content/browser/indexed_db/leveldb/leveldb_database.cc

   1 // Copyright (c) 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 "content/browser/indexed_db/leveldb/leveldb_database.h"
   6
   7 #include <cerrno>
   8
   9 #include "base/basictypes.h"
  10 #include "base/files/file.h"
  11 #include "base/logging.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/metrics/histogram.h"
  14 #include "base/strings/string16.h"
  15 #include "base/strings/string_piece.h"
  16 #include "base/strings/stringprintf.h"
  17 #include "base/strings/utf_string_conversions.h"
  18 #include "base/sys_info.h"
  19 #include "content/browser/indexed_db/indexed_db_class_factory.h"
  20 #include "content/browser/indexed_db/leveldb/leveldb_comparator.h"
  21 #include "content/browser/indexed_db/leveldb/leveldb_iterator_impl.h"
  22 #include "content/browser/indexed_db/leveldb/leveldb_write_batch.h"
  23 #include "third_party/leveldatabase/env_chromium.h"
  24 #include "third_party/leveldatabase/env_idb.h"
  25 #include "third_party/leveldatabase/src/helpers/memenv/memenv.h"
  26 #include "third_party/leveldatabase/src/include/leveldb/db.h"
  27 #include "third_party/leveldatabase/src/include/leveldb/env.h"
  28 #include "third_party/leveldatabase/src/include/leveldb/filter_policy.h"
  29 #include "third_party/leveldatabase/src/include/leveldb/slice.h"
  30
  31 using base::StringPiece;
  32
  33 namespace content {
  34
  35 // Forcing flushes to disk at the end of a transaction guarantees that the
  36 // data hit disk, but drastically impacts throughput when the filesystem is
  37 // busy with background compactions. Not syncing trades off reliability for
  38 // performance. Note that background compactions which move data from the
  39 // log to SSTs are always done with reliable writes.
  40 //
  41 // Sync writes are necessary on Windows for quota calculations; POSIX
  42 // calculates file sizes correctly even when not synced to disk.
  43 #if defined(OS_WIN)
  44 static const bool kSyncWrites = true;
  45 #else
  46 // TODO(dgrogan): Either remove the #if block or change this back to false.
  47 // See http://crbug.com/338385.
  48 static const bool kSyncWrites = true;
  49 #endif
  50
  51 static leveldb::Slice MakeSlice(const StringPiece& s) {
  52   return leveldb::Slice(s.begin(), s.size());
  53 }
  54
  55 static StringPiece MakeStringPiece(const leveldb::Slice& s) {
  56   return StringPiece(s.data(), s.size());
  57 }
  58
  59 LevelDBDatabase::ComparatorAdapter::ComparatorAdapter(
  60     const LevelDBComparator* comparator)
  61     : comparator_(comparator) {}
  62
  63 int LevelDBDatabase::ComparatorAdapter::Compare(const leveldb::Slice& a,
  64                                                 const leveldb::Slice& b) const {
  65   return comparator_->Compare(MakeStringPiece(a), MakeStringPiece(b));
  66 }
  67
  68 const char* LevelDBDatabase::ComparatorAdapter::Name() const {
  69   return comparator_->Name();
  70 }
  71
  72 // TODO(jsbell): Support the methods below in the future.
  73 void LevelDBDatabase::ComparatorAdapter::FindShortestSeparator(
  74     std::string* start,
  75     const leveldb::Slice& limit) const {}
  76
  77 void LevelDBDatabase::ComparatorAdapter::FindShortSuccessor(
  78     std::string* key) const {}
  79
  80 LevelDBSnapshot::LevelDBSnapshot(LevelDBDatabase* db)
  81     : db_(db->db_.get()), snapshot_(db_->GetSnapshot()) {}
  82
  83 LevelDBSnapshot::~LevelDBSnapshot() { db_->ReleaseSnapshot(snapshot_); }
  84
  85 LevelDBDatabase::LevelDBDatabase() {}
  86
  87 LevelDBDatabase::~LevelDBDatabase() {
  88   // db_'s destructor uses comparator_adapter_; order of deletion is important.
