Correct proc file reader, optimizations. (163e6443) · Commits · e / os / android_frameworks_base

core/java/android/net/NetworkStats.java

+71 −50

Original line number	Diff line number	Diff line
		@@ -16,10 +16,11 @@

		package android.net;

		import static com.android.internal.util.Preconditions.checkNotNull;

		import android.os.Parcel;
		import android.os.Parcelable;
		import android.os.SystemClock;
		import android.util.Log;
		import android.util.SparseBooleanArray;

		import com.android.internal.util.Objects;
		@@ -54,6 +55,8 @@ public class NetworkStats implements Parcelable {
		/** {@link #tag} value for total data across all tags. */
		public static final int TAG_NONE = 0;

		// TODO: move fields to "mVariable" notation

		/**
		* {@link SystemClock#elapsedRealtime()} timestamp when this data was
		* generated.
		@@ -295,8 +298,33 @@ public class NetworkStats implements Parcelable {
		*/
		public int findIndex(String iface, int uid, int set, int tag) {
		for (int i = 0; i < size; i++) {
		if (Objects.equal(iface, this.iface[i]) && uid == this.uid[i] && set == this.set[i]
		&& tag == this.tag[i]) {
		if (uid == this.uid[i] && set == this.set[i] && tag == this.tag[i]
		&& Objects.equal(iface, this.iface[i])) {
		return i;
		}
		}
		return -1;
		}

		/**
		* Find first stats index that matches the requested parameters, starting
		* search around the hinted index as an optimization.
		*/
		// @VisibleForTesting
		public int findIndexHinted(String iface, int uid, int set, int tag, int hintIndex) {
		for (int offset = 0; offset < size; offset++) {
		final int halfOffset = offset / 2;

		// search outwards from hint index, alternating forward and backward
		final int i;
		if (offset % 2 == 0) {
		i = (hintIndex + halfOffset) % size;
		} else {
		i = (size + hintIndex - halfOffset - 1) % size;
		}

		if (uid == this.uid[i] && set == this.set[i] && tag == this.tag[i]
		&& Objects.equal(iface, this.iface[i])) {
		return i;
		}
		}
		@@ -423,40 +451,10 @@ public class NetworkStats implements Parcelable {
		* 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.
		*
		* @throws IllegalArgumentException when given {@link NetworkStats} is
		* non-monotonic.
		*/
		public NetworkStats subtract(NetworkStats value) {
		return subtract(value, true, false);
		}

		/**
		* 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.
		* <p>
		* Instead of throwing when counters are non-monotonic, this variant clamps
		* results to never be negative.
		*/
		public NetworkStats subtractClamped(NetworkStats value) {
		return subtract(value, false, true);
		}

		/**
		* 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.
		* @param clampNegative Instead of throwing like {@code enforceMonotonic},
		* clamp resulting counters at 0 to prevent negative values.
		*/
		private NetworkStats subtract(
		NetworkStats value, boolean enforceMonotonic, boolean clampNegative) {
		public NetworkStats subtract(NetworkStats value) throws NonMonotonicException {
		final long deltaRealtime = this.elapsedRealtime - value.elapsedRealtime;
		if (enforceMonotonic && deltaRealtime < 0) {
		if (deltaRealtime < 0) {
		throw new IllegalArgumentException("found non-monotonic realtime");
		}

		@@ -470,7 +468,7 @@ public class NetworkStats implements Parcelable {
		entry.tag = tag[i];

