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Commit ff94e035 authored by Makoto Onuki's avatar Makoto Onuki
Browse files

DropBoxManagerService: Don't store redundant information 

Filenames can be calculated from other fields, so there's no need to
store them.

This will reduce the average EntryFile size from 160b to 28b, so in theory
it could save 132 KB for 1000 entries.

- Also switched from HashMap to ArrayMap, which should help a bit too.

- Also fixed unit tests and added more.

Bug: 20890386
Test: bit FrameworksServicesTests:com.android.server.DropBoxTest
Test: Boot, check the dropbox directory, run dumpsys dropbox, reboot and repeat.

Change-Id: If567750f478318acd621864d1d4ef2ed41f214bd
parent 98af408a

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

+8 −0
Original line number Diff line number Diff line
@@ -28,4 +28,12 @@ public class ObjectUtils { 
    public static <T> T firstNotNull(@Nullable T a, @NonNull T b) {

        return a != null ? a : Preconditions.checkNotNull(b);

    }



    public static <T extends Comparable> int compare(@Nullable T a, @Nullable T b) {

        if (a != null) {

            return (b != null) ? a.compareTo(b) : 1;

        } else {

            return (b != null) ? -1 : 0;

        }

    }

}

core/tests/utiltests/src/com/android/internal/util/ObjectUtilsTest.java

0 → 100644
+33 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2017 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 android.test.AndroidTestCase;

import android.test.suitebuilder.annotation.SmallTest;



@SmallTest

public class ObjectUtilsTest extends AndroidTestCase {

    public void testCompare() {

        assertEquals(0, ObjectUtils.compare(null, null));

        assertEquals(1, ObjectUtils.compare("a", null));

        assertEquals(-1, ObjectUtils.compare(null, "a"));



        assertEquals(0, ObjectUtils.compare("a", "a"));



        assertEquals(-1, ObjectUtils.compare("a", "b"));

        assertEquals(1, ObjectUtils.compare("b", "a"));

    }

}

services/core/java/com/android/server/DropBoxManagerService.java

+148 −76
Original line number Diff line number Diff line
@@ -29,18 +29,23 @@ import android.os.Debug; 
import android.os.DropBoxManager;

import android.os.FileUtils;

import android.os.Handler;

import android.os.Looper;

import android.os.Message;

import android.os.StatFs;

import android.os.SystemClock;

import android.os.UserHandle;

import android.provider.Settings;

import android.text.TextUtils;

import android.text.format.Time;

import android.util.ArrayMap;

import android.util.Slog;



import libcore.io.IoUtils;



import com.android.internal.annotations.VisibleForTesting;

import com.android.internal.os.IDropBoxManagerService;

import com.android.internal.util.DumpUtils;

import com.android.internal.util.ObjectUtils;



import java.io.BufferedOutputStream;

import java.io.File;
@@ -52,7 +57,7 @@ import java.io.InputStreamReader; 
import java.io.OutputStream;

import java.io.PrintWriter;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.Objects;

import java.util.SortedSet;

import java.util.TreeSet;

import java.util.zip.GZIPOutputStream;
@@ -87,7 +92,7 @@ public final class DropBoxManagerService extends SystemService { 
    // Accounting of all currently written log files (set in init()).



    private FileList mAllFiles = null;

    private HashMap<String, FileList> mFilesByTag = null;

    private ArrayMap<String, FileList> mFilesByTag = null;



    // Various bits of disk information
@@ -153,7 +158,7 @@ public final class DropBoxManagerService extends SystemService { 
     * @param context to use for receiving free space & gservices intents

     */

    public DropBoxManagerService(final Context context) {

        this(context, new File("/data/system/dropbox"));

        this(context, new File("/data/system/dropbox"), FgThread.get().getLooper());

    }



    /**
@@ -163,11 +168,12 @@ public final class DropBoxManagerService extends SystemService { 
     * @param context to use for receiving free space & gservices intents

     * @param path to store drop box entries in

     */

    public DropBoxManagerService(final Context context, File path) {

    @VisibleForTesting

    public DropBoxManagerService(final Context context, File path, Looper looper) {

        super(context);

        mDropBoxDir = path;

        mContentResolver = getContext().getContentResolver();

        mHandler = new Handler() {

        mHandler = new Handler(looper) {

            @Override

            public void handleMessage(Message msg) {

                if (msg.what == MSG_SEND_BROADCAST) {
@@ -338,11 +344,12 @@ public final class DropBoxManagerService extends SystemService { 
            if ((entry.flags & DropBoxManager.IS_EMPTY) != 0) {

                return new DropBoxManager.Entry(entry.tag, entry.timestampMillis);

