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.content.BroadcastReceiver; 20 import android.content.ContentResolver; 21 import android.content.Context; 22 import android.content.Intent; 23 import android.content.IntentFilter; 24 import android.content.pm.PackageManager; 25 import android.database.ContentObserver; 26 import android.net.Uri; 27 import android.os.Debug; 28 import android.os.DropBoxManager; 29 import android.os.FileUtils; 30 import android.os.Handler; 31 import android.os.StatFs; 32 import android.os.SystemClock; 33 import android.provider.Settings; 34 import android.text.format.Time; 35 import android.util.Slog; 36 37 import com.android.internal.os.IDropBoxManagerService; 38 39 import java.io.BufferedOutputStream; 40 import java.io.File; 41 import java.io.FileDescriptor; 42 import java.io.FileOutputStream; 43 import java.io.IOException; 44 import java.io.InputStream; 45 import java.io.InputStreamReader; 46 import java.io.OutputStream; 47 import java.io.PrintWriter; 48 import java.util.ArrayList; 49 import java.util.HashMap; 50 import java.util.SortedSet; 51 import java.util.TreeSet; 52 import java.util.zip.GZIPOutputStream; 53 54 /** 55 * Implementation of {@link IDropBoxManagerService} using the filesystem. 56 * Clients use {@link DropBoxManager} to access this service. 57 */ 58 public final class DropBoxManagerService extends IDropBoxManagerService.Stub { 59 private static final String TAG = "DropBoxManagerService"; 60 private static final int DEFAULT_AGE_SECONDS = 3 * 86400; 61 private static final int DEFAULT_MAX_FILES = 1000; 62 private static final int DEFAULT_QUOTA_KB = 5 * 1024; 63 private static final int DEFAULT_QUOTA_PERCENT = 10; 64 private static final int DEFAULT_RESERVE_PERCENT = 10; 65 private static final int QUOTA_RESCAN_MILLIS = 5000; 66 67 private static final boolean PROFILE_DUMP = false; 68 69 // TODO: This implementation currently uses one file per entry, which is 70 // inefficient for smallish entries -- consider using a single queue file 71 // per tag (or even globally) instead. 72 73 // The cached context and derived objects 74 75 private final Context mContext; 76 private final ContentResolver mContentResolver; 77 private final File mDropBoxDir; 78 79 // Accounting of all currently written log files (set in init()). 80 81 private FileList mAllFiles = null; 82 private HashMap<String, FileList> mFilesByTag = null; 83 84 // Various bits of disk information 85 86 private StatFs mStatFs = null; 87 private int mBlockSize = 0; 88 private int mCachedQuotaBlocks = 0; // Space we can use: computed from free space, etc. 89 private long mCachedQuotaUptimeMillis = 0; 90 91 // Ensure that all log entries have a unique timestamp 92 private long mLastTimestamp = 0; 93 94 private volatile boolean mBooted = false; 95 96 /** Receives events that might indicate a need to clean up files. */ 97 private final BroadcastReceiver mReceiver = new BroadcastReceiver() { 98 @Override 99 public void onReceive(Context context, Intent intent) { 100 if (intent != null && Intent.ACTION_BOOT_COMPLETED.equals(intent.getAction())) { 101 mBooted = true; 102 return; 103 } 104 105 // Else, for ACTION_DEVICE_STORAGE_LOW: 106 mCachedQuotaUptimeMillis = 0; // Force a re-check of quota size 107 108 // Run the initialization in the background (not this main thread). 109 // The init() and trimToFit() methods are synchronized, so they still 110 // block other users -- but at least the onReceive() call can finish. 111 new Thread() { 112 public void run() { 113 try { 114 init(); 115 trimToFit(); 116 } catch (IOException e) { 117 Slog.e(TAG, "Can't init", e); 118 } 119 } 120 }.start(); 121 } 122 }; 123 124 /** 125 * Creates an instance of managed drop box storage. Normally there is one of these 126 * run by the system, but others can be created for testing and other purposes. 