src/apps/saved_files_service.cc

   1 // Copyright 2013 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 "apps/saved_files_service.h"
   6
   7 #include <algorithm>
   8
   9 #include "apps/saved_files_service_factory.h"
  10 #include "base/basictypes.h"
  11 #include "base/containers/hash_tables.h"
  12 #include "base/value_conversions.h"
  13 #include "chrome/browser/chrome_notification_types.h"
  14 #include "chrome/browser/profiles/profile.h"
  15 #include "content/public/browser/notification_service.h"
  16 #include "extensions/browser/extension_host.h"
  17 #include "extensions/browser/extension_prefs.h"
  18 #include "extensions/browser/extension_system.h"
  19 #include "extensions/browser/extension_util.h"
  20 #include "extensions/browser/notification_types.h"
  21 #include "extensions/common/permissions/api_permission.h"
  22 #include "extensions/common/permissions/permission_set.h"
  23 #include "extensions/common/permissions/permissions_data.h"
  24
  25 namespace apps {
  26
  27 using extensions::APIPermission;
  28 using extensions::Extension;
  29 using extensions::ExtensionHost;
  30 using extensions::ExtensionPrefs;
  31
  32 namespace {
  33
  34 // Preference keys
  35
  36 // The file entries that the app has permission to access.
  37 const char kFileEntries[] = "file_entries";
  38
  39 // The path to a file entry that the app had permission to access.
  40 const char kFileEntryPath[] = "path";
  41
  42 // Whether or not the the entry refers to a directory.
  43 const char kFileEntryIsDirectory[] = "is_directory";
  44
  45 // The sequence number in the LRU of the file entry.
  46 const char kFileEntrySequenceNumber[] = "sequence_number";
  47
  48 const size_t kMaxSavedFileEntries = 500;
  49 const int kMaxSequenceNumber = kint32max;
  50
  51 // These might be different to the constant values in tests.
  52 size_t g_max_saved_file_entries = kMaxSavedFileEntries;
  53 int g_max_sequence_number = kMaxSequenceNumber;
  54
  55 // Persists a SavedFileEntry in ExtensionPrefs.
  56 void AddSavedFileEntry(ExtensionPrefs* prefs,
  57                        const std::string& extension_id,
  58                        const SavedFileEntry& file_entry) {
  59   ExtensionPrefs::ScopedDictionaryUpdate update(
  60       prefs, extension_id, kFileEntries);
  61   base::DictionaryValue* file_entries = update.Get();
  62   if (!file_entries)
  63     file_entries = update.Create();
  64   DCHECK(!file_entries->GetDictionaryWithoutPathExpansion(file_entry.id, NULL));
  65
  66   base::DictionaryValue* file_entry_dict = new base::DictionaryValue();
  67   file_entry_dict->Set(kFileEntryPath, CreateFilePathValue(file_entry.path));
  68   file_entry_dict->SetBoolean(kFileEntryIsDirectory, file_entry.is_directory);
  69   file_entry_dict->SetInteger(kFileEntrySequenceNumber,
  70                               file_entry.sequence_number);
  71   file_entries->SetWithoutPathExpansion(file_entry.id, file_entry_dict);
  72 }
  73
  74 // Updates the sequence_number of a SavedFileEntry persisted in ExtensionPrefs.
  75 void UpdateSavedFileEntry(ExtensionPrefs* prefs,
  76                           const std::string& extension_id,
  77                           const SavedFileEntry& file_entry) {
  78   ExtensionPrefs::ScopedDictionaryUpdate update(
  79       prefs, extension_id, kFileEntries);
  80   base::DictionaryValue* file_entries = update.Get();
  81   DCHECK(file_entries);
  82   base::DictionaryValue* file_entry_dict = NULL;
  83   file_entries->GetDictionaryWithoutPathExpansion(file_entry.id,
  84                                                   &file_entry_dict);
  85   DCHECK(file_entry_dict);
  86   file_entry_dict->SetInteger(kFileEntrySequenceNumber,
  87                               file_entry.sequence_number);
  88 }
  89
  90 // Removes a SavedFileEntry from ExtensionPrefs.
