FileDocCategorySizeDatePackage
DropBoxManagerService.javaAPI DocAndroid 5.1 API32133Thu Mar 12 22:22:42 GMT 2015com.android.server

DropBoxManagerService

public final class DropBoxManagerService extends IDropBoxManagerService.Stub
Implementation of {@link IDropBoxManagerService} using the filesystem. Clients use {@link DropBoxManager} to access this service.

Fields Summary
private static final String
TAG
private static final int
DEFAULT_AGE_SECONDS
private static final int
DEFAULT_MAX_FILES
private static final int
DEFAULT_QUOTA_KB
private static final int
DEFAULT_QUOTA_PERCENT
private static final int
DEFAULT_RESERVE_PERCENT
private static final int
QUOTA_RESCAN_MILLIS
private static final int
MSG_SEND_BROADCAST
private static final boolean
PROFILE_DUMP
private final android.content.Context
mContext
private final android.content.ContentResolver
mContentResolver
private final File
mDropBoxDir
private FileList
mAllFiles
private HashMap
mFilesByTag
private android.os.StatFs
mStatFs
private int
mBlockSize
private int
mCachedQuotaBlocks
private long
mCachedQuotaUptimeMillis
private volatile boolean
mBooted
private final android.os.Handler
mHandler
private final android.content.BroadcastReceiver
mReceiver
Receives events that might indicate a need to clean up files.
Constructors Summary
public DropBoxManagerService(android.content.Context context, File path)
Creates an instance of managed drop box storage. Normally there is one of these run by the system, but others can be created for testing and other purposes.

param
context to use for receiving free space & gservices intents
param
path to store drop box entries in


                                                         
          
        mDropBoxDir = path;

        // Set up intent receivers
        mContext = context;
        mContentResolver = context.getContentResolver();

        IntentFilter filter = new IntentFilter();
        filter.addAction(Intent.ACTION_DEVICE_STORAGE_LOW);
        filter.addAction(Intent.ACTION_BOOT_COMPLETED);
        context.registerReceiver(mReceiver, filter);

        mContentResolver.registerContentObserver(
            Settings.Global.CONTENT_URI, true,
            new ContentObserver(new Handler()) {
                @Override
                public void onChange(boolean selfChange) {
                    mReceiver.onReceive(context, (Intent) null);
                }
            });

        mHandler = new Handler() {
            @Override
            public void handleMessage(Message msg) {
                if (msg.what == MSG_SEND_BROADCAST) {
                    mContext.sendBroadcastAsUser((Intent)msg.obj, UserHandle.OWNER,
                            android.Manifest.permission.READ_LOGS);
                }
            }
        };

        // The real work gets done lazily in init() -- that way service creation always
        // succeeds, and things like disk problems cause individual method failures.
Methods Summary
public voidadd(DropBoxManager.Entry entry)

        File temp = null;
        OutputStream output = null;
        final String tag = entry.getTag();
        try {
            int flags = entry.getFlags();
            if ((flags & DropBoxManager.IS_EMPTY) != 0) throw new IllegalArgumentException();

            init();
            if (!isTagEnabled(tag)) return;
            long max = trimToFit();
            long lastTrim = System.currentTimeMillis();

            byte[] buffer = new byte[mBlockSize];
            InputStream input = entry.getInputStream();

            // First, accumulate up to one block worth of data in memory before
            // deciding whether to compress the data or not.

            int read = 0;
            while (read < buffer.length) {
                int n = input.read(buffer, read, buffer.length - read);
                if (n <= 0) break;
                read += n;
            }

            // If we have at least one block, compress it -- otherwise, just write
            // the data in uncompressed form.

