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   options.reuse_logs = leveldb_env::kDefaultLogReuseOptionValue;
 107   options.compression = leveldb::kSnappyCompression;
 108
 109   // For info about the troubles we've run into with this parameter, see:
 110   // https://code.google.com/p/chromium/issues/detail?id=227313#c11
 111   options.max_open_files = 80;
 112   options.env = env;
 113
 114   // ChromiumEnv assumes UTF8, converts back to FilePath before using.
 115   leveldb::Status s = leveldb::DB::Open(options, path.AsUTF8Unsafe(), db);
 116
 117   return s;
 118 }
 119
 120 leveldb::Status LevelDBDatabase::Destroy(const base::FilePath& file_name) {
 121   leveldb::Options options;
 122   options.env = leveldb::IDBEnv();
 123   // ChromiumEnv assumes UTF8, converts back to FilePath before using.
 124   return leveldb::DestroyDB(file_name.AsUTF8Unsafe(), options);
 125 }
 126
 127 namespace {
 128 class LockImpl : public LevelDBLock {
 129  public:
 130   explicit LockImpl(leveldb::Env* env, leveldb::FileLock* lock)
 131       : env_(env), lock_(lock) {}
 132   ~LockImpl() override { env_->UnlockFile(lock_); }
 133
 134  private:
 135   leveldb::Env* env_;
 136   leveldb::FileLock* lock_;
 137
 138   DISALLOW_COPY_AND_ASSIGN(LockImpl);
 139 };
 140 }  // namespace
 141
 142 scoped_ptr<LevelDBLock> LevelDBDatabase::LockForTesting(
 143     const base::FilePath& file_name) {
 144   leveldb::Env* env = leveldb::IDBEnv();
 145   base::FilePath lock_path = file_name.AppendASCII("LOCK");
 146   leveldb::FileLock* lock = NULL;
 147   leveldb::Status status = env->LockFile(lock_path.AsUTF8Unsafe(), &lock);
 148   if (!status.ok())
 149     return scoped_ptr<LevelDBLock>();
 150   DCHECK(lock);
 151   return scoped_ptr<LevelDBLock>(new LockImpl(env, lock));
 152 }
 153
 154 static int CheckFreeSpace(const char* const type,
 155                           const base::FilePath& file_name) {
 156   std::string name =
 157       std::string("WebCore.IndexedDB.LevelDB.Open") + type + "FreeDiskSpace";
 158   int64 free_disk_space_in_k_bytes =
 159       base::SysInfo::AmountOfFreeDiskSpace(file_name) / 1024;
 160   if (free_disk_space_in_k_bytes < 0) {
 161     base::Histogram::FactoryGet(
 162         "WebCore.IndexedDB.LevelDB.FreeDiskSpaceFailure",
 163         1,
 164         2 /*boundary*/,
 165         2 /*boundary*/ + 1,
 166         base::HistogramBase::kUmaTargetedHistogramFlag)->Add(1 /*sample*/);
 167     return -1;
 168   }
 169   int clamped_disk_space_k_bytes = free_disk_space_in_k_bytes > INT_MAX
 170                                        ? INT_MAX
 171                                        : free_disk_space_in_k_bytes;
 172   const uint64 histogram_max = static_cast<uint64>(1e9);
 173   static_assert(histogram_max <= INT_MAX, "histogram_max too big");
 174   base::Histogram::FactoryGet(name,
 175                               1,
 176                               histogram_max,
 177                               11 /*buckets*/,
 178                               base::HistogramBase::kUmaTargetedHistogramFlag)
 179       ->Add(clamped_disk_space_k_bytes);
 180   return clamped_disk_space_k_bytes;
 181 }
 182
 183 static void ParseAndHistogramIOErrorDetails(const std::string& histogram_name,
 184                                             const leveldb::Status& s) {
 185   leveldb_env::MethodID method;
 186   base::File::Error error = base::File::FILE_OK;
 187   leveldb_env::ErrorParsingResult result =
 188       leveldb_env::ParseMethodAndError(s, &method, &error);
 189   if (result == leveldb_env::NONE)
 190     return;
 191   std::string method_histogram_name(histogram_name);
 192   method_histogram_name.append(".EnvMethod");
 193   base::LinearHistogram::FactoryGet(
 194       method_histogram_name,
 195       1,
 196       leveldb_env::kNumEntries,
 197       leveldb_env::kNumEntries + 1,
 198       base::HistogramBase::kUmaTargetedHistogramFlag)->Add(method);
 199
 200   std::string error_histogram_name(histogram_name);
 201
 202   if (result == leveldb_env::METHOD_AND_BFE) {
 203     DCHECK_LT(error, 0);
 204     error_histogram_name.append(std::string(".BFE.") +
 205                                 leveldb_env::MethodIDToString(method));
 206     base::LinearHistogram::FactoryGet(
 207         error_histogram_name,
 208         1,
 209         -base::File::FILE_ERROR_MAX,
 210         -base::File::FILE_ERROR_MAX + 1,
