DropBoxManagerService.java revision dd60ee728d9e44a8c85ed6a99bcfa44beb0afa23
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 17package com.android.server; 18 19import android.content.BroadcastReceiver; 20import android.content.ContentResolver; 21import android.content.Context; 22import android.content.Intent; 23import android.content.IntentFilter; 24import android.content.pm.PackageManager; 25import android.database.ContentObserver; 26import android.net.Uri; 27import android.os.Debug; 28import android.os.DropBoxManager; 29import android.os.FileUtils; 30import android.os.Handler; 31import android.os.ParcelFileDescriptor; 32import android.os.StatFs; 33import android.os.SystemClock; 34import android.provider.Settings; 35import android.text.format.Time; 36import android.util.Slog; 37 38import com.android.internal.os.IDropBoxManagerService; 39 40import java.io.BufferedOutputStream; 41import java.io.File; 42import java.io.FileDescriptor; 43import java.io.FileOutputStream; 44import java.io.IOException; 45import java.io.InputStream; 46import java.io.InputStreamReader; 47import java.io.OutputStream; 48import java.io.OutputStreamWriter; 49import java.io.PrintWriter; 50import java.io.UnsupportedEncodingException; 51import java.util.ArrayList; 52import java.util.Comparator; 53import java.util.HashMap; 54import java.util.Iterator; 55import java.util.Map; 56import java.util.SortedSet; 57import java.util.TreeSet; 58import java.util.zip.GZIPOutputStream; 59 60/** 61 * Implementation of {@link IDropBoxManagerService} using the filesystem. 62 * Clients use {@link DropBoxManager} to access this service. 63 */ 64public final class DropBoxManagerService extends IDropBoxManagerService.Stub { 65 private static final String TAG = "DropBoxManagerService"; 66 private static final int DEFAULT_AGE_SECONDS = 3 * 86400; 67 private static final int DEFAULT_MAX_FILES = 1000; 68 private static final int DEFAULT_QUOTA_KB = 5 * 1024; 69 private static final int DEFAULT_QUOTA_PERCENT = 10; 70 private static final int DEFAULT_RESERVE_PERCENT = 10; 71 private static final int QUOTA_RESCAN_MILLIS = 5000; 72 73 private static final boolean PROFILE_DUMP = false; 74 75 // TODO: This implementation currently uses one file per entry, which is 76 // inefficient for smallish entries -- consider using a single queue file 77 // per tag (or even globally) instead. 78 79 // The cached context and derived objects 80 81 private final Context mContext; 82 private final ContentResolver mContentResolver; 83 private final File mDropBoxDir; 84 85 // Accounting of all currently written log files (set in init()). 86 87 private FileList mAllFiles = null; 88 private HashMap<String, FileList> mFilesByTag = null; 89 90 // Various bits of disk information 91 92 private StatFs mStatFs = null; 93 private int mBlockSize = 0; 94 private int mCachedQuotaBlocks = 0; // Space we can use: computed from free space, etc. 95 private long mCachedQuotaUptimeMillis = 0; 96 97 // Ensure that all log entries have a unique timestamp 98 private long mLastTimestamp = 0; 99 100 /** Receives events that might indicate a need to clean up files. */ 101 private final BroadcastReceiver mReceiver = new BroadcastReceiver() { 102 @Override 103 public void onReceive(Context context, Intent intent) { 104 mCachedQuotaUptimeMillis = 0; // Force a re-check of quota size 105 106 // Run the initialization in the background (not this main thread). 107 // The init() and trimToFit() methods are synchronized, so they still 108 // block other users -- but at least the onReceive() call can finish. 