src/chrome/browser/media_galleries/media_scan_manager.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/media_galleries/media_scan_manager.h"
   6
   7 #include "base/file_util.h"
   8 #include "base/files/file_enumerator.h"
   9 #include "base/logging.h"
  10 #include "base/metrics/histogram.h"
  11 #include "base/time/time.h"
  12 #include "chrome/browser/extensions/extension_service.h"
  13 #include "chrome/browser/media_galleries/media_galleries_preferences.h"
  14 #include "chrome/browser/media_galleries/media_galleries_preferences_factory.h"
  15 #include "chrome/browser/media_galleries/media_scan_manager_observer.h"
  16 #include "chrome/browser/profiles/profile.h"
  17 #include "chrome/common/extensions/api/media_galleries.h"
  18 #include "content/public/browser/browser_thread.h"
  19 #include "extensions/browser/extension_registry.h"
  20 #include "extensions/browser/extension_system.h"
  21 #include "extensions/common/extension.h"
  22
  23 using extensions::ExtensionRegistry;
  24
  25 namespace media_galleries = extensions::api::media_galleries;
  26
  27 namespace {
  28
  29 typedef std::set<std::string /*extension id*/> ScanningExtensionIdSet;
  30
  31 // When multiple scan results have the same parent, sometimes it makes sense
  32 // to combine them into a single scan result at the parent. This constant
  33 // governs when that happens; kContainerDirectoryMinimumPercent percent of the
  34 // directories in the parent directory must be scan results.
  35 const int kContainerDirectoryMinimumPercent = 80;
  36
  37 // How long after a completed media scan can we provide the cached results.
  38 const int kScanResultsExpiryTimeInHours = 24;
  39
  40 struct LocationInfo {
  41   LocationInfo()
  42       : pref_id(kInvalidMediaGalleryPrefId),
  43         type(MediaGalleryPrefInfo::kInvalidType) {}
  44   LocationInfo(MediaGalleryPrefId pref_id, MediaGalleryPrefInfo::Type type,
  45                base::FilePath path)
  46       : pref_id(pref_id), type(type), path(path) {}
  47   // Highest priority comparison by path, next by type (scan result last),
  48   // then by pref id (invalid last).
  49   bool operator<(const LocationInfo& rhs) const {
  50     if (path.value() == rhs.path.value()) {
  51       if (type == rhs.type) {
  52         return pref_id > rhs.pref_id;
  53       }
  54       return rhs.type == MediaGalleryPrefInfo::kScanResult;
  55     }
  56     return path.value() < rhs.path.value();
  57   }
  58
  59   MediaGalleryPrefId pref_id;
  60   MediaGalleryPrefInfo::Type type;
  61   base::FilePath path;
  62   MediaGalleryScanResult file_counts;
  63 };
  64
  65 // Finds new scan results that are shadowed (the same location, or a child) by
  66 // existing locations and moves them from |found_folders| to |child_folders|.
  67 // Also moves new scan results that are shadowed by other new scan results
  68 // to |child_folders|.
  69 void PartitionChildScanResults(
  70     MediaGalleriesPreferences* preferences,
  71     MediaFolderFinder::MediaFolderFinderResults* found_folders,
  72     MediaFolderFinder::MediaFolderFinderResults* child_folders) {
  73   // Construct a list with everything in it.
  74   std::vector<LocationInfo> all_locations;
  75   for (MediaFolderFinder::MediaFolderFinderResults::const_iterator it =
  76            found_folders->begin(); it != found_folders->end(); ++it) {
  77     all_locations.push_back(LocationInfo(kInvalidMediaGalleryPrefId,
  78                                          MediaGalleryPrefInfo::kScanResult,
  79                                          it->first));
  80     all_locations.back().file_counts = it->second;
  81   }
  82   const MediaGalleriesPrefInfoMap& known_galleries =
  83       preferences->known_galleries();
  84   for (MediaGalleriesPrefInfoMap::const_iterator it = known_galleries.begin();
  85        it != known_galleries.end();
  86        ++it) {
  87     all_locations.push_back(LocationInfo(it->second.pref_id, it->second.type,
  88                                          it->second.AbsolutePath()));
  89   }
  90   // Sorting on path should put all paths that are prefixes of other paths
  91   // next to each other, with the shortest one first.