            }

            final File file = entry.getFile(mDropBoxDir);

            try {

                return new DropBoxManager.Entry(

                        entry.tag, entry.timestampMillis, entry.file, entry.flags);

                        entry.tag, entry.timestampMillis, file, entry.flags);

            } catch (IOException e) {

                Slog.e(TAG, "Can't read: " + entry.file, e);

                Slog.wtf(TAG, "Can't read: " + file, e);

                // Continue to next file

            }

        }
@@ -410,7 +417,9 @@ public final class DropBoxManagerService extends SystemService { 
            numFound++;

            if (doPrint) out.append("========================================\n");

            out.append(date).append(" ").append(entry.tag == null ? "(no tag)" : entry.tag);

            if (entry.file == null) {



            final File file = entry.getFile(mDropBoxDir);

            if (file == null) {

                out.append(" (no file)\n");

                continue;

            } else if ((entry.flags & DropBoxManager.IS_EMPTY) != 0) {
@@ -420,12 +429,12 @@ public final class DropBoxManagerService extends SystemService { 
                out.append(" (");

                if ((entry.flags & DropBoxManager.IS_GZIPPED) != 0) out.append("compressed ");

                out.append((entry.flags & DropBoxManager.IS_TEXT) != 0 ? "text" : "data");

                out.append(", ").append(entry.file.length()).append(" bytes)\n");

                out.append(", ").append(file.length()).append(" bytes)\n");

            }



            if (doFile || (doPrint && (entry.flags & DropBoxManager.IS_TEXT) == 0)) {

                if (!doPrint) out.append("    ");

                out.append(entry.file.getPath()).append("\n");

                out.append(file.getPath()).append("\n");

            }



            if ((entry.flags & DropBoxManager.IS_TEXT) != 0 && (doPrint || !doFile)) {
@@ -433,7 +442,7 @@ public final class DropBoxManagerService extends SystemService { 
                InputStreamReader isr = null;

                try {

                    dbe = new DropBoxManager.Entry(

                             entry.tag, entry.timestampMillis, entry.file, entry.flags);

                             entry.tag, entry.timestampMillis, file, entry.flags);



                    if (doPrint) {

                        isr = new InputStreamReader(dbe.getInputStream());
@@ -466,7 +475,7 @@ public final class DropBoxManagerService extends SystemService { 
                    }

                } catch (IOException e) {

                    out.append("*** ").append(e.toString()).append("\n");

                    Slog.e(TAG, "Can't read: " + entry.file, e);

                    Slog.e(TAG, "Can't read: " + file, e);

                } finally {

                    if (dbe != null) dbe.close();

                    if (isr != null) {
@@ -509,29 +518,37 @@ public final class DropBoxManagerService extends SystemService { 
        }

    }



    /** Metadata describing an on-disk log file. */

    private static final class EntryFile implements Comparable<EntryFile> {

    /**

     * Metadata describing an on-disk log file.

     *

     * Note its instances do no have knowledge on what directory they're stored, just to save

     * 4/8 bytes per instance.  Instead, {@link #getFile} takes a directory so it can build a

     * fullpath.

     */

    @VisibleForTesting

    static final class EntryFile implements Comparable<EntryFile> {

        public final String tag;

        public final long timestampMillis;

        public final int flags;

        public final File file;

        public final int blocks;



        /** Sorts earlier EntryFile instances before later ones. */

        public final int compareTo(EntryFile o) {

            if (timestampMillis < o.timestampMillis) return -1;

            if (timestampMillis > o.timestampMillis) return 1;

            if (file != null && o.file != null) return file.compareTo(o.file);

            if (o.file != null) return -1;

            if (file != null) return 1;

            if (this == o) return 0;

            if (hashCode() < o.hashCode()) return -1;

            if (hashCode() > o.hashCode()) return 1;

            return 0;

            int comp = Long.compare(timestampMillis, o.timestampMillis);

            if (comp != 0) return comp;



            comp = ObjectUtils.compare(tag, o.tag);

            if (comp != 0) return comp;



            comp = Integer.compare(flags, o.flags);

            if (comp != 0) return comp;



            return Integer.compare(hashCode(), o.hashCode());

        }



        /**

         * Moves an existing temporary file to a new log filename.

