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