  92   std::sort(all_locations.begin(), all_locations.end());
  93
  94   size_t previous_parent_index = 0;
  95   for (size_t i = 1; i < all_locations.size(); i++) {
  96     const LocationInfo& current = all_locations[i];
  97     const LocationInfo& previous_parent = all_locations[previous_parent_index];
  98     bool is_child = previous_parent.path.IsParent(current.path);
  99     if (current.type == MediaGalleryPrefInfo::kScanResult &&
 100         current.pref_id == kInvalidMediaGalleryPrefId &&
 101         (is_child || previous_parent.path == current.path)) {
 102       // Move new scan results that are shadowed.
 103       (*child_folders)[current.path] = current.file_counts;
 104       found_folders->erase(current.path);
 105     } else if (!is_child) {
 106       previous_parent_index = i;
 107     }
 108   }
 109 }
 110
 111 MediaGalleryScanResult SumFilesUnderPath(
 112     const base::FilePath& path,
 113     const MediaFolderFinder::MediaFolderFinderResults& candidates) {
 114   MediaGalleryScanResult results;
 115   for (MediaFolderFinder::MediaFolderFinderResults::const_iterator it =
 116            candidates.begin(); it != candidates.end(); ++it) {
 117     if (it->first == path || path.IsParent(it->first)) {
 118       results.audio_count += it->second.audio_count;
 119       results.image_count += it->second.image_count;
 120       results.video_count += it->second.video_count;
 121     }
 122   }
 123   return results;
 124 }
 125
 126 void AddScanResultsForProfile(
 127     MediaGalleriesPreferences* preferences,
 128     const MediaFolderFinder::MediaFolderFinderResults& found_folders) {
 129   // First, remove any existing scan results where no app has been granted
 130   // permission - either it is gone, or is already in the new scan results.
 131   // This burns some pref ids, but not at an appreciable rate.
 132   MediaGalleryPrefIdSet to_remove;
 133   const MediaGalleriesPrefInfoMap& known_galleries =
 134       preferences->known_galleries();
 135   for (MediaGalleriesPrefInfoMap::const_iterator it = known_galleries.begin();
 136        it != known_galleries.end();
 137        ++it) {
 138     if (it->second.type == MediaGalleryPrefInfo::kScanResult &&
 139         !preferences->NonAutoGalleryHasPermission(it->first)) {
 140       to_remove.insert(it->first);
 141     }
 142   }
 143   for (MediaGalleryPrefIdSet::const_iterator it = to_remove.begin();
 144        it != to_remove.end();
 145        ++it) {
 146     preferences->EraseGalleryById(*it);
 147   }
 148
 149   MediaFolderFinder::MediaFolderFinderResults child_folders;
 150   MediaFolderFinder::MediaFolderFinderResults
 151       unique_found_folders(found_folders);
 152   PartitionChildScanResults(preferences, &unique_found_folders, &child_folders);
 153
 154   // Updating prefs while iterating them will invalidate the pointer, so
 155   // calculate the changes first and then apply them.
 156   std::map<MediaGalleryPrefId, MediaGalleryScanResult> to_update;
 157   for (MediaGalleriesPrefInfoMap::const_iterator it = known_galleries.begin();
 158        it != known_galleries.end();
 159        ++it) {
 160     const MediaGalleryPrefInfo& gallery = it->second;
 161     if (!gallery.IsBlackListedType()) {
 162       MediaGalleryScanResult file_counts =
 163           SumFilesUnderPath(gallery.AbsolutePath(), child_folders);
 164       if (gallery.audio_count != file_counts.audio_count ||
 165           gallery.image_count != file_counts.image_count ||
 166           gallery.video_count != file_counts.video_count) {
 167         to_update[it->first] = file_counts;
 168       }
 169     }
 170   }
 171
 172   for (std::map<MediaGalleryPrefId,
 173                 MediaGalleryScanResult>::const_iterator it = to_update.begin();
 174        it != to_update.end();
 175        ++it) {
 176     const MediaGalleryPrefInfo& gallery =
 177         preferences->known_galleries().find(it->first)->second;
 178       preferences->AddGallery(gallery.device_id, gallery.path, gallery.type,
 179                               gallery.volume_label, gallery.vendor_name,
 180                               gallery.model_name, gallery.total_size_in_bytes,
 181                               gallery.last_attach_time,
 182                               it->second.audio_count,
 183                               it->second.image_count,
 184                               it->second.video_count);
 185   }
 186
 187   // Add new scan results.