  89   db_.reset();
  90   comparator_adapter_.reset();
  91   env_.reset();
  92 }
  93
  94 static leveldb::Status OpenDB(
  95     leveldb::Comparator* comparator,
  96     leveldb::Env* env,
  97     const base::FilePath& path,
  98     leveldb::DB** db,
  99     scoped_ptr<const leveldb::FilterPolicy>* filter_policy) {
 100   filter_policy->reset(leveldb::NewBloomFilterPolicy(10));
 101   leveldb::Options options;
 102   options.comparator = comparator;
 103   options.create_if_missing = true;
 104   options.paranoid_checks = true;
 105   options.filter_policy = filter_policy->get();
 106 #if defined(OS_CHROMEOS)
 107   // Disabled on CrOS until crbug.com/460568 is fixed.
 108   options.reuse_logs = false;
 109 #else
 110   options.reuse_logs = true;
 111 #endif
 112   options.compression = leveldb::kSnappyCompression;
 113
 114   // For info about the troubles we've run into with this parameter, see:
 115   // https://code.google.com/p/chromium/issues/detail?id=227313#c11
 116   options.max_open_files = 80;
 117   options.env = env;
 118
 119   // ChromiumEnv assumes UTF8, converts back to FilePath before using.
 120   leveldb::Status s = leveldb::DB::Open(options, path.AsUTF8Unsafe(), db);
 121
 122   return s;
 123 }
 124
 125 leveldb::Status LevelDBDatabase::Destroy(const base::FilePath& file_name) {
 126   leveldb::Options options;
 127   options.env = leveldb::IDBEnv();
 128   // ChromiumEnv assumes UTF8, converts back to FilePath before using.
 129   return leveldb::DestroyDB(file_name.AsUTF8Unsafe(), options);
 130 }
 131
 132 namespace {
 133 class LockImpl : public LevelDBLock {
 134  public:
 135   explicit LockImpl(leveldb::Env* env, leveldb::FileLock* lock)
 136       : env_(env), lock_(lock) {}
 137   ~LockImpl() override { env_->UnlockFile(lock_); }
 138
 139  private:
 140   leveldb::Env* env_;
 141   leveldb::FileLock* lock_;
 142
 143   DISALLOW_COPY_AND_ASSIGN(LockImpl);
 144 };
 145 }  // namespace
 146
 147 scoped_ptr<LevelDBLock> LevelDBDatabase::LockForTesting(
 148     const base::FilePath& file_name) {
 149   leveldb::Env* env = leveldb::IDBEnv();
 150   base::FilePath lock_path = file_name.AppendASCII("LOCK");
 151   leveldb::FileLock* lock = NULL;
 152   leveldb::Status status = env->LockFile(lock_path.AsUTF8Unsafe(), &lock);
 153   if (!status.ok())
 154     return scoped_ptr<LevelDBLock>();
 155   DCHECK(lock);
 156   return scoped_ptr<LevelDBLock>(new LockImpl(env, lock));
 157 }
 158
 159 static int CheckFreeSpace(const char* const type,
 160                           const base::FilePath& file_name) {
 161   std::string name =
 162       std::string("WebCore.IndexedDB.LevelDB.Open") + type + "FreeDiskSpace";
 163   int64 free_disk_space_in_k_bytes =
 164       base::SysInfo::AmountOfFreeDiskSpace(file_name) / 1024;
 165   if (free_disk_space_in_k_bytes < 0) {
 166     base::Histogram::FactoryGet(
 167         "WebCore.IndexedDB.LevelDB.FreeDiskSpaceFailure",
 168         1,
 169         2 /*boundary*/,
 170         2 /*boundary*/ + 1,
 171         base::HistogramBase::kUmaTargetedHistogramFlag)->Add(1 /*sample*/);
 172     return -1;
 173   }
 174   int clamped_disk_space_k_bytes = free_disk_space_in_k_bytes > INT_MAX
 175                                        ? INT_MAX
 176                                        : free_disk_space_in_k_bytes;
 177   const uint64 histogram_max = static_cast<uint64>(1e9);
 178   static_assert(histogram_max <= INT_MAX, "histogram_max too big");
 179   base::Histogram::FactoryGet(name,
 180                               1,
 181                               histogram_max,
 182                               11 /*buckets*/,
 183                               base::HistogramBase::kUmaTargetedHistogramFlag)
 184       ->Add(clamped_disk_space_k_bytes);
 185   return clamped_disk_space_k_bytes;
 186 }
 187
