src/chrome/browser/spellchecker/spellcheck_hunspell_dictionary.cc

   1 // Copyright (c) 2012 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 "chrome/browser/spellchecker/spellcheck_hunspell_dictionary.h"
   6
   7 #include "base/file_util.h"
   8 #include "base/files/memory_mapped_file.h"
   9 #include "base/logging.h"
  10 #include "base/message_loop/message_loop.h"
  11 #include "base/path_service.h"
  12 #include "chrome/browser/spellchecker/spellcheck_platform_mac.h"
  13 #include "chrome/browser/spellchecker/spellcheck_service.h"
  14 #include "chrome/common/chrome_paths.h"
  15 #include "chrome/common/spellcheck_common.h"
  16 #include "chrome/common/spellcheck_messages.h"
  17 #include "content/public/browser/browser_thread.h"
  18 #include "content/public/browser/render_process_host.h"
  19 #include "net/base/load_flags.h"
  20 #include "net/url_request/url_fetcher.h"
  21 #include "net/url_request/url_request_context_getter.h"
  22 #include "third_party/hunspell/google/bdict.h"
  23 #include "url/gurl.h"
  24
  25 using content::BrowserThread;
  26
  27 namespace {
  28
  29 // Close the platform file.
  30 void CloseDictionary(base::PlatformFile file) {
  31   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  32   base::ClosePlatformFile(file);
  33 }
  34
  35 }  // namespace
  36
  37 // Dictionary file information to be passed between the FILE and UI threads.
  38 struct DictionaryFile {
  39   DictionaryFile() : descriptor(base::kInvalidPlatformFileValue) {
  40   }
  41
  42   ~DictionaryFile() {
  43     if (descriptor != base::kInvalidPlatformFileValue) {
  44       BrowserThread::PostTask(
  45           BrowserThread::FILE,
  46           FROM_HERE,
  47           base::Bind(&CloseDictionary, descriptor));
  48       descriptor = base::kInvalidPlatformFileValue;
  49     }
  50   }
  51
  52   // The desired location of the dictionary file, whether or not it exists.
  53   base::FilePath path;
  54
  55   // The file descriptor/handle for the dictionary file.
  56   base::PlatformFile descriptor;
  57
  58   DISALLOW_COPY_AND_ASSIGN(DictionaryFile);
  59 };
  60
  61 namespace {
  62
  63 // Figures out the location for the dictionary, verifies its contents, and opens
  64 // it. The default_dictionary_file can either come from the standard list of
  65 // hunspell dictionaries (determined in InitializeDictionaryLocation), or it
  66 // can be passed in via an extension. In either case, the file is checked for
  67 // existence so that it's not re-downloaded.
  68 // For systemwide installations on Windows, the default directory may not
  69 // have permissions for download. In that case, the alternate directory for
  70 // download is chrome::DIR_USER_DATA.
  71 // Returns a scoped pointer to avoid leaking the file descriptor if the caller
  72 // has been destroyed.
  73 scoped_ptr<DictionaryFile> OpenDictionaryFile(
  74     scoped_ptr<DictionaryFile> file) {
  75   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  76
  77 #if defined(OS_WIN)
  78   // Check if the dictionary exists in the fallback location. If so, use it
  79   // rather than downloading anew.
  80   base::FilePath user_dir;
  81   PathService::Get(chrome::DIR_USER_DATA, &user_dir);
  82   base::FilePath fallback = user_dir.Append(file->path.BaseName());
  83   if (!base::PathExists(file->path) && base::PathExists(fallback))
  84     file->path = fallback;
  85 #endif
  86
  87   // Read the dictionary file and scan its data to check for corruption. The
  88   // scoping closes the memory-mapped file before it is opened or deleted.
  89   bool bdict_is_valid;
  90   {
  91     base::MemoryMappedFile map;
  92     bdict_is_valid = base::PathExists(file->path) &&
  93         map.Initialize(file->path) &&
  94         hunspell::BDict::Verify(reinterpret_cast<const char*>(map.data()),
  95                                 map.length());
  96   }
  97   if (bdict_is_valid) {
  98     file->descriptor = base::CreatePlatformFile(
  99         file->path,
 100         base::PLATFORM_FILE_READ | base::PLATFORM_FILE_OPEN,
 101         NULL,
 102         NULL);
 103   } else {
 104     base::DeleteFile(file->path, false);
 105   }
 106
 107   return file.Pass();
 108 }
 109
 110 // Gets the default location for the dictionary file. The default place where
 111 // the spellcheck dictionary resides is chrome::DIR_APP_DICTIONARIES.
 112 // Returns a scoped pointer to avoid leaking the file descriptor if the caller
 113 // has been destroyed.
 114 scoped_ptr<DictionaryFile> InitializeDictionaryLocation(
 115     const std::string& language) {
 116   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 117   scoped_ptr<DictionaryFile> file(new DictionaryFile);
 118
 119   // Initialize the BDICT path. Initialization should be in the FILE thread
 120   // because it checks if there is a "Dictionaries" directory and create it.
