DropBoxManagerService.java revision 5ac72a29593ab9a20337a2225df52bdf4754be02
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.Message; 32import android.os.StatFs; 33import android.os.SystemClock; 34import android.os.UserHandle; 35import android.provider.Settings; 36import android.text.format.Time; 37import android.util.Slog; 38 39import com.android.internal.os.IDropBoxManagerService; 40 41import java.io.BufferedOutputStream; 42import java.io.File; 43import java.io.FileDescriptor; 44import java.io.FileOutputStream; 45import java.io.IOException; 46import java.io.InputStream; 47import java.io.InputStreamReader; 48import java.io.OutputStream; 49import java.io.PrintWriter; 50import java.util.ArrayList; 51import java.util.HashMap; 52import java.util.SortedSet; 53import java.util.TreeSet; 54import java.util.zip.GZIPOutputStream; 55 56/** 57 * Implementation of {@link IDropBoxManagerService} using the filesystem. 58 * Clients use {@link DropBoxManager} to access this service. 59 */ 60public final class DropBoxManagerService extends IDropBoxManagerService.Stub { 61 private static final String TAG = "DropBoxManagerService"; 62 private static final int DEFAULT_AGE_SECONDS = 3 * 86400; 63 private static final int DEFAULT_MAX_FILES = 1000; 64 private static final int DEFAULT_QUOTA_KB = 5 * 1024; 65 private static final int DEFAULT_QUOTA_PERCENT = 10; 66 private static final int DEFAULT_RESERVE_PERCENT = 10; 67 private static final int QUOTA_RESCAN_MILLIS = 5000; 68 69 // mHandler 'what' value. 70 private static final int MSG_SEND_BROADCAST = 1; 71 72 private static final boolean PROFILE_DUMP = false; 73 74 // TODO: This implementation currently uses one file per entry, which is 75 // inefficient for smallish entries -- consider using a single queue file 76 // per tag (or even globally) instead. 77 78 // The cached context and derived objects 79 80 private final Context mContext; 81 private final ContentResolver mContentResolver; 82 private final File mDropBoxDir; 83 84 // Accounting of all currently written log files (set in init()). 85 86 private FileList mAllFiles = null; 87 private HashMap<String, FileList> mFilesByTag = null; 88 89 // Various bits of disk information 90 91 private StatFs mStatFs = null; 92 private int mBlockSize = 0; 93 private int mCachedQuotaBlocks = 0; // Space we can use: computed from free space, etc. 94 private long mCachedQuotaUptimeMillis = 0; 95 96 private volatile boolean mBooted = false; 97 98 // Provide a way to perform sendBroadcast asynchronously to avoid deadlocks. 99 private final Handler mHandler; 100 101 /** Receives events that might indicate a need to clean up files. */ 102 private final BroadcastReceiver mReceiver = new BroadcastReceiver() { 103 @Override 104 public void onReceive(Context context, Intent intent) { 105 if (intent != null && Intent.ACTION_BOOT_COMPLETED.equals(intent.getAction())) { 106 mBooted = true; 107 return; 108 } 109 110 // Else, for ACTION_DEVICE_STORAGE_LOW: 111 mCachedQuotaUptimeMillis = 0; // Force a re-check of quota size 112 113 // Run the initialization in the background (not this main thread). 114 // The init() and trimToFit() methods are synchronized, so they still 115 // block other users -- but at least the onReceive() call can finish. 116 new Thread() { 117 public void run() { 118 try { 119 init(); 120 trimToFit(); 121 } catch (IOException e) { 122 Slog.e(TAG, "Can't init", e); 123 } 124 } 125 }.start(); 126 } 127 }; 128 129 /** 130 * Creates an instance of managed drop box storage. Normally there is one of these 131 * run by the system, but others can be created for testing and other purposes. 