 188 static void ParseAndHistogramIOErrorDetails(const std::string& histogram_name,
 189                                             const leveldb::Status& s) {
 190   leveldb_env::MethodID method;
 191   base::File::Error error = base::File::FILE_OK;
 192   leveldb_env::ErrorParsingResult result =
 193       leveldb_env::ParseMethodAndError(s, &method, &error);
 194   if (result == leveldb_env::NONE)
 195     return;
 196   std::string method_histogram_name(histogram_name);
 197   method_histogram_name.append(".EnvMethod");
 198   base::LinearHistogram::FactoryGet(
 199       method_histogram_name,
 200       1,
 201       leveldb_env::kNumEntries,
 202       leveldb_env::kNumEntries + 1,
 203       base::HistogramBase::kUmaTargetedHistogramFlag)->Add(method);
 204
 205   std::string error_histogram_name(histogram_name);
 206
 207   if (result == leveldb_env::METHOD_AND_PFE) {
 208     DCHECK_LT(error, 0);
 209     error_histogram_name.append(std::string(".PFE.") +
 210                                 leveldb_env::MethodIDToString(method));
 211     base::LinearHistogram::FactoryGet(
 212         error_histogram_name,
 213         1,
 214         -base::File::FILE_ERROR_MAX,
 215         -base::File::FILE_ERROR_MAX + 1,
 216         base::HistogramBase::kUmaTargetedHistogramFlag)->Add(-error);
 217   }
 218 }
 219
 220 static void ParseAndHistogramCorruptionDetails(
 221     const std::string& histogram_name,
 222     const leveldb::Status& status) {
 223   int error = leveldb_env::GetCorruptionCode(status);
 224   DCHECK_GE(error, 0);
 225   std::string corruption_histogram_name(histogram_name);
 226   corruption_histogram_name.append(".Corruption");
 227   const int kNumPatterns = leveldb_env::GetNumCorruptionCodes();
 228   base::LinearHistogram::FactoryGet(
 229       corruption_histogram_name,
 230       1,
 231       kNumPatterns,
 232       kNumPatterns + 1,
 233       base::HistogramBase::kUmaTargetedHistogramFlag)->Add(error);
 234 }
 235
 236 static void HistogramLevelDBError(const std::string& histogram_name,
 237                                   const leveldb::Status& s) {
 238   if (s.ok()) {
 239     NOTREACHED();
 240     return;
 241   }
 242   enum {
 243     LEVEL_DB_NOT_FOUND,
 244     LEVEL_DB_CORRUPTION,
 245     LEVEL_DB_IO_ERROR,
 246     LEVEL_DB_OTHER,
 247     LEVEL_DB_MAX_ERROR
 248   };
 249   int leveldb_error = LEVEL_DB_OTHER;
 250   if (s.IsNotFound())
 251     leveldb_error = LEVEL_DB_NOT_FOUND;
 252   else if (s.IsCorruption())
 253     leveldb_error = LEVEL_DB_CORRUPTION;
 254   else if (s.IsIOError())
 255     leveldb_error = LEVEL_DB_IO_ERROR;
 256   base::Histogram::FactoryGet(histogram_name,
 257                               1,
 258                               LEVEL_DB_MAX_ERROR,
 259                               LEVEL_DB_MAX_ERROR + 1,
 260                               base::HistogramBase::kUmaTargetedHistogramFlag)
 261       ->Add(leveldb_error);
 262   if (s.IsIOError())
 263     ParseAndHistogramIOErrorDetails(histogram_name, s);
 264   else
 265     ParseAndHistogramCorruptionDetails(histogram_name, s);
 266 }
 267
 268 leveldb::Status LevelDBDatabase::Open(const base::FilePath& file_name,
 269                                       const LevelDBComparator* comparator,
 270                                       scoped_ptr<LevelDBDatabase>* result,
 271                                       bool* is_disk_full) {
 272   base::TimeTicks begin_time = base::TimeTicks::Now();
 273
 274   scoped_ptr<ComparatorAdapter> comparator_adapter(
 275       new ComparatorAdapter(comparator));
 276
 277   leveldb::DB* db;
 278   scoped_ptr<const leveldb::FilterPolicy> filter_policy;
 279   const leveldb::Status s = OpenDB(comparator_adapter.get(),
 280                                    leveldb::IDBEnv(),
 281                                    file_name,