  91 void RemoveSavedFileEntry(ExtensionPrefs* prefs,
  92                           const std::string& extension_id,
  93                           const std::string& file_entry_id) {
  94   ExtensionPrefs::ScopedDictionaryUpdate update(
  95       prefs, extension_id, kFileEntries);
  96   base::DictionaryValue* file_entries = update.Get();
  97   if (!file_entries)
  98     file_entries = update.Create();
  99   file_entries->RemoveWithoutPathExpansion(file_entry_id, NULL);
 100 }
 101
 102 // Clears all SavedFileEntry for the app from ExtensionPrefs.
 103 void ClearSavedFileEntries(ExtensionPrefs* prefs,
 104                            const std::string& extension_id) {
 105   prefs->UpdateExtensionPref(extension_id, kFileEntries, NULL);
 106 }
 107
 108 // Returns all SavedFileEntries for the app.
 109 std::vector<SavedFileEntry> GetSavedFileEntries(
 110     ExtensionPrefs* prefs,
 111     const std::string& extension_id) {
 112   std::vector<SavedFileEntry> result;
 113   const base::DictionaryValue* file_entries = NULL;
 114   if (!prefs->ReadPrefAsDictionary(extension_id, kFileEntries, &file_entries))
 115     return result;
 116
 117   for (base::DictionaryValue::Iterator it(*file_entries); !it.IsAtEnd();
 118        it.Advance()) {
 119     const base::DictionaryValue* file_entry = NULL;
 120     if (!it.value().GetAsDictionary(&file_entry))
 121       continue;
 122     const base::Value* path_value;
 123     if (!file_entry->Get(kFileEntryPath, &path_value))
 124       continue;
 125     base::FilePath file_path;
 126     if (!GetValueAsFilePath(*path_value, &file_path))
 127       continue;
 128     bool is_directory = false;
 129     file_entry->GetBoolean(kFileEntryIsDirectory, &is_directory);
 130     int sequence_number = 0;
 131     if (!file_entry->GetInteger(kFileEntrySequenceNumber, &sequence_number))
 132       continue;
 133     if (!sequence_number)
 134       continue;
 135     result.push_back(
 136         SavedFileEntry(it.key(), file_path, is_directory, sequence_number));
 137   }
 138   return result;
 139 }
 140
 141 }  // namespace
 142
 143 SavedFileEntry::SavedFileEntry() : is_directory(false), sequence_number(0) {}
 144
 145 SavedFileEntry::SavedFileEntry(const std::string& id,
 146                                const base::FilePath& path,
 147                                bool is_directory,
 148                                int sequence_number)
 149     : id(id),
 150       path(path),
 151       is_directory(is_directory),
 152       sequence_number(sequence_number) {}
 153
 154 class SavedFilesService::SavedFiles {
 155  public:
 156   SavedFiles(Profile* profile, const std::string& extension_id);
 157   ~SavedFiles();
 158
 159   void RegisterFileEntry(const std::string& id,
 160                          const base::FilePath& file_path,
 161                          bool is_directory);
 162   void EnqueueFileEntry(const std::string& id);
 163   bool IsRegistered(const std::string& id) const;
 164   const SavedFileEntry* GetFileEntry(const std::string& id) const;
 165   std::vector<SavedFileEntry> GetAllFileEntries() const;
 166
 167  private:
 168   // Compacts sequence numbers if the largest sequence number is
 169   // g_max_sequence_number. Outside of testing, it is set to kint32max, so this
 170   // will almost never do any real work.
 171   void MaybeCompactSequenceNumbers();
 172
 173   void LoadSavedFileEntriesFromPreferences();
 174
 175   Profile* profile_;
 176   const std::string extension_id_;
 177
 178   // Contains all file entries that have been registered, keyed by ID. Owns
 179   // values.