 188   for (MediaFolderFinder::MediaFolderFinderResults::const_iterator it =
 189            unique_found_folders.begin();
 190        it != unique_found_folders.end();
 191        ++it) {
 192     MediaGalleryScanResult file_counts =
 193         SumFilesUnderPath(it->first, child_folders);
 194     // The top level scan result is not in |child_folders|. Add it in as well.
 195     file_counts.audio_count += it->second.audio_count;
 196     file_counts.image_count += it->second.image_count;
 197     file_counts.video_count += it->second.video_count;
 198
 199     MediaGalleryPrefInfo gallery;
 200     bool existing = preferences->LookUpGalleryByPath(it->first, &gallery);
 201     DCHECK(!existing);
 202     preferences->AddGallery(gallery.device_id, gallery.path,
 203                             MediaGalleryPrefInfo::kScanResult,
 204                             gallery.volume_label, gallery.vendor_name,
 205                             gallery.model_name, gallery.total_size_in_bytes,
 206                             gallery.last_attach_time, file_counts.audio_count,
 207                             file_counts.image_count, file_counts.video_count);
 208   }
 209   UMA_HISTOGRAM_COUNTS_10000("MediaGalleries.ScanGalleriesPopulated",
 210                              unique_found_folders.size() + to_update.size());
 211 }
 212
 213 int CountScanResultsForExtension(MediaGalleriesPreferences* preferences,
 214                                  const extensions::Extension* extension,
 215                                  MediaGalleryScanResult* file_counts) {
 216   int gallery_count = 0;
 217
 218   MediaGalleryPrefIdSet permitted_galleries =
 219       preferences->GalleriesForExtension(*extension);
 220   const MediaGalleriesPrefInfoMap& known_galleries =
 221       preferences->known_galleries();
 222   for (MediaGalleriesPrefInfoMap::const_iterator it = known_galleries.begin();
 223        it != known_galleries.end();
 224        ++it) {
 225     if (it->second.type == MediaGalleryPrefInfo::kScanResult &&
 226         !ContainsKey(permitted_galleries, it->first)) {
 227       gallery_count++;
 228       file_counts->audio_count += it->second.audio_count;
 229       file_counts->image_count += it->second.image_count;
 230       file_counts->video_count += it->second.video_count;
 231     }
 232   }
 233   return gallery_count;
 234 }
 235
 236 int CountDirectoryEntries(const base::FilePath& path) {
 237   base::FileEnumerator dir_counter(
 238       path, false /*recursive*/, base::FileEnumerator::DIRECTORIES);
 239   int count = 0;
 240   base::FileEnumerator::FileInfo info;
 241   for (base::FilePath name = dir_counter.Next(); !name.empty();
 242        name = dir_counter.Next()) {
 243     if (!base::IsLink(name))
 244       ++count;
 245   }
 246   return count;
 247 }
 248
 249 struct ContainerCount {
 250   int seen_count, entries_count;
 251   bool is_qualified;
 252
 253   ContainerCount() : seen_count(0), entries_count(-1), is_qualified(false) {}
 254 };
 255
 256 typedef std::map<base::FilePath, ContainerCount> ContainerCandidates;
 257
 258 }  // namespace
 259
 260 MediaScanManager::MediaScanManager()
 261     : scoped_extension_registry_observer_(this),
 262       weak_factory_(this) {
 263   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 264 }
 265
 266 MediaScanManager::~MediaScanManager() {
 267   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 268 }
 269
 270 void MediaScanManager::AddObserver(Profile* profile,
 271                                    MediaScanManagerObserver* observer) {
 272   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 273   DCHECK(!ContainsKey(observers_, profile));
 274   observers_[profile].observer = observer;
 275 }
 276
 277 void MediaScanManager::RemoveObserver(Profile* profile) {
 278   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 279   bool scan_in_progress = ScanInProgress();
 280   observers_.erase(profile);
 281   DCHECK_EQ(scan_in_progress, ScanInProgress());
 282 }
 283
 284 void MediaScanManager::CancelScansForProfile(Profile* profile) {
 285   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 286   observers_[profile].scanning_extensions.clear();
 287
 288   if (!ScanInProgress())
 289     folder_finder_.reset();
 290 }
 291
 292 void MediaScanManager::StartScan(Profile* profile,
 293                                  const extensions::Extension* extension,
 294                                  bool user_gesture) {
 295   DCHECK(extension);
 296   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 297
 298   ScanObserverMap::iterator scans_for_profile = observers_.find(profile);
 299   // We expect that an MediaScanManagerObserver has already been registered.