		// find remote row that matches, and subtract
		final int j = value.findIndex(entry.iface, entry.uid, entry.set, entry.tag);
		final int j = value.findIndexHinted(entry.iface, entry.uid, entry.set, entry.tag, i);
		if (j == -1) {
		// newly appearing row, return entire value
		entry.rxBytes = rxBytes[i];
		@@ -485,20 +483,10 @@ public class NetworkStats implements Parcelable {
		entry.txBytes = txBytes[i] - value.txBytes[j];
		entry.txPackets = txPackets[i] - value.txPackets[j];
		entry.operations = operations[i] - value.operations[j];
		if (enforceMonotonic
		&& (entry.rxBytes < 0 \|\| entry.rxPackets < 0 \|\| entry.txBytes < 0
		\|\| entry.txPackets < 0 \|\| entry.operations < 0)) {
		Log.v(TAG, "lhs=" + this);
		Log.v(TAG, "rhs=" + value);
		throw new IllegalArgumentException(
		"found non-monotonic values at lhs[" + i + "] - rhs[" + j + "]");
		}
		if (clampNegative) {
		entry.rxBytes = Math.max(0, entry.rxBytes);
		entry.rxPackets = Math.max(0, entry.rxPackets);
		entry.txBytes = Math.max(0, entry.txBytes);
		entry.txPackets = Math.max(0, entry.txPackets);
		entry.operations = Math.max(0, entry.operations);

		if (entry.rxBytes < 0 \|\| entry.rxPackets < 0 \|\| entry.txBytes < 0
		\|\| entry.txPackets < 0 \|\| entry.operations < 0) {
		throw new NonMonotonicException(this, i, value, j);
		}
		}

		@@ -564,6 +552,24 @@ public class NetworkStats implements Parcelable {
		return stats;
		}

		/**
		* Return all rows except those attributed to the requested UID; doesn't
		* mutate the original structure.
		*/
		public NetworkStats withoutUid(int uid) {
		final NetworkStats stats = new NetworkStats(elapsedRealtime, 10);

		Entry entry = new Entry();
		for (int i = 0; i < size; i++) {
		entry = getValues(i, entry);
		if (entry.uid != uid) {
		stats.addValues(entry);
		}
		}

		return stats;
		}

		public void dump(String prefix, PrintWriter pw) {
		pw.print(prefix);
		pw.print("NetworkStats: elapsedRealtime="); pw.println(elapsedRealtime);
		@@ -625,4 +631,19 @@ public class NetworkStats implements Parcelable {
		return new NetworkStats[size];
		}
		};

		public static class NonMonotonicException extends Exception {
		public final NetworkStats left;
		public final NetworkStats right;
		public final int leftIndex;
		public final int rightIndex;

		public NonMonotonicException(
		NetworkStats left, int leftIndex, NetworkStats right, int rightIndex) {
		this.left = checkNotNull(left, "missing left");
		this.right = checkNotNull(right, "missing right");
		this.leftIndex = leftIndex;
		this.rightIndex = rightIndex;
		}
		}
		}

core/java/android/net/TrafficStats.java

+10 −6

Original line number	Diff line number	Diff line
		@@ -20,6 +20,7 @@ import android.app.DownloadManager;
		import android.app.backup.BackupManager;
		import android.content.Context;
		import android.media.MediaPlayer;
		import android.net.NetworkStats.NonMonotonicException;
		import android.os.RemoteException;
		import android.os.ServiceManager;

		@@ -192,12 +193,15 @@ public class TrafficStats {
		throw new IllegalStateException("not profiling data");
		}

		try {
		// subtract starting values and return delta
		final NetworkStats profilingStop = getDataLayerSnapshotForUid(context);
		final NetworkStats profilingDelta = profilingStop.subtractClamped(
		sActiveProfilingStart);
		final NetworkStats profilingDelta = profilingStop.subtract(sActiveProfilingStart);
		sActiveProfilingStart = null;
		return profilingDelta;
		} catch (NonMonotonicException e) {
		throw new RuntimeException(e);
		}
		}
		}

core/java/com/android/internal/net/NetworkStatsFactory.java

+29 −37

Original line number	Diff line number	Diff line
		@@ -25,12 +25,14 @@ import android.net.NetworkStats;
		import android.os.SystemClock;
		import android.util.Slog;

		import com.android.internal.util.ProcFileReader;
		import com.google.android.collect.Lists;
		import com.google.android.collect.Maps;
		import com.google.android.collect.Sets;

		import java.io.BufferedReader;
		import java.io.File;
		import java.io.FileInputStream;
		import java.io.FileReader;
		import java.io.IOException;
		import java.util.ArrayList;
		@@ -107,6 +109,7 @@ public class NetworkStatsFactory {
		final NetworkStats stats = new NetworkStats(SystemClock.elapsedRealtime(), 6);
		final NetworkStats.Entry entry = new NetworkStats.Entry();

