DropBoxManagerService.java revision 8a9b22056b13477f59df934928c00c58b5871c95
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.Handler; 30import android.os.ParcelFileDescriptor; 31import android.os.StatFs; 32import android.os.SystemClock; 33import android.provider.Settings; 34import android.text.format.Time; 35import android.util.Slog; 36 37import com.android.internal.os.IDropBoxManagerService; 38 39import java.io.File; 40import java.io.FileDescriptor; 41import java.io.FileOutputStream; 42import java.io.IOException; 43import java.io.InputStream; 44import java.io.InputStreamReader; 45import java.io.OutputStream; 46import java.io.OutputStreamWriter; 47import java.io.PrintWriter; 48import java.io.UnsupportedEncodingException; 49import java.util.ArrayList; 50import java.util.Comparator; 51import java.util.HashMap; 52import java.util.Iterator; 53import java.util.Map; 54import java.util.SortedSet; 55import java.util.TreeSet; 56import java.util.zip.GZIPOutputStream; 57 58/** 59 * Implementation of {@link IDropBoxManagerService} using the filesystem. 60 * Clients use {@link DropBoxManager} to access this service. 61 */ 62public final class DropBoxManagerService extends IDropBoxManagerService.Stub { 63 private static final String TAG = "DropBoxManagerService"; 64 private static final int DEFAULT_RESERVE_PERCENT = 10; 65 private static final int DEFAULT_QUOTA_PERCENT = 10; 66 private static final int DEFAULT_QUOTA_KB = 5 * 1024; 67 private static final int DEFAULT_AGE_SECONDS = 3 * 86400; 68 private static final int QUOTA_RESCAN_MILLIS = 5000; 69 70 private static final boolean PROFILE_DUMP = false; 71 72 // TODO: This implementation currently uses one file per entry, which is 73 // inefficient for smallish entries -- consider using a single queue file 74 // per tag (or even globally) instead. 75 76 // The cached context and derived objects 77 78 private final Context mContext; 79 private final ContentResolver mContentResolver; 80 private final File mDropBoxDir; 81 82 // Accounting of all currently written log files (set in init()). 83 84 private FileList mAllFiles = null; 85 private HashMap<String, FileList> mFilesByTag = null; 86 87 // Various bits of disk information 88 89 private StatFs mStatFs = null; 90 private int mBlockSize = 0; 91 private int mCachedQuotaBlocks = 0; // Space we can use: computed from free space, etc. 92 private long mCachedQuotaUptimeMillis = 0; 93 94 // Ensure that all log entries have a unique timestamp 95 private long mLastTimestamp = 0; 96 97 /** Receives events that might indicate a need to clean up files. */ 98 private final BroadcastReceiver mReceiver = new BroadcastReceiver() { 99 @Override 100 public void onReceive(Context context, Intent intent) { 101 mCachedQuotaUptimeMillis = 0; // Force a re-check of quota size 102 try { 103 init(); 104 trimToFit(); 105 } catch (IOException e) { 106 Slog.e(TAG, "Can't init", e); 107 } 108 } 109 }; 110 111 /** 112 * Creates an instance of managed drop box storage. Normally there is one of these 113 * run by the system, but others can be created for testing and other purposes. 