DropBoxManagerService.java revision 5ec249abe376898d3249e978b44fd2ee0cc8c573
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.net.Uri; 26import android.os.Debug; 27import android.os.DropBoxManager; 28import android.os.ParcelFileDescriptor; 29import android.os.StatFs; 30import android.os.SystemClock; 31import android.provider.Settings; 32import android.text.format.Time; 33import android.util.Log; 34 35import com.android.internal.os.IDropBoxManagerService; 36 37import java.io.File; 38import java.io.FileDescriptor; 39import java.io.FileOutputStream; 40import java.io.IOException; 41import java.io.InputStream; 42import java.io.InputStreamReader; 43import java.io.OutputStream; 44import java.io.OutputStreamWriter; 45import java.io.PrintWriter; 46import java.io.UnsupportedEncodingException; 47import java.util.ArrayList; 48import java.util.Comparator; 49import java.util.HashMap; 50import java.util.Iterator; 51import java.util.Map; 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_RESERVE_PERCENT = 10; 63 private static final int DEFAULT_QUOTA_PERCENT = 10; 64 private static final int DEFAULT_QUOTA_KB = 5 * 1024; 65 private static final int DEFAULT_AGE_SECONDS = 3 * 86400; 66 private static final int QUOTA_RESCAN_MILLIS = 5000; 67 68 private static final boolean PROFILE_DUMP = false; 69 70 // TODO: This implementation currently uses one file per entry, which is 71 // inefficient for smallish entries -- consider using a single queue file 72 // per tag (or even globally) instead. 73 74 // The cached context and derived objects 75 76 private final Context mContext; 77 private final ContentResolver mContentResolver; 78 private final File mDropBoxDir; 79 80 // Accounting of all currently written log files (set in init()). 81 82 private FileList mAllFiles = null; 83 private HashMap<String, FileList> mFilesByTag = null; 84 85 // Various bits of disk information 86 87 private StatFs mStatFs = null; 88 private int mBlockSize = 0; 89 private int mCachedQuotaBlocks = 0; // Space we can use: computed from free space, etc. 90 private long mCachedQuotaUptimeMillis = 0; 91 92 // Ensure that all log entries have a unique timestamp 93 private long mLastTimestamp = 0; 94 95 /** Receives events that might indicate a need to clean up files. */ 96 private final BroadcastReceiver mReceiver = new BroadcastReceiver() { 97 @Override 98 public void onReceive(Context context, Intent intent) { 99 mCachedQuotaUptimeMillis = 0; // Force a re-check of quota size 100 try { 101 init(); 102 trimToFit(); 103 } catch (IOException e) { 104 Log.e(TAG, "Can't init", e); 105 } 106 } 107 }; 108 109 /** 110 * Creates an instance of managed drop box storage. Normally there is one of these 111 * run by the system, but others can be created for testing and other purposes. 112 * 113 * @param context to use for receiving free space & gservices intents 114 * @param path to store drop box entries in 115 */ 116 public DropBoxManagerService(Context context, File path) { 117 mDropBoxDir = path; 118 119 // Set up intent receivers 120 mContext = context; 121 mContentResolver = context.getContentResolver(); 122 context.registerReceiver(mReceiver, new IntentFilter(Intent.ACTION_DEVICE_STORAGE_LOW)); 123 context.registerReceiver(mReceiver, new IntentFilter(Settings.Gservices.CHANGED_ACTION)); 124 125 // The real work gets done lazily in init() -- that way service creation always 126 // succeeds, and things like disk problems cause individual method failures. 