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