114 * 115 * @param context to use for receiving free space & gservices intents 116 * @param path to store drop box entries in 117 */ 118 public DropBoxManagerService(final Context context, File path) { 119 mDropBoxDir = path; 120 121 // Set up intent receivers 122 mContext = context; 123 mContentResolver = context.getContentResolver(); 124 context.registerReceiver(mReceiver, new IntentFilter(Intent.ACTION_DEVICE_STORAGE_LOW)); 125 126 mContentResolver.registerContentObserver( 127 Settings.Secure.CONTENT_URI, true, 128 new ContentObserver(new Handler()) { 129 public void onChange(boolean selfChange) { 130 mReceiver.onReceive(context, (Intent) null); 131 } 132 }); 133 134 // The real work gets done lazily in init() -- that way service creation always 135 // succeeds, and things like disk problems cause individual method failures. 136 } 137 138 /** Unregisters broadcast receivers and any other hooks -- for test instances */ 139 public void stop() { 140 mContext.unregisterReceiver(mReceiver); 141 } 142 143 public void add(DropBoxManager.Entry entry) { 144 File temp = null; 145 OutputStream output = null; 146 final String tag = entry.getTag(); 147 try { 148 int flags = entry.getFlags(); 149 if ((flags & DropBoxManager.IS_EMPTY) != 0) throw new IllegalArgumentException(); 150 151 init(); 152 if (!isTagEnabled(tag)) return; 153 long max = trimToFit(); 154 long lastTrim = System.currentTimeMillis(); 155 156 byte[] buffer = new byte[mBlockSize]; 157 InputStream input = entry.getInputStream(); 158 159 // First, accumulate up to one block worth of data in memory before 160 // deciding whether to compress the data or not. 161 162 int read = 0; 163 while (read < buffer.length) { 164 int n = input.read(buffer, read, buffer.length - read); 165 if (n <= 0) break; 166 read += n; 167 } 168 169 // If we have at least one block, compress it -- otherwise, just write 170 // the data in uncompressed form. 171 172 temp = new File(mDropBoxDir, "drop" + Thread.currentThread().getId() + ".tmp"); 173 output = new FileOutputStream(temp); 174 if (read == buffer.length && ((flags & DropBoxManager.IS_GZIPPED) == 0)) { 175 output = new GZIPOutputStream(output); 176 flags = flags | DropBoxManager.IS_GZIPPED; 177 } 178 179 do { 180 output.write(buffer, 0, read); 181 182 long now = System.currentTimeMillis(); 183 if (now - lastTrim > 30 * 1000) { 184 max = trimToFit(); // In case data dribbles in slowly 185 lastTrim = now; 186 } 187 188 read = input.read(buffer); 189 if (read <= 0) { 190 output.close(); // Get a final size measurement 191 output = null; 192 } else { 193 output.flush(); // So the size measurement is pseudo-reasonable 194 } 195 196 long len = temp.length(); 197 if (len > max) { 198 Slog.w(TAG, "Dropping: " + tag + " (" + temp.length() + " > " + max + " bytes)"); 199 temp.delete(); 200 temp = null; // Pass temp = null to createEntry() to leave a tombstone 201 break; 202 } 203 } while (read > 0); 204 205 createEntry(temp, tag, flags); 206 temp = null; 207 } catch (IOException e) { 208 Slog.e(TAG, "Can't write: " + tag, e); 209 } finally { 210 try { if (output != null) output.close(); } catch (IOException e) {} 211 entry.close(); 212 if (temp != null) temp.delete(); 213 } 214 } 215 216 public boolean isTagEnabled(String tag) { 217 return !"disabled".equals(Settings.Secure.getString( 218 mContentResolver, Settings.Secure.DROPBOX_TAG_PREFIX + tag)); 219 } 220 221 public synchronized DropBoxManager.Entry getNextEntry(String tag, long millis) { 222 if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.READ_LOGS) 223 != PackageManager.PERMISSION_GRANTED) { 224 throw new SecurityException("READ_LOGS permission required"); 225 } 226 227 try { 228 init(); 229 } catch (IOException e) { 230 Slog.e(TAG, "Can't