 121   base::FilePath dict_dir;
 122   PathService::Get(chrome::DIR_APP_DICTIONARIES, &dict_dir);
 123   file->path = chrome::spellcheck_common::GetVersionedFileName(
 124       language, dict_dir);
 125
 126   return OpenDictionaryFile(file.Pass());
 127 }
 128
 129 // Saves |data| to file at |path|. Returns true on successful save, otherwise
 130 // returns false.
 131 bool SaveDictionaryData(scoped_ptr<std::string> data,
 132                         const base::FilePath& path) {
 133   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 134
 135   size_t bytes_written =
 136       file_util::WriteFile(path, data->data(), data->length());
 137   if (bytes_written != data->length()) {
 138     bool success = false;
 139 #if defined(OS_WIN)
 140     base::FilePath dict_dir;
 141     PathService::Get(chrome::DIR_USER_DATA, &dict_dir);
 142     base::FilePath fallback_file_path =
 143         dict_dir.Append(path.BaseName());
 144     bytes_written =
 145         file_util::WriteFile(fallback_file_path, data->data(), data->length());
 146     if (bytes_written == data->length())
 147       success = true;
 148 #endif
 149
 150     if (!success) {
 151       base::DeleteFile(path, false);
 152       return false;
 153     }
 154   }
 155
 156   return true;
 157 }
 158
 159 }  // namespace
 160
 161 SpellcheckHunspellDictionary::SpellcheckHunspellDictionary(
 162     const std::string& language,
 163     net::URLRequestContextGetter* request_context_getter,
 164     SpellcheckService* spellcheck_service)
 165     : language_(language),
 166       use_platform_spellchecker_(false),
 167       request_context_getter_(request_context_getter),
 168       spellcheck_service_(spellcheck_service),
 169       download_status_(DOWNLOAD_NONE),
 170       dictionary_file_(new DictionaryFile),
 171       weak_ptr_factory_(this) {
 172 }
 173
 174 SpellcheckHunspellDictionary::~SpellcheckHunspellDictionary() {
 175 }
 176
 177 void SpellcheckHunspellDictionary::Load() {
 178   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 179
 180 #if defined(OS_MACOSX)
 181   if (spellcheck_mac::SpellCheckerAvailable() &&
 182       spellcheck_mac::PlatformSupportsLanguage(language_)) {
 183     use_platform_spellchecker_ = true;
 184     spellcheck_mac::SetLanguage(language_);
 185     base::MessageLoop::current()->PostTask(FROM_HERE,
 186         base::Bind(
 187             &SpellcheckHunspellDictionary::InformListenersOfInitialization,
 188             weak_ptr_factory_.GetWeakPtr()));
 189     return;
 190   }
 191 #endif  // OS_MACOSX
 192
 193   BrowserThread::PostTaskAndReplyWithResult(
 194       BrowserThread::FILE,
 195       FROM_HERE,
 196       base::Bind(&InitializeDictionaryLocation, language_),
 197       base::Bind(
 198           &SpellcheckHunspellDictionary::InitializeDictionaryLocationComplete,
 199           weak_ptr_factory_.GetWeakPtr()));
 200 }
 201
 202 void SpellcheckHunspellDictionary::RetryDownloadDictionary(
 203       net::URLRequestContextGetter* request_context_getter) {
 204   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 205   request_context_getter_ = request_context_getter;
 206   DownloadDictionary(GetDictionaryURL());
 207 }
 208
 209 bool SpellcheckHunspellDictionary::IsReady() const {
 210   return GetDictionaryFile() !=
 211       base::kInvalidPlatformFileValue || IsUsingPlatformChecker();
 212 }
 213
 214 const base::PlatformFile&
 215 SpellcheckHunspellDictionary::GetDictionaryFile() const {
 216   return dictionary_file_->descriptor;
 217 }
 218
 219 const std::string& SpellcheckHunspellDictionary::GetLanguage() const {
 220   return language_;
 221 }
 222
 223 bool SpellcheckHunspellDictionary::IsUsingPlatformChecker() const {
 224   return use_platform_spellchecker_;
 225 }
 226
 227 void SpellcheckHunspellDictionary::AddObserver(Observer* observer) {
 228   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 229   observers_.AddObserver(observer);
 230 }
 231
 232 void SpellcheckHunspellDictionary::RemoveObserver(Observer* observer) {
 233   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 234   observers_.RemoveObserver(observer);
 235 }
 236
 237 bool SpellcheckHunspellDictionary::IsDownloadInProgress() {
 238   return download_status_ == DOWNLOAD_IN_PROGRESS;
 239 }
 240
 241 bool SpellcheckHunspellDictionary::IsDownloadFailure() {
 242   return download_status_ == DOWNLOAD_FAILED;
 243 }
 244
 245 void SpellcheckHunspellDictionary::OnURLFetchComplete(
 246     const net::URLFetcher* source) {
 247   DCHECK(source);
 248   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 249   scoped_ptr<net::URLFetcher> fetcher_destructor(fetcher_.release());
 250
 251   if ((source->GetResponseCode() / 100) != 2) {
 252     // Initialize will not try to download the file a second time.
