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 the entry refers to a directory.
  40 const char kFileEntryIsDirectory[] = "is_directory";
  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(kFileEntryIsDirectory, file_entry.is_directory);
  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 is_directory = false;
 126     file_entry->GetBoolean(kFileEntryIsDirectory, &is_directory);
 127     int sequence_number = 0;
 128     if (!file_entry->GetInteger(kFileEntrySequenceNumber, &sequence_number))
 129       continue;
 130     if (!sequence_number)
 131       continue;
 132     result.push_back(
 133         SavedFileEntry(it.key(), file_path, is_directory, sequence_number));
 134   }
 135   return result;
 136 }
 137
 138 }  // namespace
 139
 140 SavedFileEntry::SavedFileEntry() : is_directory(false), sequence_number(0) {}
 141
 142 SavedFileEntry::SavedFileEntry(const std::string& id,
 143                                const base::FilePath& path,
 144                                bool is_directory,
 145                                int sequence_number)
 146     : id(id),
 147       path(path),
 148       is_directory(is_directory),
 149       sequence_number(sequence_number) {}
 150
 151 class SavedFilesService::SavedFiles {
 152  public:
 153   SavedFiles(Profile* profile, const std::string& extension_id);
 154   ~SavedFiles();
 155
 156   void RegisterFileEntry(const std::string& id,
 157                          const base::FilePath& file_path,
 158                          bool is_directory);
 159   void EnqueueFileEntry(const std::string& id);
 160   bool IsRegistered(const std::string& id) const;
 161   const SavedFileEntry* GetFileEntry(const std::string& id) const;
 162   std::vector<SavedFileEntry> GetAllFileEntries() const;
 163
 164  private:
 165   // Compacts sequence numbers if the largest sequence number is
 166   // g_max_sequence_number. Outside of testing, it is set to kint32max, so this
 167   // will almost never do any real work.
 168   void MaybeCompactSequenceNumbers();
 169
 170   void LoadSavedFileEntriesFromPreferences();
 171
 172   Profile* profile_;
 173   const std::string extension_id_;
 174
 175   // Contains all file entries that have been registered, keyed by ID. Owns
 176   // values.
 177   base::hash_map<std::string, SavedFileEntry*> registered_file_entries_;
 178   STLValueDeleter<base::hash_map<std::string, SavedFileEntry*> >
 179       registered_file_entries_deleter_;
 180
 181   // The queue of file entries that have been retained, keyed by
 182   // sequence_number. Values are a subset of values in registered_file_entries_.
 183   // This should be kept in sync with file entries stored in extension prefs.
 184   std::map<int, SavedFileEntry*> saved_file_lru_;
 185
 186   DISALLOW_COPY_AND_ASSIGN(SavedFiles);
 187 };
 188
 189 // static
 190 SavedFilesService* SavedFilesService::Get(Profile* profile) {
 191   return SavedFilesServiceFactory::GetForProfile(profile);
 192 }
 193
 194 SavedFilesService::SavedFilesService(Profile* profile)
 195     : extension_id_to_saved_files_deleter_(&extension_id_to_saved_files_),
 196       profile_(profile) {
 197   registrar_.Add(this,
 198                  chrome::NOTIFICATION_EXTENSION_HOST_DESTROYED,
 199                  content::NotificationService::AllSources());
 200   registrar_.Add(this,
 201                  chrome::NOTIFICATION_APP_TERMINATING,
 202                  content::NotificationService::AllSources());
 203 }
 204
 205 SavedFilesService::~SavedFilesService() {}
 206
 207 void SavedFilesService::Observe(int type,
 208                                 const content::NotificationSource& source,
 209                                 const content::NotificationDetails& details) {
 210   switch (type) {
 211     case chrome::NOTIFICATION_EXTENSION_HOST_DESTROYED: {
 212       ExtensionHost* host = content::Details<ExtensionHost>(details).ptr();
 213       const Extension* extension = host->extension();
 214       if (extension) {
 215         ClearQueueIfNoRetainPermission(extension);
 216         Clear(extension->id());
 217       }
 218       break;
 219     }
 220
 221     case chrome::NOTIFICATION_APP_TERMINATING: {
 222       // Stop listening to NOTIFICATION_EXTENSION_HOST_DESTROYED in particular
 223       // as all extension hosts will be destroyed as a result of shutdown.