 300   DCHECK(scans_for_profile != observers_.end());
 301   bool scan_in_progress = ScanInProgress();
 302   // Ignore requests for extensions that are already scanning.
 303   ScanningExtensionIdSet* scanning_extensions;
 304   scanning_extensions = &scans_for_profile->second.scanning_extensions;
 305   if (scan_in_progress && ContainsKey(*scanning_extensions, extension->id()))
 306     return;
 307
 308   // Provide cached result if there is not already a scan in progress,
 309   // there is no user gesture, and the previous results are unexpired.
 310   MediaGalleriesPreferences* preferences =
 311       MediaGalleriesPreferencesFactory::GetForProfile(profile);
 312   base::TimeDelta time_since_last_scan =
 313       base::Time::Now() - preferences->GetLastScanCompletionTime();
 314   if (!scan_in_progress && !user_gesture && time_since_last_scan <
 315           base::TimeDelta::FromHours(kScanResultsExpiryTimeInHours)) {
 316     MediaGalleryScanResult file_counts;
 317     int gallery_count =
 318         CountScanResultsForExtension(preferences, extension, &file_counts);
 319     scans_for_profile->second.observer->OnScanStarted(extension->id());
 320     scans_for_profile->second.observer->OnScanFinished(extension->id(),
 321                                                        gallery_count,
 322                                                        file_counts);
 323     return;
 324   }
 325
 326   // On first scan for the |profile|, register to listen for extension unload.
 327   if (scanning_extensions->empty())
 328     scoped_extension_registry_observer_.Add(ExtensionRegistry::Get(profile));
 329
 330   scanning_extensions->insert(extension->id());
 331   scans_for_profile->second.observer->OnScanStarted(extension->id());
 332
 333   if (folder_finder_)
 334     return;
 335
 336   MediaFolderFinder::MediaFolderFinderResultsCallback callback =
 337       base::Bind(&MediaScanManager::OnScanCompleted,
 338                  weak_factory_.GetWeakPtr());
 339   if (testing_folder_finder_factory_.is_null()) {
 340     folder_finder_.reset(new MediaFolderFinder(callback));
 341   } else {
 342     folder_finder_.reset(testing_folder_finder_factory_.Run(callback));
 343   }
 344   scan_start_time_ = base::Time::Now();
 345   folder_finder_->StartScan();
 346 }
 347
 348 void MediaScanManager::CancelScan(Profile* profile,
 349                                   const extensions::Extension* extension) {
 350   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 351
 352   // Erases the logical scan if found, early exit otherwise.
 353   ScanObserverMap::iterator scans_for_profile = observers_.find(profile);
 354   if (scans_for_profile == observers_.end() ||
 355       !scans_for_profile->second.scanning_extensions.erase(extension->id())) {
 356     return;
 357   }
 358
 359   scans_for_profile->second.observer->OnScanCancelled(extension->id());
 360
 361   // No more scanning extensions for |profile|, so stop listening for unloads.