 253     InformListenersOfDownloadFailure();
 254     return;
 255   }
 256
 257   // Basic sanity check on the dictionary. There's a small chance of 200 status
 258   // code for a body that represents some form of failure.
 259   scoped_ptr<std::string> data(new std::string);
 260   source->GetResponseAsString(data.get());
 261   if (data->size() < 4 || data->compare(0, 4, "BDic") != 0) {
 262     InformListenersOfDownloadFailure();
 263     return;
 264   }
 265
 266   // To prevent corrupted dictionary data from causing a renderer crash, scan
 267   // the dictionary data and verify it is sane before save it to a file.
 268   // TODO(rlp): Adding metrics to RecordDictionaryCorruptionStats
 269   if (!hunspell::BDict::Verify(data->data(), data->size())) {
 270     // Let PostTaskAndReply caller send to InformListenersOfInitialization
 271     // through SaveDictionaryDataComplete().
 272     SaveDictionaryDataComplete(false);
 273     return;
 274   }
 275
 276   BrowserThread::PostTaskAndReplyWithResult<bool>(
 277       BrowserThread::FILE,
 278       FROM_HERE,
 279       base::Bind(&SaveDictionaryData,
 280                  base::Passed(&data),
 281                  dictionary_file_->path),
 282       base::Bind(&SpellcheckHunspellDictionary::SaveDictionaryDataComplete,
 283                  weak_ptr_factory_.GetWeakPtr()));
 284 }
 285
 286 GURL SpellcheckHunspellDictionary::GetDictionaryURL() {
 287   static const char kDownloadServerUrl[] =
 288       "http://cache.pack.google.com/edgedl/chrome/dict/";
 289   std::string bdict_file = dictionary_file_->path.BaseName().MaybeAsASCII();
 290
 291   DCHECK(!bdict_file.empty());
 292
 293   return GURL(std::string(kDownloadServerUrl) +
 294               StringToLowerASCII(bdict_file));
 295 }
 296
 297 void SpellcheckHunspellDictionary::DownloadDictionary(GURL url) {
 298   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 299   DCHECK(request_context_getter_);
 300
 301   download_status_ = DOWNLOAD_IN_PROGRESS;
 302   FOR_EACH_OBSERVER(Observer, observers_, OnHunspellDictionaryDownloadBegin());
 303
 304   fetcher_.reset(net::URLFetcher::Create(url, net::URLFetcher::GET, this));
 305   fetcher_->SetRequestContext(request_context_getter_);
 306   fetcher_->SetLoadFlags(
 307       net::LOAD_DO_NOT_SEND_COOKIES | net::LOAD_DO_NOT_SAVE_COOKIES);
 308   fetcher_->Start();
 309   // Attempt downloading the dictionary only once.
 310   request_context_getter_ = NULL;
 311 }
 312
 313 void SpellcheckHunspellDictionary::InitializeDictionaryLocationComplete(
 314     scoped_ptr<DictionaryFile> file) {
 315   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 316   dictionary_file_ = file.Pass();
 317
 318   if (dictionary_file_->descriptor == base::kInvalidPlatformFileValue) {
 319
 320     // Notify browser tests that this dictionary is corrupted. Skip downloading
 321     // the dictionary in browser tests.
 322     // TODO(rouslan): Remove this test-only case.
 323     if (spellcheck_service_->SignalStatusEvent(
 324           SpellcheckService::BDICT_CORRUPTED)) {
 325       request_context_getter_ = NULL;
 326     }
 327
 328     if (request_context_getter_) {
 329       // Download from the UI thread to check that |request_context_getter_| is
 330       // still valid.
 331       DownloadDictionary(GetDictionaryURL());
 332       return;
 333     }
 334   }
 335
 336   InformListenersOfInitialization();
 337 }
 338
 339 void SpellcheckHunspellDictionary::SaveDictionaryDataComplete(
 340     bool dictionary_saved) {
 341   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 342
 343   if (dictionary_saved) {
 344     download_status_ = DOWNLOAD_NONE;
 345     FOR_EACH_OBSERVER(Observer,
 346                       observers_,
 347                       OnHunspellDictionaryDownloadSuccess());
 348     Load();
 349   } else {
 350     InformListenersOfDownloadFailure();
 351     InformListenersOfInitialization();
 352   }
 353 }
 354
 355 void SpellcheckHunspellDictionary::InformListenersOfInitialization() {
 356   FOR_EACH_OBSERVER(Observer, observers_, OnHunspellDictionaryInitialized());
 357 }
 358
 359 void SpellcheckHunspellDictionary::InformListenersOfDownloadFailure() {
 360   download_status_ = DOWNLOAD_FAILED;
 361   FOR_EACH_OBSERVER(Observer,
 362                     observers_,
 363                     OnHunspellDictionaryDownloadFailure());
 364 }