127 * 128 * @param context to use for receiving free space & gservices intents 129 * @param path to store drop box entries in 130 */ 131 public DropBoxManagerService(final Context context, File path) { 132 mDropBoxDir = path; 133 134 // Set up intent receivers 135 mContext = context; 136 mContentResolver = context.getContentResolver(); 137 138 IntentFilter filter = new IntentFilter(); 139 filter.addAction(Intent.ACTION_DEVICE_STORAGE_LOW); 140 filter.addAction(Intent.ACTION_BOOT_COMPLETED); 141 context.registerReceiver(mReceiver, filter); 142 143 mContentResolver.registerContentObserver( 144 Settings.Secure.CONTENT_URI, true, 145 new ContentObserver(new Handler()) { 146 public void onChange(boolean selfChange) { 147 mReceiver.onReceive(context, (Intent) null); 148 } 149 }); 150 151 // The real work gets done lazily in init() -- that way service creation always 152 // succeeds, and things like disk problems cause individual method failures. 153 } 154 155 /** Unregisters broadcast receivers and any other hooks -- for test instances */ 156 public void stop() { 157 mContext.unregisterReceiver(mReceiver); 158 } 159 160 public void add(DropBoxManager.Entry entry) { 161 File temp = null; 162 OutputStream output = null; 163 final String tag = entry.getTag(); 164 try { 165 int flags = entry.getFlags(); 166 if ((flags & DropBoxManager.IS_EMPTY) != 0) throw new IllegalArgumentException(); 167 168 init(); 169 if (!isTagEnabled(tag)) return; 170 long max = trimToFit(); 171 long lastTrim = System.currentTimeMillis(); 172 173 byte[] buffer = new byte[mBlockSize]; 174 InputStream input = entry.getInputStream(); 175 176 // First, accumulate up to one block worth of data in memory before 177 // deciding whether to compress the data or not. 178 179 int read = 0; 180 while (read < buffer.length) { 181 int n = input.read(buffer, read, buffer.length - read); 182 if (n <= 0) break; 183 read += n; 184 } 185 186 // If we have at least one block, compress it -- otherwise, just write 187 // the data in uncompressed form. 188 189 temp = new File(mDropBoxDir, "drop" + Thread.currentThread().getId() + ".tmp"); 190 int bufferSize = mBlockSize; 191 if (bufferSize > 4096) bufferSize = 4096; 192 if (bufferSize < 512) bufferSize = 512; 193 FileOutputStream foutput = new FileOutputStream(temp); 194 output = new BufferedOutputStream(foutput, bufferSize); 195 if (read == buffer.length && ((flags & DropBoxManager.IS_GZIPPED) == 0)) { 196 output = new GZIPOutputStream(output); 197 flags = flags | DropBoxManager.IS_GZIPPED; 198 } 199 200 do { 201 output.write(buffer, 0, read); 202 203 long now = System.currentTimeMillis(); 204 if (now - lastTrim > 30 * 1000) { 205 max = trimToFit(); // In case data dribbles in slowly 206 lastTrim = now; 207 } 208 209 read = input.read(buffer); 210 if (read <= 0) { 211 FileUtils.sync(foutput); 212 output.close(); // Get a final size measurement 213 output = null; 214 } else { 215 output.flush(); // So the size measurement is pseudo-reasonable 216 } 217 218 long len = temp.length(); 219 if (len > max) { 220 Slog.w(TAG, "Dropping: " + tag + " (" + temp.length() + " > " + max + " bytes)"); 221 temp.delete(); 222 temp = null; // Pass temp = null to createEntry() to leave a tombstone 223 break; 224 } 225 } while (read > 0); 226 227 long time = createEntry(temp, tag, flags); 228 temp = null; 229 230 Intent dropboxIntent = new Intent(DropBoxManager.ACTION_DROPBOX_ENTRY_ADDED); 231 dropboxIntent.putExtra(DropBoxManager.EXTRA_TAG, tag); 232 