127 } 128 129 /** Unregisters broadcast receivers and any other hooks -- for test instances */ 130 public void stop() { 131 mContext.unregisterReceiver(mReceiver); 132 } 133 134 public void add(DropBoxManager.Entry entry) { 135 File temp = null; 136 OutputStream output = null; 137 final String tag = entry.getTag(); 138 try { 139 int flags = entry.getFlags(); 140 if ((flags & DropBoxManager.IS_EMPTY) != 0) throw new IllegalArgumentException(); 141 142 init(); 143 if (!isTagEnabled(tag)) return; 144 long max = trimToFit(); 145 long lastTrim = System.currentTimeMillis(); 146 147 byte[] buffer = new byte[mBlockSize]; 148 InputStream input = entry.getInputStream(); 149 150 // First, accumulate up to one block worth of data in memory before 151 // deciding whether to compress the data or not. 152 153 int read = 0; 154 while (read < buffer.length) { 155 int n = input.read(buffer, read, buffer.length - read); 156 if (n <= 0) break; 157 read += n; 158 } 159 160 // If we have at least one block, compress it -- otherwise, just write 161 // the data in uncompressed form. 162 163 temp = new File(mDropBoxDir, "drop" + Thread.currentThread().getId() + ".tmp"); 164 output = new FileOutputStream(temp); 165 if (read == buffer.length && ((flags & DropBoxManager.IS_GZIPPED) == 0)) { 166 output = new GZIPOutputStream(output); 167 flags = flags | DropBoxManager.IS_GZIPPED; 168 } 169 170 do { 171 output.write(buffer, 0, read); 172 173 long now = System.currentTimeMillis(); 174 if (now - lastTrim > 30 * 1000) { 175 max = trimToFit(); // In case data dribbles in slowly 176 lastTrim = now; 177 } 178 179 read = input.read(buffer); 180 if (read <= 0) { 181 output.close(); // Get a final size measurement 182 output = null; 183 } else { 184 output.flush(); // So the size measurement is pseudo-reasonable 185 } 186 187 long len = temp.length(); 188 if (len > max) { 189 Log.w(TAG, "Dropping: " + tag + " (" + temp.length() + " > " + max + " bytes)"); 190 temp.delete(); 191 temp = null; // Pass temp = null to createEntry() to leave a tombstone 192 break; 193 } 194 } while (read > 0); 195 196 createEntry(temp, tag, flags); 197 temp = null; 198 } catch (IOException e) { 199 Log.e(TAG, "Can't write: " + tag, e); 200 } finally { 201 try { if (output != null) output.close(); } catch (IOException e) {} 202 entry.close(); 203 if (temp != null) temp.delete(); 204 } 205 } 206 207 public boolean isTagEnabled(String tag) { 208 return !"disabled".equals(Settings.Gservices.getString( 209 mContentResolver, Settings.Gservices.DROPBOX_TAG_PREFIX + tag)); 210 } 211 212 public synchronized DropBoxManager.Entry getNextEntry(String tag, long millis) { 213 if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.READ_LOGS) 214 != PackageManager.PERMISSION_GRANTED) { 215 throw new SecurityException("READ_LOGS permission required"); 216 } 217 218 try { 219 init(); 220 } catch (IOException e) { 221 Log.e(TAG, "Can't init", e); 222 return null; 223 } 224 225 FileList list = tag == null ? mAllFiles : mFilesByTag.get(tag); 226 if (list == null) return null; 227 228 for (EntryFile entry : list.contents.tailSet(new EntryFile(millis + 1))) { 229 if (entry.tag == null) continue; 230 if ((entry.flags & DropBoxManager.IS_EMPTY) != 0) { 231 return new DropBoxManager.Entry(entry.tag, entry.timestampMillis); 232 } 233 try { 234 return new DropBoxManager.Entry( 235 entry.tag, entry.timestampMillis, entry.file, entry.flags); 236 } catch (IOException e) { 237 Log.e(TAG, "Can't read: " + entry.file, e); 238 // Continue to next file 239 } 240 } 241 242 return null; 243 } 244 245 public synchronized void dump(FileDescriptor fd, PrintWriter pw, String[] args) { 246 if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.DUMP) 247 != PackageManager.PERMISSION_GRANTED) { 248 pw.println("Permission Denial: Can't dump DropBoxManagerService"); 249 return; 250 } 251 252 try { 253 init(); 254 } catch (IOException e) { 255 pw.println("Can't initialize: " + e); 256 Log.e(TAG, "Can't init", e); 257 return; 258 } 259 260 if (PROFILE_DUMP) Debug.startMethodTracing("/data/trace/dropbox.dump"); 261 262 StringBuilder out = new StringBuilder(); 263 boolean doPrint = false, doFile = false; 264 ArrayList<String> searchArgs = new ArrayList<String>(); 265 for (int i = 0; args != null && i < args.length; i++) { 266 