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1 /*
2  * Copyright (C) 2009 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.server;
18 
19 import android.app.ActivityManager;
20 import android.content.BroadcastReceiver;
21 import android.content.ContentResolver;
22 import android.content.Context;
23 import android.content.Intent;
24 import android.content.IntentFilter;
25 import android.content.pm.PackageManager;
26 import android.database.ContentObserver;
27 import android.net.Uri;
28 import android.os.Binder;
29 import android.os.Debug;
30 import android.os.DropBoxManager;
31 import android.os.FileUtils;
32 import android.os.Handler;
33 import android.os.Looper;
34 import android.os.Message;
35 import android.os.StatFs;
36 import android.os.SystemClock;
37 import android.os.UserHandle;
38 import android.provider.Settings;
39 import android.text.TextUtils;
40 import android.text.format.Time;
41 import android.util.ArrayMap;
42 import android.util.Slog;
43 
44 import libcore.io.IoUtils;
45 
46 import com.android.internal.annotations.VisibleForTesting;
47 import com.android.internal.os.IDropBoxManagerService;
48 import com.android.internal.util.DumpUtils;
49 import com.android.internal.util.ObjectUtils;
50 
51 import java.io.BufferedOutputStream;
52 import java.io.File;
53 import java.io.FileDescriptor;
54 import java.io.FileOutputStream;
55 import java.io.IOException;
56 import java.io.InputStream;
57 import java.io.InputStreamReader;
58 import java.io.OutputStream;
59 import java.io.PrintWriter;
60 import java.util.ArrayList;
61 import java.util.Objects;
62 import java.util.SortedSet;
63 import java.util.TreeSet;
64 import java.util.zip.GZIPOutputStream;
65 
66 /**
67  * Implementation of {@link IDropBoxManagerService} using the filesystem.
68  * Clients use {@link DropBoxManager} to access this service.
69  */
70 public final class DropBoxManagerService extends SystemService {
71     private static final String TAG = "DropBoxManagerService";
72     private static final int DEFAULT_AGE_SECONDS = 3 * 86400;
73     private static final int DEFAULT_MAX_FILES = 1000;
74     private static final int DEFAULT_MAX_FILES_LOWRAM = 300;
75     private static final int DEFAULT_QUOTA_KB = 5 * 1024;
76     private static final int DEFAULT_QUOTA_PERCENT = 10;
77     private static final int DEFAULT_RESERVE_PERCENT = 10;
78     private static final int QUOTA_RESCAN_MILLIS = 5000;
79 
80     // mHandler 'what' value.
81     private static final int MSG_SEND_BROADCAST = 1;
82 
83     private static final boolean PROFILE_DUMP = false;
84 
85     // TODO: This implementation currently uses one file per entry, which is
86     // inefficient for smallish entries -- consider using a single queue file
87     // per tag (or even globally) instead.
88 
89     // The cached context and derived objects
90 
91     private final ContentResolver mContentResolver;
92     private final File mDropBoxDir;
93 
94     // Accounting of all currently written log files (set in init()).
95 
96     private FileList mAllFiles = null;
97     private ArrayMap<String, FileList> mFilesByTag = null;
98 
99     // Various bits of disk information
100 
101     private StatFs mStatFs = null;
102     private int mBlockSize = 0;
103     private int mCachedQuotaBlocks = 0;  // Space we can use: computed from free space, etc.
104     private long mCachedQuotaUptimeMillis = 0;
105 
106     private volatile boolean mBooted = false;
107 
108     // Provide a way to perform sendBroadcast asynchronously to avoid deadlocks.
109     private final Handler mHandler;
110 
111     private int mMaxFiles = -1; // -1 means uninitialized.
112 
113     /** Receives events that might indicate a need to clean up files. */
114     private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
115         @Override
116         public void onReceive(Context context, Intent intent) {
117             // For ACTION_DEVICE_STORAGE_LOW:
118             mCachedQuotaUptimeMillis = 0;  // Force a re-check of quota size
119 
120             // Run the initialization in the background (not this main thread).
121             // The init() and trimToFit() methods are synchronized, so they still
122             // block other users -- but at least the onReceive() call can finish.