109 new Thread() { 110 public void run() { 111 try { 112 init(); 113 trimToFit(); 114 } catch (IOException e) { 115 Slog.e(TAG, "Can't init", e); 116 } 117 } 118 }.start(); 119 } 120 }; 121 122 /** 123 * Creates an instance of managed drop box storage. Normally there is one of these 124 * run by the system, but others can be created for testing and other purposes. 125 * 126 * @param context to use for receiving free space & gservices intents 127 * @param path to store drop box entries in 128 */ 129 public DropBoxManagerService(final Context context, File path) { 130 mDropBoxDir = path; 131 132 // Set up intent receivers 133 mContext = context; 134 mContentResolver = context.getContentResolver(); 135 context.registerReceiver(mReceiver, new IntentFilter(Intent.ACTION_DEVICE_STORAGE_LOW)); 136 137 mContentResolver.registerContentObserver( 138 Settings.Secure.CONTENT_URI, true, 139 new ContentObserver(new Handler()) { 140 public void onChange(boolean selfChange) { 141 mReceiver.onReceive(context, (Intent) null); 142 } 143 }); 144 145 // The real work gets done lazily in init() -- that way service creation always 146 // succeeds, and things like disk problems cause individual method failures. 147 } 148 149 /** Unregisters broadcast receivers and any other hooks -- for test instances */ 150 public void stop() { 151 mContext.unregisterReceiver(mReceiver); 152 } 153 154 public void add(DropBoxManager.Entry entry) { 155 File temp = null; 156 OutputStream output = null; 157 final String tag = entry.getTag(); 158 try { 159 int flags = entry.getFlags(); 160 if ((flags & DropBoxManager.IS_EMPTY) != 0) throw new IllegalArgumentException(); 161 162 init(); 163 if (!isTagEnabled(tag)) return; 164 long max = trimToFit(); 165 long lastTrim = System.currentTimeMillis(); 166 167 byte[] buffer = new byte[mBlockSize]; 168 InputStream input = entry.getInputStream(); 169 170 // First, accumulate up to one block worth of data in memory before 171 // deciding whether to compress the data or not. 172 173 int read = 0; 174 while (read < buffer.length) { 175 int n = input.read(buffer, read, buffer.length - read); 176 if (n <= 0) break; 177 read += n; 178 } 179 180 // If we have at least one block, compress it -- otherwise, just write 181 // the data in uncompressed form. 182 183 temp = new File(mDropBoxDir, "drop" + Thread.currentThread().getId() + ".tmp"); 184 int bufferSize = mBlockSize; 185 if (bufferSize > 4096) bufferSize = 4096; 186 if (bufferSize < 512) bufferSize = 512; 187 FileOutputStream foutput = new FileOutputStream(temp); 188 output = new BufferedOutputStream(foutput, bufferSize); 189 if (read == buffer.length && ((flags & DropBoxManager.IS_GZIPPED) == 0)) { 190 output = new GZIPOutputStream(output); 191 flags = flags | DropBoxManager.IS_GZIPPED; 192 } 193 194 do { 195 output.write(buffer, 0, read); 196 197 long now = System.currentTimeMillis(); 198 if (now - lastTrim > 30 * 1000) { 199 max = trimToFit(); // In case data dribbles in slowly 200 lastTrim = now; 201 } 202 203 read = input.read(buffer); 204 if (read <= 0) { 205 FileUtils.sync(foutput); 206 output.close(); // Get a final size measurement 207 output = null; 208 } else { 209 output.flush(); // So the size measurement is pseudo-reasonable 210 } 211 212 long len = temp.length(); 213 if (len > max) { 214 Slog.w(TAG, "Dropping: " + tag + " (" + temp.length() + " > " + max + " bytes)"); 215 temp.delete(); 216 temp = null; // Pass temp = null to createEntry() to leave a tombstone 217 break; 218 } 219 } while (read > 0); 220 221 long time = createEntry(temp, tag, flags); 222 temp = null; 223 224 Intent dropboxIntent = new Intent(DropBoxManager.ACTION_DROPBOX_ENTRY_ADDED); 225 dropboxIntent.putExtra(DropBoxManager.EXTRA_TAG, tag); 