         *

         * @param temp file to rename

         * @param dir to store file in

         * @param tag to use for new log file name
@@ -544,55 +561,56 @@ public final class DropBoxManagerService extends SystemService { 
                         int flags, int blockSize) throws IOException {

            if ((flags & DropBoxManager.IS_EMPTY) != 0) throw new IllegalArgumentException();



            this.tag = tag;

            this.tag = TextUtils.safeIntern(tag);

            this.timestampMillis = timestampMillis;

            this.flags = flags;

            this.file = new File(dir, Uri.encode(tag) + "@" + timestampMillis +

                    ((flags & DropBoxManager.IS_TEXT) != 0 ? ".txt" : ".dat") +

                    ((flags & DropBoxManager.IS_GZIPPED) != 0 ? ".gz" : ""));



            if (!temp.renameTo(this.file)) {

                throw new IOException("Can't rename " + temp + " to " + this.file);

            final File file = this.getFile(dir);

            if (!temp.renameTo(file)) {

                throw new IOException("Can't rename " + temp + " to " + file);

            }

            this.blocks = (int) ((this.file.length() + blockSize - 1) / blockSize);

            this.blocks = (int) ((file.length() + blockSize - 1) / blockSize);

        }



        /**

         * Creates a zero-length tombstone for a file whose contents were lost.

         *

         * @param dir to store file in

         * @param tag to use for new log file name

         * @param timestampMillis of log entry

         * @throws IOException if the file can't be created.

         */

        public EntryFile(File dir, String tag, long timestampMillis) throws IOException {

            this.tag = tag;

            this.tag = TextUtils.safeIntern(tag);

            this.timestampMillis = timestampMillis;

            this.flags = DropBoxManager.IS_EMPTY;

            this.file = new File(dir, Uri.encode(tag) + "@" + timestampMillis + ".lost");

            this.blocks = 0;

            new FileOutputStream(this.file).close();

            new FileOutputStream(getFile(dir)).close();

        }



        /**

         * Extracts metadata from an existing on-disk log filename.

         *

         * Note when a filename is not recognizable, it will create an instance that

         * {@link #hasFile()} would return false on, and also remove the file.

         *

         * @param file name of existing log file

         * @param blockSize to use for space accounting

         */

        public EntryFile(File file, int blockSize) {

            this.file = file;

            this.blocks = (int) ((this.file.length() + blockSize - 1) / blockSize);



            String name = file.getName();

            int at = name.lastIndexOf('@');

            if (at < 0) {

                this.tag = null;

                this.timestampMillis = 0;

                this.flags = DropBoxManager.IS_EMPTY;

                return;

            }

            boolean parseFailure = false;



            String name = file.getName();

            int flags = 0;

            this.tag = Uri.decode(name.substring(0, at));

            String tag = null;

            long millis = 0;



            final int at = name.lastIndexOf('@');

            if (at < 0) {

                parseFailure = true;

            } else {

                tag = Uri.decode(name.substring(0, at));

                if (name.endsWith(".gz")) {

                    flags |= DropBoxManager.IS_GZIPPED;

                    name = name.substring(0, name.length() - 3);
@@ -606,14 +624,31 @@ public final class DropBoxManagerService extends SystemService { 
                } else if (name.endsWith(".dat")) {

                    name = name.substring(at + 1, name.length() - 4);

                } else {

                    parseFailure = true;

                }

                if (!parseFailure) {

                    try {

                        millis = Long.parseLong(name);

                    } catch (NumberFormatException e) {

                        parseFailure = true;

                    }

                }

            }

            if (parseFailure) {

                Slog.wtf(TAG, "Invalid filename: " + file);



                // Remove the file and return an empty instance.

                file.delete();

                this.tag = null;

                this.flags = DropBoxManager.IS_EMPTY;

                this.timestampMillis = 0;

                this.blocks = 0;

                return;

            }

            this.flags = flags;



            long millis;

            try { millis = Long.parseLong(name); } catch (NumberFormatException e) { millis = 0; }

            this.blocks = (int) ((file.length() + blockSize - 1) / blockSize);

            this.tag = TextUtils.safeIntern(tag);

            this.flags = flags;

            this.timestampMillis = millis;

        }
@@ -625,9 +660,50 @@ public final class DropBoxManagerService extends SystemService { 
            this.tag = null;

            this.timestampMillis = millis;

            this.flags = DropBoxManager.IS_EMPTY;

            this.file = null;

            this.blocks = 0;

        }



        /**

         * @return whether an entry actually has a backing file, or it's an empty "tombstone"

         * entry.

         */

        public boolean hasFile() {

            return tag != null;

        }



        /** @return File extension for the flags. */

        private String getExtension() {

            if ((flags &  DropBoxManager.IS_EMPTY) != 0) {

                return ".lost";

            }

            return ((flags & DropBoxManager.IS_TEXT) != 0 ? ".txt" : ".dat") +

                    ((flags & DropBoxManager.IS_GZIPPED) != 0 ? ".gz" : "");

        }



        /**

         * @return filename for this entry without the pathname.