if (args[i].equals("-p") || args[i].equals("--print")) { 267 doPrint = true; 268 } else if (args[i].equals("-f") || args[i].equals("--file")) { 269 doFile = true; 270 } else if (args[i].startsWith("-")) { 271 out.append("Unknown argument: ").append(args[i]).append("\n"); 272 } else { 273 searchArgs.add(args[i]); 274 } 275 } 276 277 out.append("Drop box contents: ").append(mAllFiles.contents.size()).append(" entries\n"); 278 279 if (!searchArgs.isEmpty()) { 280 out.append("Searching for:"); 281 for (String a : searchArgs) out.append(" ").append(a); 282 out.append("\n"); 283 } 284 285 int numFound = 0, numArgs = searchArgs.size(); 286 Time time = new Time(); 287 out.append("\n"); 288 for (EntryFile entry : mAllFiles.contents) { 289 time.set(entry.timestampMillis); 290 String date = time.format("%Y-%m-%d %H:%M:%S"); 291 boolean match = true; 292 for (int i = 0; i < numArgs && match; i++) { 293 String arg = searchArgs.get(i); 294 match = (date.contains(arg) || arg.equals(entry.tag)); 295 } 296 if (!match) continue; 297 298 numFound++; 299 out.append(date).append(" ").append(entry.tag == null ? "(no tag)" : entry.tag); 300 if (entry.file == null) { 301 out.append(" (no file)\n"); 302 continue; 303 } else if ((entry.flags & DropBoxManager.IS_EMPTY) != 0) { 304 out.append(" (contents lost)\n"); 305 continue; 306 } else { 307 out.append(" ("); 308 if ((entry.flags & DropBoxManager.IS_GZIPPED) != 0) out.append("compressed "); 309 out.append((entry.flags & DropBoxManager.IS_TEXT) != 0 ? "text" : "data"); 310 out.append(", ").append(entry.file.length()).append(" bytes)\n"); 311 } 312 313 if (doFile || (doPrint && (entry.flags & DropBoxManager.IS_TEXT) == 0)) { 314 if (!doPrint) out.append(" "); 315 out.append(entry.file.getPath()).append("\n"); 316 } 317 318 if ((entry.flags & DropBoxManager.IS_TEXT) != 0 && (doPrint || !doFile)) { 319 DropBoxManager.Entry dbe = null; 320 try { 321 dbe = new DropBoxManager.Entry( 322 entry.tag, entry.timestampMillis, entry.file, entry.flags); 323 324 if (doPrint) { 325 InputStreamReader r = new InputStreamReader(dbe.getInputStream()); 326 char[] buf = new char[4096]; 327 boolean newline = false; 328 for (;;) { 329 int n = r.read(buf); 330 if (n <= 0) break; 331 out.append(buf, 0, n); 332 newline = (buf[n - 1] == '\n'); 333 } 334 if (!newline) out.append("\n"); 335 } else { 336 String text = dbe.getText(70); 337 boolean truncated = (text.length() == 70); 338 out.append(" ").append(text.trim().replace('\n', '/')); 339 if (truncated) out.append(" ..."); 340 out.append("\n"); 341 } 342 } catch (IOException e) { 343 out.append("*** ").append(e.toString()).append("\n"); 344 Log.e(TAG, "Can't read: " + entry.file, e); 345 } finally { 346 if (dbe != null) dbe.close(); 347 } 348 } 349 350 if (doPrint) out.append("\n"); 351 } 352 353 if (numFound == 0) out.append("(No entries found.)\n"); 354 355 if (args == null || args.length == 0) { 356 if (!doPrint) out.append("\n"); 357 out.append("Usage: dumpsys dropbox [--print|--file] [YYYY-mm-dd] [HH:MM:SS] [tag]\n"); 358 } 359 360 pw.write(out.toString()); 361 if (PROFILE_DUMP) Debug.stopMethodTracing(); 362 } 363 364 /////////////////////////////////////////////////////////////////////////// 365 366 /** Chronologically sorted list of {@link #EntryFile} */ 367 private static final class FileList implements Comparable<FileList> { 368 public int blocks = 0; 369 public final TreeSet<EntryFile> contents = new TreeSet<EntryFile>(); 370 371 /** Sorts bigger FileList instances before smaller ones. */ 372 public final int compareTo(FileList o) { 373 if (blocks != o.blocks) return o.blocks - blocks; 374 if (this == o) return 0; 375 if (hashCode() < o.hashCode()) return -1; 376 if (hashCode() > o.hashCode()) return 1; 377 return 0; 378 } 379 } 380 381 /** Metadata describing an on-disk log file. */ 382 private static final class EntryFile implements Comparable<EntryFile> { 