132 * 133 * @param context to use for receiving free space & gservices intents 134 * @param path to store drop box entries in 135 */ 136 public DropBoxManagerService(final Context context, File path) { 137 mDropBoxDir = path; 138 139 // Set up intent receivers 140 mContext = context; 141 mContentResolver = context.getContentResolver(); 142 143 IntentFilter filter = new IntentFilter(); 144 filter.addAction(Intent.ACTION_DEVICE_STORAGE_LOW); 145 filter.addAction(Intent.ACTION_BOOT_COMPLETED); 146 context.registerReceiver(mReceiver, filter); 147 148 mContentResolver.registerContentObserver( 149 Settings.Secure.CONTENT_URI, true, 150 new ContentObserver(new Handler()) { 151 @Override 152 public void onChange(boolean selfChange) { 153 mReceiver.onReceive(context, (Intent) null); 154 } 155 }); 156 157 mHandler = new Handler() { 158 @Override 159 public void handleMessage(Message msg) { 160 if (msg.what == MSG_SEND_BROADCAST) { 161 mContext.sendBroadcastAsUser((Intent)msg.obj, UserHandle.OWNER, 162 android.Manifest.permission.READ_LOGS); 163 } 164 } 165 }; 166 167 // The real work gets done lazily in init() -- that way service creation always 168 // succeeds, and things like disk problems cause individual method failures. 169 } 170 171 /** Unregisters broadcast receivers and any other hooks -- for test instances */ 172 public void stop() { 173 mContext.unregisterReceiver(mReceiver); 174 } 175 176 @Override 177 public void add(DropBoxManager.Entry entry) { 178 File temp = null; 179 OutputStream output = null; 180 final String tag = entry.getTag(); 181 try { 182 int flags = entry.getFlags(); 183 if ((flags & DropBoxManager.IS_EMPTY) != 0) throw new IllegalArgumentException(); 184 185 init(); 186 if (!isTagEnabled(tag)) return; 187 long max = trimToFit(); 188 long lastTrim = System.currentTimeMillis(); 189 190 byte[] buffer = new byte[mBlockSize]; 191 InputStream input = entry.getInputStream(); 192 193 // First, accumulate up to one block worth of data in memory before 194 // deciding whether to compress the data or not. 195 196 int read = 0; 197 while (read < buffer.length) { 198 int n = input.read(buffer, read, buffer.length - read); 199 if (n <= 0) break; 200 read += n; 201 } 202 203 // If we have at least one block, compress it -- otherwise, just write 204 // the data in uncompressed form. 205 206 temp = new File(mDropBoxDir, "drop" + Thread.currentThread().getId() + ".tmp"); 207 int bufferSize = mBlockSize; 208 if (bufferSize > 4096) bufferSize = 4096; 209 if (bufferSize < 512) bufferSize = 512; 210 FileOutputStream foutput = new FileOutputStream(temp); 211 output = new BufferedOutputStream(foutput, bufferSize); 212 if (read == buffer.length && ((flags & DropBoxManager.IS_GZIPPED) == 0)) { 213 output = new GZIPOutputStream(output); 214 flags = flags | DropBoxManager.IS_GZIPPED; 215 } 216 217 do { 218 output.write(buffer, 0, read); 219 220 long now = System.currentTimeMillis(); 221 if (now - lastTrim > 30 * 1000) { 222 max = trimToFit(); // In case data dribbles in slowly 223 lastTrim = now; 224 } 225 226 read = input.read(buffer); 227 if (read <= 0) { 228 FileUtils.sync(foutput); 229 output.close(); // Get a final size measurement 230 output = null; 231 } else { 232 output.flush(); // So the size measurement is pseudo-reasonable 233 } 234 235 long len = temp.length(); 236 if (len > max) { 237 Slog.w(TAG, "Dropping: " + tag + " (" + temp.length() + " > " + max + " bytes)"); 238 temp.delete(); 239 temp = null; // Pass temp = null to createEntry() to leave a tombstone 240 break; 241 } 242 } while (read > 0); 243 244 long time = createEntry(temp, tag, flags); 245 temp = null; 246 247 final Intent dropboxIntent = new Intent(DropBoxManager.ACTION_DROPBOX_ENTRY_ADDED); 248 dropboxIntent.putExtra(DropBoxManager.EXTRA_TAG, tag); 249 dropboxIntent.putExtra(DropBoxManager.EXTRA_TIME, time); 