		// TODO: transition to ProcFileReader
		// TODO: read directly from proc once headers are added
		final ArrayList<String> keys = Lists.newArrayList(KEY_IFACE, KEY_ACTIVE, KEY_SNAP_RX_BYTES,
		KEY_SNAP_RX_PACKETS, KEY_SNAP_TX_BYTES, KEY_SNAP_TX_PACKETS, KEY_RX_BYTES,
		@@ -257,71 +260,58 @@ public class NetworkStatsFactory {
		final NetworkStats stats = new NetworkStats(SystemClock.elapsedRealtime(), 24);
		final NetworkStats.Entry entry = new NetworkStats.Entry();

		// TODO: remove knownLines check once 5087722 verified
		final HashSet<String> knownLines = Sets.newHashSet();
		// TODO: remove lastIdx check once 5270106 verified
		int lastIdx;
		int idx = 1;
		int lastIdx = 1;

		final ArrayList<String> keys = Lists.newArrayList();
		final ArrayList<String> values = Lists.newArrayList();
		final HashMap<String, String> parsed = Maps.newHashMap();

		BufferedReader reader = null;
		String line = null;
		ProcFileReader reader = null;
		try {
		reader = new BufferedReader(new FileReader(mStatsXtUid));

		// parse first line as header
		line = reader.readLine();
		splitLine(line, keys);
		lastIdx = 1;

		// parse remaining lines
		while ((line = reader.readLine()) != null) {
		splitLine(line, values);
		parseLine(keys, values, parsed);
		// open and consume header line
		reader = new ProcFileReader(new FileInputStream(mStatsXtUid));
		reader.finishLine();

		if (!knownLines.add(line)) {
		throw new IllegalStateException("duplicate proc entry: " + line);
		}

		final int idx = getParsedInt(parsed, KEY_IDX);
		while (reader.hasMoreData()) {
		idx = reader.nextInt();
		if (idx != lastIdx + 1) {
		throw new IllegalStateException(
		"inconsistent idx=" + idx + " after lastIdx=" + lastIdx);
		}
		lastIdx = idx;

		entry.iface = parsed.get(KEY_IFACE);
		entry.uid = getParsedInt(parsed, KEY_UID);
		entry.set = getParsedInt(parsed, KEY_COUNTER_SET);
		entry.tag = kernelToTag(parsed.get(KEY_TAG_HEX));
		entry.rxBytes = getParsedLong(parsed, KEY_RX_BYTES);
		entry.rxPackets = getParsedLong(parsed, KEY_RX_PACKETS);
		entry.txBytes = getParsedLong(parsed, KEY_TX_BYTES);
		entry.txPackets = getParsedLong(parsed, KEY_TX_PACKETS);
		entry.iface = reader.nextString();
		entry.tag = kernelToTag(reader.nextString());
		entry.uid = reader.nextInt();
		entry.set = reader.nextInt();
		entry.rxBytes = reader.nextLong();
		entry.rxPackets = reader.nextLong();
		entry.txBytes = reader.nextLong();
		entry.txPackets = reader.nextLong();

		if (limitUid == UID_ALL \|\| limitUid == entry.uid) {
		stats.addValues(entry);
		}

		reader.finishLine();
		}
		} catch (NullPointerException e) {
		throw new IllegalStateException("problem parsing line: " + line, e);
		throw new IllegalStateException("problem parsing idx " + idx, e);
		} catch (NumberFormatException e) {
		throw new IllegalStateException("problem parsing line: " + line, e);
		throw new IllegalStateException("problem parsing idx " + idx, e);
		} catch (IOException e) {
		throw new IllegalStateException("problem parsing line: " + line, e);
		throw new IllegalStateException("problem parsing idx " + idx, e);
		} finally {
		IoUtils.closeQuietly(reader);
		}

		return stats;
		}

		@Deprecated
		private static int getParsedInt(HashMap<String, String> parsed, String key) {
		final String value = parsed.get(key);
		return value != null ? Integer.parseInt(value) : 0;
		}