123             new Thread() {
124                 public void run() {
125                     try {
126                         init();
127                         trimToFit();
128                     } catch (IOException e) {
129                         Slog.e(TAG, "Can't init", e);
130                     }
131                 }
132             }.start();
133         }
134     };
135 
136     private final IDropBoxManagerService.Stub mStub = new IDropBoxManagerService.Stub() {
137         @Override
138         public void add(DropBoxManager.Entry entry) {
139             DropBoxManagerService.this.add(entry);
140         }
141 
142         @Override
143         public boolean isTagEnabled(String tag) {
144             return DropBoxManagerService.this.isTagEnabled(tag);
145         }
146 
147         @Override
148         public DropBoxManager.Entry getNextEntry(String tag, long millis) {
149             return DropBoxManagerService.this.getNextEntry(tag, millis);
150         }
151 
152         @Override
153         public void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
154             DropBoxManagerService.this.dump(fd, pw, args);
155         }
156     };
157 
158     /**
159      * Creates an instance of managed drop box storage using the default dropbox
160      * directory.
161      *
162      * @param context to use for receiving free space & gservices intents
163      */
DropBoxManagerService(final Context context)164     public DropBoxManagerService(final Context context) {
165         this(context, new File("/data/system/dropbox"), FgThread.get().getLooper());
166     }
167 
168     /**
169      * Creates an instance of managed drop box storage.  Normally there is one of these
170      * run by the system, but others can be created for testing and other purposes.
171      *
172      * @param context to use for receiving free space & gservices intents
173      * @param path to store drop box entries in
174      */
175     @VisibleForTesting
DropBoxManagerService(final Context context, File path, Looper looper)176     public DropBoxManagerService(final Context context, File path, Looper looper) {
177         super(context);
178         mDropBoxDir = path;
179         mContentResolver = getContext().getContentResolver();
180         mHandler = new Handler(looper) {
181             @Override
182             public void handleMessage(Message msg) {
183                 if (msg.what == MSG_SEND_BROADCAST) {
184                     getContext().sendBroadcastAsUser((Intent)msg.obj, UserHandle.SYSTEM,
185                             android.Manifest.permission.READ_LOGS);
186                 }
187             }
188         };
189     }
190 
191     @Override
onStart()192     public void onStart() {
193         publishBinderService(Context.DROPBOX_SERVICE, mStub);
194 
195         // The real work gets done lazily in init() -- that way service creation always
196         // succeeds, and things like disk problems cause individual method failures.
197     }
198 
199     @Override
onBootPhase(int phase)200     public void onBootPhase(int phase) {
201         switch (phase) {
202             case PHASE_SYSTEM_SERVICES_READY:
203                 IntentFilter filter = new IntentFilter();
204                 filter.addAction(Intent.ACTION_DEVICE_STORAGE_LOW);
205                 getContext().registerReceiver(mReceiver, filter);
206 
207                 mContentResolver.registerContentObserver(
208                     Settings.Global.CONTENT_URI, true,
209                     new ContentObserver(new Handler()) {
210                         @Override
211                         public void onChange(boolean selfChange) {
212                             mReceiver.onReceive(getContext(), (Intent) null);
213                         }
214                     });
215                 break;
216 
217             case PHASE_BOOT_COMPLETED:
218                 mBooted = true;
219                 break;
220         }
221     }
222 
223     /** Retrieves the binder stub -- for test instances */
getServiceStub()224     public IDropBoxManagerService getServiceStub() {
225         return mStub;
226     }
227 
add(DropBoxManager.Entry entry)228     public void add(DropBoxManager.Entry entry) {
229         File temp = null;
230         InputStream input = null;
231         OutputStream output = null;
232         final String tag = entry.getTag();
233         try {
234             int flags = entry.getFlags();
235             if ((flags & DropBoxManager.IS_EMPTY) != 0) throw new IllegalArgumentException();
236 
237             init();
238             if (!isTagEnabled(tag)) return;
239             long max = trimToFit();
240             long lastTrim = System.currentTimeMillis();
241 
242             byte[] buffer = new byte[mBlockSize];
243             input = entry.getInputStream();
244 
245             // First, accumulate up to one block worth of data in memory before
246             // deciding whether to compress the data or not.
247 
248             int read = 0;
249             while (read < buffer.length) {
250                 int n = input.read(buffer, read, buffer.length - read);
251                 if (n <= 0) break;
252                 read += n;
253             }
254 
255             // If we have at least one block, compress it -- otherwise, just write
256             // the data in uncompressed form.