init", e); 231 return null; 232 } 233 234 FileList list = tag == null ? mAllFiles : mFilesByTag.get(tag); 235 if (list == null) return null; 236 237 for (EntryFile entry : list.contents.tailSet(new EntryFile(millis + 1))) { 238 if (entry.tag == null) continue; 239 if ((entry.flags & DropBoxManager.IS_EMPTY) != 0) { 240 return new DropBoxManager.Entry(entry.tag, entry.timestampMillis); 241 } 242 try { 243 return new DropBoxManager.Entry( 244 entry.tag, entry.timestampMillis, entry.file, entry.flags); 245 } catch (IOException e) { 246 Slog.e(TAG, "Can't read: " + entry.file, e); 247 // Continue to next file 248 } 249 } 250 251 return null; 252 } 253 254 public synchronized void dump(FileDescriptor fd, PrintWriter pw, String[] args) { 255 if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.DUMP) 256 != PackageManager.PERMISSION_GRANTED) { 257 pw.println("Permission Denial: Can't dump DropBoxManagerService"); 258 return; 259 } 260 261 try { 262 init(); 263 } catch (IOException e) { 264 pw.println("Can't initialize: " + e); 265 Slog.e(TAG, "Can't init", e); 266 return; 267 } 268 269 if (PROFILE_DUMP) Debug.startMethodTracing("/data/trace/dropbox.dump"); 270 271 StringBuilder out = new StringBuilder(); 272 boolean doPrint = false, doFile = false; 273 ArrayList<String> searchArgs = new ArrayList<String>(); 274 for (int i = 0; args != null && i < args.length; i++) { 275 if (args[i].equals("-p") || args[i].equals("--print")) { 276 doPrint = true; 277 } else if (args[i].equals("-f") || args[i].equals("--file")) { 278 doFile = true; 279 } else if (args[i].startsWith("-")) { 280 out.append("Unknown argument: ").append(args[i]).append("\n"); 281 } else { 282 searchArgs.add(args[i]); 283 } 284 } 285 286 out.append("Drop box contents: ").append(mAllFiles.contents.size()).append(" entries\n"); 287 288 if (!searchArgs.isEmpty()) { 289 out.append("Searching for:"); 290 for (String a : searchArgs) out.append(" ").append(a); 291 out.append("\n"); 292 } 293 294 int numFound = 0, numArgs = searchArgs.size(); 295 Time time = new Time(); 296 out.append("\n"); 297 for (EntryFile entry : mAllFiles.contents) { 298 time.set(entry.timestampMillis); 299 String date = time.format("%Y-%m-%d %H:%M:%S"); 300 boolean match = true; 301 for (int i = 0; i < numArgs && match; i++) { 302 String arg = searchArgs.get(i); 303 match = (date.contains(arg) || arg.equals(entry.tag)); 304 } 305 if (!match) continue; 306 307 numFound++; 308 if (doPrint) out.append("========================================\n"); 309 out.append(date).append(" ").append(entry.tag == null ? "(no tag)" : entry.tag); 310 if (entry.file == null) { 311 out.append(" (no file)\n"); 312 continue; 313 } else if ((entry.flags & DropBoxManager.IS_EMPTY) != 0) { 314 out.append(" (contents lost)\n"); 315 continue; 316 } else { 317 out.append(" ("); 318 if ((entry.flags & DropBoxManager.IS_GZIPPED) != 0) out.append("compressed "); 319 out.append((entry.flags & DropBoxManager.IS_TEXT) != 0 ? "text" : "data"); 320 out.append(", ").append(entry.file.length()).append(" bytes)\n"); 321 } 322 323 if (doFile || (doPrint && (entry.flags & DropBoxManager.IS_TEXT) == 0)) { 324 if (!doPrint) out.append(" "); 325 out.append(entry.file.getPath()).append("\n"); 326 } 327 328 if ((entry.flags & DropBoxManager.IS_TEXT) != 0 && (doPrint || !doFile)) { 329 DropBoxManager.Entry dbe = null; 330 try { 331 dbe = new DropBoxManager.Entry( 332 entry.tag, entry.timestampMillis, entry.file, entry.flags); 333 334 if (doPrint) { 335 InputStreamReader r = new InputStreamReader(dbe.getInputStream()); 336 char[] buf = new char[4096]; 337 boolean newline = false; 338 for (;;) { 339 int n = r.read(buf); 340 if (n <= 0) break; 341 out.append(buf, 0, n); 342 newline = (buf[n - 1] == '\n'); 343 344 // Flush periodically when printing to avoid out-of-memory. 