226 dropboxIntent.putExtra(DropBoxManager.EXTRA_TIME, time); 227 mContext.sendBroadcast(dropboxIntent, android.Manifest.permission.READ_LOGS); 228 229 } catch (IOException e) { 230 Slog.e(TAG, "Can't write: " + tag, e); 231 } finally { 232 try { if (output != null) output.close(); } catch (IOException e) {} 233 entry.close(); 234 if (temp != null) temp.delete(); 235 } 236 } 237 238 public boolean isTagEnabled(String tag) { 239 return !"disabled".equals(Settings.Secure.getString( 240 mContentResolver, Settings.Secure.DROPBOX_TAG_PREFIX + tag)); 241 } 242 243 public synchronized DropBoxManager.Entry getNextEntry(String tag, long millis) { 244 if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.READ_LOGS) 245 != PackageManager.PERMISSION_GRANTED) { 246 throw new SecurityException("READ_LOGS permission required"); 247 } 248 249 try { 250 init(); 251 } catch (IOException e) { 252 Slog.e(TAG, "Can't init", e); 253 return null; 254 } 255 256 FileList list = tag == null ? mAllFiles : mFilesByTag.get(tag); 257 if (list == null) return null; 258 259 for (EntryFile entry : list.contents.tailSet(new EntryFile(millis + 1))) { 260 if (entry.tag == null) continue; 261 if ((entry.flags & DropBoxManager.IS_EMPTY) != 0) { 262 return new DropBoxManager.Entry(entry.tag, entry.timestampMillis); 263 } 264 try { 265 return new DropBoxManager.Entry( 266 entry.tag, entry.timestampMillis, entry.file, entry.flags); 267 } catch (IOException e) { 268 Slog.e(TAG, "Can't read: " + entry.file, e); 269 // Continue to next file 270 } 271 } 272 273 return null; 274 } 275 276 public synchronized void dump(FileDescriptor fd, PrintWriter pw, String[] args) { 277 if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.DUMP) 278 != PackageManager.PERMISSION_GRANTED) { 279 pw.println("Permission Denial: Can't dump DropBoxManagerService"); 280 return; 281 } 282 283 try { 284 init(); 285 } catch (IOException e) { 286 pw.println("Can't initialize: " + e); 287 Slog.e(TAG, "Can't init", e); 288 return; 289 } 290 291 if (PROFILE_DUMP) Debug.startMethodTracing("/data/trace/dropbox.dump"); 292 293 StringBuilder out = new StringBuilder(); 294 boolean doPrint = false, doFile = false; 295 ArrayList<String> searchArgs = new ArrayList<String>(); 296 for (int i = 0; args != null && i < args.length; i++) { 297 if (args[i].equals("-p") || args[i].equals("--print")) { 298 doPrint = true; 299 } else if (args[i].equals("-f") || args[i].equals("--file")) { 300 doFile = true; 301 } else if (args[i].startsWith("-")) { 302 out.append("Unknown argument: ").append(args[i]).append("\n"); 303 } else { 304 searchArgs.add(args[i]); 305 } 306 } 307 308 out.append("Drop box contents: ").append(mAllFiles.contents.size()).append(" entries\n"); 309 310 if (!searchArgs.isEmpty()) { 311 out.append("Searching for:"); 312 for (String a : searchArgs) out.append(" ").append(a); 313 out.append("\n"); 314 } 315 316 int numFound = 0, numArgs = searchArgs.size(); 317 Time time = new Time(); 318 out.append("\n"); 319 for (EntryFile entry : mAllFiles.contents) { 320 time.set(entry.timestampMillis); 321 String date = time.format("%Y-%m-%d %H:%M:%S"); 322 boolean match = true; 323 for (int i = 0; i < numArgs && match; i++) { 324 String arg = searchArgs.get(i); 325 match = (date.contains(arg) || arg.equals(entry.tag)); 326 } 327 if (!match) continue; 328 329 numFound++; 330 if (doPrint) out.append("========================================\n"); 331 out.append(date).append(" ").append(entry.tag == null ? "(no tag)" : entry.tag); 332 if (entry.file == null) { 333 out.append(" (no file)\n"); 334 continue; 335 } else if ((entry.flags & DropBoxManager.IS_EMPTY) != 0) { 336 