257 
258             temp = new File(mDropBoxDir, "drop" + Thread.currentThread().getId() + ".tmp");
259             int bufferSize = mBlockSize;
260             if (bufferSize > 4096) bufferSize = 4096;
261             if (bufferSize < 512) bufferSize = 512;
262             FileOutputStream foutput = new FileOutputStream(temp);
263             output = new BufferedOutputStream(foutput, bufferSize);
264             if (read == buffer.length && ((flags & DropBoxManager.IS_GZIPPED) == 0)) {
265                 output = new GZIPOutputStream(output);
266                 flags = flags | DropBoxManager.IS_GZIPPED;
267             }
268 
269             do {
270                 output.write(buffer, 0, read);
271 
272                 long now = System.currentTimeMillis();
273                 if (now - lastTrim > 30 * 1000) {
274                     max = trimToFit();  // In case data dribbles in slowly
275                     lastTrim = now;
276                 }
277 
278                 read = input.read(buffer);
279                 if (read <= 0) {
280                     FileUtils.sync(foutput);
281                     output.close();  // Get a final size measurement
282                     output = null;
283                 } else {
284                     output.flush();  // So the size measurement is pseudo-reasonable
285                 }
286 
287                 long len = temp.length();
288                 if (len > max) {
289                     Slog.w(TAG, "Dropping: " + tag + " (" + temp.length() + " > " + max + " bytes)");
290                     temp.delete();
291                     temp = null;  // Pass temp = null to createEntry() to leave a tombstone
292                     break;
293                 }
294             } while (read > 0);
295 
296             long time = createEntry(temp, tag, flags);
297             temp = null;
298 
299             final Intent dropboxIntent = new Intent(DropBoxManager.ACTION_DROPBOX_ENTRY_ADDED);
300             dropboxIntent.putExtra(DropBoxManager.EXTRA_TAG, tag);
301             dropboxIntent.putExtra(DropBoxManager.EXTRA_TIME, time);
302             if (!mBooted) {
303                 dropboxIntent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);
304             }
305             // Call sendBroadcast after returning from this call to avoid deadlock. In particular
306             // the caller may be holding the WindowManagerService lock but sendBroadcast requires a
307             // lock in ActivityManagerService. ActivityManagerService has been caught holding that
308             // very lock while waiting for the WindowManagerService lock.
309             mHandler.sendMessage(mHandler.obtainMessage(MSG_SEND_BROADCAST, dropboxIntent));
310         } catch (IOException e) {
311             Slog.e(TAG, "Can't write: " + tag, e);
312         } finally {
313             IoUtils.closeQuietly(output);
314             IoUtils.closeQuietly(input);
315             entry.close();
316             if (temp != null) temp.delete();
317         }
318     }
319 
isTagEnabled(String tag)320     public boolean isTagEnabled(String tag) {
321         final long token = Binder.clearCallingIdentity();
322         try {
323             return !"disabled".equals(Settings.Global.getString(
324                     mContentResolver, Settings.Global.DROPBOX_TAG_PREFIX + tag));
325         } finally {
326             Binder.restoreCallingIdentity(token);
327         }
328     }
329 
getNextEntry(String tag, long millis)330     public synchronized DropBoxManager.Entry getNextEntry(String tag, long millis) {
331         if (getContext().checkCallingOrSelfPermission(android.Manifest.permission.READ_LOGS)
332                 != PackageManager.PERMISSION_GRANTED) {
333             throw new SecurityException("READ_LOGS permission required");
334         }
335 
336         try {
337             init();
338         } catch (IOException e) {
339             Slog.e(TAG, "Can't init", e);
340             return null;
341         }
342 
343         FileList list = tag == null ? mAllFiles : mFilesByTag.get(tag);
344         if (list == null) return null;
345 
346         for (EntryFile entry : list.contents.tailSet(new EntryFile(millis + 1))) {
347             if (entry.tag == null) continue;
348             if ((entry.flags & DropBoxManager.IS_EMPTY) != 0) {
349                 return new DropBoxManager.Entry(entry.tag, entry.timestampMillis);
350             }
351             final File file = entry.getFile(mDropBoxDir);
352             try {
353                 return new DropBoxManager.Entry(
354                         entry.tag, entry.timestampMillis, file, entry.flags);
355             } catch (IOException e) {
356                 Slog.wtf(TAG, "Can't read: " + file, e);
357                 // Continue to next file
358             }
359         }
360 
361         return null;
362     }
363 