383 public final String tag; 384 public final long timestampMillis; 385 public final int flags; 386 public final File file; 387 public final int blocks; 388 389 /** Sorts earlier EntryFile instances before later ones. */ 390 public final int compareTo(EntryFile o) { 391 if (timestampMillis < o.timestampMillis) return -1; 392 if (timestampMillis > o.timestampMillis) return 1; 393 if (file != null && o.file != null) return file.compareTo(o.file); 394 if (o.file != null) return -1; 395 if (file != null) return 1; 396 if (this == o) return 0; 397 if (hashCode() < o.hashCode()) return -1; 398 if (hashCode() > o.hashCode()) return 1; 399 return 0; 400 } 401 402 /** 403 * Moves an existing temporary file to a new log filename. 404 * @param temp file to rename 405 * @param dir to store file in 406 * @param tag to use for new log file name 407 * @param timestampMillis of log entry 408 * @param flags for the entry data 409 * @param blockSize to use for space accounting 410 * @throws IOException if the file can't be moved 411 */ 412 public EntryFile(File temp, File dir, String tag,long timestampMillis, 413 int flags, int blockSize) throws IOException { 414 if ((flags & DropBoxManager.IS_EMPTY) != 0) throw new IllegalArgumentException(); 415 416 this.tag = tag; 417 this.timestampMillis = timestampMillis; 418 this.flags = flags; 419 this.file = new File(dir, Uri.encode(tag) + "@" + timestampMillis + 420 ((flags & DropBoxManager.IS_TEXT) != 0 ? ".txt" : ".dat") + 421 ((flags & DropBoxManager.IS_GZIPPED) != 0 ? ".gz" : "")); 422 423 if (!temp.renameTo(this.file)) { 424 throw new IOException("Can't rename " + temp + " to " + this.file); 425 } 426 this.blocks = (int) ((this.file.length() + blockSize - 1) / blockSize); 427 } 428 429 /** 430 * Creates a zero-length tombstone for a file whose contents were lost. 431 * @param dir to store file in 432 * @param tag to use for new log file name 433 * @param timestampMillis of log entry 434 * @throws IOException if the file can't be created. 435 */ 436 public EntryFile(File dir, String tag, long timestampMillis) throws IOException { 437 this.tag = tag; 438 this.timestampMillis = timestampMillis; 439 this.flags = DropBoxManager.IS_EMPTY; 440 this.file = new File(dir, Uri.encode(tag) + "@" + timestampMillis + ".lost"); 441 this.blocks = 0; 442 new FileOutputStream(this.file).close(); 443 } 444 445 /** 446 * Extracts metadata from an existing on-disk log filename. 447 * @param file name of existing log file 448 * @param blockSize to use for space accounting 449 */ 450 public EntryFile(File file, int blockSize) { 451 this.file = file; 452 this.blocks = (int) ((this.file.length() + blockSize - 1) / blockSize); 453 454 String name = file.getName(); 455 int at = name.lastIndexOf('@'); 456 if (at < 0) { 457 this.tag = null; 458 this.timestampMillis = 0; 459 this.flags = DropBoxManager.IS_EMPTY; 460 return; 461 } 462 463 int flags = 0; 464 this.tag = Uri.decode(name.substring(0, at)); 465 if (name.endsWith(".gz")) { 466 flags |= DropBoxManager.IS_GZIPPED; 467 name = name.substring(0, name.length() - 3); 468 } 469 if (name.endsWith(".lost")) { 470 flags |= DropBoxManager.IS_EMPTY; 471 name = name.substring(at + 1, name.length() - 5); 472 } else if (name.endsWith(".txt")) { 473 flags |= DropBoxManager.IS_TEXT; 474 name = name.substring(at + 1, name.length() - 4); 475 } else if (name.endsWith(".dat")) { 476 name = name.substring(at + 1, name.length() - 4); 477 } else { 478 this.flags = DropBoxManager.IS_EMPTY; 479 this.timestampMillis = 0; 480 return; 481 } 482 this.flags = flags; 483 484 long millis; 485 try { millis = Long.valueOf(name); } catch (NumberFormatException e) { millis = 0; } 486 this.timestampMillis = millis; 487 } 488 489 /** 490 * Creates a EntryFile object with only a timestamp for comparison purposes. 