 180   base::hash_map<std::string, SavedFileEntry*> registered_file_entries_;
 181   STLValueDeleter<base::hash_map<std::string, SavedFileEntry*> >
 182       registered_file_entries_deleter_;
 183
 184   // The queue of file entries that have been retained, keyed by
 185   // sequence_number. Values are a subset of values in registered_file_entries_.
 186   // This should be kept in sync with file entries stored in extension prefs.
 187   std::map<int, SavedFileEntry*> saved_file_lru_;
 188
 189   DISALLOW_COPY_AND_ASSIGN(SavedFiles);
 190 };
 191
 192 // static
 193 SavedFilesService* SavedFilesService::Get(Profile* profile) {
 194   return SavedFilesServiceFactory::GetForProfile(profile);
 195 }
 196
 197 SavedFilesService::SavedFilesService(Profile* profile)
 198     : extension_id_to_saved_files_deleter_(&extension_id_to_saved_files_),
 199       profile_(profile) {
 200   registrar_.Add(this,
 201                  extensions::NOTIFICATION_EXTENSION_HOST_DESTROYED,
 202                  content::NotificationService::AllSources());
 203   registrar_.Add(this,
 204                  chrome::NOTIFICATION_APP_TERMINATING,
 205                  content::NotificationService::AllSources());
 206 }
 207
 208 SavedFilesService::~SavedFilesService() {}
 209
 210 void SavedFilesService::Observe(int type,
 211                                 const content::NotificationSource& source,
 212                                 const content::NotificationDetails& details) {
 213   switch (type) {
 214     case extensions::NOTIFICATION_EXTENSION_HOST_DESTROYED: {
 215       ExtensionHost* host = content::Details<ExtensionHost>(details).ptr();
 216       const Extension* extension = host->extension();
 217       if (extension) {
 218         ClearQueueIfNoRetainPermission(extension);
 219         Clear(extension->id());
 220       }
 221       break;
 222     }
 223
 224     case chrome::NOTIFICATION_APP_TERMINATING: {
 225       // Stop listening to NOTIFICATION_EXTENSION_HOST_DESTROYED in particular
 226       // as all extension hosts will be destroyed as a result of shutdown.
 227       registrar_.RemoveAll();
 228       break;
 229     }
 230   }
 231 }
 232
 233 void SavedFilesService::RegisterFileEntry(const std::string& extension_id,
 234                                           const std::string& id,
 235                                           const base::FilePath& file_path,
 236                                           bool is_directory) {
 237   GetOrInsert(extension_id)->RegisterFileEntry(id, file_path, is_directory);
 238 }
 239
 240 void SavedFilesService::EnqueueFileEntry(const std::string& extension_id,
 241                                          const std::string& id) {
 242   GetOrInsert(extension_id)->EnqueueFileEntry(id);
 243 }
 244
 245 std::vector<SavedFileEntry> SavedFilesService::GetAllFileEntries(
 246     const std::string& extension_id) {
 247   SavedFiles* saved_files = Get(extension_id);
 248   if (saved_files)
 249     return saved_files->GetAllFileEntries();
 250   return GetSavedFileEntries(ExtensionPrefs::Get(profile_), extension_id);
 251 }
 252
 253 bool SavedFilesService::IsRegistered(const std::string& extension_id,
 254                                      const std::string& id) {
 255   return GetOrInsert(extension_id)->IsRegistered(id);
 256 }
 257
 258 const SavedFileEntry* SavedFilesService::GetFileEntry(