dropboxIntent.putExtra(DropBoxManager.EXTRA_TIME, time); 233 if (!mBooted) { 234 dropboxIntent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY); 235 } 236 mContext.sendBroadcast(dropboxIntent, android.Manifest.permission.READ_LOGS); 237 238 } catch (IOException e) { 239 Slog.e(TAG, "Can't write: " + tag, e); 240 } finally { 241 try { if (output != null) output.close(); } catch (IOException e) {} 242 entry.close(); 243 if (temp != null) temp.delete(); 244 } 245 } 246 247 public boolean isTagEnabled(String tag) { 248 return !"disabled".equals(Settings.Secure.getString( 249 mContentResolver, Settings.Secure.DROPBOX_TAG_PREFIX + tag)); 250 } 251 252 public synchronized DropBoxManager.Entry getNextEntry(String tag, long millis) { 253 if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.READ_LOGS) 254 != PackageManager.PERMISSION_GRANTED) { 255 throw new SecurityException("READ_LOGS permission required"); 256 } 257 258 try { 259 init(); 260 } catch (IOException e) { 261 Slog.e(TAG, "Can't init", e); 262 return null; 263 } 264 265 FileList list = tag == null ? mAllFiles : mFilesByTag.get(tag); 266 if (list == null) return null; 267 268 for (EntryFile entry : list.contents.tailSet(new EntryFile(millis + 1))) { 269 if (entry.tag == null) continue; 270 if ((entry.flags & DropBoxManager.IS_EMPTY) != 0) { 271 return new DropBoxManager.Entry(entry.tag, entry.timestampMillis); 272 } 273 try { 274 return new DropBoxManager.Entry( 275 entry.tag, entry.timestampMillis, entry.file, entry.flags); 276 } catch (IOException e) { 277 Slog.e(TAG, "Can't read: " + entry.file, e); 278 // Continue to next file 279 } 280 } 281 282 return null; 283 } 284 285 public synchronized void dump(FileDescriptor fd, PrintWriter pw, String[] args) { 286 if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.DUMP) 287 != PackageManager.PERMISSION_GRANTED) { 288 pw.println("Permission Denial: Can't dump DropBoxManagerService"); 289 return; 290 } 291 292 try { 293 init(); 294 } catch (IOException e) { 295 pw.println("Can't initialize: " + e); 296 Slog.e(TAG, "Can't init", e); 297 return; 298 } 299 300 if (PROFILE_DUMP) Debug.startMethodTracing("/data/trace/dropbox.dump"); 301 302 StringBuilder out = new StringBuilder(); 303 boolean doPrint = false, doFile = false; 304 ArrayList<String> searchArgs = new ArrayList<String>(); 305 for (int i = 0; args != null && i < args.length; i++) { 306 if (args[i].equals("-p") || args[i].equals("--print")) { 307 doPrint = true; 308 } else if (args[i].equals("-f") || args[i].equals("--file")) { 309 doFile = true; 310 } else if (args[i].startsWith("-")) { 311 out.append("Unknown argument: ").append(args[i]).append("\n"); 312 } else { 313 searchArgs.add(args[i]); 314 } 315 } 316 317 out.append("Drop box contents: ").append(mAllFiles.contents.size()).append(" entries\n"); 318 319 if (!searchArgs.isEmpty()) { 320 out.append("Searching for:"); 321 for (String a : searchArgs) out.append(" ").append(a); 322 out.append("\n"); 323 } 324 325 int numFound = 0, numArgs = searchArgs.size(); 326 Time time = new Time(); 327 out.append("\n"); 328 for (EntryFile entry : mAllFiles.contents) { 329 time.set(entry.timestampMillis); 330 String date = time.format("%Y-%m-%d %H:%M:%S"); 331 boolean match = true; 332 for (int i = 0; i < numArgs && match; i++) { 333 String arg = searchArgs.get(i); 334 match = (date.contains(arg) || arg.equals(entry.tag)); 335 } 336 if (!match) continue; 337 338 numFound++; 339 if (doPrint) out.append("========================================\n"); 340 out.append(date).append(" ").append(entry.tag == null ? "(no tag)" : entry.tag); 341 if (entry.file == null) { 342 out.append(" (no file)\n"); 343 continue; 