         */

        public String getFilename() {

            return hasFile() ? Uri.encode(tag) + "@" + timestampMillis + getExtension() : null;

        }



        /**

         * Get a full-path {@link File} representing this entry.

         * @param dir Parent directly.  The caller needs to pass it because {@link EntryFile}s don't

         *            know in which directory they're stored.

         */

        public File getFile(File dir) {

            return hasFile() ? new File(dir, getFilename()) : null;

        }



        /**

         * If an entry has a backing file, remove it.

         */

        public void deleteFile(File dir) {

            if (hasFile()) {

                getFile(dir).delete();

            }

        }

    }



    ///////////////////////////////////////////////////////////////////////////
@@ -651,7 +727,7 @@ public final class DropBoxManagerService extends SystemService { 
            if (files == null) throw new IOException("Can't list files: " + mDropBoxDir);



            mAllFiles = new FileList();

            mFilesByTag = new HashMap<String, FileList>();

            mFilesByTag = new ArrayMap<>();



            // Scan pre-existing files.

            for (File file : files) {
@@ -662,19 +738,15 @@ public final class DropBoxManagerService extends SystemService { 
                }



                EntryFile entry = new EntryFile(file, mBlockSize);

                if (entry.tag == null) {

                    Slog.w(TAG, "Unrecognized file: " + file);

                    continue;

                } else if (entry.timestampMillis == 0) {

                    Slog.w(TAG, "Invalid filename: " + file);

                    file.delete();

                    continue;

                }



                if (entry.hasFile()) {

                    // Enroll only when the filename is valid.  Otherwise the above constructor

                    // has removed the file already.

                    enrollEntry(entry);

                }

            }

        }

    }



    /** Adds a disk log file to in-memory tracking for accounting and enumeration. */

    private synchronized void enrollEntry(EntryFile entry) {
@@ -684,11 +756,11 @@ public final class DropBoxManagerService extends SystemService { 
        // mFilesByTag is used for trimming, so don't list empty files.

        // (Zero-length/lost files are trimmed by date from mAllFiles.)



        if (entry.tag != null && entry.file != null && entry.blocks > 0) {

        if (entry.hasFile() && entry.blocks > 0) {

            FileList tagFiles = mFilesByTag.get(entry.tag);

            if (tagFiles == null) {

                tagFiles = new FileList();

                mFilesByTag.put(entry.tag, tagFiles);

                mFilesByTag.put(TextUtils.safeIntern(entry.tag), tagFiles);

            }

            tagFiles.contents.add(entry);

            tagFiles.blocks += entry.blocks;
@@ -722,8 +794,8 @@ public final class DropBoxManagerService extends SystemService { 
                    tagFiles.blocks -= late.blocks;

                }

                if ((late.flags & DropBoxManager.IS_EMPTY) == 0) {

                    enrollEntry(new EntryFile(

                            late.file, mDropBoxDir, late.tag, t++, late.flags, mBlockSize));

                    enrollEntry(new EntryFile(late.getFile(mDropBoxDir), mDropBoxDir,

                            late.tag, t++, late.flags, mBlockSize));

                } else {

                    enrollEntry(new EntryFile(mDropBoxDir, late.tag, t++));

                }
@@ -757,7 +829,7 @@ public final class DropBoxManagerService extends SystemService { 
            FileList tag = mFilesByTag.get(entry.tag);

            if (tag != null && tag.contents.remove(entry)) tag.blocks -= entry.blocks;

            if (mAllFiles.contents.remove(entry)) mAllFiles.blocks -= entry.blocks;

            if (entry.file != null) entry.file.delete();

            entry.deleteFile(mDropBoxDir);

        }



        // Compute overall quota (a fraction of available free space) in blocks.
@@ -823,7 +895,7 @@ public final class DropBoxManagerService extends SystemService { 
                    if (mAllFiles.contents.remove(entry)) mAllFiles.blocks -= entry.blocks;



                    try {

                        if (entry.file != null) entry.file.delete();

                        entry.deleteFile(mDropBoxDir);

                        enrollEntry(new EntryFile(mDropBoxDir, entry.tag, entry.timestampMillis));

                    } catch (IOException e) {

                        Slog.e(TAG, "Can't write tombstone file", e);

services/tests/servicestests/src/com/android/server/DropBoxTest.java

+278 −19

File changed.

Preview size limit exceeded, changes collapsed.