 282                                    &db,
 283                                    &filter_policy);
 284
 285   if (!s.ok()) {
 286     HistogramLevelDBError("WebCore.IndexedDB.LevelDBOpenErrors", s);
 287     int free_space_k_bytes = CheckFreeSpace("Failure", file_name);
 288     // Disks with <100k of free space almost never succeed in opening a
 289     // leveldb database.
 290     if (is_disk_full)
 291       *is_disk_full = free_space_k_bytes >= 0 && free_space_k_bytes < 100;
 292
 293     LOG(ERROR) << "Failed to open LevelDB database from "
 294                << file_name.AsUTF8Unsafe() << "," << s.ToString();
 295     return s;
 296   }
 297
 298   UMA_HISTOGRAM_MEDIUM_TIMES("WebCore.IndexedDB.LevelDB.OpenTime",
 299                              base::TimeTicks::Now() - begin_time);
 300
 301   CheckFreeSpace("Success", file_name);
 302
 303   (*result).reset(new LevelDBDatabase);
 304   (*result)->db_ = make_scoped_ptr(db);
 305   (*result)->comparator_adapter_ = comparator_adapter.Pass();
 306   (*result)->comparator_ = comparator;
 307   (*result)->filter_policy_ = filter_policy.Pass();
 308
 309   return s;
 310 }
 311
 312 scoped_ptr<LevelDBDatabase> LevelDBDatabase::OpenInMemory(
 313     const LevelDBComparator* comparator) {
 314   scoped_ptr<ComparatorAdapter> comparator_adapter(
 315       new ComparatorAdapter(comparator));
 316   scoped_ptr<leveldb::Env> in_memory_env(leveldb::NewMemEnv(leveldb::IDBEnv()));
 317
 318   leveldb::DB* db;
 319   scoped_ptr<const leveldb::FilterPolicy> filter_policy;
 320   const leveldb::Status s = OpenDB(comparator_adapter.get(),
 321                                    in_memory_env.get(),
 322                                    base::FilePath(),
 323                                    &db,
 324                                    &filter_policy);
 325
 326   if (!s.ok()) {
 327     LOG(ERROR) << "Failed to open in-memory LevelDB database: " << s.ToString();
 328     return scoped_ptr<LevelDBDatabase>();
 329   }
 330
 331   scoped_ptr<LevelDBDatabase> result(new LevelDBDatabase);
 332   result->env_ = in_memory_env.Pass();
 333   result->db_ = make_scoped_ptr(db);
 334   result->comparator_adapter_ = comparator_adapter.Pass();
 335   result->comparator_ = comparator;
 336   result->filter_policy_ = filter_policy.Pass();
 337
 338   return result.Pass();
 339 }
 340
 341 leveldb::Status LevelDBDatabase::Put(const StringPiece& key,
 342                                      std::string* value) {
 343   base::TimeTicks begin_time = base::TimeTicks::Now();
 344
 345   leveldb::WriteOptions write_options;
 346   write_options.sync = kSyncWrites;
 347
 348   const leveldb::Status s =
 349       db_->Put(write_options, MakeSlice(key), MakeSlice(*value));
 350   if (!s.ok())
 351     LOG(ERROR) << "LevelDB put failed: " << s.ToString();
 352   else
 353     UMA_HISTOGRAM_TIMES("WebCore.IndexedDB.LevelDB.PutTime",
 354                         base::TimeTicks::Now() - begin_time);
 355   return s;
 356 }
 357
 358 leveldb::Status LevelDBDatabase::Remove(const StringPiece& key) {
 359   leveldb::WriteOptions write_options;
 360   write_options.sync = kSyncWrites;
 361
 362   const leveldb::Status s = db_->Delete(write_options, MakeSlice(key));
 363   if (!s.IsNotFound())
 364     LOG(ERROR) << "LevelDB remove failed: " << s.ToString();
 365   return s;
 366 }
 367
 368 leveldb::Status LevelDBDatabase::Get(const StringPiece& key,
 369                                      std::string* value,
 370                                      bool* found,
 371                                      const LevelDBSnapshot* snapshot) {
 372   *found = false;
 373   leveldb::ReadOptions read_options;
 374   read_options.verify_checksums = true;  // TODO(jsbell): Disable this if the
 375                                          // performance impact is too great.