 259     const std::string& extension_id,
 260     const std::string& id) {
 261   return GetOrInsert(extension_id)->GetFileEntry(id);
 262 }
 263
 264 void SavedFilesService::ClearQueueIfNoRetainPermission(
 265     const Extension* extension) {
 266   if (extensions::util::IsEphemeralApp(extension->id(), profile_) ||
 267       !extension->permissions_data()->active_permissions()->HasAPIPermission(
 268           APIPermission::kFileSystemRetainEntries)) {
 269     ClearQueue(extension);
 270   }
 271 }
 272
 273 void SavedFilesService::ClearQueue(const extensions::Extension* extension) {
 274   ClearSavedFileEntries(ExtensionPrefs::Get(profile_), extension->id());
 275   Clear(extension->id());
 276 }
 277
 278 SavedFilesService::SavedFiles* SavedFilesService::Get(
 279     const std::string& extension_id) const {
 280   std::map<std::string, SavedFiles*>::const_iterator it =
 281       extension_id_to_saved_files_.find(extension_id);
 282   if (it != extension_id_to_saved_files_.end())
 283     return it->second;
 284
 285   return NULL;
 286 }
 287
 288 SavedFilesService::SavedFiles* SavedFilesService::GetOrInsert(
 289     const std::string& extension_id) {
 290   SavedFiles* saved_files = Get(extension_id);
 291   if (saved_files)
 292     return saved_files;
 293
 294   saved_files = new SavedFiles(profile_, extension_id);
 295   extension_id_to_saved_files_.insert(
 296       std::make_pair(extension_id, saved_files));
 297   return saved_files;
 298 }
 299
 300 void SavedFilesService::Clear(const std::string& extension_id) {
 301   std::map<std::string, SavedFiles*>::iterator it =
 302       extension_id_to_saved_files_.find(extension_id);
 303   if (it != extension_id_to_saved_files_.end()) {
 304     delete it->second;
 305     extension_id_to_saved_files_.erase(it);
 306   }
 307 }
 308
 309 SavedFilesService::SavedFiles::SavedFiles(Profile* profile,
 310                                           const std::string& extension_id)
 311     : profile_(profile),
 312       extension_id_(extension_id),
 313       registered_file_entries_deleter_(&registered_file_entries_) {
 314   LoadSavedFileEntriesFromPreferences();
 315 }
 316
 317 SavedFilesService::SavedFiles::~SavedFiles() {}
 318
 319 void SavedFilesService::SavedFiles::RegisterFileEntry(
 320     const std::string& id,
 321     const base::FilePath& file_path,
 322     bool is_directory) {
 323   if (ContainsKey(registered_file_entries_, id))
 324     return;
 325
 326   registered_file_entries_.insert(
 327       std::make_pair(id, new SavedFileEntry(id, file_path, is_directory, 0)));
 328 }
 329
 330 void SavedFilesService::SavedFiles::EnqueueFileEntry(const std::string& id) {
 331   base::hash_map<std::string, SavedFileEntry*>::iterator it =
 332       registered_file_entries_.find(id);
 333   DCHECK(it != registered_file_entries_.end());
 334
 335   SavedFileEntry* file_entry = it->second;
 336   int old_sequence_number = file_entry->sequence_number;
 337   if (!saved_file_lru_.empty()) {
 338     // Get the sequence number after the last file entry in the LRU.
 339     std::map<int, SavedFileEntry*>::reverse_iterator it =
 340         saved_file_lru_.rbegin();
 341     if (it->second == file_entry)
 342       return;
 343
 344     file_entry->sequence_number = it->first + 1;
 345   } else {
 346     // The first sequence number is 1, as 0 means the entry is not in the LRU.