            temp = new File(mDropBoxDir, "drop" + Thread.currentThread().getId() + ".tmp");
            int bufferSize = mBlockSize;
            if (bufferSize > 4096) bufferSize = 4096;
            if (bufferSize < 512) bufferSize = 512;
            FileOutputStream foutput = new FileOutputStream(temp);
            output = new BufferedOutputStream(foutput, bufferSize);
            if (read == buffer.length && ((flags & DropBoxManager.IS_GZIPPED) == 0)) {
                output = new GZIPOutputStream(output);
                flags = flags | DropBoxManager.IS_GZIPPED;
            }

            do {
                output.write(buffer, 0, read);

                long now = System.currentTimeMillis();
                if (now - lastTrim > 30 * 1000) {
                    max = trimToFit();  // In case data dribbles in slowly
                    lastTrim = now;
                }

                read = input.read(buffer);
                if (read <= 0) {
                    FileUtils.sync(foutput);
                    output.close();  // Get a final size measurement
                    output = null;
                } else {
                    output.flush();  // So the size measurement is pseudo-reasonable
                }

                long len = temp.length();
                if (len > max) {
                    Slog.w(TAG, "Dropping: " + tag + " (" + temp.length() + " > " + max + " bytes)");
                    temp.delete();
                    temp = null;  // Pass temp = null to createEntry() to leave a tombstone
                    break;
                }
            } while (read > 0);

            long time = createEntry(temp, tag, flags);
            temp = null;

            final Intent dropboxIntent = new Intent(DropBoxManager.ACTION_DROPBOX_ENTRY_ADDED);
            dropboxIntent.putExtra(DropBoxManager.EXTRA_TAG, tag);
            dropboxIntent.putExtra(DropBoxManager.EXTRA_TIME, time);
            if (!mBooted) {
                dropboxIntent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);
            }
            // Call sendBroadcast after returning from this call to avoid deadlock. In particular
            // the caller may be holding the WindowManagerService lock but sendBroadcast requires a
            // lock in ActivityManagerService. ActivityManagerService has been caught holding that
            // very lock while waiting for the WindowManagerService lock.
            mHandler.sendMessage(mHandler.obtainMessage(MSG_SEND_BROADCAST, dropboxIntent));
        } catch (IOException e) {
            Slog.e(TAG, "Can't write: " + tag, e);
        } finally {
            try { if (output != null) output.close(); } catch (IOException e) {}
            entry.close();
            if (temp != null) temp.delete();
        }
private synchronized longcreateEntry(java.io.File temp, java.lang.String tag, int flags)
Moves a temporary file to a final log filename and enrolls it.

        long t = System.currentTimeMillis();

        // Require each entry to have a unique timestamp; if there are entries
        // >10sec in the future (due to clock skew), drag them back to avoid
        // keeping them around forever.

        SortedSet<EntryFile> tail = mAllFiles.contents.tailSet(new EntryFile(t + 10000));
        EntryFile[] future = null;
        if (!tail.isEmpty()) {
            future = tail.toArray(new EntryFile[tail.size()]);
            tail.clear();  // Remove from mAllFiles
        }

        if (!mAllFiles.contents.isEmpty()) {
            t = Math.max(t, mAllFiles.contents.last().timestampMillis + 1);
        }

        if (future != null) {
            for (EntryFile late : future) {
                mAllFiles.blocks -= late.blocks;
                FileList tagFiles = mFilesByTag.get(late.tag);
                if (tagFiles != null && tagFiles.contents.remove(late)) {
                    tagFiles.blocks -= late.blocks;
                }
                if ((late.flags & DropBoxManager.IS_EMPTY) == 0) {
                    enrollEntry(new EntryFile(
                            late.file, mDropBoxDir, late.tag, t++, late.flags, mBlockSize));
                } else {
                    enrollEntry(new EntryFile(mDropBoxDir, late.tag, t++));
                }
            }
        }

        if (temp == null) {
            enrollEntry(new EntryFile(mDropBoxDir, tag, t));
        } else {
            enrollEntry(new EntryFile(temp, mDropBoxDir, tag, t, flags, mBlockSize));
        }
        return t;
public synchronized voiddump(java.io.FileDescriptor fd, java.io.PrintWriter pw, java.lang.String[] args)

        if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.DUMP)
                != PackageManager.PERMISSION_GRANTED) {
            pw.println("Permission Denial: Can't dump DropBoxManagerService");
            return;
        }

        try {
            init();
        } catch (IOException e) {
            pw.println("Can't initialize: " + e);
            Slog.e(TAG, "Can't init", e);
            return;
        }

        if (PROFILE_DUMP) Debug.startMethodTracing("/data/trace/dropbox.dump");