dump(FileDescriptor fd, PrintWriter pw, String[] args)364     public synchronized void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
365         if (!DumpUtils.checkDumpAndUsageStatsPermission(getContext(), TAG, pw)) return;
366 
367         try {
368             init();
369         } catch (IOException e) {
370             pw.println("Can't initialize: " + e);
371             Slog.e(TAG, "Can't init", e);
372             return;
373         }
374 
375         if (PROFILE_DUMP) Debug.startMethodTracing("/data/trace/dropbox.dump");
376 
377         StringBuilder out = new StringBuilder();
378         boolean doPrint = false, doFile = false;
379         ArrayList<String> searchArgs = new ArrayList<String>();
380         for (int i = 0; args != null && i < args.length; i++) {
381             if (args[i].equals("-p") || args[i].equals("--print")) {
382                 doPrint = true;
383             } else if (args[i].equals("-f") || args[i].equals("--file")) {
384                 doFile = true;
385             } else if (args[i].equals("-h") || args[i].equals("--help")) {
386                 pw.println("Dropbox (dropbox) dump options:");
387                 pw.println("  [-h|--help] [-p|--print] [-f|--file] [timestamp]");
388                 pw.println("    -h|--help: print this help");
389                 pw.println("    -p|--print: print full contents of each entry");
390                 pw.println("    -f|--file: print path of each entry's file");
391                 pw.println("  [timestamp] optionally filters to only those entries.");
392                 return;
393             } else if (args[i].startsWith("-")) {
394                 out.append("Unknown argument: ").append(args[i]).append("\n");
395             } else {
396                 searchArgs.add(args[i]);
397             }
398         }
399 
400         out.append("Drop box contents: ").append(mAllFiles.contents.size()).append(" entries\n");
401         out.append("Max entries: ").append(mMaxFiles).append("\n");
402 
403         if (!searchArgs.isEmpty()) {
404             out.append("Searching for:");
405             for (String a : searchArgs) out.append(" ").append(a);
406             out.append("\n");
407         }
408 
409         int numFound = 0, numArgs = searchArgs.size();
410         Time time = new Time();
411         out.append("\n");
412         for (EntryFile entry : mAllFiles.contents) {
413             time.set(entry.timestampMillis);
414             String date = time.format("%Y-%m-%d %H:%M:%S");
415             boolean match = true;
416             for (int i = 0; i < numArgs && match; i++) {
417                 String arg = searchArgs.get(i);
418                 match = (date.contains(arg) || arg.equals(entry.tag));
419             }
420             if (!match) continue;
421 
422             numFound++;
423             if (doPrint) out.append("========================================\n");
424             out.append(date).append(" ").append(entry.tag == null ? "(no tag)" : entry.tag);
425 
426             final File file = entry.getFile(mDropBoxDir);
427             if (file == null) {
428                 out.append(" (no file)\n");
429                 continue;
430             } else if ((entry.flags & DropBoxManager.IS_EMPTY) != 0) {
431                 out.append(" (contents lost)\n");
432                 continue;
433             } else {
434                 out.append(" (");
435                 if ((entry.flags & DropBoxManager.IS_GZIPPED) != 0) out.append("compressed ");
436                 out.append((entry.flags & DropBoxManager.IS_TEXT) != 0 ? "text" : "data");
437                 out.append(", ").append(file.length()).append(" bytes)\n");
438             }
439 
440             if (doFile || (doPrint && (entry.flags & DropBoxManager.IS_TEXT) == 0)) {
441                 if (!doPrint) out.append("    ");
442                 out.append(file.getPath()).append("\n");
443             }
444 
445             if ((entry.flags & DropBoxManager.IS_TEXT) != 0 && (doPrint || !doFile)) {
446                 DropBoxManager.Entry dbe = null;
447                 InputStreamReader isr = null;
448                 try {
449                     dbe = new DropBoxManager.Entry(
450                              entry.tag, entry.timestampMillis, file, entry.flags);
451 
452                     if (doPrint) {
453                         isr = new InputStreamReader(dbe.getInputStream());
454                         char[] buf = new char[4096];
455                         boolean newline = false;
456                         for (;;) {
457                             int n = isr.read(buf);
458                             if (n <= 0) break;
459                             out.append(buf, 0, n);
460                             newline = (buf[n - 1] == '\n');
461 
462                             // Flush periodically when printing to avoid out-of-memory.
