+        if (txBytes != null) txBytes = EmptyArray.LONG;
+        if (txPackets != null) txPackets = EmptyArray.LONG;
+        if (operations != null) operations = EmptyArray.LONG;
+        bucketCount = 0;
+        totalBytes = 0;
+    }
+
+    /**
+     * Remove buckets older than requested cutoff.
+     */
+    @Deprecated
+    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);
+            if (activeTime != null) activeTime = Arrays.copyOfRange(activeTime, i, length);
+            if (rxBytes != null) rxBytes = Arrays.copyOfRange(rxBytes, i, length);
+            if (rxPackets != null) rxPackets = Arrays.copyOfRange(rxPackets, i, length);
+            if (txBytes != null) txBytes = Arrays.copyOfRange(txBytes, i, length);
+            if (txPackets != null) txPackets = Arrays.copyOfRange(txPackets, i, length);
+            if (operations != null) operations = Arrays.copyOfRange(operations, i, length);
+            bucketCount -= i;
+
+            // TODO: subtract removed values from totalBytes
+        }
+    }
+
+    /**
+     * Return interpolated data usage across the requested range. Interpolates
+     * across buckets, so values may be rounded slightly.
+     *
+     * <p>If the active bucket is not completed yet, it returns the proportional value of it
+     * based on its duration and the {@code end} param.
+     *
+     * @param start - start of the range, timestamp in milliseconds since the epoch.
+     * @param end - end of the range, timestamp in milliseconds since the epoch.
+     * @param recycle - entry instance for performance, could be null.
+     */
+    @UnsupportedAppUsage
+    public Entry getValues(long start, long end, Entry recycle) {
+        return getValues(start, end, Long.MAX_VALUE, recycle);
+    }
+
+    /**
+     * Return interpolated data usage across the requested range. Interpolates
+     * across buckets, so values may be rounded slightly.
+     *
+     * @param start - start of the range, timestamp in milliseconds since the epoch.
+     * @param end - end of the range, timestamp in milliseconds since the epoch.
+     * @param now - current timestamp in milliseconds since the epoch (wall clock).
+     * @param recycle - entry instance for performance, could be null.
+     */
+    @UnsupportedAppUsage
+    public Entry getValues(long start, long end, long now, Entry recycle) {
+        final Entry entry = recycle != null ? recycle : new Entry();
+        entry.bucketDuration = end - start;
+        entry.bucketStart = start;
+        entry.activeTime = activeTime != null ? 0 : UNKNOWN;
+        entry.rxBytes = rxBytes != null ? 0 : UNKNOWN;
+        entry.rxPackets = rxPackets != null ? 0 : UNKNOWN;
+        entry.txBytes = txBytes != null ? 0 : UNKNOWN;
+        entry.txPackets = txPackets != null ? 0 : UNKNOWN;
+        entry.operations = operations != null ? 0 : UNKNOWN;
+
+        final int startIndex = getIndexAfter(end);
+        for (int i = startIndex; i >= 0; i--) {
+            final long curStart = bucketStart[i];
+            long curEnd = curStart + bucketDuration;
+
+            // bucket is older than request; we're finished
+            if (curEnd <= start) break;
+            // bucket is newer than request; keep looking
+            if (curStart >= end) continue;
+
+            // the active bucket is shorter then a normal completed bucket
+            if (curEnd > now) curEnd = now;
+            // usually this is simply bucketDuration
+            final long bucketSpan = curEnd - curStart;
+            // prevent division by zero
+            if (bucketSpan <= 0) continue;
+
+            final long overlapEnd = curEnd < end ? curEnd : end;
+            final long overlapStart = curStart > start ? curStart : start;
+            final long overlap = overlapEnd - overlapStart;
+            if (overlap <= 0) continue;
+
+            // integer math each time is faster than floating point
+            if (activeTime != null) {
+                entry.activeTime += multiplySafeByRational(activeTime[i], overlap, bucketSpan);
+            }
+            if (rxBytes != null) {
+                entry.rxBytes += multiplySafeByRational(rxBytes[i], overlap, bucketSpan);
+            }
+            if (rxPackets != null) {
+                entry.rxPackets += multiplySafeByRational(rxPackets[i], overlap, bucketSpan);
+            }
+            if (txBytes != null) {
+                entry.txBytes += multiplySafeByRational(txBytes[i], overlap, bucketSpan);
+            }
+            if (txPackets != null) {
+                entry.txPackets += multiplySafeByRational(txPackets[i], overlap, bucketSpan);
+            }
+            if (operations != null) {
+                entry.operations += multiplySafeByRational(operations[i], overlap, bucketSpan);
+            }
+        }
+        return entry;
+    }
+
+    /**
+     * @deprecated only for temporary testing
+     */
+    @Deprecated
+    public void generateRandom(long start, long end, long bytes) {
+        final Random r = new Random();
+