        StringBuilder out = new StringBuilder();
        boolean doPrint = false, doFile = false;
        ArrayList<String> searchArgs = new ArrayList<String>();
        for (int i = 0; args != null && i < args.length; i++) {
            if (args[i].equals("-p") || args[i].equals("--print")) {
                doPrint = true;
            } else if (args[i].equals("-f") || args[i].equals("--file")) {
                doFile = true;
            } else if (args[i].startsWith("-")) {
                out.append("Unknown argument: ").append(args[i]).append("\n");
            } else {
                searchArgs.add(args[i]);
            }
        }

        out.append("Drop box contents: ").append(mAllFiles.contents.size()).append(" entries\n");

        if (!searchArgs.isEmpty()) {
            out.append("Searching for:");
            for (String a : searchArgs) out.append(" ").append(a);
            out.append("\n");
        }

        int numFound = 0, numArgs = searchArgs.size();
        Time time = new Time();
        out.append("\n");
        for (EntryFile entry : mAllFiles.contents) {
            time.set(entry.timestampMillis);
            String date = time.format("%Y-%m-%d %H:%M:%S");
            boolean match = true;
            for (int i = 0; i < numArgs && match; i++) {
                String arg = searchArgs.get(i);
                match = (date.contains(arg) || arg.equals(entry.tag));
            }
            if (!match) continue;

            numFound++;
            if (doPrint) out.append("========================================\n");
            out.append(date).append(" ").append(entry.tag == null ? "(no tag)" : entry.tag);
            if (entry.file == null) {
                out.append(" (no file)\n");
                continue;
            } else if ((entry.flags & DropBoxManager.IS_EMPTY) != 0) {
                out.append(" (contents lost)\n");
                continue;
            } else {
                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");
            }

            if (doFile || (doPrint && (entry.flags & DropBoxManager.IS_TEXT) == 0)) {
                if (!doPrint) out.append("    ");
                out.append(entry.file.getPath()).append("\n");
            }

            if ((entry.flags & DropBoxManager.IS_TEXT) != 0 && (doPrint || !doFile)) {
                DropBoxManager.Entry dbe = null;
                InputStreamReader isr = null;
                try {
                    dbe = new DropBoxManager.Entry(
                             entry.tag, entry.timestampMillis, entry.file, entry.flags);

                    if (doPrint) {
                        isr = new InputStreamReader(dbe.getInputStream());
                        char[] buf = new char[4096];
                        boolean newline = false;
                        for (;;) {
                            int n = isr.read(buf);
                            if (n <= 0) break;
                            out.append(buf, 0, n);
                            newline = (buf[n - 1] == '\n");

                            // Flush periodically when printing to avoid out-of-memory.
                            if (out.length() > 65536) {
                                pw.write(out.toString());
                                out.setLength(0);
                            }
                        }
                        if (!newline) out.append("\n");
                    } else {
                        String text = dbe.getText(70);
                        out.append("    ");
                        if (text == null) {
                            out.append("[null]");
                        } else {
                            boolean truncated = (text.length() == 70);
                            out.append(text.trim().replace('\n", '/"));
                            if (truncated) out.append(" ...");
                        }
                        out.append("\n");
                    }
                } catch (IOException e) {
                    out.append("*** ").append(e.toString()).append("\n");
                    Slog.e(TAG, "Can't read: " + entry.file, e);
                } finally {
                    if (dbe != null) dbe.close();
                    if (isr != null) {
                        try {
                            isr.close();
                        } catch (IOException unused) {
                        }
                    }
                }
            }