491 * @param timestampMillis to compare with. 492 */ 493 public EntryFile(long millis) { 494 this.tag = null; 495 this.timestampMillis = millis; 496 this.flags = DropBoxManager.IS_EMPTY; 497 this.file = null; 498 this.blocks = 0; 499 } 500 } 501 502 /////////////////////////////////////////////////////////////////////////// 503 504 /** If never run before, scans disk contents to build in-memory tracking data. */ 505 private synchronized void init() throws IOException { 506 if (mStatFs == null) { 507 if (!mDropBoxDir.isDirectory() && !mDropBoxDir.mkdirs()) { 508 throw new IOException("Can't mkdir: " + mDropBoxDir); 509 } 510 try { 511 mStatFs = new StatFs(mDropBoxDir.getPath()); 512 mBlockSize = mStatFs.getBlockSize(); 513 } catch (IllegalArgumentException e) { // StatFs throws this on error 514 throw new IOException("Can't statfs: " + mDropBoxDir); 515 } 516 } 517 518 if (mAllFiles == null) { 519 File[] files = mDropBoxDir.listFiles(); 520 if (files == null) throw new IOException("Can't list files: " + mDropBoxDir); 521 522 mAllFiles = new FileList(); 523 mFilesByTag = new HashMap<String, FileList>(); 524 525 // Scan pre-existing files. 526 for (File file : files) { 527 if (file.getName().endsWith(".tmp")) { 528 Log.i(TAG, "Cleaning temp file: " + file); 529 file.delete(); 530 continue; 531 } 532 533 EntryFile entry = new EntryFile(file, mBlockSize); 534 if (entry.tag == null) { 535 Log.w(TAG, "Unrecognized file: " + file); 536 continue; 537 } else if (entry.timestampMillis == 0) { 538 Log.w(TAG, "Invalid filename: " + file); 539 file.delete(); 540 continue; 541 } 542 543 enrollEntry(entry); 544 } 545 } 546 } 547 548 /** Adds a disk log file to in-memory tracking for accounting and enumeration. */ 549 private synchronized void enrollEntry(EntryFile entry) { 550 mAllFiles.contents.add(entry); 551 mAllFiles.blocks += entry.blocks; 552 553 // mFilesByTag is used for trimming, so don't list empty files. 554 // (Zero-length/lost files are trimmed by date from mAllFiles.) 555 556 if (entry.tag != null && entry.file != null && entry.blocks > 0) { 557 FileList tagFiles = mFilesByTag.get(entry.tag); 558 if (tagFiles == null) { 559 tagFiles = new FileList(); 560 mFilesByTag.put(entry.tag, tagFiles); 561 } 562 tagFiles.contents.add(entry); 563 tagFiles.blocks += entry.blocks; 564 } 565 } 566 567 /** Moves a temporary file to a final log filename and enrolls it. */ 568 private synchronized void createEntry(File temp, String tag, int flags) throws IOException { 569 long t = System.currentTimeMillis(); 570 571 // Require each entry to have a unique timestamp; if there are entries 572 // >10sec in the future (due to clock skew), drag them back to avoid 573 // keeping them around forever. 574 575 SortedSet<EntryFile> tail = mAllFiles.contents.tailSet(new EntryFile(t + 10000)); 576 EntryFile[] future = null; 577 if (!tail.isEmpty()) { 578 future = tail.toArray(new EntryFile[tail.size()]); 579 tail.clear(); // Remove from mAllFiles 580 } 581 582 if (!mAllFiles.contents.isEmpty()) { 583 t = Math.max(t, mAllFiles.contents.last().timestampMillis + 1); 584 } 585 586 if (future != null) { 587 for (EntryFile late : future) { 588 mAllFiles.blocks -= late.blocks; 589 FileList tagFiles = mFilesByTag.get(late.tag); 590 if (tagFiles.contents.remove(late)) tagFiles.blocks -= late.blocks; 591 if ((late.flags & DropBoxManager.IS_EMPTY) == 0) { 592 enrollEntry(new EntryFile( 593 late.file, mDropBoxDir, late.tag, t++, late.flags, mBlockSize)); 594 } else { 595 enrollEntry(new EntryFile(mDropBoxDir, late.tag, t++)); 596 } 597 } 598 } 599 600 if (temp == null) { 601 enrollEntry(new EntryFile(mDropBoxDir, tag, t)); 602 } else { 603 enrollEntry(new EntryFile(temp, mDropBoxDir, tag, t, flags, mBlockSize)); 604 } 605 } 606 607 /** 608 * Trims the files on disk to make sure they aren't using too much space. 609 * @return the overall quota for storage (in bytes) 610 */ 611 private synchronized long trimToFit() { 612 // Expunge aged items (including tombstones marking deleted data). 