345 if (out.length() > 65536) { 346 pw.write(out.toString()); 347 out.setLength(0); 348 } 349 } 350 if (!newline) out.append("\n"); 351 } else { 352 String text = dbe.getText(70); 353 boolean truncated = (text.length() == 70); 354 out.append(" ").append(text.trim().replace('\n', '/')); 355 if (truncated) out.append(" ..."); 356 out.append("\n"); 357 } 358 } catch (IOException e) { 359 out.append("*** ").append(e.toString()).append("\n"); 360 Slog.e(TAG, "Can't read: " + entry.file, e); 361 } finally { 362 if (dbe != null) dbe.close(); 363 } 364 } 365 366 if (doPrint) out.append("\n"); 367 } 368 369 if (numFound == 0) out.append("(No entries found.)\n"); 370 371 if (args == null || args.length == 0) { 372 if (!doPrint) out.append("\n"); 373 out.append("Usage: dumpsys dropbox [--print|--file] [YYYY-mm-dd] [HH:MM:SS] [tag]\n"); 374 } 375 376 pw.write(out.toString()); 377 if (PROFILE_DUMP) Debug.stopMethodTracing(); 378 } 379 380 /////////////////////////////////////////////////////////////////////////// 381 382 /** Chronologically sorted list of {@link #EntryFile} */ 383 private static final class FileList implements Comparable<FileList> { 384 public int blocks = 0; 385 public final TreeSet<EntryFile> contents = new TreeSet<EntryFile>(); 386 387 /** Sorts bigger FileList instances before smaller ones. */ 388 public final int compareTo(FileList o) { 389 if (blocks != o.blocks) return o.blocks - blocks; 390 if (this == o) return 0; 391 if (hashCode() < o.hashCode()) return -1; 392 if (hashCode() > o.hashCode()) return 1; 393 return 0; 394 } 395 } 396 397 /** Metadata describing an on-disk log file. */ 398 private static final class EntryFile implements Comparable<EntryFile> { 399 public final String tag; 400 public final long timestampMillis; 401 public final int flags; 402 public final File file; 403 public final int blocks; 404 405 /** Sorts earlier EntryFile instances before later ones. */ 406 public final int compareTo(EntryFile o) { 407 if (timestampMillis < o.timestampMillis) return -1; 408 if (timestampMillis > o.timestampMillis) return 1; 409 if (file != null && o.file != null) return file.compareTo(o.file); 410 if (o.file != null) return -1; 411 if (file != null) return 1; 412 if (this == o) return 0; 413 if (hashCode() < o.hashCode()) return -1; 414 if (hashCode() > o.hashCode()) return 1; 415 return 0; 416 } 417 418 /** 419 * Moves an existing temporary file to a new log filename. 420 * @param temp file to rename 421 * @param dir to store file in 422 * @param tag to use for new log file name 423 * @param timestampMillis of log entry 424 * @param flags for the entry data 425 * @param blockSize to use for space accounting 426 * @throws IOException if the file can't be moved 427 */ 428 public EntryFile(File temp, File dir, String tag,long timestampMillis, 429 int flags, int blockSize) throws IOException { 430 if ((flags & DropBoxManager.IS_EMPTY) != 0) throw new IllegalArgumentException(); 431 432 this.tag = tag; 433 this.timestampMillis = timestampMillis; 434 this.flags = flags; 435 