250 if (!mBooted) { 251 dropboxIntent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY); 252 } 253 // Call sendBroadcast after returning from this call to avoid deadlock. In particular 254 // the caller may be holding the WindowManagerService lock but sendBroadcast requires a 255 // lock in ActivityManagerService. ActivityManagerService has been caught holding that 256 // very lock while waiting for the WindowManagerService lock. 257 mHandler.sendMessage(mHandler.obtainMessage(MSG_SEND_BROADCAST, dropboxIntent)); 258 } catch (IOException e) { 259 Slog.e(TAG, "Can't write: " + tag, e); 260 } finally { 261 try { if (output != null) output.close(); } catch (IOException e) {} 262 entry.close(); 263 if (temp != null) temp.delete(); 264 } 265 } 266 267 public boolean isTagEnabled(String tag) { 268 return !"disabled".equals(Settings.Secure.getString( 269 mContentResolver, Settings.Secure.DROPBOX_TAG_PREFIX + tag)); 270 } 271 272 public synchronized DropBoxManager.Entry getNextEntry(String tag, long millis) { 273 if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.READ_LOGS) 274 != PackageManager.PERMISSION_GRANTED) { 275 throw new SecurityException("READ_LOGS permission required"); 276 } 277 278 try { 279 init(); 280 } catch (IOException e) { 281 Slog.e(TAG, "Can't init", e); 282 return null; 283 } 284 285 FileList list = tag == null ? mAllFiles : mFilesByTag.get(tag); 286 if (list == null) return null; 287 288 for (EntryFile entry : list.contents.tailSet(new EntryFile(millis + 1))) { 289 if (entry.tag == null) continue; 290 if ((entry.flags & DropBoxManager.IS_EMPTY) != 0) { 291 return new DropBoxManager.Entry(entry.tag, entry.timestampMillis); 292 } 293 try { 294 return new DropBoxManager.Entry( 295 entry.tag, entry.timestampMillis, entry.file, entry.flags); 296 } catch (IOException e) { 297 Slog.e(TAG, "Can't read: " + entry.file, e); 298 // Continue to next file 299 } 300 } 301 302 return null; 303 } 304 305 public synchronized void dump(FileDescriptor fd, PrintWriter pw, String[] args) { 306 if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.DUMP) 307 != PackageManager.PERMISSION_GRANTED) { 308 pw.println("Permission Denial: Can't dump DropBoxManagerService"); 309 return; 310 } 311 312 try { 313 init(); 314 } catch (IOException e) { 315 pw.println("Can't initialize: " + e); 316 Slog.e(TAG, "Can't init", e); 317 return; 318 } 319 320 if (PROFILE_DUMP) Debug.startMethodTracing("/data/trace/dropbox.dump"); 321 322 StringBuilder out = new StringBuilder(); 323 boolean doPrint = false, doFile = false; 324 ArrayList<String> searchArgs = new ArrayList<String>(); 325 for (int i = 0; args != null && i < args.length; i++) { 326 if (args[i].equals("-p") || args[i].equals("--print")) { 327 doPrint = true; 328 } else if (args[i].equals("-f") || args[i].equals("--file")) { 329 doFile = true; 330 } else if (args[i].startsWith("-")) { 331 out.append("Unknown argument: ").append(args[i]).append("\n"); 332 } else { 333 searchArgs.add(args[i]); 334 } 335 } 336 337 out.append("Drop box contents: ").append(mAllFiles.contents.size()).append(" entries\n"); 338 339 if (!searchArgs.isEmpty()) { 340 out.append("Searching for:"); 341 for (String a : searchArgs) out.append(" ").append(a); 342 out.append("\n"); 343 } 344 345 int numFound = 0, numArgs = searchArgs.size(); 346 Time time = new Time(); 347 out.append("\n"); 348 for (EntryFile entry : mAllFiles.contents) { 349 time.set(entry.timestampMillis); 350 String date = time.format("%Y-%m-%d %H:%M:%S"); 351 boolean match = true; 352 for (int i = 0; i < numArgs && match; i++) { 353 String arg = searchArgs.get(i); 354 match = (date.contains(arg) || arg.equals(entry.tag)); 355 } 356 if (!match) continue; 357 358 numFound++; 