DropBoxManagerService.java revision 3d40df335e4c0df972720271a84277077f168f65
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.Formatter; 50import java.util.HashMap; 51import java.util.Iterator; 52import java.util.Map; 53import java.util.SortedSet; 54import java.util.TreeSet; 55import java.util.zip.GZIPOutputStream; 56 57/** 58 * Implementation of {@link IDropBoxManagerService} using the filesystem. 59 * Clients use {@link DropBoxManager} to access this service. 60 */ 61public final class DropBoxManagerService extends IDropBoxManagerService.Stub { 62 private static final String TAG = "DropBoxManagerService"; 63 private static final int DEFAULT_RESERVE_PERCENT = 10; 64 private static final int DEFAULT_QUOTA_PERCENT = 10; 65 private static final int DEFAULT_QUOTA_KB = 5 * 1024; 66 private static final int DEFAULT_AGE_SECONDS = 3 * 86400; 67 private static final int QUOTA_RESCAN_MILLIS = 5000; 68 69 private static final boolean PROFILE_DUMP = false; 70 71 // TODO: This implementation currently uses one file per entry, which is 72 // inefficient for smallish entries -- consider using a single queue file 73 // per tag (or even globally) instead. 74 75 // The cached context and derived objects 76 77 private final Context mContext; 78 private final ContentResolver mContentResolver; 79 private final File mDropBoxDir; 80 81 // Accounting of all currently written log files (set in init()). 82 83 private FileList mAllFiles = null; 84 private HashMap<String, FileList> mFilesByTag = null; 85 86 // Various bits of disk information 87 88 private StatFs mStatFs = null; 89 private int mBlockSize = 0; 90 private int mCachedQuotaBlocks = 0; // Space we can use: computed from free space, etc. 91 private long mCachedQuotaUptimeMillis = 0; 92 93 // Ensure that all log entries have a unique timestamp 94 private long mLastTimestamp = 0; 95 96 /** Receives events that might indicate a need to clean up files. */ 97 private final BroadcastReceiver mReceiver = new BroadcastReceiver() { 98 @Override 99 public void onReceive(Context context, Intent intent) { 100 mCachedQuotaUptimeMillis = 0; // Force a re-check of quota size 101 try { 102 init(); 103 trimToFit(); 104 } catch (IOException e) { 105 Log.e(TAG, "Can't init", e); 106 } 107 } 108 }; 109 110 /** 111 * Creates an instance of managed drop box storage. Normally there is one of these 112 * run by the system, but others can be created for testing and other purposes. 113 * 114 * @param context to use for receiving free space & gservices intents 115 * @param path to store drop box entries in 116 */ 117 public DropBoxManagerService(Context context, File path) { 118 mDropBoxDir = path; 119 120 // Set up intent receivers 121 mContext = context; 122 mContentResolver = context.getContentResolver(); 123 context.registerReceiver(mReceiver, new IntentFilter(Intent.ACTION_DEVICE_STORAGE_LOW)); 124 context.registerReceiver(mReceiver, new IntentFilter(Settings.Gservices.CHANGED_ACTION)); 125 126 // The real work gets done lazily in init() -- that way service creation always 127 // succeeds, and things like disk problems cause individual method failures. 128 } 129 130 /** Unregisters broadcast receivers and any other hooks -- for test instances */ 131 public void stop() { 132 mContext.unregisterReceiver(mReceiver); 133 } 134 135 public void add(DropBoxManager.Entry entry) { 136 File temp = null; 137 OutputStream output = null; 138 final String tag = entry.getTag(); 139 try { 140 int flags = entry.getFlags(); 141 if ((flags & DropBoxManager.IS_EMPTY) != 0) throw new IllegalArgumentException(); 142 143 init(); 144 if (!isTagEnabled(tag)) return; 145 long max = trimToFit(); 146 long lastTrim = System.currentTimeMillis(); 147 148 byte[] buffer = new byte[mBlockSize]; 149 InputStream input = entry.getInputStream(); 150 151 // First, accumulate up to one block worth of data in memory before 152 // deciding whether to compress the data or not. 153 154 int read = 0; 155 while (read < buffer.length) { 156 int n = input.read(buffer, read, buffer.length - read); 157 if (n <= 0) break; 158 read += n; 159 } 160 161 // If we have at least one block, compress it -- otherwise, just write 162 // the data in uncompressed form. 163 164 temp = new File(mDropBoxDir, "drop" + Thread.currentThread().getId() + ".tmp"); 165 output = new FileOutputStream(temp); 166 if (read == buffer.length && ((flags & DropBoxManager.IS_GZIPPED) == 0)) { 167 output = new GZIPOutputStream(output); 168 flags = flags | DropBoxManager.IS_GZIPPED; 169 } 170 171 do { 172 output.write(buffer, 0, read); 173 174 long now = System.currentTimeMillis(); 175 if (now - lastTrim > 30 * 1000) { 176 max = trimToFit(); // In case data dribbles in slowly 177 lastTrim = now; 178 } 179 180 read = input.read(buffer); 181 if (read <= 0) { 182 output.close(); // Get a final size measurement 183 output = null; 184 } else { 185 output.flush(); // So the size measurement is pseudo-reasonable 186 } 187 188 long len = temp.length(); 189 if (len > max) { 190 Log.w(TAG, "Dropping: " + tag + " (" + temp.length() + " > " + max + " bytes)"); 191 temp.delete(); 192 temp = null; // Pass