463                             if (out.length() > 65536) {
464                                 pw.write(out.toString());
465                                 out.setLength(0);
466                             }
467                         }
468                         if (!newline) out.append("\n");
469                     } else {
470                         String text = dbe.getText(70);
471                         out.append("    ");
472                         if (text == null) {
473                             out.append("[null]");
474                         } else {
475                             boolean truncated = (text.length() == 70);
476                             out.append(text.trim().replace('\n', '/'));
477                             if (truncated) out.append(" ...");
478                         }
479                         out.append("\n");
480                     }
481                 } catch (IOException e) {
482                     out.append("*** ").append(e.toString()).append("\n");
483                     Slog.e(TAG, "Can't read: " + file, e);
484                 } finally {
485                     if (dbe != null) dbe.close();
486                     if (isr != null) {
487                         try {
488                             isr.close();
489                         } catch (IOException unused) {
490                         }
491                     }
492                 }
493             }
494 
495             if (doPrint) out.append("\n");
496         }
497 
498         if (numFound == 0) out.append("(No entries found.)\n");
499 
500         if (args == null || args.length == 0) {
501             if (!doPrint) out.append("\n");
502             out.append("Usage: dumpsys dropbox [--print|--file] [YYYY-mm-dd] [HH:MM:SS] [tag]\n");
503         }
504 
505         pw.write(out.toString());
506         if (PROFILE_DUMP) Debug.stopMethodTracing();
507     }
508 
509     ///////////////////////////////////////////////////////////////////////////
510 
511     /** Chronologically sorted list of {@link EntryFile} */
512     private static final class FileList implements Comparable<FileList> {
513         public int blocks = 0;
514         public final TreeSet<EntryFile> contents = new TreeSet<EntryFile>();
515 
516         /** Sorts bigger FileList instances before smaller ones. */
compareTo(FileList o)517         public final int compareTo(FileList o) {
518             if (blocks != o.blocks) return o.blocks - blocks;
519             if (this == o) return 0;
520             if (hashCode() < o.hashCode()) return -1;
521             if (hashCode() > o.hashCode()) return 1;
522             return 0;
523         }
524     }
525 
526     /**
527      * Metadata describing an on-disk log file.
528      *
529      * Note its instances do no have knowledge on what directory they're stored, just to save
530      * 4/8 bytes per instance.  Instead, {@link #getFile} takes a directory so it can build a
531      * fullpath.
532      */
533     @VisibleForTesting
534     static final class EntryFile implements Comparable<EntryFile> {
535         public final String tag;
536         public final long timestampMillis;
537         public final int flags;
538         public final int blocks;
539 
540         /** Sorts earlier EntryFile instances before later ones. */
compareTo(EntryFile o)541         public final int compareTo(EntryFile o) {
542             int comp = Long.compare(timestampMillis, o.timestampMillis);
543             if (comp != 0) return comp;
544 
545             comp = ObjectUtils.compare(tag, o.tag);
546             if (comp != 0) return comp;
547 
548             comp = Integer.compare(flags, o.flags);
549             if (comp != 0) return comp;
550 
551             return Integer.compare(hashCode(), o.hashCode());
552         }
553 
554         /**
555          * Moves an existing temporary file to a new log filename.
556          *
557          * @param temp file to rename
558          * @param dir to store file in
559          * @param tag to use for new log file name
560          * @param timestampMillis of log entry
561          * @param flags for the entry data
562          * @param blockSize to use for space accounting
563          * @throws IOException if the file can't be moved
564          */
EntryFile(File temp, File dir, String tag,long timestampMillis, int flags, int blockSize)565         public EntryFile(File temp, File dir, String tag,long timestampMillis,
566                          int flags, int blockSize) throws IOException {
567             if ((flags & DropBoxManager.IS_EMPTY) != 0) throw new IllegalArgumentException();
568 
569             this.tag = TextUtils.safeIntern(tag);
570             this.timestampMillis = timestampMillis;
571             this.flags = flags;
572 
573             final File file = this.getFile(dir);
574             if (!temp.renameTo(file)) {
575                 throw new IOException("Can't rename " + temp + " to " + file);
576             }
577             this.blocks = (int) ((file.length() + blockSize - 1) / blockSize);
578         }
579 
580         /**
581          * Creates a zero-length tombstone for a file whose contents were lost.
582          *
583          * @param dir to store file in
584          * @param tag to use for new log file name
585          * @param timestampMillis of log entry
586          * @throws IOException if the file can't be created.
587          */
EntryFile(File dir, String tag, long timestampMillis)588         public EntryFile(File dir, String tag, long timestampMillis) throws IOException {
589             this.tag = TextUtils.safeIntern(tag);
590             this.timestampMillis = timestampMillis;
591             this.flags = DropBoxManager.IS_EMPTY;
592             this.blocks = 0;
593             new FileOutputStream(getFile(dir)).close();
594         }
595 
596         /**
597          * Extracts metadata from an existing on-disk log filename.
598          *
599          * Note when a filename is not recognizable, it will create an instance that
600          * {@link #hasFile()} would return false on, and also remove the file.