 362   if (scans_for_profile->second.scanning_extensions.empty())
 363     scoped_extension_registry_observer_.Remove(ExtensionRegistry::Get(profile));
 364
 365   if (!ScanInProgress()) {
 366     folder_finder_.reset();
 367     DCHECK(!scan_start_time_.is_null());
 368     UMA_HISTOGRAM_LONG_TIMES("MediaGalleries.ScanCancelTime",
 369                              base::Time::Now() - scan_start_time_);
 370     scan_start_time_ = base::Time();
 371   }
 372 }
 373
 374 void MediaScanManager::SetMediaFolderFinderFactory(
 375     const MediaFolderFinderFactory& factory) {
 376   testing_folder_finder_factory_ = factory;
 377 }
 378
 379 // A single directory may contain many folders with media in them, without
 380 // containing any media itself. In fact, the primary purpose of that directory
 381 // may be to contain media directories. This function tries to find those
 382 // container directories.
 383 MediaFolderFinder::MediaFolderFinderResults
 384 MediaScanManager::FindContainerScanResults(
 385     const MediaFolderFinder::MediaFolderFinderResults& found_folders,
 386     const std::vector<base::FilePath>& sensitive_locations) {
 387   DCHECK_CURRENTLY_ON(content::BrowserThread::FILE);
 388   std::vector<base::FilePath> abs_sensitive_locations;
 389   for (size_t i = 0; i < sensitive_locations.size(); ++i) {
 390     base::FilePath path = base::MakeAbsoluteFilePath(sensitive_locations[i]);
 391     if (!path.empty())
 392       abs_sensitive_locations.push_back(path);
 393   }
 394   // Recursively find parent directories with majority of media directories,
 395   // or container directories.
 396   // |candidates| keeps track of directories which might have enough
 397   // such directories to have us return them.
 398   typedef std::map<base::FilePath, ContainerCount> ContainerCandidates;
 399   ContainerCandidates candidates;
 400   for (MediaFolderFinder::MediaFolderFinderResults::const_iterator it =
 401            found_folders.begin();
 402        it != found_folders.end();
 403        ++it) {
 404     base::FilePath child_directory = it->first;
 405     base::FilePath parent_directory = child_directory.DirName();
 406
 407     // Parent of root is root.
 408     while (!parent_directory.empty() && child_directory != parent_directory) {
 409       // Skip sensitive folders and their ancestors.
 410       base::FilePath abs_parent_directory =
 411           base::MakeAbsoluteFilePath(parent_directory);
 412       if (abs_parent_directory.empty())
 413         break;
 414       bool is_sensitive = false;
 415       for (size_t i = 0; i < abs_sensitive_locations.size(); ++i) {
 416         if (abs_parent_directory == abs_sensitive_locations[i] ||
 417             abs_parent_directory.IsParent(abs_sensitive_locations[i])) {
 418           is_sensitive = true;
 419           break;
 420         }
 421       }
 422       if (is_sensitive)
 423         break;
 424
 425       // Don't bother with ones we already have.
 426       if (found_folders.find(parent_directory) != found_folders.end())
 427         continue;
 428
 429       ContainerCandidates::iterator parent_it =
 430           candidates.find(parent_directory);
 431       if (parent_it == candidates.end()) {
 432         ContainerCount count;
 433         count.seen_count = 1;
 434         count.entries_count = CountDirectoryEntries(parent_directory);
 435         parent_it =
 436             candidates.insert(std::make_pair(parent_directory, count)).first;
 437       } else {
 438         ++candidates[parent_directory].seen_count;
 439       }
 440       // If previously sufficient, or not sufficient, bail.
 441       if (parent_it->second.is_qualified ||
 442           parent_it->second.seen_count * 100 / parent_it->second.entries_count <
 443               kContainerDirectoryMinimumPercent) {
 444         break;
 445       }
 446       // Otherwise, mark qualified and check parent.
 447       parent_it->second.is_qualified = true;
 448       child_directory = parent_directory;
 449       parent_directory = child_directory.DirName();
 450     }
 451   }
 452   MediaFolderFinder::MediaFolderFinderResults result;
 453   // Copy and return worthy results.