		@Deprecated
		private static long getParsedLong(HashMap<String, String> parsed, String key) {
		final String value = parsed.get(key);
		return value != null ? Long.parseLong(value) : 0;
		@@ -330,6 +320,7 @@ public class NetworkStatsFactory {
		/**
		* Split given line into {@link ArrayList}.
		*/
		@Deprecated
		private static void splitLine(String line, ArrayList<String> outSplit) {
		outSplit.clear();

		@@ -343,6 +334,7 @@ public class NetworkStatsFactory {
		* Zip the two given {@link ArrayList} as key and value pairs into
		* {@link HashMap}.
		*/
		@Deprecated
		private static void parseLine(
		ArrayList<String> keys, ArrayList<String> values, HashMap<String, String> outParsed) {
		outParsed.clear();

core/java/com/android/internal/util/ProcFileReader.java

0 → 100644

+199 −0

Original line number	Diff line number	Diff line
		/*
		* 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 com.android.internal.util;

		import java.io.Closeable;
		import java.io.IOException;
		import java.io.InputStream;
		import java.nio.charset.Charsets;

		/**
		* Reader that specializes in parsing {@code /proc/} files quickly. Walks
		* through the stream using a single space {@code ' '} as token separator, and
		* requires each line boundary to be explicitly acknowledged using
		* {@link #finishLine()}. Assumes {@link Charsets#US_ASCII} encoding.
		* <p>
		* Currently doesn't support formats based on {@code \0}, tabs, or repeated
		* delimiters.
		*/
		public class ProcFileReader implements Closeable {
		private final InputStream mStream;
		private final byte[] mBuffer;

		/** Write pointer in {@link #mBuffer}. */
		private int mTail;
		/** Flag when last read token finished current line. */
		private boolean mLineFinished;

		public ProcFileReader(InputStream stream) throws IOException {
		this(stream, 4096);
		}

		public ProcFileReader(InputStream stream, int bufferSize) throws IOException {
		mStream = stream;
		mBuffer = new byte[bufferSize];

		// read enough to answer hasMoreData
		fillBuf();
		}

		/**
		* Read more data from {@link #mStream} into internal buffer.
		*/
		private int fillBuf() throws IOException {
		final int length = mBuffer.length - mTail;
		if (length == 0) {
		throw new IOException("attempting to fill already-full buffer");
		}

		final int read = mStream.read(mBuffer, mTail, length);
		if (read != -1) {
		mTail += read;
		}
		return read;
		}

		/**
		* Consume number of bytes from beginning of internal buffer. If consuming
		* all remaining bytes, will attempt to {@link #fillBuf()}.
		*/
		private void consumeBuf(int count) throws IOException {
		// TODO: consider moving to read pointer, but for now traceview says
		// these copies aren't a bottleneck.
		System.arraycopy(mBuffer, count, mBuffer, 0, mTail - count);
		mTail -= count;
		if (mTail == 0) {
		fillBuf();
		}
		}

		/**
		* Find buffer index of next token delimiter, usually space or newline. Will
		* fill buffer as needed.
		*/
		private int nextTokenIndex() throws IOException {
		if (mLineFinished) {
		throw new IOException("no tokens remaining on current line");
		}

		int i = 0;
		do {
		// scan forward for token boundary
		for (; i < mTail; i++) {
		final byte b = mBuffer[i];
		if (b == '\n') {
		mLineFinished = true;
		return i;
		}
		if (b == ' ') {
		return i;
		}
		}
		} while (fillBuf() > 0);

		throw new IOException("end of stream while looking for token boundary");
		}

		/**
		* Check if stream has more data to be parsed.
		*/
		public boolean hasMoreData() {
		return mTail > 0;
		}