601          *
602          * @param file name of existing log file
603          * @param blockSize to use for space accounting
604          */
EntryFile(File file, int blockSize)605         public EntryFile(File file, int blockSize) {
606 
607             boolean parseFailure = false;
608 
609             String name = file.getName();
610             int flags = 0;
611             String tag = null;
612             long millis = 0;
613 
614             final int at = name.lastIndexOf('@');
615             if (at < 0) {
616                 parseFailure = true;
617             } else {
618                 tag = Uri.decode(name.substring(0, at));
619                 if (name.endsWith(".gz")) {
620                     flags |= DropBoxManager.IS_GZIPPED;
621                     name = name.substring(0, name.length() - 3);
622                 }
623                 if (name.endsWith(".lost")) {
624                     flags |= DropBoxManager.IS_EMPTY;
625                     name = name.substring(at + 1, name.length() - 5);
626                 } else if (name.endsWith(".txt")) {
627                     flags |= DropBoxManager.IS_TEXT;
628                     name = name.substring(at + 1, name.length() - 4);
629                 } else if (name.endsWith(".dat")) {
630                     name = name.substring(at + 1, name.length() - 4);
631                 } else {
632                     parseFailure = true;
633                 }
634                 if (!parseFailure) {
635                     try {
636                         millis = Long.parseLong(name);
637                     } catch (NumberFormatException e) {
638                         parseFailure = true;
639                     }
640                 }
641             }
642             if (parseFailure) {
643                 Slog.wtf(TAG, "Invalid filename: " + file);
644 
645                 // Remove the file and return an empty instance.
646                 file.delete();
647                 this.tag = null;
648                 this.flags = DropBoxManager.IS_EMPTY;
649                 this.timestampMillis = 0;
650                 this.blocks = 0;
651                 return;
652             }
653 
654             this.blocks = (int) ((file.length() + blockSize - 1) / blockSize);
655             this.tag = TextUtils.safeIntern(tag);
656             this.flags = flags;
657             this.timestampMillis = millis;
658         }
659 
660         /**
661          * Creates a EntryFile object with only a timestamp for comparison purposes.
662          * @param millis to compare with.
663          */
EntryFile(long millis)664         public EntryFile(long millis) {
665             this.tag = null;
666             this.timestampMillis = millis;
667             this.flags = DropBoxManager.IS_EMPTY;
668             this.blocks = 0;
669         }
670 
671         /**
672          * @return whether an entry actually has a backing file, or it's an empty "tombstone"
673          * entry.
674          */
hasFile()675         public boolean hasFile() {
676             return tag != null;
677         }
678 
679         /** @return File extension for the flags. */
getExtension()680         private String getExtension() {
681             if ((flags &  DropBoxManager.IS_EMPTY) != 0) {
682                 return ".lost";
683             }
684             return ((flags & DropBoxManager.IS_TEXT) != 0 ? ".txt" : ".dat") +
685                     ((flags & DropBoxManager.IS_GZIPPED) != 0 ? ".gz" : "");
686         }
687 
688         /**
689          * @return filename for this entry without the pathname.
690          */
getFilename()691         public String getFilename() {
692             return hasFile() ? Uri.encode(tag) + "@" + timestampMillis + getExtension() : null;
693         }
694 
695         /**
696          * Get a full-path {@link File} representing this entry.
697          * @param dir Parent directly.  The caller needs to pass it because {@link EntryFile}s don't
698          *            know in which directory they're stored.
699          */
getFile(File dir)700         public File getFile(File dir) {
701             return hasFile() ? new File(dir, getFilename()) : null;
702         }
703 
704         /**
705          * If an entry has a backing file, remove it.
706          */
deleteFile(File dir)707         public void deleteFile(File dir) {
708             if (hasFile()) {
709                 getFile(dir).delete();
710             }
711         }
712     }
713 
714     ///////////////////////////////////////////////////////////////////////////
715 
716     /** If never run before, scans disk contents to build in-memory tracking data. */
init()717     private synchronized void init() throws IOException {
718         if (mStatFs == null) {
719             if (!mDropBoxDir.isDirectory() && !mDropBoxDir.mkdirs()) {
720                 throw new IOException("Can't mkdir: " + mDropBoxDir);
721             }
722             try {
723                 mStatFs = new StatFs(mDropBoxDir.getPath());
724                 mBlockSize = mStatFs.getBlockSize();
725             } catch (IllegalArgumentException e) {  // StatFs throws this on error
726                 throw new IOException("Can't statfs: " + mDropBoxDir);
727             }
728         }
729 
730         if (mAllFiles == null) {
731             File[] files = mDropBoxDir.listFiles();
732             if (files == null) throw new IOException("Can't list files: " + mDropBoxDir);
733 
734             mAllFiles = new FileList();
735             mFilesByTag = new ArrayMap<>();
736 
737             // Scan pre-existing files.