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

        if (numFound == 0) out.append("(No entries found.)\n");

        if (args == null || args.length == 0) {
            if (!doPrint) out.append("\n");
            out.append("Usage: dumpsys dropbox [--print|--file] [YYYY-mm-dd] [HH:MM:SS] [tag]\n");
        }

        pw.write(out.toString());
        if (PROFILE_DUMP) Debug.stopMethodTracing();
private synchronized voidenrollEntry(com.android.server.DropBoxManagerService$EntryFile entry)
Adds a disk log file to in-memory tracking for accounting and enumeration.

        mAllFiles.contents.add(entry);
        mAllFiles.blocks += entry.blocks;

        // 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) {
            FileList tagFiles = mFilesByTag.get(entry.tag);
            if (tagFiles == null) {
                tagFiles = new FileList();
                mFilesByTag.put(entry.tag, tagFiles);
            }
            tagFiles.contents.add(entry);
            tagFiles.blocks += entry.blocks;
        }
public synchronized DropBoxManager.EntrygetNextEntry(java.lang.String tag, long millis)

        if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.READ_LOGS)
                != PackageManager.PERMISSION_GRANTED) {
            throw new SecurityException("READ_LOGS permission required");
        }

        try {
            init();
        } catch (IOException e) {
            Slog.e(TAG, "Can't init", e);
            return null;
        }

        FileList list = tag == null ? mAllFiles : mFilesByTag.get(tag);
        if (list == null) return null;

        for (EntryFile entry : list.contents.tailSet(new EntryFile(millis + 1))) {
            if (entry.tag == null) continue;
            if ((entry.flags & DropBoxManager.IS_EMPTY) != 0) {
                return new DropBoxManager.Entry(entry.tag, entry.timestampMillis);
            }
            try {
                return new DropBoxManager.Entry(
                        entry.tag, entry.timestampMillis, entry.file, entry.flags);
            } catch (IOException e) {
                Slog.e(TAG, "Can't read: " + entry.file, e);
                // Continue to next file
            }
        }

        return null;
private synchronized voidinit()
If never run before, scans disk contents to build in-memory tracking data.

        if (mStatFs == null) {
            if (!mDropBoxDir.isDirectory() && !mDropBoxDir.mkdirs()) {
                throw new IOException("Can't mkdir: " + mDropBoxDir);
            }
            try {
                mStatFs = new StatFs(mDropBoxDir.getPath());
                mBlockSize = mStatFs.getBlockSize();
            } catch (IllegalArgumentException e) {  // StatFs throws this on error
                throw new IOException("Can't statfs: " + mDropBoxDir);
            }
        }

        if (mAllFiles == null) {
            File[] files = mDropBoxDir.listFiles();
            if (files == null) throw new IOException("Can't list files: " + mDropBoxDir);

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

            // Scan pre-existing files.
            for (File file : files) {
                if (file.getName().endsWith(".tmp")) {
                    Slog.i(TAG, "Cleaning temp file: " + file);
                    file.delete();
                    continue;
                }

                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;
                }

                enrollEntry(entry);
            }
        }
public booleanisTagEnabled(java.lang.String tag)

        final long token = Binder.clearCallingIdentity();
        try {
            return !"disabled".equals(Settings.Global.getString(
                    mContentResolver, Settings.Global.DROPBOX_TAG_PREFIX + tag));
        } finally {
            Binder.restoreCallingIdentity(token);
        }
public voidstop()
Unregisters broadcast receivers and any other hooks -- for test instances

        mContext.unregisterReceiver(mReceiver);
private synchronized longtrimToFit()
Trims the files on disk to make sure they aren't using too much space.

return
the overall quota for storage (in bytes)

        // Expunge aged items (including tombstones marking deleted data).