344 } else if ((entry.flags & DropBoxManager.IS_EMPTY) != 0) { 345 out.append(" (contents lost)\n"); 346 continue; 347 } else { 348 out.append(" ("); 349 if ((entry.flags & DropBoxManager.IS_GZIPPED) != 0) out.append("compressed "); 350 out.append((entry.flags & DropBoxManager.IS_TEXT) != 0 ? "text" : "data"); 351 out.append(", ").append(entry.file.length()).append(" bytes)\n"); 352 } 353 354 if (doFile || (doPrint && (entry.flags & DropBoxManager.IS_TEXT) == 0)) { 355 if (!doPrint) out.append(" "); 356 out.append(entry.file.getPath()).append("\n"); 357 } 358 359 if ((entry.flags & DropBoxManager.IS_TEXT) != 0 && (doPrint || !doFile)) { 360 DropBoxManager.Entry dbe = null; 361 InputStreamReader isr = null; 362 try { 363 dbe = new DropBoxManager.Entry( 364 entry.tag, entry.timestampMillis, entry.file, entry.flags); 365 366 if (doPrint) { 367 isr = new InputStreamReader(dbe.getInputStream()); 368 char[] buf = new char[4096]; 369 boolean newline = false; 370 for (;;) { 371 int n = isr.read(buf); 372 if (n <= 0) break; 373 out.append(buf, 0, n); 374 newline = (buf[n - 1] == '\n'); 375 376 // Flush periodically when printing to avoid out-of-memory. 377 if (out.length() > 65536) { 378 pw.write(out.toString()); 379 out.setLength(0); 380 } 381 } 382 if (!newline) out.append("\n"); 383 } else { 384 String text = dbe.getText(70); 385 boolean truncated = (text.length() == 70); 386 out.append(" ").append(text.trim().replace('\n', '/')); 387 if (truncated) out.append(" ..."); 388 out.append("\n"); 389 } 390 } catch (IOException e) { 391 out.append("*** ").append(e.toString()).append("\n"); 392 Slog.e(TAG, "Can't read: " + entry.file, e); 393 } finally { 394 if (dbe != null) dbe.close(); 395 if (isr != null) { 396 try { 397 isr.close(); 398 } catch (IOException unused) { 399 } 400 } 401 } 402 } 403 404 if (doPrint) out.append("\n"); 405 } 406 407 if (numFound == 0) out.append("(No entries found.)\n"); 408 409 if (args == null || args.length == 0) { 410 if (!doPrint) out.append("\n"); 411 out.append("Usage: dumpsys dropbox [--print|--file] [YYYY-mm-dd] [HH:MM:SS] [tag]\n"); 412 } 413 414 pw.write(out.toString()); 415 if (PROFILE_DUMP) Debug.stopMethodTracing(); 416 } 417 418 /////////////////////////////////////////////////////////////////////////// 419 420 /** Chronologically sorted list of {@link #EntryFile} */ 421 private static final class FileList implements Comparable<FileList> { 422 public int blocks = 0; 423 public final TreeSet<EntryFile> contents = new TreeSet<EntryFile>(); 424 425 /** Sorts bigger FileList instances before smaller ones. */ 426 public final int compareTo(FileList o) { 427 if (blocks != o.blocks) return o.blocks - blocks; 428 if (this == o) return 0; 429 if (hashCode() < o.hashCode()) return -1; 430 if (hashCode() > o.hashCode()) return 1; 431 return 0; 432 } 433 } 434 435 /** Metadata describing an on-disk log file. */ 436 private static final class EntryFile implements Comparable<EntryFile> { 437 public final String tag; 438 public final long timestampMillis; 439 public final int flags; 440 public final File file; 441 public final int blocks; 442 443 /** Sorts earlier EntryFile instances before later ones. */ 444 public final int compareTo(EntryFile o) { 445 if (timestampMillis < o.timestampMillis) return -1; 446 if (timestampMillis > o.timestampMillis) return 1; 447 if (file != null && o.file != null) return file.compareTo(o.file); 448 if (o.file != null) return -1; 449 if (file != null) return 1; 450 if (this == o) return 0; 451 if (hashCode() < o.hashCode()) return -1; 452 if (hashCode() > o.hashCode()) return 1; 453 return 0; 454 } 455 456 /** 457 * Moves an existing temporary file to a new log filename. 