		/**
		* Finish current line, skipping any remaining data.
		*/
		public void finishLine() throws IOException {
		// last token already finished line; reset silently
		if (mLineFinished) {
		mLineFinished = false;
		return;
		}

		int i = 0;
		do {
		// scan forward for line boundary and consume
		for (; i < mTail; i++) {
		if (mBuffer[i] == '\n') {
		consumeBuf(i + 1);
		return;
		}
		}
		} while (fillBuf() > 0);

		throw new IOException("end of stream while looking for line boundary");
		}

		/**
		* Parse and return next token as {@link String}.
		*/
		public String nextString() throws IOException {
		final int tokenIndex = nextTokenIndex();
		final String s = new String(mBuffer, 0, tokenIndex, Charsets.US_ASCII);
		consumeBuf(tokenIndex + 1);
		return s;
		}

		/**
		* Parse and return next token as base-10 encoded {@code long}.
		*/
		public long nextLong() throws IOException {
		final int tokenIndex = nextTokenIndex();
		final boolean negative = mBuffer[0] == '-';

		// TODO: refactor into something like IntegralToString
		long result = 0;
		for (int i = negative ? 1 : 0; i < tokenIndex; i++) {
		final int digit = mBuffer[i] - '0';
		if (digit < 0 \|\| digit > 9) {
		throw invalidLong(tokenIndex);
		}

		// always parse as negative number and apply sign later; this
		// correctly handles MIN_VALUE which is "larger" than MAX_VALUE.
		final long next = result * 10 - digit;
		if (next > result) {
		throw invalidLong(tokenIndex);
		}
		result = next;
		}

		consumeBuf(tokenIndex + 1);
		return negative ? result : -result;
		}

		private NumberFormatException invalidLong(int tokenIndex) {
		return new NumberFormatException(
		"invalid long: " + new String(mBuffer, 0, tokenIndex, Charsets.US_ASCII));
		}

		/**
		* Parse and return next token as base-10 encoded {@code int}.
		*/
		public int nextInt() throws IOException {
		final long value = nextLong();
		if (value > Integer.MAX_VALUE \|\| value < Integer.MIN_VALUE) {
		throw new NumberFormatException("parsed value larger than integer");
		}
		return (int) value;
		}

		public void close() throws IOException {
		mStream.close();
		}
		}

core/tests/bandwidthtests/src/com/android/bandwidthtest/BandwidthTest.java

+3 −3

Original line number	Diff line number	Diff line
		@@ -89,7 +89,7 @@ public class BandwidthTest extends InstrumentationTestCase {
		* Ensure that downloading on wifi reports reasonable stats.
		*/
		@LargeTest
		public void testWifiDownload() {
		public void testWifiDownload() throws Exception {
		assertTrue(setDeviceWifiAndAirplaneMode(mSsid));
		NetworkStats pre_test_stats = fetchDataFromProc(mUid);
		String ts = Long.toString(System.currentTimeMillis());
		@@ -123,7 +123,7 @@ public class BandwidthTest extends InstrumentationTestCase {
		* Ensure that downloading on wifi reports reasonable stats.
		*/
		@LargeTest
		public void testWifiUpload() {
		public void testWifiUpload() throws Exception {
		assertTrue(setDeviceWifiAndAirplaneMode(mSsid));
		// Download a file from the server.
		String ts = Long.toString(System.currentTimeMillis());
		@@ -160,7 +160,7 @@ public class BandwidthTest extends InstrumentationTestCase {
		* accounting still goes to the app making the call and that the numbers still make sense.
		*/
		@LargeTest
		public void testWifiDownloadWithDownloadManager() {
		public void testWifiDownloadWithDownloadManager() throws Exception {
		assertTrue(setDeviceWifiAndAirplaneMode(mSsid));
		// If we are using the download manager, then the data that is written to /proc/uid_stat/
		// is accounted against download manager's uid, since it uses pre-ICS API.