359 if (doPrint) out.append("========================================\n"); 360 out.append(date).append(" ").append(entry.tag == null ? "(no tag)" : entry.tag); 361 if (entry.file == null) { 362 out.append(" (no file)\n"); 363 continue; 364 } else if ((entry.flags & DropBoxManager.IS_EMPTY) != 0) { 365 out.append(" (contents lost)\n"); 366 continue; 367 } else { 368 out.append(" ("); 369 if ((entry.flags & DropBoxManager.IS_GZIPPED) != 0) out.append("compressed "); 370 out.append((entry.flags & DropBoxManager.IS_TEXT) != 0 ? "text" : "data"); 371 out.append(", ").append(entry.file.length()).append(" bytes)\n"); 372 } 373 374 if (doFile || (doPrint && (entry.flags & DropBoxManager.IS_TEXT) == 0)) { 375 if (!doPrint) out.append(" "); 376 out.append(entry.file.getPath()).append("\n"); 377 } 378 379 if ((entry.flags & DropBoxManager.IS_TEXT) != 0 && (doPrint || !doFile)) { 380 DropBoxManager.Entry dbe = null; 381 InputStreamReader isr = null; 382 try { 383 dbe = new DropBoxManager.Entry( 384 entry.tag, entry.timestampMillis, entry.file, entry.flags); 385 386 if (doPrint) { 387 isr = new InputStreamReader(dbe.getInputStream()); 388 char[] buf = new char[4096]; 389 boolean newline = false; 390 for (;;) { 391 int n = isr.read(buf); 392 if (n <= 0) break; 393 out.append(buf, 0, n); 394 newline = (buf[n - 1] == '\n'); 395 396 // Flush periodically when printing to avoid out-of-memory. 397 if (out.length() > 65536) { 398 pw.write(out.toString()); 399 out.setLength(0); 400 } 401 } 402 if (!newline) out.append("\n"); 403 } else { 404 String text = dbe.getText(70); 405 boolean truncated = (text.length() == 70); 406 out.append(" ").append(text.trim().replace('\n', '/')); 407 if (truncated) out.append(" ..."); 408 out.append("\n"); 409 } 410 } catch (IOException e) { 411 out.append("*** ").append(e.toString()).append("\n"); 412 Slog.e(TAG, "Can't read: " + entry.file, e); 413 } finally { 414 if (dbe != null) dbe.close(); 415 if (isr != null) { 416 try { 417 isr.close(); 418 } catch (IOException unused) { 419 } 420 } 421 } 422 } 423 424 if (doPrint) out.append("\n"); 425 } 426 427 if (numFound == 0) out.append("(No entries found.)\n"); 428 429 if (args == null || args.length == 0) { 430 if (!doPrint) out.append("\n"); 431 out.append("Usage: dumpsys dropbox [--print|--file] [YYYY-mm-dd] [HH:MM:SS] [tag]\n"); 432 } 433 434 pw.write(out.toString()); 435 if (PROFILE_DUMP) Debug.stopMethodTracing(); 436 } 437 438 /////////////////////////////////////////////////////////////////////////// 439 440 /** Chronologically sorted list of {@link #EntryFile} */ 441 private static final class FileList implements Comparable<FileList> { 442 public int blocks = 0; 443 public final TreeSet<EntryFile> contents = new TreeSet<EntryFile>(); 444 445 /** Sorts bigger FileList instances before smaller ones. */ 446 public final int compareTo(FileList o) { 447 if (blocks != o.blocks) return o.blocks - blocks; 448 if (this == o) return 0; 449 if (hashCode() < o.hashCode()) return -1; 450 if (hashCode() > o.hashCode()) return 1; 451 return 0; 452 } 453 } 454 455 /** Metadata describing an on-disk log file. */ 456 private static final class EntryFile implements Comparable<EntryFile> { 457 public final String tag; 458 public final long timestampMillis; 459 public final int flags; 460 public final File file; 461 public final int blocks; 462 463 /** Sorts earlier EntryFile instances before later ones. */ 464 public final int compareTo(EntryFile o) { 465 if (timestampMillis < o.timestampMillis) return -1; 466 if (timestampMillis > o.timestampMillis) return 1; 467 if (file != null && o.file != null) return file.compareTo(o.file); 468 if (o.file != null) return -1; 469 if (file != null) return 1; 470 if (this == o) return 0; 471 if (hashCode() < o.hashCode()) return -1; 472 if (hashCode() > o.hashCode()) return 1; 473 return 0; 474 } 475 476 /** 477 * Moves an existing temporary file to a new log filename. 