458 * @param temp file to rename 459 * @param dir to store file in 460 * @param tag to use for new log file name 461 * @param timestampMillis of log entry 462 * @param flags for the entry data 463 * @param blockSize to use for space accounting 464 * @throws IOException if the file can't be moved 465 */ 466 public EntryFile(File temp, File dir, String tag,long timestampMillis, 467 int flags, int blockSize) throws IOException { 468 if ((flags & DropBoxManager.IS_EMPTY) != 0) throw new IllegalArgumentException(); 469 470 this.tag = tag; 471 this.timestampMillis = timestampMillis; 472 this.flags = flags; 473 this.file = new File(dir, Uri.encode(tag) + "@" + timestampMillis + 474 ((flags & DropBoxManager.IS_TEXT) != 0 ? ".txt" : ".dat") + 475 ((flags & DropBoxManager.IS_GZIPPED) != 0 ? ".gz" : "")); 476 477 if (!temp.renameTo(this.file)) { 478 throw new IOException("Can't rename " + temp + " to " + this.file); 479 } 480 this.blocks = (int) ((this.file.length() + blockSize - 1) / blockSize); 481 } 482 483 /** 484 * Creates a zero-length tombstone for a file whose contents were lost. 485 * @param dir to store file in 486 * @param tag to use for new log file name 487 * @param timestampMillis of log entry 488 * @throws IOException if the file can't be created. 489 */ 490 public EntryFile(File dir, String tag, long timestampMillis) throws IOException { 491 this.tag = tag; 492 this.timestampMillis = timestampMillis; 493 this.flags = DropBoxManager.IS_EMPTY; 494 this.file = new File(dir, Uri.encode(tag) + "@" + timestampMillis + ".lost"); 495 this.blocks = 0; 496 new FileOutputStream(this.file).close(); 497 } 498 499 /** 500 * Extracts metadata from an existing on-disk log filename. 501 * @param file name of existing log file 502 * @param blockSize to use for space accounting 503 */ 504 public EntryFile(File file, int blockSize) { 505 this.file = file; 506 this.blocks = (int) ((this.file.length() + blockSize - 1) / blockSize); 507 508 String name = file.getName(); 509 int at = name.lastIndexOf('@'); 510 if (at < 0) { 511 this.tag = null; 512 this.timestampMillis = 0; 513 this.flags = DropBoxManager.IS_EMPTY; 514 return; 515 } 516 517 int flags = 0; 518 this.tag = Uri.decode(name.substring(0, at)); 519 if (name.endsWith(".gz")) { 520 flags |= DropBoxManager.IS_GZIPPED; 521 name = name.substring(0, name.length() - 3); 522 } 523 if (name.endsWith(".lost")) { 524 flags |= DropBoxManager.IS_EMPTY; 525 name = name.substring(at + 1, name.length() - 5); 526 } else if (name.endsWith(".txt")) { 527 flags |= DropBoxManager.IS_TEXT; 528 name = name.substring(at + 1, name.length() - 4); 529 } else if (name.endsWith(".dat")) { 530 name = name.substring(at + 1, name.length() - 4); 531 } else { 532 this.flags = DropBoxManager.IS_EMPTY; 533 this.timestampMillis = 0; 534 return; 535 } 536 this.flags = flags; 537 538 long millis; 539 try { millis = Long.valueOf(name); } catch (NumberFormatException e) { millis = 0; } 540 this.timestampMillis = millis; 541 } 542 543 /** 544 * Creates a EntryFile object with only a timestamp for comparison purposes. 545 * @param timestampMillis to compare with. 546 */ 547 public EntryFile(long millis) { 548 this.tag = null; 549 this.timestampMillis = millis; 550 this.flags = DropBoxManager.IS_EMPTY; 551 this.file = null; 552 this.blocks = 0; 553 } 554 } 555 556 /////////////////////////////////////////////////////////////////////////// 557 558 /** If never run before, scans disk contents to build in-memory tracking data. */ 559 private synchronized void init() throws IOException { 560 if (mStatFs == null) { 561 if (!mDropBoxDir.isDirectory() && !mDropBoxDir.mkdirs()) { 562 throw new