out.append(" (contents lost)\n"); 337 continue; 338 } else { 339 out.append(" ("); 340 if ((entry.flags & DropBoxManager.IS_GZIPPED) != 0) out.append("compressed "); 341 out.append((entry.flags & DropBoxManager.IS_TEXT) != 0 ? "text" : "data"); 342 out.append(", ").append(entry.file.length()).append(" bytes)\n"); 343 } 344 345 if (doFile || (doPrint && (entry.flags & DropBoxManager.IS_TEXT) == 0)) { 346 if (!doPrint) out.append(" "); 347 out.append(entry.file.getPath()).append("\n"); 348 } 349 350 if ((entry.flags & DropBoxManager.IS_TEXT) != 0 && (doPrint || !doFile)) { 351 DropBoxManager.Entry dbe = null; 352 InputStreamReader isr = null; 353 try { 354 dbe = new DropBoxManager.Entry( 355 entry.tag, entry.timestampMillis, entry.file, entry.flags); 356 357 if (doPrint) { 358 isr = new InputStreamReader(dbe.getInputStream()); 359 char[] buf = new char[4096]; 360 boolean newline = false; 361 for (;;) { 362 int n = isr.read(buf); 363 if (n <= 0) break; 364 out.append(buf, 0, n); 365 newline = (buf[n - 1] == '\n'); 366 367 // Flush periodically when printing to avoid out-of-memory. 368 if (out.length() > 65536) { 369 pw.write(out.toString()); 370 out.setLength(0); 371 } 372 } 373 if (!newline) out.append("\n"); 374 } else { 375 String text = dbe.getText(70); 376 boolean truncated = (text.length() == 70); 377 out.append(" ").append(text.trim().replace('\n', '/')); 378 if (truncated) out.append(" ..."); 379 out.append("\n"); 380 } 381 } catch (IOException e) { 382 out.append("*** ").append(e.toString()).append("\n"); 383 Slog.e(TAG, "Can't read: " + entry.file, e); 384 } finally { 385 if (dbe != null) dbe.close(); 386 if (isr != null) { 387 try { 388 isr.close(); 389 } catch (IOException unused) { 390 } 391 } 392 } 393 } 394 395 if (doPrint) out.append("\n"); 396 } 397 398 if (numFound == 0) out.append("(No entries found.)\n"); 399 400 if (args == null || args.length == 0) { 401 if (!doPrint) out.append("\n"); 402 out.append("Usage: dumpsys dropbox [--print|--file] [YYYY-mm-dd] [HH:MM:SS] [tag]\n"); 403 } 404 405 pw.write(out.toString()); 406 if (PROFILE_DUMP) Debug.stopMethodTracing(); 407 } 408 409 /////////////////////////////////////////////////////////////////////////// 410 411 /** Chronologically sorted list of {@link #EntryFile} */ 412 private static final class FileList implements Comparable<FileList> { 413 public int blocks = 0; 414 public final TreeSet<EntryFile> contents = new TreeSet<EntryFile>(); 415 416 /** Sorts bigger FileList instances before smaller ones. */ 417 public final int compareTo(FileList o) { 418 if (blocks != o.blocks) return o.blocks - blocks; 419 if (this == o) return 0; 420 if (hashCode() < o.hashCode()) return -1; 421 if (hashCode() > o.hashCode()) return 1; 422 return 0; 423 } 424 } 425 426 /** Metadata describing an on-disk log file. */ 427 private static final class EntryFile implements Comparable<EntryFile> { 428 public final String tag; 429 public final long timestampMillis; 430 public final int flags; 431 public final File file; 432 public final int blocks; 433 434 /** Sorts earlier EntryFile instances before later ones. */ 435 public final int compareTo(EntryFile o) { 436 if (timestampMillis < o.timestampMillis) return -1; 437 if (timestampMillis > o.timestampMillis) return 1; 438 if (file != null && o.file != null) return file.compareTo(o.file); 439 if (o.file != null) return -1; 440 if (file != null) return 1; 441 if (this == o) return 0; 442 if (hashCode() < o.hashCode()) return -1; 443 if (hashCode() > o.hashCode()) return 1; 444 return 0; 445 } 446 447 /** 448 * Moves an existing temporary file to a new log filename. 