 224       registrar_.RemoveAll();
 225       break;
 226     }
 227   }
 228 }
 229
 230 void SavedFilesService::RegisterFileEntry(const std::string& extension_id,
 231                                           const std::string& id,
 232                                           const base::FilePath& file_path,
 233                                           bool is_directory) {
 234   GetOrInsert(extension_id)->RegisterFileEntry(id, file_path, is_directory);
 235 }
 236
 237 void SavedFilesService::EnqueueFileEntry(const std::string& extension_id,
 238                                          const std::string& id) {
 239   GetOrInsert(extension_id)->EnqueueFileEntry(id);
 240 }
 241
 242 std::vector<SavedFileEntry> SavedFilesService::GetAllFileEntries(
 243     const std::string& extension_id) {
 244   SavedFiles* saved_files = Get(extension_id);
 245   if (saved_files)
 246     return saved_files->GetAllFileEntries();
 247   return GetSavedFileEntries(ExtensionPrefs::Get(profile_), extension_id);
 248 }
 249
 250 bool SavedFilesService::IsRegistered(const std::string& extension_id,
 251                                      const std::string& id) {
 252   return GetOrInsert(extension_id)->IsRegistered(id);
 253 }
 254
 255 const SavedFileEntry* SavedFilesService::GetFileEntry(
 256     const std::string& extension_id,
 257     const std::string& id) {
 258   return GetOrInsert(extension_id)->GetFileEntry(id);
 259 }
 260
 261 void SavedFilesService::ClearQueueIfNoRetainPermission(
 262     const Extension* extension) {
 263   if (!extension->GetActivePermissions()->HasAPIPermission(
 264           APIPermission::kFileSystemRetainEntries)) {
 265     ClearQueue(extension);
 266   }
 267 }
 268
 269 void SavedFilesService::ClearQueue(const extensions::Extension* extension) {
 270   ClearSavedFileEntries(ExtensionPrefs::Get(profile_), extension->id());
 271   Clear(extension->id());
 272 }
 273
 274 SavedFilesService::SavedFiles* SavedFilesService::Get(
 275     const std::string& extension_id) const {
 276   std::map<std::string, SavedFiles*>::const_iterator it =
 277       extension_id_to_saved_files_.find(extension_id);
 278   if (it != extension_id_to_saved_files_.end())
 279     return it->second;
 280
 281   return NULL;
 282 }
 283
 284 SavedFilesService::SavedFiles* SavedFilesService::GetOrInsert(
 285     const std::string& extension_id) {
 286   SavedFiles* saved_files = Get(extension_id);
 287   if (saved_files)
 288     return saved_files;
 289
 290   saved_files = new SavedFiles(profile_, extension_id);
 291   extension_id_to_saved_files_.insert(
 292       std::make_pair(extension_id, saved_files));
 293   return saved_files;
 294 }
 295
 296 void SavedFilesService::Clear(const std::string& extension_id) {
 297   std::map<std::string, SavedFiles*>::iterator it =
 298       extension_id_to_saved_files_.find(extension_id);
 299   if (it != extension_id_to_saved_files_.end()) {
 300     delete it->second;
 301     extension_id_to_saved_files_.erase(it);
 302   }
 303 }
 304
 305 SavedFilesService::SavedFiles::SavedFiles(Profile* profile,
 306                                           const std::string& extension_id)
 307     : profile_(profile),
 308       extension_id_(extension_id),
 309       registered_file_entries_deleter_(&registered_file_entries_) {
 310   LoadSavedFileEntriesFromPreferences();
 311 }
 312
 313 SavedFilesService::SavedFiles::~SavedFiles() {}
 314
 315 void SavedFilesService::SavedFiles::RegisterFileEntry(
 316     const std::string& id,
 317     const base::FilePath& file_path,
 318     bool is_directory) {
 319   if (ContainsKey(registered_file_entries_, id))
 320     return;
 321
 322   registered_file_entries_.insert(
 323       std::make_pair(id, new SavedFileEntry(id, file_path, is_directory, 0)));
 324 }
 325
 326 void SavedFilesService::SavedFiles::EnqueueFileEntry(const std::string& id) {
 327   base::hash_map<std::string, SavedFileEntry*>::iterator it =
 328       registered_file_entries_.find(id);
 329   DCHECK(it != registered_file_entries_.end());
 330
 331   SavedFileEntry* file_entry = it->second;
 332   int old_sequence_number = file_entry->sequence_number;
 333   if (!saved_file_lru_.empty()) {
 334     // Get the sequence number after the last file entry in the LRU.
 335     std::map<int, SavedFileEntry*>::reverse_iterator it =
 336         saved_file_lru_.rbegin();
 337     if (it->second == file_entry)
 338       return;
 339
 340     file_entry->sequence_number = it->first + 1;
 341   } else {
 342     // The first sequence number is 1, as 0 means the entry is not in the LRU.