        int ageSeconds = Settings.Global.getInt(mContentResolver,
                Settings.Global.DROPBOX_AGE_SECONDS, DEFAULT_AGE_SECONDS);
        int maxFiles = Settings.Global.getInt(mContentResolver,
                Settings.Global.DROPBOX_MAX_FILES, DEFAULT_MAX_FILES);
        long cutoffMillis = System.currentTimeMillis() - ageSeconds * 1000;
        while (!mAllFiles.contents.isEmpty()) {
            EntryFile entry = mAllFiles.contents.first();
            if (entry.timestampMillis > cutoffMillis && mAllFiles.contents.size() < maxFiles) break;

            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();
        }

        // Compute overall quota (a fraction of available free space) in blocks.
        // The quota changes dynamically based on the amount of free space;
        // that way when lots of data is available we can use it, but we'll get
        // out of the way if storage starts getting tight.

        long uptimeMillis = SystemClock.uptimeMillis();
        if (uptimeMillis > mCachedQuotaUptimeMillis + QUOTA_RESCAN_MILLIS) {
            int quotaPercent = Settings.Global.getInt(mContentResolver,
                    Settings.Global.DROPBOX_QUOTA_PERCENT, DEFAULT_QUOTA_PERCENT);
            int reservePercent = Settings.Global.getInt(mContentResolver,
                    Settings.Global.DROPBOX_RESERVE_PERCENT, DEFAULT_RESERVE_PERCENT);
            int quotaKb = Settings.Global.getInt(mContentResolver,
                    Settings.Global.DROPBOX_QUOTA_KB, DEFAULT_QUOTA_KB);

            mStatFs.restat(mDropBoxDir.getPath());
            int available = mStatFs.getAvailableBlocks();
            int nonreserved = available - mStatFs.getBlockCount() * reservePercent / 100;
            int maximum = quotaKb * 1024 / mBlockSize;
            mCachedQuotaBlocks = Math.min(maximum, Math.max(0, nonreserved * quotaPercent / 100));
            mCachedQuotaUptimeMillis = uptimeMillis;
        }

        // If we're using too much space, delete old items to make room.
        //
        // We trim each tag independently (this is why we keep per-tag lists).
        // Space is "fairly" shared between tags -- they are all squeezed
        // equally until enough space is reclaimed.
        //
        // A single circular buffer (a la logcat) would be simpler, but this
        // way we can handle fat/bursty data (like 1MB+ bugreports, 300KB+
        // kernel crash dumps, and 100KB+ ANR reports) without swamping small,
        // well-behaved data streams (event statistics, profile data, etc).
        //
        // Deleted files are replaced with zero-length tombstones to mark what
        // was lost.  Tombstones are expunged by age (see above).

        if (mAllFiles.blocks > mCachedQuotaBlocks) {
            // Find a fair share amount of space to limit each tag
            int unsqueezed = mAllFiles.blocks, squeezed = 0;
            TreeSet<FileList> tags = new TreeSet<FileList>(mFilesByTag.values());
            for (FileList tag : tags) {
                if (squeezed > 0 && tag.blocks <= (mCachedQuotaBlocks - unsqueezed) / squeezed) {
                    break;
                }
                unsqueezed -= tag.blocks;
                squeezed++;
            }
            int tagQuota = (mCachedQuotaBlocks - unsqueezed) / squeezed;

            // Remove old items from each tag until it meets the per-tag quota.
            for (FileList tag : tags) {
                if (mAllFiles.blocks < mCachedQuotaBlocks) break;
                while (tag.blocks > tagQuota && !tag.contents.isEmpty()) {
                    EntryFile entry = tag.contents.first();
                    if (tag.contents.remove(entry)) tag.blocks -= entry.blocks;
                    if (mAllFiles.contents.remove(entry)) mAllFiles.blocks -= entry.blocks;

                    try {
                        if (entry.file != null) entry.file.delete();
                        enrollEntry(new EntryFile(mDropBoxDir, entry.tag, entry.timestampMillis));
                    } catch (IOException e) {
                        Slog.e(TAG, "Can't write tombstone file", e);
                    }
                }
            }
        }

        return mCachedQuotaBlocks * mBlockSize;