449 * @param temp file to rename 450 * @param dir to store file in 451 * @param tag to use for new log file name 452 * @param timestampMillis of log entry 453 * @param flags for the entry data 454 * @param blockSize to use for space accounting 455 * @throws IOException if the file can't be moved 456 */ 457 public EntryFile(File temp, File dir, String tag,long timestampMillis, 458 int flags, int blockSize) throws IOException { 459 if ((flags & DropBoxManager.IS_EMPTY) != 0) throw new IllegalArgumentException(); 460 461 this.tag = tag; 462 this.timestampMillis = timestampMillis; 463 this.flags = flags; 464 this.file = new File(dir, Uri.encode(tag) + "@" + timestampMillis + 465 ((flags & DropBoxManager.IS_TEXT) != 0 ? ".txt" : ".dat") + 466 ((flags & DropBoxManager.IS_GZIPPED) != 0 ? ".gz" : "")); 467 468 if (!temp.renameTo(this.file)) { 469 throw new IOException("Can't rename " + temp + " to " + this.file); 470 } 471 this.blocks = (int) ((this.file.length() + blockSize - 1) / blockSize); 472 } 473 474 /** 475 * Creates a zero-length tombstone for a file whose contents were lost. 476 * @param dir to store file in 477 * @param tag to use for new log file name 478 * @param timestampMillis of log entry 479 * @throws IOException if the file can't be created. 480 */ 481 public EntryFile(File dir, String tag, long timestampMillis) throws IOException { 482 this.tag = tag; 483 this.timestampMillis = timestampMillis; 484 this.flags = DropBoxManager.IS_EMPTY; 485 this.file = new File(dir, Uri.encode(tag) + "@" + timestampMillis + ".lost"); 486 this.blocks = 0; 487 new FileOutputStream(this.file).close(); 488 } 489 490 /** 491 * Extracts metadata from an existing on-disk log filename. 492 * @param file name of existing log file 493 * @param blockSize to use for space accounting 494 */ 495 public EntryFile(File file, int blockSize) { 496 this.file = file; 497 this.blocks = (int) ((this.file.length() + blockSize - 1) / blockSize); 498 499 String name = file.getName(); 500 int at = name.lastIndexOf('@'); 501 if (at < 0) { 502 this.tag = null; 503 this.timestampMillis = 0; 504 this.flags = DropBoxManager.IS_EMPTY; 505 return; 506 } 507 508 int flags = 0; 509 this.tag = Uri.decode(name.substring(0, at)); 510 if (name.endsWith(".gz")) { 511 flags |= DropBoxManager.IS_GZIPPED; 512 name = name.substring(0, name.length() - 3); 513 } 514 if (name.endsWith(".lost")) { 515 flags |= DropBoxManager.IS_EMPTY; 516 name = name.substring(at + 1, name.length() - 5); 517 } else if (name.endsWith(".txt")) { 518 flags |= DropBoxManager.IS_TEXT; 519 name = name.substring(at + 1, name.length() - 4); 520 } else if (name.endsWith(".dat")) { 521 name = name.substring(at + 1, name.length() - 4); 522 } else { 523 this.flags = DropBoxManager.IS_EMPTY; 524 this.timestampMillis = 0; 525 return; 526 } 527 this.flags = flags; 528 529 long millis; 530 try { millis = Long.valueOf(name); } catch (NumberFormatException e) { millis = 0; } 531 this.timestampMillis = millis; 532 } 533 534 /** 535 * Creates a EntryFile object with only a timestamp for comparison purposes. 536 * @param timestampMillis to compare with. 537 */ 538 public EntryFile(long millis) { 539 this.tag = null; 540 this.timestampMillis = millis; 541 this.flags = DropBoxManager.IS_EMPTY; 542 this.file = null; 543 this.blocks = 0; 544 } 545 } 546 547 /////////////////////////////////////////////////////////////////////////// 548 549 /** If never run before, scans disk contents to build in-memory tracking data. */ 550 private synchronized void init() throws IOException { 551 if (mStatFs == null) { 552 if (!mDropBoxDir.isDirectory() && !mDropBoxDir.mkdirs()) { 553 throw new IOException("Can't mkdir: " + mDropBoxDir); 554 } 555 try { 556 mStatFs = new StatFs(mDropBoxDir.getPath()); 557 mBlockSize = mStatFs.getBlockSize(); 558 } catch (IllegalArgumentException e) { // StatFs throws this on error 559 throw new IOException("Can't statfs: " + mDropBoxDir); 560 } 561 } 562 563 if (mAllFiles == null) { 564 File[] files = mDropBoxDir.listFiles(); 565 if (files == null) throw new IOException("Can't list files: " + mDropBoxDir); 566 567 mAllFiles = new FileList(); 568 mFilesByTag = new HashMap<String, FileList>(); 569 570 // Scan pre-existing files. 