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