 211         base::HistogramBase::kUmaTargetedHistogramFlag)->Add(-error);
 212   }
 213 }
 214
 215 static void ParseAndHistogramCorruptionDetails(
 216     const std::string& histogram_name,
 217     const leveldb::Status& status) {
 218   int error = leveldb_env::GetCorruptionCode(status);
 219   DCHECK_GE(error, 0);
 220   std::string corruption_histogram_name(histogram_name);
 221   corruption_histogram_name.append(".Corruption");
 222   const int kNumPatterns = leveldb_env::GetNumCorruptionCodes();
 223   base::LinearHistogram::FactoryGet(
 224       corruption_histogram_name,
 225       1,
 226       kNumPatterns,
 227       kNumPatterns + 1,
 228       base::HistogramBase::kUmaTargetedHistogramFlag)->Add(error);
 229 }
 230
 231 static void HistogramLevelDBError(const std::string& histogram_name,
 232                                   const leveldb::Status& s) {
 233   if (s.ok()) {
 234     NOTREACHED();
 235     return;
 236   }
 237   enum {
 238     LEVEL_DB_NOT_FOUND,
 239     LEVEL_DB_CORRUPTION,
 240     LEVEL_DB_IO_ERROR,
 241     LEVEL_DB_OTHER,
 242     LEVEL_DB_MAX_ERROR
 243   };
 244   int leveldb_error = LEVEL_DB_OTHER;
 245   if (s.IsNotFound())
 246     leveldb_error = LEVEL_DB_NOT_FOUND;
 247   else if (s.IsCorruption())
 248     leveldb_error = LEVEL_DB_CORRUPTION;
 249   else if (s.IsIOError())
 250     leveldb_error = LEVEL_DB_IO_ERROR;
 251   base::Histogram::FactoryGet(histogram_name,
 252                               1,
 253                               LEVEL_DB_MAX_ERROR,
 254                               LEVEL_DB_MAX_ERROR + 1,
 255                               base::HistogramBase::kUmaTargetedHistogramFlag)
 256       ->Add(leveldb_error);
 257   if (s.IsIOError())
 258     ParseAndHistogramIOErrorDetails(histogram_name, s);
 259   else
 260     ParseAndHistogramCorruptionDetails(histogram_name, s);
 261 }
 262
 263 leveldb::Status LevelDBDatabase::Open(const base::FilePath& file_name,
 264                                       const LevelDBComparator* comparator,
 265                                       scoped_ptr<LevelDBDatabase>* result,
 266                                       bool* is_disk_full) {
 267   base::TimeTicks begin_time = base::TimeTicks::Now();
 268
 269   scoped_ptr<ComparatorAdapter> comparator_adapter(
 270       new ComparatorAdapter(comparator));
 271
 272   leveldb::DB* db;
 273   scoped_ptr<const leveldb::FilterPolicy> filter_policy;
 274   const leveldb::Status s = OpenDB(comparator_adapter.get(),
 275                                    leveldb::IDBEnv(),
 276                                    file_name,
 277                                    &db,
 278                                    &filter_policy);
 279
 280   if (!s.ok()) {
 281     HistogramLevelDBError("WebCore.IndexedDB.LevelDBOpenErrors", s);
 282     int free_space_k_bytes = CheckFreeSpace("Failure", file_name);
 283     // Disks with <100k of free space almost never succeed in opening a
 284     // leveldb database.
 285     if (is_disk_full)
 286       *is_disk_full = free_space_k_bytes >= 0 && free_space_k_bytes < 100;
 287
 288     LOG(ERROR) << "Failed to open LevelDB database from "
 289                << file_name.AsUTF8Unsafe() << "," << s.ToString();
 290     return s;
 291   }
 292
 293   UMA_HISTOGRAM_MEDIUM_TIMES("WebCore.IndexedDB.LevelDB.OpenTime",
 294                              base::TimeTicks::Now() - begin_time);
 295
 296   CheckFreeSpace("Success", file_name);
 297
 298   (*result).reset(new LevelDBDatabase);
 299   (*result)->db_ = make_scoped_ptr(db);
 300   (*result)->comparator_adapter_ = comparator_adapter.Pass();
 301   (*result)->comparator_ = comparator;
 302   (*result)->filter_policy_ = filter_policy.Pass();
 303
 304   return s;
 305 }
 306
 307 scoped_ptr<LevelDBDatabase> LevelDBDatabase::OpenInMemory(
 308     const LevelDBComparator* comparator) {
 309   scoped_ptr<ComparatorAdapter> comparator_adapter(
 310       new ComparatorAdapter(comparator));
 311   scoped_ptr<leveldb::Env> in_memory_env(leveldb::NewMemEnv(leveldb::IDBEnv()));
 312
 313   leveldb::DB* db;
 314   scoped_ptr<const leveldb::FilterPolicy> filter_policy;
 315   const leveldb::Status s = OpenDB(comparator_adapter.get(),
 316                                    in_memory_env.get(),
 317                                    base::FilePath(),
 318                                    &db,
 319                                    &filter_policy);