478 * @param temp file to rename 479 * @param dir to store file in 480 * @param tag to use for new log file name 481 * @param timestampMillis of log entry 482 * @param flags for the entry data 483 * @param blockSize to use for space accounting 484 * @throws IOException if the file can't be moved 485 */ 486 public EntryFile(File temp, File dir, String tag,long timestampMillis, 487 int flags, int blockSize) throws IOException { 488 if ((flags & DropBoxManager.IS_EMPTY) != 0) throw new IllegalArgumentException(); 489 490 this.tag = tag; 491 this.timestampMillis = timestampMillis; 492 this.flags = flags; 493 this.file = new File(dir, Uri.encode(tag) + "@" + timestampMillis + 494 ((flags & DropBoxManager.IS_TEXT) != 0 ? ".txt" : ".dat") + 495 ((flags & DropBoxManager.IS_GZIPPED) != 0 ? ".gz" : "")); 496 497 if (!temp.renameTo(this.file)) { 498 throw new IOException("Can't rename " + temp + " to " + this.file); 499 } 500 this.blocks = (int) ((this.file.length() + blockSize - 1) / blockSize); 501 } 502 503 /** 504 * Creates a zero-length tombstone for a file whose contents were lost. 505 * @param dir to store file in 506 * @param tag to use for new log file name 507 * @param timestampMillis of log entry 508 * @throws IOException if the file can't be created. 509 */ 510 public EntryFile(File dir, String tag, long timestampMillis) throws IOException { 511 this.tag = tag; 512 this.timestampMillis = timestampMillis; 513 this.flags = DropBoxManager.IS_EMPTY; 514 this.file = new File(dir, Uri.encode(tag) + "@" + timestampMillis + ".lost"); 515 this.blocks = 0; 516 new FileOutputStream(this.file).close(); 517 } 518 519 /** 520 * Extracts metadata from an existing on-disk log filename. 521 * @param file name of existing log file 522 * @param blockSize to use for space accounting 523 */ 524 public EntryFile(File file, int blockSize) { 525 this.file = file; 526 this.blocks = (int) ((this.file.length() + blockSize - 1) / blockSize); 527 528 String name = file.getName(); 529 int at = name.lastIndexOf('@'); 530 if (at < 0) { 531 this.tag = null; 532 this.timestampMillis = 0; 533 this.flags = DropBoxManager.IS_EMPTY; 534 return; 535 } 536 537 int flags = 0; 538 this.tag = Uri.decode(name.substring(0, at)); 539 if (name.endsWith(".gz")) { 540 flags |= DropBoxManager.IS_GZIPPED; 541 name = name.substring(0, name.length() - 3); 542 } 543 if (name.endsWith(".lost")) { 544 flags |= DropBoxManager.IS_EMPTY; 545 name = name.substring(at + 1, name.length() - 5); 546 } else if (name.endsWith(".txt")) { 547 flags |= DropBoxManager.IS_TEXT; 548 name = name.substring(at + 1, name.length() - 4); 549 } else if (name.endsWith(".dat")) { 550 name = name.substring(at + 1, name.length() - 4); 551 } else { 552 this.flags = DropBoxManager.IS_EMPTY; 553 this.timestampMillis = 0; 554 return; 555 } 556 this.flags = flags; 557 558 long millis; 559 try { millis = Long.valueOf(name); } catch (NumberFormatException e) { millis = 0; } 560 this.timestampMillis = millis; 561 } 562 563 /** 564 * Creates a EntryFile object with only a timestamp for comparison purposes. 