571 for (File file : files) { 572 if (file.getName().endsWith(".tmp")) { 573 Slog.i(TAG, "Cleaning temp file: " + file); 574 file.delete(); 575 continue; 576 } 577 578 EntryFile entry = new EntryFile(file, mBlockSize); 579 if (entry.tag == null) { 580 Slog.w(TAG, "Unrecognized file: " + file); 581 continue; 582 } else if (entry.timestampMillis == 0) { 583 Slog.w(TAG, "Invalid filename: " + file); 584 file.delete(); 585 continue; 586 } 587 588 enrollEntry(entry); 589 } 590 } 591 } 592 593 /** Adds a disk log file to in-memory tracking for accounting and enumeration. */ 594 private synchronized void enrollEntry(EntryFile entry) { 595 mAllFiles.contents.add(entry); 596 mAllFiles.blocks += entry.blocks; 597 598 // mFilesByTag is used for trimming, so don't list empty files. 599 // (Zero-length/lost files are trimmed by date from mAllFiles.) 600 601 if (entry.tag != null && entry.file != null && entry.blocks > 0) { 602 FileList tagFiles = mFilesByTag.get(entry.tag); 603 if (tagFiles == null) { 604 tagFiles = new FileList(); 605 mFilesByTag.put(entry.tag, tagFiles); 606 } 607 tagFiles.contents.add(entry); 608 tagFiles.blocks += entry.blocks; 609 } 610 } 611 612 /** Moves a temporary file to a final log filename and enrolls it. */ 613 private synchronized long createEntry(File temp, String tag, int flags) throws IOException { 614 long t = System.currentTimeMillis(); 615 616 // Require each entry to have a unique timestamp; if there are entries 617 // >10sec in the future (due to clock skew), drag them back to avoid 618 // keeping them around forever. 619 620 SortedSet<EntryFile> tail = mAllFiles.contents.tailSet(new EntryFile(t + 10000)); 621 EntryFile[] future = null; 622 if (!tail.isEmpty()) { 623 future = tail.toArray(new EntryFile[tail.size()]); 624 tail.clear(); // Remove from mAllFiles 625 } 626 627 if (!mAllFiles.contents.isEmpty()) { 628 t = Math.max(t, mAllFiles.contents.last().timestampMillis + 1); 629 } 630 631 if (future != null) { 632 for (EntryFile late : future) { 633 mAllFiles.blocks -= late.blocks; 634 FileList tagFiles = mFilesByTag.get(late.tag); 635 if (tagFiles != null && tagFiles.contents.remove(late)) { 636 tagFiles.blocks -= late.blocks; 637 } 638 if ((late.flags & DropBoxManager.IS_EMPTY) == 0) { 639 enrollEntry(new EntryFile( 640 late.file, mDropBoxDir, late.tag, t++, late.flags, mBlockSize)); 641 } else { 642 enrollEntry(new EntryFile(mDropBoxDir, late.tag, t++)); 643 } 644 } 645 } 646 647 if (temp == null) { 648 enrollEntry(new EntryFile(mDropBoxDir, tag, t)); 649 } else { 650 enrollEntry(new EntryFile(temp, mDropBoxDir, tag, t, flags, mBlockSize)); 651 } 652 return t; 653 } 654 655 /** 656 * Trims the files on disk to make sure they aren't using too much space. 657 * @return the overall quota for storage (in bytes) 658 */ 659 private synchronized long trimToFit() { 660 // Expunge aged items (including tombstones marking deleted data). 