this.file = new File(dir, Uri.encode(tag) + "@" + timestampMillis + 436 ((flags & DropBoxManager.IS_TEXT) != 0 ? ".txt" : ".dat") + 437 ((flags & DropBoxManager.IS_GZIPPED) != 0 ? ".gz" : "")); 438 439 if (!temp.renameTo(this.file)) { 440 throw new IOException("Can't rename " + temp + " to " + this.file); 441 } 442 this.blocks = (int) ((this.file.length() + blockSize - 1) / blockSize); 443 } 444 445 /** 446 * Creates a zero-length tombstone for a file whose contents were lost. 447 * @param dir to store file in 448 * @param tag to use for new log file name 449 * @param timestampMillis of log entry 450 * @throws IOException if the file can't be created. 451 */ 452 public EntryFile(File dir, String tag, long timestampMillis) throws IOException { 453 this.tag = tag; 454 this.timestampMillis = timestampMillis; 455 this.flags = DropBoxManager.IS_EMPTY; 456 this.file = new File(dir, Uri.encode(tag) + "@" + timestampMillis + ".lost"); 457 this.blocks = 0; 458 new FileOutputStream(this.file).close(); 459 } 460 461 /** 462 * Extracts metadata from an existing on-disk log filename. 463 * @param file name of existing log file 464 * @param blockSize to use for space accounting 465 */ 466 public EntryFile(File file, int blockSize) { 467 this.file = file; 468 this.blocks = (int) ((this.file.length() + blockSize - 1) / blockSize); 469 470 String name = file.getName(); 471 int at = name.lastIndexOf('@'); 472 if (at < 0) { 473 this.tag = null; 474 this.timestampMillis = 0; 475 this.flags = DropBoxManager.IS_EMPTY; 476 return; 477 } 478 479 int flags = 0; 480 this.tag = Uri.decode(name.substring(0, at)); 481 if (name.endsWith(".gz")) { 482 flags |= DropBoxManager.IS_GZIPPED; 483 name = name.substring(0, name.length() - 3); 484 } 485 if (name.endsWith(".lost")) { 486 flags |= DropBoxManager.IS_EMPTY; 487 name = name.substring(at + 1, name.length() - 5); 488 } else if (name.endsWith(".txt")) { 489 flags |= DropBoxManager.IS_TEXT; 490 name = name.substring(at + 1, name.length() - 4); 491 } else if (name.endsWith(".dat")) { 492 name = name.substring(at + 1, name.length() - 4); 493 } else { 494 this.flags = DropBoxManager.IS_EMPTY; 495 this.timestampMillis = 0; 496 return; 497 } 498 this.flags = flags; 499 500 long millis; 501 try { millis = Long.valueOf(name); } catch (NumberFormatException e) { millis = 0; } 502 this.timestampMillis = millis; 503 } 504 505 /** 506 * Creates a EntryFile object with only a timestamp for comparison purposes. 507 * @param timestampMillis to compare with. 508 */ 509 public EntryFile(long millis) { 510 this.tag = null; 511 this.timestampMillis = millis; 512 this.flags = DropBoxManager.IS_EMPTY; 513 this.file = null; 514 this.blocks = 0; 515 } 516 } 517 518 /////////////////////////////////////////////////////////////////////////// 519 520 /** If never run before, scans disk contents to build in-memory tracking data. */ 521 private synchronized void init() throws IOException { 522 if (mStatFs == null) { 523 if (!mDropBoxDir.isDirectory() && !mDropBoxDir.mkdirs()) { 524 throw new IOException("Can't mkdir: " + mDropBoxDir); 525 } 526 try { 527 mStatFs = new StatFs(mDropBoxDir.getPath()); 528 mBlockSize = mStatFs.getBlockSize(); 529 } catch (IllegalArgumentException e) { // StatFs throws this on error 530 throw new IOException("Can't statfs: " + mDropBoxDir); 531 } 532 } 533 534 if (mAllFiles == null) { 535 File[] files = mDropBoxDir.listFiles(); 536 if (files == null) throw new IOException("Can't list files: " + mDropBoxDir); 537 538 mAllFiles = new FileList(); 539 mFilesByTag = new HashMap<String, FileList>(); 540 541 // Scan pre-existing files. 