+        final float fractionRx = r.nextFloat();
+        final long rxBytes = (long) (bytes * fractionRx);
+        final long txBytes = (long) (bytes * (1 - fractionRx));
+
+        final long rxPackets = rxBytes / 1024;
+        final long txPackets = txBytes / 1024;
+        final long operations = rxBytes / 2048;
+
+        generateRandom(start, end, rxBytes, rxPackets, txBytes, txPackets, operations, r);
+    }
+
+    /**
+     * @deprecated only for temporary testing
+     */
+    @Deprecated
+    public void generateRandom(long start, long end, long rxBytes, long rxPackets, long txBytes,
+            long txPackets, long operations, Random r) {
+        ensureBuckets(start, end);
+
+        final NetworkStats.Entry entry = new NetworkStats.Entry(
+                IFACE_ALL, UID_ALL, SET_DEFAULT, TAG_NONE, 0L, 0L, 0L, 0L, 0L);
+        while (rxBytes > 1024 || rxPackets > 128 || txBytes > 1024 || txPackets > 128
+                || operations > 32) {
+            final long curStart = randomLong(r, start, end);
+            final long curEnd = curStart + randomLong(r, 0, (end - curStart) / 2);
+
+            entry.rxBytes = randomLong(r, 0, rxBytes);
+            entry.rxPackets = randomLong(r, 0, rxPackets);
+            entry.txBytes = randomLong(r, 0, txBytes);
+            entry.txPackets = randomLong(r, 0, txPackets);
+            entry.operations = randomLong(r, 0, operations);
+
+            rxBytes -= entry.rxBytes;
+            rxPackets -= entry.rxPackets;
+            txBytes -= entry.txBytes;
+            txPackets -= entry.txPackets;
+            operations -= entry.operations;
+
+            recordData(curStart, curEnd, entry);
+        }
+    }
+
+    public static long randomLong(Random r, long start, long end) {
+        return (long) (start + (r.nextFloat() * (end - start)));
+    }
+
+    /**
+     * Quickly determine if this history intersects with given window.
+     */
+    public boolean intersects(long start, long end) {
+        final long dataStart = getStart();
+        final long dataEnd = getEnd();
+        if (start >= dataStart && start <= dataEnd) return true;
+        if (end >= dataStart && end <= dataEnd) return true;
+        if (dataStart >= start && dataStart <= end) return true;
+        if (dataEnd >= start && dataEnd <= end) return true;
+        return false;
+    }
+
+    public void dump(IndentingPrintWriter pw, boolean fullHistory) {
+        pw.print("NetworkStatsHistory: bucketDuration=");
+        pw.println(bucketDuration / SECOND_IN_MILLIS);
+        pw.increaseIndent();
+
+        final int start = fullHistory ? 0 : Math.max(0, bucketCount - 32);
+        if (start > 0) {
+            pw.print("(omitting "); pw.print(start); pw.println(" buckets)");
+        }
+
+        for (int i = start; i < bucketCount; i++) {
+            pw.print("st="); pw.print(bucketStart[i] / SECOND_IN_MILLIS);
+            if (rxBytes != null) { pw.print(" rb="); pw.print(rxBytes[i]); }
+            if (rxPackets != null) { pw.print(" rp="); pw.print(rxPackets[i]); }
+            if (txBytes != null) { pw.print(" tb="); pw.print(txBytes[i]); }
+            if (txPackets != null) { pw.print(" tp="); pw.print(txPackets[i]); }
+            if (operations != null) { pw.print(" op="); pw.print(operations[i]); }
+            pw.println();
+        }
+
+        pw.decreaseIndent();
+    }
+
+    public void dumpCheckin(PrintWriter pw) {
+        pw.print("d,");
+        pw.print(bucketDuration / SECOND_IN_MILLIS);
+        pw.println();
+
+        for (int i = 0; i < bucketCount; i++) {
+            pw.print("b,");
+            pw.print(bucketStart[i] / SECOND_IN_MILLIS); pw.print(',');
+            if (rxBytes != null) { pw.print(rxBytes[i]); } else { pw.print("*"); } pw.print(',');
+            if (rxPackets != null) { pw.print(rxPackets[i]); } else { pw.print("*"); } pw.print(',');
+            if (txBytes != null) { pw.print(txBytes[i]); } else { pw.print("*"); } pw.print(',');
+            if (txPackets != null) { pw.print(txPackets[i]); } else { pw.print("*"); } pw.print(',');
+            if (operations != null) { pw.print(operations[i]); } else { pw.print("*"); }
+            pw.println();
+        }
+    }
+
+    public void dumpDebug(ProtoOutputStream proto, long tag) {
+        final long start = proto.start(tag);
+
+        proto.write(NetworkStatsHistoryProto.BUCKET_DURATION_MS, bucketDuration);
+
+        for (int i = 0; i < bucketCount; i++) {
+            final long startBucket = proto.start(NetworkStatsHistoryProto.BUCKETS);
+
+            proto.write(NetworkStatsHistoryBucketProto.BUCKET_START_MS, bucketStart[i]);
+            dumpDebug(proto, NetworkStatsHistoryBucketProto.RX_BYTES, rxBytes, i);
+            dumpDebug(proto, NetworkStatsHistoryBucketProto.RX_PACKETS, rxPackets, i);
+            dumpDebug(proto, NetworkStatsHistoryBucketProto.TX_BYTES, txBytes, i);
+            dumpDebug(proto, NetworkStatsHistoryBucketProto.TX_PACKETS, txPackets, i);
+            dumpDebug(proto, NetworkStatsHistoryBucketProto.OPERATIONS, operations, i);