 320
 321   if (!s.ok()) {
 322     LOG(ERROR) << "Failed to open in-memory LevelDB database: " << s.ToString();
 323     return scoped_ptr<LevelDBDatabase>();
 324   }
 325
 326   scoped_ptr<LevelDBDatabase> result(new LevelDBDatabase);
 327   result->env_ = in_memory_env.Pass();
 328   result->db_ = make_scoped_ptr(db);
 329   result->comparator_adapter_ = comparator_adapter.Pass();
 330   result->comparator_ = comparator;
 331   result->filter_policy_ = filter_policy.Pass();
 332
 333   return result.Pass();
 334 }
 335
 336 leveldb::Status LevelDBDatabase::Put(const StringPiece& key,
 337                                      std::string* value) {
 338   base::TimeTicks begin_time = base::TimeTicks::Now();
 339
 340   leveldb::WriteOptions write_options;
 341   write_options.sync = kSyncWrites;
 342
 343   const leveldb::Status s =
 344       db_->Put(write_options, MakeSlice(key), MakeSlice(*value));
 345   if (!s.ok())
 346     LOG(ERROR) << "LevelDB put failed: " << s.ToString();
 347   else
 348     UMA_HISTOGRAM_TIMES("WebCore.IndexedDB.LevelDB.PutTime",
 349                         base::TimeTicks::Now() - begin_time);
 350   return s;
 351 }
 352
 353 leveldb::Status LevelDBDatabase::Remove(const StringPiece& key) {
 354   leveldb::WriteOptions write_options;
 355   write_options.sync = kSyncWrites;
 356
 357   const leveldb::Status s = db_->Delete(write_options, MakeSlice(key));
 358   if (!s.IsNotFound())
 359     LOG(ERROR) << "LevelDB remove failed: " << s.ToString();
 360   return s;
 361 }
 362
 363 leveldb::Status LevelDBDatabase::Get(const StringPiece& key,
 364                                      std::string* value,
 365                                      bool* found,
 366                                      const LevelDBSnapshot* snapshot) {
 367   *found = false;
 368   leveldb::ReadOptions read_options;
 369   read_options.verify_checksums = true;  // TODO(jsbell): Disable this if the
 370                                          // performance impact is too great.
 371   read_options.snapshot = snapshot ? snapshot->snapshot_ : 0;
 372
 373   const leveldb::Status s = db_->Get(read_options, MakeSlice(key), value);
 374   if (s.ok()) {
 375     *found = true;
 376     return s;
 377   }
 378   if (s.IsNotFound())
 379     return leveldb::Status::OK();
 380   HistogramLevelDBError("WebCore.IndexedDB.LevelDBReadErrors", s);
 381   LOG(ERROR) << "LevelDB get failed: " << s.ToString();
 382   return s;
 383 }
 384
 385 leveldb::Status LevelDBDatabase::Write(const LevelDBWriteBatch& write_batch) {
 386   base::TimeTicks begin_time = base::TimeTicks::Now();
 387   leveldb::WriteOptions write_options;
 388   write_options.sync = kSyncWrites;
 389
 390   const leveldb::Status s =
 391       db_->Write(write_options, write_batch.write_batch_.get());
 392   if (!s.ok()) {
 393     HistogramLevelDBError("WebCore.IndexedDB.LevelDBWriteErrors", s);
 394     LOG(ERROR) << "LevelDB write failed: " << s.ToString();
 395   } else {
 396     UMA_HISTOGRAM_TIMES("WebCore.IndexedDB.LevelDB.WriteTime",
 397                         base::TimeTicks::Now() - begin_time);
 398   }
 399   return s;
 400 }
 401
 402 scoped_ptr<LevelDBIterator> LevelDBDatabase::CreateIterator(
 403     const LevelDBSnapshot* snapshot) {
 404   leveldb::ReadOptions read_options;
 405   read_options.verify_checksums = true;  // TODO(jsbell): Disable this if the
 406                                          // performance impact is too great.
 407   read_options.snapshot = snapshot ? snapshot->snapshot_ : 0;
 408
 409   scoped_ptr<leveldb::Iterator> i(db_->NewIterator(read_options));
 410   return scoped_ptr<LevelDBIterator>(
 411       IndexedDBClassFactory::Get()->CreateIteratorImpl(i.Pass()));
 412 }
 413
 414 const LevelDBComparator* LevelDBDatabase::Comparator() const {
 415   return comparator_;
 416 }
 417
 418 void LevelDBDatabase::Compact(const base::StringPiece& start,
 419                               const base::StringPiece& stop) {
 420   const leveldb::Slice start_slice = MakeSlice(start);
 421   const leveldb::Slice stop_slice = MakeSlice(stop);
 422   // NULL batch means just wait for earlier writes to be done
 423   db_->Write(leveldb::WriteOptions(), NULL);
 424   db_->CompactRange(&start_slice, &stop_slice);
 425 }
 426
 427 void LevelDBDatabase::CompactAll() { db_->CompactRange(NULL, NULL); }
 428
 429 }  // namespace content