565 * @param timestampMillis to compare with. 566 */ 567 public EntryFile(long millis) { 568 this.tag = null; 569 this.timestampMillis = millis; 570 this.flags = DropBoxManager.IS_EMPTY; 571 this.file = null; 572 this.blocks = 0; 573 } 574 } 575 576 /////////////////////////////////////////////////////////////////////////// 577 578 /** If never run before, scans disk contents to build in-memory tracking data. */ 579 private synchronized void init() throws IOException { 580 if (mStatFs == null) { 581 if (!mDropBoxDir.isDirectory() && !mDropBoxDir.mkdirs()) { 582 throw new IOException("Can't mkdir: " + mDropBoxDir); 583 } 584 try { 585 mStatFs = new StatFs(mDropBoxDir.getPath()); 586 mBlockSize = mStatFs.getBlockSize(); 587 } catch (IllegalArgumentException e) { // StatFs throws this on error 588 throw new IOException("Can't statfs: " + mDropBoxDir); 589 } 590 } 591 592 if (mAllFiles == null) { 593 File[] files = mDropBoxDir.listFiles(); 594 if (files == null) throw new IOException("Can't list files: " + mDropBoxDir); 595 596 mAllFiles = new FileList(); 597 mFilesByTag = new HashMap<String, FileList>(); 598 599 // Scan pre-existing files. 600 for (File file : files) { 601 if (file.getName().endsWith(".tmp")) { 602 Slog.i(TAG, "Cleaning temp file: " + file); 603 file.delete(); 604 continue; 605 } 606 607 EntryFile entry = new EntryFile(file, mBlockSize); 608 if (entry.tag == null) { 609 Slog.w(TAG, "Unrecognized file: " + file); 610 continue; 611 } else if (entry.timestampMillis == 0) { 612 Slog.w(TAG, "Invalid filename: " + file); 613 file.delete(); 614 continue; 615 } 616 617 enrollEntry(entry); 618 } 619 } 620 } 621 622 /** Adds a disk log file to in-memory tracking for accounting and enumeration. */ 623 private synchronized void enrollEntry(EntryFile entry) { 624 mAllFiles.contents.add(entry); 625 mAllFiles.blocks += entry.blocks; 626 627 // mFilesByTag is used for trimming, so don't list empty files. 628 // (Zero-length/lost files are trimmed by date from mAllFiles.) 629 630 if (entry.tag != null && entry.file != null && entry.blocks > 0) { 631 FileList tagFiles = mFilesByTag.get(entry.tag); 632 if (tagFiles == null) { 633 tagFiles = new FileList(); 634 mFilesByTag.put(entry.tag, tagFiles); 635 } 636 tagFiles.contents.add(entry); 637 tagFiles.blocks += entry.blocks; 638 } 639 } 640 641 /** Moves a temporary file to a final log filename and enrolls it. */ 642 private synchronized long createEntry(File temp, String tag, int flags) throws IOException { 643 long t = System.currentTimeMillis(); 644 645 // Require each entry to have a unique timestamp; if there are entries 646 // >10sec in the future (due to clock skew), drag them back to avoid 647 // keeping them around forever. 648 649 SortedSet<EntryFile> tail = mAllFiles.contents.tailSet(new EntryFile(t + 10000)); 650 EntryFile[] future = null; 651 if (!tail.isEmpty()) { 652 future = tail.toArray(new EntryFile[tail.size()]); 653 tail.clear(); // Remove from mAllFiles 654 } 655 656 if (!mAllFiles.contents.isEmpty()) { 657 t = Math.max(t, mAllFiles.contents.last().timestampMillis + 1); 658 } 659 660 if (future != null) { 661 for (EntryFile late : future) { 662 mAllFiles.blocks -= late.blocks; 663 FileList tagFiles = mFilesByTag.get(late.tag); 664 if (tagFiles != null && tagFiles.contents.remove(late)) { 665 tagFiles.blocks -= late.blocks; 666 } 667 if ((late.flags & DropBoxManager.IS_EMPTY) == 0) { 668 enrollEntry(new EntryFile( 669 late.file, mDropBoxDir, late.tag, t++, late.flags, mBlockSize)); 670 } else { 671 enrollEntry(new EntryFile(mDropBoxDir, late.tag, t++)); 672 } 673 } 674 } 675 676 if (temp == null) { 677 enrollEntry(new EntryFile(mDropBoxDir, tag, t)); 678 } else { 679 enrollEntry(new EntryFile(temp, mDropBoxDir, tag, t, flags, mBlockSize)); 680 } 681 return t; 682 } 683 684 /** 685 * Trims the files on disk to make sure they aren't using too much space. 686 * @return the overall quota for storage (in bytes) 687 */ 688 private synchronized long trimToFit() { 689 // Expunge aged items (including tombstones marking deleted data). 