| /* |
| * 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.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; |
| |
| // TODO: teach about varint encoding to use less disk space |
| |
| public final long bucketDuration; |
| |
| public int bucketCount; |
| public long[] bucketStart; |
| public long[] rx; |
| public long[] tx; |
| |
| public NetworkStatsHistory(long bucketDuration) { |
| this(bucketDuration, 10); |
| } |
| |
| public NetworkStatsHistory(long bucketDuration, int initialSize) { |
| this.bucketDuration = bucketDuration; |
| bucketStart = new long[initialSize]; |
| rx = new long[initialSize]; |
| tx = new long[initialSize]; |
| bucketCount = 0; |
| } |
| |
| public NetworkStatsHistory(Parcel in) { |
| bucketDuration = in.readLong(); |
| bucketStart = readLongArray(in); |
| rx = in.createLongArray(); |
| tx = in.createLongArray(); |
| bucketCount = bucketStart.length; |
| } |
| |
| /** {@inheritDoc} */ |
| public void writeToParcel(Parcel out, int flags) { |
| 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(); |
| switch (version) { |
| case VERSION_INIT: { |
| bucketDuration = in.readLong(); |
| bucketStart = readLongArray(in); |
| rx = readLongArray(in); |
| tx = readLongArray(in); |
| bucketCount = bucketStart.length; |
| break; |
| } |
| default: { |
| throw new ProtocolException("unexpected version: " + version); |
| } |
| } |
| } |
| |
| public void writeToStream(DataOutputStream out) throws IOException { |
| out.writeInt(VERSION_INIT); |
| 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) { |
| if (rx < 0 || tx < 0) { |
| throw new IllegalArgumentException( |
| "tried recording negative data: rx=" + rx + ", tx=" + 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; |
| } |
| } |
| } |
| |
| /** |
| * Record an entire {@link NetworkStatsHistory} into this history. Usually |
| * for combining together stats for external reporting. |
| */ |
| public void recordEntireHistory(NetworkStatsHistory input) { |
| for (int i = 0; i < input.bucketCount; i++) { |
| final long start = input.bucketStart[i]; |
| final long end = start + input.bucketDuration; |
| recordData(start, end, input.rx[i], input.tx[i]); |
| } |
| } |
| |
| /** |
| * 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); |
| 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; |
| } |
| } |
| |
| /** |
| * Return interpolated data usage across the requested range. Interpolates |
| * across buckets, so values may be rounded slightly. |
| */ |
| public long[] getTotalData(long start, long end, long[] outTotal) { |
| long rx = 0; |
| long tx = 0; |
| |
| 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) { |
| rx += this.rx[i] * overlap / bucketDuration; |
| tx += this.tx[i] * overlap / bucketDuration; |
| } |
| } |
| |
| if (outTotal == null || outTotal.length != 2) { |
| outTotal = new long[2]; |
| } |
| outTotal[0] = rx; |
| outTotal[1] = tx; |
| return outTotal; |
| } |
| |
| /** |
| * @deprecated only for temporary testing |
| */ |
| @Deprecated |
| public void generateRandom(long start, long end, long rx, long tx) { |
| ensureBuckets(start, end); |
| |
| final Random r = new Random(); |
| while (rx > 1024 && tx > 1024) { |
| final long curStart = randomLong(r, start, end); |
| final long curEnd = randomLong(r, curStart, end); |
| final long curRx = randomLong(r, 0, rx); |
| final long curTx = randomLong(r, 0, tx); |
| |
| recordData(curStart, curEnd, curRx, curTx); |
| |
| rx -= curRx; |
| tx -= curTx; |
| } |
| } |
| |
| private static long randomLong(Random r, long start, long end) { |
| return (long) (start + (r.nextFloat() * (end - start))); |
| } |
| |
| public void dump(String prefix, PrintWriter pw) { |
| pw.print(prefix); |
| pw.print("NetworkStatsHistory: bucketDuration="); pw.println(bucketDuration); |
| for (int i = 0; i < bucketCount; i++) { |
| pw.print(prefix); |
| pw.print(" bucketStart="); 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]); |
| } |
| } |
| |
| } |