613 614 int ageSeconds = Settings.Gservices.getInt(mContentResolver, 615 Settings.Gservices.DROPBOX_AGE_SECONDS, DEFAULT_AGE_SECONDS); 616 long cutoffMillis = System.currentTimeMillis() - ageSeconds * 1000; 617 while (!mAllFiles.contents.isEmpty()) { 618 EntryFile entry = mAllFiles.contents.first(); 619 if (entry.timestampMillis > cutoffMillis) break; 620 621 FileList tag = mFilesByTag.get(entry.tag); 622 if (tag != null && tag.contents.remove(entry)) tag.blocks -= entry.blocks; 623 if (mAllFiles.contents.remove(entry)) mAllFiles.blocks -= entry.blocks; 624 if (entry.file != null) entry.file.delete(); 625 } 626 627 // Compute overall quota (a fraction of available free space) in blocks. 628 // The quota changes dynamically based on the amount of free space; 629 // that way when lots of data is available we can use it, but we'll get 630 // out of the way if storage starts getting tight. 631 632 long uptimeMillis = SystemClock.uptimeMillis(); 633 if (uptimeMillis > mCachedQuotaUptimeMillis + QUOTA_RESCAN_MILLIS) { 634 int quotaPercent = Settings.Gservices.getInt(mContentResolver, 635 Settings.Gservices.DROPBOX_QUOTA_PERCENT, DEFAULT_QUOTA_PERCENT); 636 int reservePercent = Settings.Gservices.getInt(mContentResolver, 637 Settings.Gservices.DROPBOX_RESERVE_PERCENT, DEFAULT_RESERVE_PERCENT); 638 int quotaKb = Settings.Gservices.getInt(mContentResolver, 639 Settings.Gservices.DROPBOX_QUOTA_KB, DEFAULT_QUOTA_KB); 640 641 mStatFs.restat(mDropBoxDir.getPath()); 642 int available = mStatFs.getAvailableBlocks(); 643 int nonreserved = available - mStatFs.getBlockCount() * reservePercent / 100; 644 int maximum = quotaKb * 1024 / mBlockSize; 645 mCachedQuotaBlocks = Math.min(maximum, Math.max(0, nonreserved * quotaPercent / 100)); 646 mCachedQuotaUptimeMillis = uptimeMillis; 647 } 648 649 // If we're using too much space, delete old items to make room. 650 // 651 // We trim each tag independently (this is why we keep per-tag lists). 652 // Space is "fairly" shared between tags -- they are all squeezed 653 // equally until enough space is reclaimed. 654 // 655 // A single circular buffer (a la logcat) would be simpler, but this 656 // way we can handle fat/bursty data (like 1MB+ bugreports, 300KB+ 657 // kernel crash dumps, and 100KB+ ANR reports) without swamping small, 658 // well-behaved data // streams (event statistics, profile data, etc). 659 // 660 // Deleted files are replaced with zero-length tombstones to mark what 661 // was lost. Tombstones are expunged by age (see above). 662 663 if (mAllFiles.blocks > mCachedQuotaBlocks) { 664 Log.i(TAG, "Usage (" + mAllFiles.blocks + ") > Quota (" + mCachedQuotaBlocks + ")"); 665 666 // Find a fair share amount of space to limit each tag 667 int unsqueezed = mAllFiles.blocks, squeezed = 0; 668 TreeSet<FileList> tags = new TreeSet<FileList>(mFilesByTag.values()); 669 for (FileList tag : tags) { 670 if (squeezed > 0 && tag.blocks <= (mCachedQuotaBlocks - unsqueezed) / squeezed) { 671 break; 672 } 673 unsqueezed -= tag.blocks; 674 squeezed++; 675 } 676 int tagQuota = (mCachedQuotaBlocks - unsqueezed) / squeezed; 677 678 // Remove old items from each tag until it meets the per-tag quota. 679 for (FileList tag : tags) { 680 if (mAllFiles.blocks < mCachedQuotaBlocks) break; 681 while (tag.blocks > tagQuota && !tag.contents.isEmpty()) { 682 EntryFile entry = tag.contents.first(); 683 if (tag.contents.remove(entry)) tag.blocks -= entry.blocks; 684 if (mAllFiles.contents.remove(entry)) mAllFiles.blocks -= entry.blocks; 685 686 try { 687 if (entry.file != null) entry.file.delete(); 688 enrollEntry(new EntryFile(mDropBoxDir, entry.tag, entry.timestampMillis)); 689 } catch (IOException e) { 690 Log.e(TAG, "Can't write tombstone file", e); 691 } 692 } 693 } 694 } 695 696 return mCachedQuotaBlocks * mBlockSize; 697 } 698} 699