 343     file_entry->sequence_number = 1;
 344   }
 345   saved_file_lru_.insert(
 346       std::make_pair(file_entry->sequence_number, file_entry));
 347   ExtensionPrefs* prefs = ExtensionPrefs::Get(profile_);
 348   if (old_sequence_number) {
 349     saved_file_lru_.erase(old_sequence_number);
 350     UpdateSavedFileEntry(prefs, extension_id_, *file_entry);
 351   } else {
 352     AddSavedFileEntry(prefs, extension_id_, *file_entry);
 353     if (saved_file_lru_.size() > g_max_saved_file_entries) {
 354       std::map<int, SavedFileEntry*>::iterator it = saved_file_lru_.begin();
 355       it->second->sequence_number = 0;
 356       RemoveSavedFileEntry(prefs, extension_id_, it->second->id);
 357       saved_file_lru_.erase(it);
 358     }
 359   }
 360   MaybeCompactSequenceNumbers();
 361 }
 362
 363 bool SavedFilesService::SavedFiles::IsRegistered(const std::string& id) const {
 364   return ContainsKey(registered_file_entries_, id);
 365 }
 366
 367 const SavedFileEntry* SavedFilesService::SavedFiles::GetFileEntry(
 368     const std::string& id) const {
 369   base::hash_map<std::string, SavedFileEntry*>::const_iterator it =
 370       registered_file_entries_.find(id);
 371   if (it == registered_file_entries_.end())
 372     return NULL;
 373
 374   return it->second;
 375 }
 376
 377 std::vector<SavedFileEntry> SavedFilesService::SavedFiles::GetAllFileEntries()
 378     const {
 379   std::vector<SavedFileEntry> result;
 380   for (base::hash_map<std::string, SavedFileEntry*>::const_iterator it =
 381            registered_file_entries_.begin();
 382        it != registered_file_entries_.end();
 383        ++it) {
 384     result.push_back(*it->second);
 385   }
 386   return result;
 387 }
 388
 389 void SavedFilesService::SavedFiles::MaybeCompactSequenceNumbers() {
 390   DCHECK_GE(g_max_sequence_number, 0);
 391   DCHECK_GE(static_cast<size_t>(g_max_sequence_number),
 392             g_max_saved_file_entries);
 393   std::map<int, SavedFileEntry*>::reverse_iterator it =
 394       saved_file_lru_.rbegin();
 395   if (it == saved_file_lru_.rend())
 396     return;
 397
 398   // Only compact sequence numbers if the last entry's sequence number is the
 399   // maximum value.  This should almost never be the case.
 400   if (it->first < g_max_sequence_number)
 401     return;
 402
 403   int sequence_number = 0;
 404   ExtensionPrefs* prefs = ExtensionPrefs::Get(profile_);
 405   for (std::map<int, SavedFileEntry*>::iterator it = saved_file_lru_.begin();
 406        it != saved_file_lru_.end();
 407        ++it) {
 408     sequence_number++;
 409     if (it->second->sequence_number == sequence_number)
 410       continue;
 411
 412     SavedFileEntry* file_entry = it->second;
 413     file_entry->sequence_number = sequence_number;
 414     UpdateSavedFileEntry(prefs, extension_id_, *file_entry);
 415     saved_file_lru_.erase(it++);
 416     // Provide the following element as an insert hint. While optimized
 417     // insertion time with the following element as a hint is only supported by
 418     // the spec in C++11, the implementations do support this.
 419     it = saved_file_lru_.insert(
 420         it, std::make_pair(file_entry->sequence_number, file_entry));
 421   }
 422 }
 423
 424 void SavedFilesService::SavedFiles::LoadSavedFileEntriesFromPreferences() {
 425   ExtensionPrefs* prefs = ExtensionPrefs::Get(profile_);
 426   std::vector<SavedFileEntry> saved_entries =
 427       GetSavedFileEntries(prefs, extension_id_);
 428   for (std::vector<SavedFileEntry>::iterator it = saved_entries.begin();
 429        it != saved_entries.end();
 430        ++it) {
 431     SavedFileEntry* file_entry = new SavedFileEntry(*it);
 432     registered_file_entries_.insert(std::make_pair(file_entry->id, file_entry));
 433     saved_file_lru_.insert(
 434         std::make_pair(file_entry->sequence_number, file_entry));
 435   }
 436 }
 437
 438 // static
 439 void SavedFilesService::SetMaxSequenceNumberForTest(int max_value) {
 440   g_max_sequence_number = max_value;
 441 }
 442
 443 // static
 444 void SavedFilesService::ClearMaxSequenceNumberForTest() {
 445   g_max_sequence_number = kMaxSequenceNumber;
 446 }
 447
 448 // static
 449 void SavedFilesService::SetLruSizeForTest(int size) {
 450   g_max_saved_file_entries = size;
 451 }
 452
 453 // static
 454 void SavedFilesService::ClearLruSizeForTest() {
 455   g_max_saved_file_entries = kMaxSavedFileEntries;
 456 }
 457
 458 }  // namespace apps