IOException("Can't mkdir: " + mDropBoxDir); 563 } 564 try { 565 mStatFs = new StatFs(mDropBoxDir.getPath()); 566 mBlockSize = mStatFs.getBlockSize(); 567 } catch (IllegalArgumentException e) { // StatFs throws this on error 568 throw new IOException("Can't statfs: " + mDropBoxDir); 569 } 570 } 571 572 if (mAllFiles == null) { 573 File[] files = mDropBoxDir.listFiles(); 574 if (files == null) throw new IOException("Can't list files: " + mDropBoxDir); 575 576 mAllFiles = new FileList(); 577 mFilesByTag = new HashMap<String, FileList>(); 578 579 // Scan pre-existing files. 580 for (File file : files) { 581 if (file.getName().endsWith(".tmp")) { 582 Slog.i(TAG, "Cleaning temp file: " + file); 583 file.delete(); 584 continue; 585 } 586 587 EntryFile entry = new EntryFile(file, mBlockSize); 588 if (entry.tag == null) { 589 Slog.w(TAG, "Unrecognized file: " + file); 590 continue; 591 } else if (entry.timestampMillis == 0) { 592 Slog.w(TAG, "Invalid filename: " + file); 593 file.delete(); 594 continue; 595 } 596 597 enrollEntry(entry); 598 } 599 } 600 } 601 602 /** Adds a disk log file to in-memory tracking for accounting and enumeration. */ 603 private synchronized void enrollEntry(EntryFile entry) { 604 mAllFiles.contents.add(entry); 605 mAllFiles.blocks += entry.blocks; 606 607 // mFilesByTag is used for trimming, so don't list empty files. 608 // (Zero-length/lost files are trimmed by date from mAllFiles.) 609 610 if (entry.tag != null && entry.file != null && entry.blocks > 0) { 611 FileList tagFiles = mFilesByTag.get(entry.tag); 612 if (tagFiles == null) { 613 tagFiles = new FileList(); 614 mFilesByTag.put(entry.tag, tagFiles); 615 } 616 tagFiles.contents.add(entry); 617 tagFiles.blocks += entry.blocks; 618 } 619 } 620 621 /** Moves a temporary file to a final log filename and enrolls it. */ 622 private synchronized long createEntry(File temp, String tag, int flags) throws IOException { 623 long t = System.currentTimeMillis(); 624 625 // Require each entry to have a unique timestamp; if there are entries 626 // >10sec in the future (due to clock skew), drag them back to avoid 627 // keeping them around forever. 628 629 SortedSet<EntryFile> tail = mAllFiles.contents.tailSet(new EntryFile(t + 10000)); 630 EntryFile[] future = null; 631 if (!tail.isEmpty()) { 632 future = tail.toArray(new EntryFile[tail.size()]); 633 tail.clear(); // Remove from mAllFiles 634 } 635 636 if (!mAllFiles.contents.isEmpty()) { 637 t = Math.max(t, mAllFiles.contents.last().timestampMillis + 1); 638 } 639 640 if (future != null) { 641 for (EntryFile late : future) { 642 mAllFiles.blocks -= late.blocks; 643 FileList tagFiles = mFilesByTag.get(late.tag); 644 if (tagFiles != null && tagFiles.contents.remove(late)) { 645 tagFiles.blocks -= late.blocks; 646 } 647 if ((late.flags & DropBoxManager.IS_EMPTY) == 0) { 648 enrollEntry(new EntryFile( 649 late.file, mDropBoxDir, late.tag, t++, late.flags, mBlockSize)); 650 } else { 651 enrollEntry(new EntryFile(mDropBoxDir, late.tag, t++)); 652 } 653 } 654 } 655 656 if (temp == null) { 657 enrollEntry(new EntryFile(mDropBoxDir, tag, t)); 658 } else { 659 enrollEntry(new EntryFile(temp, mDropBoxDir, tag, t, flags, mBlockSize)); 660 } 661 return t; 662 } 663 664 /** 665 * Trims the files on disk to make sure they aren't using too much space. 666 * @return the overall quota for storage (in bytes) 667 */ 668 private synchronized long trimToFit() { 669 // Expunge aged items (including tombstones marking deleted data). 