+
+            proto.end(startBucket);
+        }
+
+        proto.end(start);
+    }
+
+    private static void dumpDebug(ProtoOutputStream proto, long tag, long[] array, int index) {
+        if (array != null) {
+            proto.write(tag, array[index]);
+        }
+    }
+
+    @Override
+    public String toString() {
+        final CharArrayWriter writer = new CharArrayWriter();
+        dump(new IndentingPrintWriter(writer, "  "), false);
+        return writer.toString();
+    }
+
+    @UnsupportedAppUsage
+    public static final @android.annotation.NonNull Creator<NetworkStatsHistory> CREATOR = new Creator<NetworkStatsHistory>() {
+        @Override
+        public NetworkStatsHistory createFromParcel(Parcel in) {
+            return new NetworkStatsHistory(in);
+        }
+
+        @Override
+        public NetworkStatsHistory[] newArray(int size) {
+            return new NetworkStatsHistory[size];
+        }
+    };
+
+    private static long getLong(long[] array, int i, long value) {
+        return array != null ? array[i] : value;
+    }
+
+    private static void setLong(long[] array, int i, long value) {
+        if (array != null) array[i] = value;
+    }
+
+    private static void addLong(long[] array, int i, long value) {
+        if (array != null) array[i] += value;
+    }
+
+    public int estimateResizeBuckets(long newBucketDuration) {
+        return (int) (size() * getBucketDuration() / newBucketDuration);
+    }
+
+    /**
+     * Utility methods for interacting with {@link DataInputStream} and
+     * {@link DataOutputStream}, mostly dealing with writing partial arrays.
+     */
+    public static class DataStreamUtils {
+        @Deprecated
+        public static long[] readFullLongArray(DataInput in) throws IOException {
+            final int size = in.readInt();
+            if (size < 0) throw new ProtocolException("negative array size");
+            final long[] values = new long[size];
+            for (int i = 0; i < values.length; i++) {
+                values[i] = in.readLong();
+            }
+            return values;
+        }
+
+        /**
+         * Read variable-length {@link Long} using protobuf-style approach.
+         */
+        public static long readVarLong(DataInput in) throws IOException {
+            int shift = 0;
+            long result = 0;
+            while (shift < 64) {
+                byte b = in.readByte();
+                result |= (long) (b & 0x7F) << shift;
+                if ((b & 0x80) == 0)
+                    return result;
+                shift += 7;
+            }
+            throw new ProtocolException("malformed long");
+        }
+
+        /**
+         * Write variable-length {@link Long} using protobuf-style approach.
+         */
+        public static void writeVarLong(DataOutput out, long value) throws IOException {
+            while (true) {
+                if ((value & ~0x7FL) == 0) {
+                    out.writeByte((int) value);
+                    return;
+                } else {
+                    out.writeByte(((int) value & 0x7F) | 0x80);
+                    value >>>= 7;
+                }
+            }
+        }
+
+        public static long[] readVarLongArray(DataInput in) throws IOException {
+            final int size = in.readInt();
+            if (size == -1) return null;
+            if (size < 0) throw new ProtocolException("negative array size");
+            final long[] values = new long[size];
+            for (int i = 0; i < values.length; i++) {
+                values[i] = readVarLong(in);
+            }
+            return values;
+        }
+
+        public static void writeVarLongArray(DataOutput out, long[] values, int size)
+                throws IOException {
+            if (values == null) {
+                out.writeInt(-1);
+                return;
+            }
+            if (size > values.length) {
+                throw new IllegalArgumentException("size larger than length");
+            }
+            out.writeInt(size);
+            for (int i = 0; i < size; i++) {
+                writeVarLong(out, values[i]);
+            }
+        }
+    }
+
+    /**
+     * Utility methods for interacting with {@link Parcel} structures, mostly
+     * dealing with writing partial arrays.
+     */
+    public static class ParcelUtils {
+        public static long[] readLongArray(Parcel in) {
+            final int size = in.readInt();
+            if (size == -1) return null;
+            final long[] values = new long[size];
+            for (int i = 0; i < values.length; i++) {
+                values[i] = in.readLong();
+            }
+            return values;
+        }
+
+        public static void writeLongArray(Parcel out, long[] values, int size) {
+            if (values == null) {
+                out.writeInt(-1);
+                return;
+            }
+            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]);
+            }
+        }
+    }
+
+}