 376   read_options.snapshot = snapshot ? snapshot->snapshot_ : 0;
 377
 378   const leveldb::Status s = db_->Get(read_options, MakeSlice(key), value);
 379   if (s.ok()) {
 380     *found = true;
 381     return s;
 382   }
 383   if (s.IsNotFound())
 384     return leveldb::Status::OK();
 385   HistogramLevelDBError("WebCore.IndexedDB.LevelDBReadErrors", s);
 386   LOG(ERROR) << "LevelDB get failed: " << s.ToString();
 387   return s;
 388 }
 389
 390 leveldb::Status LevelDBDatabase::Write(const LevelDBWriteBatch& write_batch) {
 391   base::TimeTicks begin_time = base::TimeTicks::Now();
 392   leveldb::WriteOptions write_options;
 393   write_options.sync = kSyncWrites;
 394
 395   const leveldb::Status s =
 396       db_->Write(write_options, write_batch.write_batch_.get());
 397   if (!s.ok()) {
 398     HistogramLevelDBError("WebCore.IndexedDB.LevelDBWriteErrors", s);
 399     LOG(ERROR) << "LevelDB write failed: " << s.ToString();
 400   } else {
 401     UMA_HISTOGRAM_TIMES("WebCore.IndexedDB.LevelDB.WriteTime",
 402                         base::TimeTicks::Now() - begin_time);
 403   }
 404   return s;
 405 }
 406
 407 scoped_ptr<LevelDBIterator> LevelDBDatabase::CreateIterator(
 408     const LevelDBSnapshot* snapshot) {
 409   leveldb::ReadOptions read_options;
 410   read_options.verify_checksums = true;  // TODO(jsbell): Disable this if the
 411                                          // performance impact is too great.
 412   read_options.snapshot = snapshot ? snapshot->snapshot_ : 0;
 413
 414   scoped_ptr<leveldb::Iterator> i(db_->NewIterator(read_options));
 415   return scoped_ptr<LevelDBIterator>(
 416       IndexedDBClassFactory::Get()->CreateIteratorImpl(i.Pass()));
 417 }
 418
 419 const LevelDBComparator* LevelDBDatabase::Comparator() const {
 420   return comparator_;
 421 }
 422
 423 void LevelDBDatabase::Compact(const base::StringPiece& start,
 424                               const base::StringPiece& stop) {
 425   const leveldb::Slice start_slice = MakeSlice(start);
 426   const leveldb::Slice stop_slice = MakeSlice(stop);
 427   // NULL batch means just wait for earlier writes to be done
 428   db_->Write(leveldb::WriteOptions(), NULL);
 429   db_->CompactRange(&start_slice, &stop_slice);
 430 }
 431
 432 void LevelDBDatabase::CompactAll() { db_->CompactRange(NULL, NULL); }
 433
 434 }  // namespace content