 347     file_entry->sequence_number = 1;
 348   }
 349   saved_file_lru_.insert(
 350       std::make_pair(file_entry->sequence_number, file_entry));
 351   ExtensionPrefs* prefs = ExtensionPrefs::Get(profile_);
 352   if (old_sequence_number) {
 353     saved_file_lru_.erase(old_sequence_number);
 354     UpdateSavedFileEntry(prefs, extension_id_, *file_entry);
 355   } else {
 356     AddSavedFileEntry(prefs, extension_id_, *file_entry);
 357     if (saved_file_lru_.size() > g_max_saved_file_entries) {
 358       std::map<int, SavedFileEntry*>::iterator it = saved_file_lru_.begin();
 359       it->second->sequence_number = 0;
 360       RemoveSavedFileEntry(prefs, extension_id_, it->second->id);
 361       saved_file_lru_.erase(it);
 362     }
 363   }
 364   MaybeCompactSequenceNumbers();
 365 }
 366
 367 bool SavedFilesService::SavedFiles::IsRegistered(const std::string& id) const {
 368   return ContainsKey(registered_file_entries_, id);
 369 }
 370
 371 const SavedFileEntry* SavedFilesService::SavedFiles::GetFileEntry(
 372     const std::string& id) const {
 373   base::hash_map<std::string, SavedFileEntry*>::const_iterator it =
 374       registered_file_entries_.find(id);
 375   if (it == registered_file_entries_.end())
 376     return NULL;
 377
 378   return it->second;
 379 }
 380
 381 std::vector<SavedFileEntry> SavedFilesService::SavedFiles::GetAllFileEntries()
 382     const {
 383   std::vector<SavedFileEntry> result;
 384   for (base::hash_map<std::string, SavedFileEntry*>::const_iterator it =
 385            registered_file_entries_.begin();
 386        it != registered_file_entries_.end();
 387        ++it) {
 388     result.push_back(*it->second);
 389   }
 390   return result;
 391 }
 392
 393 void SavedFilesService::SavedFiles::MaybeCompactSequenceNumbers() {
 394   DCHECK_GE(g_max_sequence_number, 0);
 395   DCHECK_GE(static_cast<size_t>(g_max_sequence_number),
 396             g_max_saved_file_entries);
 397   std::map<int, SavedFileEntry*>::reverse_iterator it =
 398       saved_file_lru_.rbegin();
 399   if (it == saved_file_lru_.rend())
 400     return;
 401
 402   // Only compact sequence numbers if the last entry's sequence number is the
 403   // maximum value.  This should almost never be the case.
 404   if (it->first < g_max_sequence_number)
 405     return;
 406
 407   int sequence_number = 0;
 408   ExtensionPrefs* prefs = ExtensionPrefs::Get(profile_);
 409   for (std::map<int, SavedFileEntry*>::iterator it = saved_file_lru_.begin();
 410        it != saved_file_lru_.end();
 411        ++it) {
 412     sequence_number++;
 413     if (it->second->sequence_number == sequence_number)
 414       continue;
 415
 416     SavedFileEntry* file_entry = it->second;
 417     file_entry->sequence_number = sequence_number;
 418     UpdateSavedFileEntry(prefs, extension_id_, *file_entry);
 419     saved_file_lru_.erase(it++);
 420     // Provide the following element as an insert hint. While optimized
 421     // insertion time with the following element as a hint is only supported by
 422     // the spec in C++11, the implementations do support this.
 423     it = saved_file_lru_.insert(
 424         it, std::make_pair(file_entry->sequence_number, file_entry));
 425   }
 426 }
 427
 428 void SavedFilesService::SavedFiles::LoadSavedFileEntriesFromPreferences() {
 429   ExtensionPrefs* prefs = ExtensionPrefs::Get(profile_);
 430   std::vector<SavedFileEntry> saved_entries =
 431       GetSavedFileEntries(prefs, extension_id_);
 432   for (std::vector<SavedFileEntry>::iterator it = saved_entries.begin();
 433        it != saved_entries.end();
 434        ++it) {
 435     SavedFileEntry* file_entry = new SavedFileEntry(*it);
 436     registered_file_entries_.insert(std::make_pair(file_entry->id, file_entry));
 437     saved_file_lru_.insert(
 438         std::make_pair(file_entry->sequence_number, file_entry));
 439   }
 440 }
 441
 442 // static
 443 void SavedFilesService::SetMaxSequenceNumberForTest(int max_value) {
 444   g_max_sequence_number = max_value;
 445 }
 446
 447 // static
 448 void SavedFilesService::ClearMaxSequenceNumberForTest() {
 449   g_max_sequence_number = kMaxSequenceNumber;
 450 }
 451
 452 // static
 453 void SavedFilesService::SetLruSizeForTest(int size) {
 454   g_max_saved_file_entries = size;
 455 }
 456
 457 // static
 458 void SavedFilesService::ClearLruSizeForTest() {
 459   g_max_saved_file_entries = kMaxSavedFileEntries;
 460 }
 461
 462 }  // namespace apps