542 for (File file : files) { 543 if (file.getName().endsWith(".tmp")) { 544 Slog.i(TAG, "Cleaning temp file: " + file); 545 file.delete(); 546 continue; 547 } 548 549 EntryFile entry = new EntryFile(file, mBlockSize); 550 if (entry.tag == null) { 551 Slog.w(TAG, "Unrecognized file: " + file); 552 continue; 553 } else if (entry.timestampMillis == 0) { 554 Slog.w(TAG, "Invalid filename: " + file); 555 file.delete(); 556 continue; 557 } 558 559 enrollEntry(entry); 560 } 561 } 562 } 563 564 /** Adds a disk log file to in-memory tracking for accounting and enumeration. */ 565 private synchronized void enrollEntry(EntryFile entry) { 566 mAllFiles.contents.add(entry); 567 mAllFiles.blocks += entry.blocks; 568 569 // mFilesByTag is used for trimming, so don't list empty files. 570 // (Zero-length/lost files are trimmed by date from mAllFiles.) 571 572 if (entry.tag != null && entry.file != null && entry.blocks > 0) { 573 FileList tagFiles = mFilesByTag.get(entry.tag); 574 if (tagFiles == null) { 575 tagFiles = new FileList(); 576 mFilesByTag.put(entry.tag, tagFiles); 577 } 578 tagFiles.contents.add(entry); 579 tagFiles.blocks += entry.blocks; 580 } 581 } 582 583 /** Moves a temporary file to a final log filename and enrolls it. */ 584 private synchronized void createEntry(File temp, String tag, int flags) throws IOException { 585 long t = System.currentTimeMillis(); 586 587 // Require each entry to have a unique timestamp; if there are entries 588 // >10sec in the future (due to clock skew), drag them back to avoid 589 // keeping them around forever. 590 591 SortedSet<EntryFile> tail = mAllFiles.contents.tailSet(new EntryFile(t + 10000)); 592 EntryFile[] future = null; 593 if (!tail.isEmpty()) { 594 future = tail.toArray(new EntryFile[tail.size()]); 595 tail.clear(); // Remove from mAllFiles 596 } 597 598 if (!mAllFiles.contents.isEmpty()) { 599 t = Math.max(t, mAllFiles.contents.last().timestampMillis + 1); 600 } 601 602 if (future != null) { 603 for (EntryFile late : future) { 604 mAllFiles.blocks -= late.blocks; 605 FileList tagFiles = mFilesByTag.get(late.tag); 606 if (tagFiles.contents.remove(late)) tagFiles.blocks -= late.blocks; 607 if ((late.flags & DropBoxManager.IS_EMPTY) == 0) { 608 enrollEntry(new EntryFile( 609 late.file, mDropBoxDir, late.tag, t++, late.flags, mBlockSize)); 610 } else { 611 enrollEntry(new EntryFile(mDropBoxDir, late.tag, t++)); 612 } 613 } 614 } 615 616 if (temp == null) { 617 enrollEntry(new EntryFile(mDropBoxDir, tag, t)); 618 } else { 619 enrollEntry(new EntryFile(temp, mDropBoxDir, tag, t, flags, mBlockSize)); 620 } 621 } 622 623 /** 624 * Trims the files on disk to make sure they aren't using too much space. 625 * @return the overall quota for storage (in bytes) 626 */ 627 private synchronized long trimToFit() { 628 // Expunge aged items (including tombstones marking deleted data). 629 630 int ageSeconds = Settings.Secure.getInt(mContentResolver, 631 Settings.Secure.DROPBOX_AGE_SECONDS, DEFAULT_AGE_SECONDS); 632 long cutoffMillis = System.currentTimeMillis() - ageSeconds * 1000; 633 while (!mAllFiles.contents.isEmpty()) { 634 EntryFile entry = mAllFiles.contents.first(); 635 if (entry.timestampMillis > cutoffMillis) break; 636 637 FileList tag = mFilesByTag.get(entry.tag); 638 if (tag != null && tag.contents.remove(entry)) tag.blocks -= entry.blocks; 639 if (mAllFiles.contents.remove(entry)) mAllFiles.blocks -= entry.blocks; 640 if (entry.file != null) entry.file.delete(); 641 } 642 643 // Compute overall quota (a fraction of available free space) in blocks. 