738             for (File file : files) {
739                 if (file.getName().endsWith(".tmp")) {
740                     Slog.i(TAG, "Cleaning temp file: " + file);
741                     file.delete();
742                     continue;
743                 }
744 
745                 EntryFile entry = new EntryFile(file, mBlockSize);
746 
747                 if (entry.hasFile()) {
748                     // Enroll only when the filename is valid.  Otherwise the above constructor
749                     // has removed the file already.
750                     enrollEntry(entry);
751                 }
752             }
753         }
754     }
755 
756     /** Adds a disk log file to in-memory tracking for accounting and enumeration. */
enrollEntry(EntryFile entry)757     private synchronized void enrollEntry(EntryFile entry) {
758         mAllFiles.contents.add(entry);
759         mAllFiles.blocks += entry.blocks;
760 
761         // mFilesByTag is used for trimming, so don't list empty files.
762         // (Zero-length/lost files are trimmed by date from mAllFiles.)
763 
764         if (entry.hasFile() && entry.blocks > 0) {
765             FileList tagFiles = mFilesByTag.get(entry.tag);
766             if (tagFiles == null) {
767                 tagFiles = new FileList();
768                 mFilesByTag.put(TextUtils.safeIntern(entry.tag), tagFiles);
769             }
770             tagFiles.contents.add(entry);
771             tagFiles.blocks += entry.blocks;
772         }
773     }
774 
775     /** Moves a temporary file to a final log filename and enrolls it. */
createEntry(File temp, String tag, int flags)776     private synchronized long createEntry(File temp, String tag, int flags) throws IOException {
777         long t = System.currentTimeMillis();
778 
779         // Require each entry to have a unique timestamp; if there are entries
780         // >10sec in the future (due to clock skew), drag them back to avoid
781         // keeping them around forever.
782 
783         SortedSet<EntryFile> tail = mAllFiles.contents.tailSet(new EntryFile(t + 10000));
784         EntryFile[] future = null;
785         if (!tail.isEmpty()) {
786             future = tail.toArray(new EntryFile[tail.size()]);
787             tail.clear();  // Remove from mAllFiles
788         }
789 
790         if (!mAllFiles.contents.isEmpty()) {
791             t = Math.max(t, mAllFiles.contents.last().timestampMillis + 1);
792         }
793 
794         if (future != null) {
795             for (EntryFile late : future) {
796                 mAllFiles.blocks -= late.blocks;
797                 FileList tagFiles = mFilesByTag.get(late.tag);
798                 if (tagFiles != null && tagFiles.contents.remove(late)) {
799                     tagFiles.blocks -= late.blocks;
800                 }
801                 if ((late.flags & DropBoxManager.IS_EMPTY) == 0) {
802                     enrollEntry(new EntryFile(late.getFile(mDropBoxDir), mDropBoxDir,
803                             late.tag, t++, late.flags, mBlockSize));
804                 } else {
805                     enrollEntry(new EntryFile(mDropBoxDir, late.tag, t++));
806                 }
807             }
808         }
809 
810         if (temp == null) {
811             enrollEntry(new EntryFile(mDropBoxDir, tag, t));
812         } else {
813             enrollEntry(new EntryFile(temp, mDropBoxDir, tag, t, flags, mBlockSize));
814         }
815         return t;
816     }
817 
818     /**
819      * Trims the files on disk to make sure they aren't using too much space.
820      * @return the overall quota for storage (in bytes)
821      */
trimToFit()822     private synchronized long trimToFit() throws IOException {
823         // Expunge aged items (including tombstones marking deleted data).
824 
825         int ageSeconds = Settings.Global.getInt(mContentResolver,
826                 Settings.Global.DROPBOX_AGE_SECONDS, DEFAULT_AGE_SECONDS);
827         mMaxFiles = Settings.Global.getInt(mContentResolver,
828                 Settings.Global.DROPBOX_MAX_FILES,
829                 (ActivityManager.isLowRamDeviceStatic()
830                         ?  DEFAULT_MAX_FILES_LOWRAM : DEFAULT_MAX_FILES));
831         long cutoffMillis = System.currentTimeMillis() - ageSeconds * 1000;
832         while (!mAllFiles.contents.isEmpty()) {
833             EntryFile entry = mAllFiles.contents.first();
834             if (entry.timestampMillis > cutoffMillis && mAllFiles.contents.size() < mMaxFiles) {
835                 break;
836             }
837 
838             FileList tag = mFilesByTag.get(entry.tag);
839             if (tag != null && tag.contents.remove(entry)) tag.blocks -= entry.blocks;
840             if (mAllFiles.contents.remove(entry)) mAllFiles.blocks -= entry.blocks;
841             entry.deleteFile(mDropBoxDir);
842         }
843 
844         // Compute overall quota (a fraction of available free space) in blocks.