661 662 int ageSeconds = Settings.Secure.getInt(mContentResolver, 663 Settings.Secure.DROPBOX_AGE_SECONDS, DEFAULT_AGE_SECONDS); 664 int maxFiles = Settings.Secure.getInt(mContentResolver, 665 Settings.Secure.DROPBOX_MAX_FILES, DEFAULT_MAX_FILES); 666 long cutoffMillis = System.currentTimeMillis() - ageSeconds * 1000; 667 while (!mAllFiles.contents.isEmpty()) { 668 EntryFile entry = mAllFiles.contents.first(); 669 if (entry.timestampMillis > cutoffMillis && mAllFiles.contents.size() < maxFiles) break; 670 671 FileList tag = mFilesByTag.get(entry.tag); 672 if (tag != null && tag.contents.remove(entry)) tag.blocks -= entry.blocks; 673 if (mAllFiles.contents.remove(entry)) mAllFiles.blocks -= entry.blocks; 674 if (entry.file != null) entry.file.delete(); 675 } 676 677 // Compute overall quota (a fraction of available free space) in blocks. 678 // The quota changes dynamically based on the amount of free space; 679 // that way when lots of data is available we can use it, but we'll get 680 // out of the way if storage starts getting tight. 681 682 long uptimeMillis = SystemClock.uptimeMillis(); 683 if (uptimeMillis > mCachedQuotaUptimeMillis + QUOTA_RESCAN_MILLIS) { 684 int quotaPercent = Settings.Secure.getInt(mContentResolver, 685 Settings.Secure.DROPBOX_QUOTA_PERCENT, DEFAULT_QUOTA_PERCENT); 686 int reservePercent = Settings.Secure.getInt(mContentResolver, 687 Settings.Secure.DROPBOX_RESERVE_PERCENT, DEFAULT_RESERVE_PERCENT); 688 int quotaKb = Settings.Secure.getInt(mContentResolver, 689 Settings.Secure.DROPBOX_QUOTA_KB, DEFAULT_QUOTA_KB); 690 691 mStatFs.restat(mDropBoxDir.getPath()); 692 int available = mStatFs.getAvailableBlocks(); 693 int nonreserved = available - mStatFs.getBlockCount() * reservePercent / 100; 694 int maximum = quotaKb * 1024 / mBlockSize; 695 mCachedQuotaBlocks = Math.min(maximum, Math.max(0, nonreserved * quotaPercent / 100)); 696 mCachedQuotaUptimeMillis = uptimeMillis; 697 } 698 699 // If we're using too much space, delete old items to make room. 700 // 701 // We trim each tag independently (this is why we keep per-tag lists). 702 // Space is "fairly" shared between tags -- they are all squeezed 703 // equally until enough space is reclaimed. 704 // 705 // A single circular buffer (a la logcat) would be simpler, but this 706 // way we can handle fat/bursty data (like 1MB+ bugreports, 300KB+ 707 // kernel crash dumps, and 100KB+ ANR reports) without swamping small, 708 // well-behaved data streams (event statistics, profile data, etc). 709 // 710 // Deleted files are replaced with zero-length tombstones to mark what 711 // was lost. Tombstones are expunged by age (see above). 712 713 if (mAllFiles.blocks > mCachedQuotaBlocks) { 714 // Find a fair share amount of space to limit each tag 715 int unsqueezed = mAllFiles.blocks, squeezed = 0; 716 TreeSet<FileList> tags = new TreeSet<FileList>(mFilesByTag.values()); 717 for (FileList tag : tags) { 718 if (squeezed > 0 && tag.blocks <= (mCachedQuotaBlocks - unsqueezed) / squeezed) { 719 break; 720 } 721 unsqueezed -= tag.blocks; 722 squeezed++; 723 } 724 int tagQuota = (mCachedQuotaBlocks - unsqueezed) / squeezed; 725 726 // Remove old items from each tag until it meets the per-tag quota. 727 for (FileList tag : tags) { 728 if (mAllFiles.blocks < mCachedQuotaBlocks) break; 729 while (tag.blocks > tagQuota && !tag.contents.isEmpty()) { 730 EntryFile entry = tag.contents.first(); 731 if (tag.contents.remove(entry)) tag.blocks -= entry.blocks; 732 if (mAllFiles.contents.remove(entry)) mAllFiles.blocks -= entry.blocks; 733 734 try { 735 if (entry.file != null) entry.file.delete(); 736 enrollEntry(new EntryFile(mDropBoxDir, entry.tag, entry.timestampMillis)); 737 } catch (IOException e) { 738 Slog.e(TAG, "Can't write tombstone file", e); 739 } 740 } 741 } 742 } 743 744 return mCachedQuotaBlocks * mBlockSize; 745 } 746} 747