644 // The quota changes dynamically based on the amount of free space; 645 // that way when lots of data is available we can use it, but we'll get 646 // out of the way if storage starts getting tight. 647 648 long uptimeMillis = SystemClock.uptimeMillis(); 649 if (uptimeMillis > mCachedQuotaUptimeMillis + QUOTA_RESCAN_MILLIS) { 650 int quotaPercent = Settings.Secure.getInt(mContentResolver, 651 Settings.Secure.DROPBOX_QUOTA_PERCENT, DEFAULT_QUOTA_PERCENT); 652 int reservePercent = Settings.Secure.getInt(mContentResolver, 653 Settings.Secure.DROPBOX_RESERVE_PERCENT, DEFAULT_RESERVE_PERCENT); 654 int quotaKb = Settings.Secure.getInt(mContentResolver, 655 Settings.Secure.DROPBOX_QUOTA_KB, DEFAULT_QUOTA_KB); 656 657 mStatFs.restat(mDropBoxDir.getPath()); 658 int available = mStatFs.getAvailableBlocks(); 659 int nonreserved = available - mStatFs.getBlockCount() * reservePercent / 100; 660 int maximum = quotaKb * 1024 / mBlockSize; 661 mCachedQuotaBlocks = Math.min(maximum, Math.max(0, nonreserved * quotaPercent / 100)); 662 mCachedQuotaUptimeMillis = uptimeMillis; 663 } 664 665 // If we're using too much space, delete old items to make room. 666 // 667 // We trim each tag independently (this is why we keep per-tag lists). 668 // Space is "fairly" shared between tags -- they are all squeezed 669 // equally until enough space is reclaimed. 670 // 671 // A single circular buffer (a la logcat) would be simpler, but this 672 // way we can handle fat/bursty data (like 1MB+ bugreports, 300KB+ 673 // kernel crash dumps, and 100KB+ ANR reports) without swamping small, 674 // well-behaved data // streams (event statistics, profile data, etc). 675 // 676 // Deleted files are replaced with zero-length tombstones to mark what 677 // was lost. Tombstones are expunged by age (see above). 678 679 if (mAllFiles.blocks > mCachedQuotaBlocks) { 680 Slog.i(TAG, "Usage (" + mAllFiles.blocks + ") > Quota (" + mCachedQuotaBlocks + ")"); 681 682 // Find a fair share amount of space to limit each tag 683 int unsqueezed = mAllFiles.blocks, squeezed = 0; 684 TreeSet<FileList> tags = new TreeSet<FileList>(mFilesByTag.values()); 685 for (FileList tag : tags) { 686 if (squeezed > 0 && tag.blocks <= (mCachedQuotaBlocks - unsqueezed) / squeezed) { 687 break; 688 } 689 unsqueezed -= tag.blocks; 690 squeezed++; 691 } 692 int tagQuota = (mCachedQuotaBlocks - unsqueezed) / squeezed; 693 694 // Remove old items from each tag until it meets the per-tag quota. 695 for (FileList tag : tags) { 696 if (mAllFiles.blocks < mCachedQuotaBlocks) break; 697 while (tag.blocks > tagQuota && !tag.contents.isEmpty()) { 698 EntryFile entry = tag.contents.first(); 699 if (tag.contents.remove(entry)) tag.blocks -= entry.blocks; 700 if (mAllFiles.contents.remove(entry)) mAllFiles.blocks -= entry.blocks; 701 702 try { 703 if (entry.file != null) entry.file.delete(); 704 enrollEntry(new EntryFile(mDropBoxDir, entry.tag, entry.timestampMillis)); 705 } catch (IOException e) { 706 Slog.e(TAG, "Can't write tombstone file", e); 707 } 708 } 709 } 710 } 711 712 return mCachedQuotaBlocks * mBlockSize; 713 } 714} 715