845         // The quota changes dynamically based on the amount of free space;
846         // that way when lots of data is available we can use it, but we'll get
847         // out of the way if storage starts getting tight.
848 
849         long uptimeMillis = SystemClock.uptimeMillis();
850         if (uptimeMillis > mCachedQuotaUptimeMillis + QUOTA_RESCAN_MILLIS) {
851             int quotaPercent = Settings.Global.getInt(mContentResolver,
852                     Settings.Global.DROPBOX_QUOTA_PERCENT, DEFAULT_QUOTA_PERCENT);
853             int reservePercent = Settings.Global.getInt(mContentResolver,
854                     Settings.Global.DROPBOX_RESERVE_PERCENT, DEFAULT_RESERVE_PERCENT);
855             int quotaKb = Settings.Global.getInt(mContentResolver,
856                     Settings.Global.DROPBOX_QUOTA_KB, DEFAULT_QUOTA_KB);
857 
858             String dirPath = mDropBoxDir.getPath();
859             try {
860                 mStatFs.restat(dirPath);
861             } catch (IllegalArgumentException e) {  // restat throws this on error
862                 throw new IOException("Can't restat: " + mDropBoxDir);
863             }
864             int available = mStatFs.getAvailableBlocks();
865             int nonreserved = available - mStatFs.getBlockCount() * reservePercent / 100;
866             int maximum = quotaKb * 1024 / mBlockSize;
867             mCachedQuotaBlocks = Math.min(maximum, Math.max(0, nonreserved * quotaPercent / 100));
868             mCachedQuotaUptimeMillis = uptimeMillis;
869         }
870 
871         // If we're using too much space, delete old items to make room.
872         //
873         // We trim each tag independently (this is why we keep per-tag lists).
874         // Space is "fairly" shared between tags -- they are all squeezed
875         // equally until enough space is reclaimed.
876         //
877         // A single circular buffer (a la logcat) would be simpler, but this
878         // way we can handle fat/bursty data (like 1MB+ bugreports, 300KB+
879         // kernel crash dumps, and 100KB+ ANR reports) without swamping small,
880         // well-behaved data streams (event statistics, profile data, etc).
881         //
882         // Deleted files are replaced with zero-length tombstones to mark what
883         // was lost.  Tombstones are expunged by age (see above).
884 
885         if (mAllFiles.blocks > mCachedQuotaBlocks) {
886             // Find a fair share amount of space to limit each tag
887             int unsqueezed = mAllFiles.blocks, squeezed = 0;
888             TreeSet<FileList> tags = new TreeSet<FileList>(mFilesByTag.values());
889             for (FileList tag : tags) {
890                 if (squeezed > 0 && tag.blocks <= (mCachedQuotaBlocks - unsqueezed) / squeezed) {
891                     break;
892                 }
893                 unsqueezed -= tag.blocks;
894                 squeezed++;
895             }
896             int tagQuota = (mCachedQuotaBlocks - unsqueezed) / squeezed;
897 
898             // Remove old items from each tag until it meets the per-tag quota.
899             for (FileList tag : tags) {
900                 if (mAllFiles.blocks < mCachedQuotaBlocks) break;
901                 while (tag.blocks > tagQuota && !tag.contents.isEmpty()) {
902                     EntryFile entry = tag.contents.first();
903                     if (tag.contents.remove(entry)) tag.blocks -= entry.blocks;
904                     if (mAllFiles.contents.remove(entry)) mAllFiles.blocks -= entry.blocks;
905 
906                     try {
907                         entry.deleteFile(mDropBoxDir);
908                         enrollEntry(new EntryFile(mDropBoxDir, entry.tag, entry.timestampMillis));
909                     } catch (IOException e) {
910                         Slog.e(TAG, "Can't write tombstone file", e);
911                     }
912                 }
913             }
914         }
915 
916         return mCachedQuotaBlocks * mBlockSize;
917     }
918 }
919