690 691 int ageSeconds = Settings.Secure.getInt(mContentResolver, 692 Settings.Secure.DROPBOX_AGE_SECONDS, DEFAULT_AGE_SECONDS); 693 int maxFiles = Settings.Secure.getInt(mContentResolver, 694 Settings.Secure.DROPBOX_MAX_FILES, DEFAULT_MAX_FILES); 695 long cutoffMillis = System.currentTimeMillis() - ageSeconds * 1000; 696 while (!mAllFiles.contents.isEmpty()) { 697 EntryFile entry = mAllFiles.contents.first(); 698 if (entry.timestampMillis > cutoffMillis && mAllFiles.contents.size() < maxFiles) break; 699 700 FileList tag = mFilesByTag.get(entry.tag); 701 if (tag != null && tag.contents.remove(entry)) tag.blocks -= entry.blocks; 702 if (mAllFiles.contents.remove(entry)) mAllFiles.blocks -= entry.blocks; 703 if (entry.file != null) entry.file.delete(); 704 } 705 706 // Compute overall quota (a fraction of available free space) in blocks. 707 // The quota changes dynamically based on the amount of free space; 708 // that way when lots of data is available we can use it, but we'll get 709 // out of the way if storage starts getting tight. 710 711 long uptimeMillis = SystemClock.uptimeMillis(); 712 if (uptimeMillis > mCachedQuotaUptimeMillis + QUOTA_RESCAN_MILLIS) { 713 int quotaPercent = Settings.Secure.getInt(mContentResolver, 714 Settings.Secure.DROPBOX_QUOTA_PERCENT, DEFAULT_QUOTA_PERCENT); 715 int reservePercent = Settings.Secure.getInt(mContentResolver, 716 Settings.Secure.DROPBOX_RESERVE_PERCENT, DEFAULT_RESERVE_PERCENT); 717 int quotaKb = Settings.Secure.getInt(mContentResolver, 718 Settings.Secure.DROPBOX_QUOTA_KB, DEFAULT_QUOTA_KB); 719 720 mStatFs.restat(mDropBoxDir.getPath()); 721 int available = mStatFs.getAvailableBlocks(); 722 int nonreserved = available - mStatFs.getBlockCount() * reservePercent / 100; 723 int maximum = quotaKb * 1024 / mBlockSize; 724 mCachedQuotaBlocks = Math.min(maximum, Math.max(0, nonreserved * quotaPercent / 100)); 725 mCachedQuotaUptimeMillis = uptimeMillis; 726 } 727 728 // If we're using too much space, delete old items to make room. 729 // 730 // We trim each tag independently (this is why we keep per-tag lists). 731 // Space is "fairly" shared between tags -- they are all squeezed 732 // equally until enough space is reclaimed. 733 // 734 // A single circular buffer (a la logcat) would be simpler, but this 735 // way we can handle fat/bursty data (like 1MB+ bugreports, 300KB+ 736 // kernel crash dumps, and 100KB+ ANR reports) without swamping small, 737 // well-behaved data streams (event statistics, profile data, etc). 738 // 739 // Deleted files are replaced with zero-length tombstones to mark what 740 // was lost. Tombstones are expunged by age (see above). 741 742 if (mAllFiles.blocks > mCachedQuotaBlocks) { 743 // Find a fair share amount of space to limit each tag 744 int unsqueezed = mAllFiles.blocks, squeezed = 0; 745 TreeSet<FileList> tags = new TreeSet<FileList>(mFilesByTag.values()); 746 for (FileList tag : tags) { 747 if (squeezed > 0 && tag.blocks <= (mCachedQuotaBlocks - unsqueezed) / squeezed) { 748 break; 749 } 750 unsqueezed -= tag.blocks; 751 squeezed++; 752 } 753 int tagQuota = (mCachedQuotaBlocks - unsqueezed) / squeezed; 754 755 // Remove old items from each tag until it meets the per-tag quota. 756 for (FileList tag : tags) { 757 if (mAllFiles.blocks < mCachedQuotaBlocks) break; 758 while (tag.blocks > tagQuota && !tag.contents.isEmpty()) { 759 EntryFile entry = tag.contents.first(); 760 if (tag.contents.remove(entry)) tag.blocks -= entry.blocks; 761 if (mAllFiles.contents.remove(entry)) mAllFiles.blocks -= entry.blocks; 762 763 try { 764 if (entry.file != null) entry.file.delete(); 765 enrollEntry(new EntryFile(mDropBoxDir, entry.tag, entry.timestampMillis)); 766 } catch (IOException e) { 767 Slog.e(TAG, "Can't write tombstone file", e); 768 } 769 } 770 } 771 } 772 773 return mCachedQuotaBlocks * mBlockSize; 774 } 775} 776