 454   for (ContainerCandidates::const_iterator it = candidates.begin();
 455        it != candidates.end();
 456        ++it) {
 457     if (it->second.is_qualified && it->second.seen_count >= 2)
 458       result[it->first] = MediaGalleryScanResult();
 459   }
 460   return result;
 461 }
 462
 463 MediaScanManager::ScanObservers::ScanObservers() : observer(NULL) {}
 464 MediaScanManager::ScanObservers::~ScanObservers() {}
 465
 466 void MediaScanManager::OnExtensionUnloaded(
 467     content::BrowserContext* browser_context,
 468     const extensions::Extension* extension,
 469     extensions::UnloadedExtensionInfo::Reason reason) {
 470   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 471   CancelScan(Profile::FromBrowserContext(browser_context), extension);
 472 }
 473
 474 bool MediaScanManager::ScanInProgress() const {
 475   for (ScanObserverMap::const_iterator it = observers_.begin();
 476        it != observers_.end();
 477        ++it) {
 478     if (!it->second.scanning_extensions.empty())
 479       return true;
 480   }
 481   return false;
 482 }
 483
 484 void MediaScanManager::OnScanCompleted(
 485     bool success,
 486     const MediaFolderFinder::MediaFolderFinderResults& found_folders) {
 487   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 488   if (!folder_finder_ || !success) {
 489     folder_finder_.reset();
 490     return;
 491   }
 492
 493   UMA_HISTOGRAM_COUNTS_10000("MediaGalleries.ScanDirectoriesFound",
 494                              found_folders.size());
 495   DCHECK(!scan_start_time_.is_null());
 496   UMA_HISTOGRAM_LONG_TIMES("MediaGalleries.ScanFinishedTime",
 497                            base::Time::Now() - scan_start_time_);
 498   scan_start_time_ = base::Time();
 499
 500   content::BrowserThread::PostTaskAndReplyWithResult(
 501       content::BrowserThread::FILE, FROM_HERE,
 502       base::Bind(FindContainerScanResults,
 503                  found_folders,
 504                  folder_finder_->graylisted_folders()),
 505       base::Bind(&MediaScanManager::OnFoundContainerDirectories,
 506                  weak_factory_.GetWeakPtr(),
 507                  found_folders));
 508 }
 509
 510 void MediaScanManager::OnFoundContainerDirectories(
 511     const MediaFolderFinder::MediaFolderFinderResults& found_folders,
 512     const MediaFolderFinder::MediaFolderFinderResults& container_folders) {
 513   MediaFolderFinder::MediaFolderFinderResults folders;
 514   folders.insert(found_folders.begin(), found_folders.end());
 515   folders.insert(container_folders.begin(), container_folders.end());
 516
 517   for (ScanObserverMap::iterator scans_for_profile = observers_.begin();
 518        scans_for_profile != observers_.end();
 519        ++scans_for_profile) {
 520     if (scans_for_profile->second.scanning_extensions.empty())
 521       continue;
 522     Profile* profile = scans_for_profile->first;
 523     MediaGalleriesPreferences* preferences =
 524         MediaGalleriesPreferencesFactory::GetForProfile(profile);
 525     ExtensionService* extension_service =
 526         extensions::ExtensionSystem::Get(profile)->extension_service();
 527     if (!extension_service)
 528       continue;
 529
 530     AddScanResultsForProfile(preferences, folders);
 531
 532     ScanningExtensionIdSet* scanning_extensions =
 533         &scans_for_profile->second.scanning_extensions;
 534     for (ScanningExtensionIdSet::const_iterator extension_id_it =
 535              scanning_extensions->begin();
 536          extension_id_it != scanning_extensions->end();
 537          ++extension_id_it) {
 538       const extensions::Extension* extension =
 539           extension_service->GetExtensionById(*extension_id_it, false);
 540       if (extension) {
 541         MediaGalleryScanResult file_counts;
 542         int gallery_count = CountScanResultsForExtension(preferences, extension,
 543                                                          &file_counts);
 544         scans_for_profile->second.observer->OnScanFinished(*extension_id_it,
 545                                                            gallery_count,
 546                                                            file_counts);
 547       }
 548     }
 549     scanning_extensions->clear();
 550     preferences->SetLastScanCompletionTime(base::Time::Now());
 551   }
 552   scoped_extension_registry_observer_.RemoveAll();
 553   folder_finder_.reset();
 554 }