temp = null to createEntry() to leave a tombstone 193 break; 194 } 195 } while (read > 0); 196 197 createEntry(temp, tag, flags); 198 temp = null; 199 } catch (IOException e) { 200 Log.e(TAG, "Can't write: " + tag, e); 201 } finally { 202 try { if (output != null) output.close(); } catch (IOException e) {} 203 entry.close(); 204 if (temp != null) temp.delete(); 205 } 206 } 207 208 public boolean isTagEnabled(String tag) { 209 return !"disabled".equals(Settings.Gservices.getString( 210 mContentResolver, Settings.Gservices.DROPBOX_TAG_PREFIX + tag)); 211 } 212 213 public synchronized DropBoxManager.Entry getNextEntry(String tag, long millis) { 214 if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.READ_LOGS) 215 != PackageManager.PERMISSION_GRANTED) { 216 throw new SecurityException("READ_LOGS permission required"); 217 } 218 219 try { 220 init(); 221 } catch (IOException e) { 222 Log.e(TAG, "Can't init", e); 223 return null; 224 } 225 226 FileList list = tag == null ? mAllFiles : mFilesByTag.get(tag); 227 if (list == null) return null; 228 229 for (EntryFile entry : list.contents.tailSet(new EntryFile(millis + 1))) { 230 if (entry.tag == null) continue; 231 if ((entry.flags & DropBoxManager.IS_EMPTY) != 0) { 232 return new DropBoxManager.Entry(entry.tag, entry.timestampMillis); 233 } 234 try { 235 return new DropBoxManager.Entry( 236 entry.tag, entry.timestampMillis, entry.file, entry.flags); 237 } catch (IOException e) { 238 Log.e(TAG, "Can't read: " + entry.file, e); 239 // Continue to next file 240 } 241 } 242 243 return null; 244 } 245 246 public synchronized void dump(FileDescriptor fd, PrintWriter pw, String[] args) { 247 if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.DUMP) 248 != PackageManager.PERMISSION_GRANTED) { 249 pw.println("Permission Denial: Can't dump DropBoxManagerService"); 250 return; 251 } 252 253 try { 254 init(); 255 } catch (IOException e) { 256 pw.println("Can't initialize: " + e); 257 Log.e(TAG, "Can't init", e); 258 return; 259 } 260 261 if (PROFILE_DUMP) Debug.startMethodTracing("/data/trace/dropbox.dump"); 262 263 Formatter out = new Formatter(); 264 boolean doPrint = false, doFile = false; 265 ArrayList<String> searchArgs = new ArrayList<String>(); 266 for (int i = 0; args != null && i < args.length; i++) { 267 if (args[i].equals("-p") || args[i].equals("--print")) { 268 doPrint = true; 269 } else if (args[i].equals("-f") || args[i].equals("--file")) { 270 doFile = true; 271 } else if (args[i].startsWith("-")) { 272 out.format("Unknown argument: %s\n", args[i]); 273 } else { 274 searchArgs.add(args[i]); 275 } 276 } 277 278 out.format("Drop box contents: %d entries\n", mAllFiles.contents.size()); 279 280 if (!searchArgs.isEmpty()) { 281 out.format("Searching for:"); 282 for (String a : searchArgs) out.format(" %s", a); 283 out.format("\n"); 284 } 285 286 int numFound = 0, numArgs = searchArgs.size(); 287 Time time = new Time(); 288 out.format("\n"); 289 for (EntryFile entry : mAllFiles.contents) { 290 time.set(entry.timestampMillis); 291 String date = time.format("%Y-%m-%d %H:%M:%S"); 292 boolean match = true; 293 for (int i = 0; i < numArgs && match; i++) { 294 String arg = searchArgs.get(i); 295 match = (date.contains(arg) || arg.equals(entry.tag)); 296 } 297 if (!match) continue; 298 299 numFound++; 300 out.format("%s.%03d %s", date, entry.timestampMillis % 1000, 301 entry.tag == null ? "(no tag)" : entry.tag); 302 if (entry.file == null) { 303 out.format(" (no file)\n"); 304 continue; 305 } else if ((entry.flags & DropBoxManager.IS_EMPTY) != 0) { 306 out.format(" (contents lost)\n"); 307 continue; 308 } else { 309 out.format(" (%s%s, %d bytes)\n", 310 (entry.flags & DropBoxManager.IS_GZIPPED) != 0 ? "compressed " : "", 311 (entry.flags & DropBoxManager.IS_TEXT) != 0 ? "text" : "data", 312 entry.file.length()); 313 } 314 315 if (doFile || (doPrint && (entry.flags & DropBoxManager.IS_TEXT) == 0)) { 316 out.format("%s%s\n", (doPrint ? "" : " "), entry.file.getPath()); 317 } 318 319 if ((entry.flags & DropBoxManager.IS_TEXT) != 0 && (doPrint || !doFile)) { 320 DropBoxManager.Entry dbe = null; 321 try { 322 dbe = new DropBoxManager.Entry( 323 entry.tag, entry.timestampMillis, entry.file, entry.flags); 324 325 if (doPrint) { 326 InputStreamReader r = new InputStreamReader(dbe.getInputStream()); 327 char[] buf = new char[4096]; 328 boolean newline = false; 329 for (;;) { 330 int n = r.read(buf); 331 if (n <= 0) break; 332 out.format("%s", new String(buf, 0, n)); 333 newline = (buf[n - 1] == '\n'); 334 } 335 if (!newline) out.format("\n"); 336 } else { 337 String text = dbe.getText(70); 338 boolean truncated = (text.length() == 70); 339 out.format(" %s%s\n", text.trim().replace('\n', '/'), 340 truncated ? " ..." : ""); 341 } 342 } catch (IOException e) { 343 out.format("*** %s\n", e.toString()); 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.format("\n"); 351 } 352 353 if (numFound == 0) out.format("(No entries found.)\n"); 354 355 if (args == null || args.length == 0) { 356 if (!doPrint) out.format("\n"); 357 out.format("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