670 671 int ageSeconds = Settings.Secure.getInt(mContentResolver, 672 Settings.Secure.DROPBOX_AGE_SECONDS, DEFAULT_AGE_SECONDS); 673 int maxFiles = Settings.Secure.getInt(mContentResolver, 674 Settings.Secure.DROPBOX_MAX_FILES, DEFAULT_MAX_FILES); 675 long cutoffMillis = System.currentTimeMillis() - ageSeconds * 1000; 676 while (!mAllFiles.contents.isEmpty()) { 677 EntryFile entry = mAllFiles.contents.first(); 678 if (entry.timestampMillis > cutoffMillis && mAllFiles.contents.size() < maxFiles) break; 679 680 FileList tag = mFilesByTag.get(entry.tag); 681 if (tag != null && tag.contents.remove(entry)) tag.blocks -= entry.blocks; 682 if (mAllFiles.contents.remove(entry)) mAllFiles.blocks -= entry.blocks; 683 if (entry.file != null) entry.file.delete(); 684 } 685 686 // Compute overall quota (a fraction of available free space) in blocks. 687 // The quota changes dynamically based on the amount of free space; 688 // that way when lots of data is available we can use it, but we'll get 689 // out of the way if storage starts getting tight. 690 691 long uptimeMillis = SystemClock.uptimeMillis(); 692 if (uptimeMillis > mCachedQuotaUptimeMillis + QUOTA_RESCAN_MILLIS) { 693 int quotaPercent = Settings.Secure.getInt(mContentResolver, 694 Settings.Secure.DROPBOX_QUOTA_PERCENT, DEFAULT_QUOTA_PERCENT); 695 int reservePercent = Settings.Secure.getInt(mContentResolver, 696 Settings.Secure.DROPBOX_RESERVE_PERCENT, DEFAULT_RESERVE_PERCENT); 697 int quotaKb = Settings.Secure.getInt(mContentResolver, 698 Settings.Secure.DROPBOX_QUOTA_KB, DEFAULT_QUOTA_KB); 699 700 mStatFs.restat(mDropBoxDir.getPath()); 701 int available = mStatFs.getAvailableBlocks(); 702 int nonreserved = available - mStatFs.getBlockCount() * reservePercent / 100; 703 int maximum = quotaKb * 1024 / mBlockSize; 704 mCachedQuotaBlocks = Math.min(maximum, Math.max(0, nonreserved * quotaPercent / 100)); 705 mCachedQuotaUptimeMillis = uptimeMillis; 706 } 707 708 // If we're using too much space, delete old items to make room. 709 // 710 // We trim each tag independently (this is why we keep per-tag lists). 711 // Space is "fairly" shared between tags -- they are all squeezed 712 // equally until enough space is reclaimed. 713 // 714 // A single circular buffer (a la logcat) would be simpler, but this 715 // way we can handle fat/bursty data (like 1MB+ bugreports, 300KB+ 716 // kernel crash dumps, and 100KB+ ANR reports) without swamping small, 717 // well-behaved data streams (event statistics, profile data, etc). 718 // 719 // Deleted files are replaced with zero-length tombstones to mark what 720 // was lost. Tombstones are expunged by age (see above). 721 722 if (mAllFiles.blocks > mCachedQuotaBlocks) { 723 // Find a fair share amount of space to limit each tag 724 int unsqueezed = mAllFiles.blocks, squeezed = 0; 725 TreeSet<FileList> tags = new TreeSet<FileList>(mFilesByTag.values()); 726 for (FileList tag : tags) { 727 if (squeezed > 0 && tag.blocks <= (mCachedQuotaBlocks - unsqueezed) / squeezed) { 728 break; 729 } 730 unsqueezed -= tag.blocks; 731 squeezed++; 732 } 733 int tagQuota = (mCachedQuotaBlocks - unsqueezed) / squeezed; 734 735 // Remove old items from each tag until it meets the per-tag quota. 736 for (FileList tag : tags) { 737 if (mAllFiles.blocks < mCachedQuotaBlocks) break; 738 while (tag.blocks > tagQuota && !tag.contents.isEmpty()) { 739 EntryFile entry = tag.contents.first(); 740 if (tag.contents.remove(entry)) tag.blocks -= entry.blocks; 741 if (mAllFiles.contents.remove(entry)) mAllFiles.blocks -= entry.blocks; 742 743 try { 744 if (entry.file != null) entry.file.delete(); 745 enrollEntry(new EntryFile(mDropBoxDir, entry.tag, entry.timestampMillis)); 746 } catch (IOException e) { 747 Slog.e(TAG, "Can't write tombstone file", e); 748 } 749 } 750 } 751 } 752 753 return mCachedQuotaBlocks * mBlockSize; 754 } 755 } 756
