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_env.h"
  22 #include "content/browser/indexed_db/leveldb/leveldb_iterator_impl.h"
  23 #include "content/browser/indexed_db/leveldb/leveldb_write_batch.h"
  24 #include "third_party/leveldatabase/env_chromium.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   CloseDatabase();
  90   comparator_adapter_.reset();
  91   env_.reset();
  92 }
  93
  94 void LevelDBDatabase::CloseDatabase() {
  95   if (db_) {
  96     base::TimeTicks begin_time = base::TimeTicks::Now();
  97     db_.reset();
  98     UMA_HISTOGRAM_MEDIUM_TIMES("WebCore.IndexedDB.LevelDB.CloseTime",
  99                                base::TimeTicks::Now() - begin_time);
 100   }
 101 }
 102
 103 static leveldb::Status OpenDB(
 104     leveldb::Comparator* comparator,
 105     leveldb::Env* env,
 106     const base::FilePath& path,
 107     leveldb::DB** db,
 108     scoped_ptr<const leveldb::FilterPolicy>* filter_policy) {
 109   filter_policy->reset(leveldb::NewBloomFilterPolicy(10));
 110   leveldb::Options options;
 111   options.comparator = comparator;
 112   options.create_if_missing = true;
 113   options.paranoid_checks = true;
 114   options.filter_policy = filter_policy->get();
 115   options.reuse_logs = leveldb_env::kDefaultLogReuseOptionValue;
 116   options.compression = leveldb::kSnappyCompression;
 117
 118   // For info about the troubles we've run into with this parameter, see:
 119   // https://code.google.com/p/chromium/issues/detail?id=227313#c11
 120   options.max_open_files = 80;
 121   options.env = env;
 122
 123   // ChromiumEnv assumes UTF8, converts back to FilePath before using.
 124   leveldb::Status s = leveldb::DB::Open(options, path.AsUTF8Unsafe(), db);
 125
 126   return s;
 127 }
 128
 129 leveldb::Status LevelDBDatabase::Destroy(const base::FilePath& file_name) {
 130   leveldb::Options options;
 131   options.env = LevelDBEnv::Get();
 132   // ChromiumEnv assumes UTF8, converts back to FilePath before using.
 133   return leveldb::DestroyDB(file_name.AsUTF8Unsafe(), options);
 134 }
 135
 136 namespace {
 137 class LockImpl : public LevelDBLock {
 138  public:
 139   explicit LockImpl(leveldb::Env* env, leveldb::FileLock* lock)
 140       : env_(env), lock_(lock) {}
 141   ~LockImpl() override { env_->UnlockFile(lock_); }
 142
 143  private:
 144   leveldb::Env* env_;
 145   leveldb::FileLock* lock_;
 146
 147   DISALLOW_COPY_AND_ASSIGN(LockImpl);
 148 };
 149 }  // namespace
 150
 151 scoped_ptr<LevelDBLock> LevelDBDatabase::LockForTesting(
 152     const base::FilePath& file_name) {
 153   leveldb::Env* env = LevelDBEnv::Get();
 154   base::FilePath lock_path = file_name.AppendASCII("LOCK");
 155   leveldb::FileLock* lock = NULL;
 156   leveldb::Status status = env->LockFile(lock_path.AsUTF8Unsafe(), &lock);
 157   if (!status.ok())
 158     return scoped_ptr<LevelDBLock>();
 159   DCHECK(lock);
 160   return scoped_ptr<LevelDBLock>(new LockImpl(env, lock));
 161 }
 162
 163 static int CheckFreeSpace(const char* const type,
 164                           const base::FilePath& file_name) {
 165   std::string name =
 166       std::string("WebCore.IndexedDB.LevelDB.Open") + type + "FreeDiskSpace";
 167   int64 free_disk_space_in_k_bytes =
 168       base::SysInfo::AmountOfFreeDiskSpace(file_name) / 1024;
 169   if (free_disk_space_in_k_bytes < 0) {
 170     base::Histogram::FactoryGet(
 171         "WebCore.IndexedDB.LevelDB.FreeDiskSpaceFailure",
 172         1,
 173         2 /*boundary*/,
 174         2 /*boundary*/ + 1,
 175         base::HistogramBase::kUmaTargetedHistogramFlag)->Add(1 /*sample*/);
 176     return -1;
 177   }
 178   int clamped_disk_space_k_bytes = free_disk_space_in_k_bytes > INT_MAX
 179                                        ? INT_MAX
 180                                        : free_disk_space_in_k_bytes;
 181   const uint64 histogram_max = static_cast<uint64>(1e9);
 182   static_assert(histogram_max <= INT_MAX, "histogram_max too big");
 183   base::Histogram::FactoryGet(name,
 184                               1,
 185                               histogram_max,
 186                               11 /*buckets*/,
 187                               base::HistogramBase::kUmaTargetedHistogramFlag)
 188       ->Add(clamped_disk_space_k_bytes);
 189   return clamped_disk_space_k_bytes;
 190 }
 191
 192 static void ParseAndHistogramIOErrorDetails(const std::string& histogram_name,
 193                                             const leveldb::Status& s) {
 194   leveldb_env::MethodID method;
 195   base::File::Error error = base::File::FILE_OK;
 196   leveldb_env::ErrorParsingResult result =
 197       leveldb_env::ParseMethodAndError(s, &method, &error);
 198   if (result == leveldb_env::NONE)
 199     return;
 200   std::string method_histogram_name(histogram_name);
 201   method_histogram_name.append(".EnvMethod");
 202   base::LinearHistogram::FactoryGet(
 203       method_histogram_name,
 204       1,
 205       leveldb_env::kNumEntries,
 206       leveldb_env::kNumEntries + 1,
 207       base::HistogramBase::kUmaTargetedHistogramFlag)->Add(method);
 208
 209   std::string error_histogram_name(histogram_name);
 210
 211   if (result == leveldb_env::METHOD_AND_BFE) {
 212     DCHECK_LT(error, 0);
 213     error_histogram_name.append(std::string(".BFE.") +
 214                                 leveldb_env::MethodIDToString(method));
 215     base::LinearHistogram::FactoryGet(
 216         error_histogram_name,
 217         1,
 218         -base::File::FILE_ERROR_MAX,
 219         -base::File::FILE_ERROR_MAX + 1,
 220         base::HistogramBase::kUmaTargetedHistogramFlag)->Add(-error);
 221   }
 222 }
 223
 224 static void ParseAndHistogramCorruptionDetails(
 225     const std::string& histogram_name,
 226     const leveldb::Status& status) {
 227   int error = leveldb_env::GetCorruptionCode(status);
 228   DCHECK_GE(error, 0);
 229   std::string corruption_histogram_name(histogram_name);
 230   corruption_histogram_name.append(".Corruption");
 231   const int kNumPatterns = leveldb_env::GetNumCorruptionCodes();
 232   base::LinearHistogram::FactoryGet(
 233       corruption_histogram_name,
 234       1,
 235       kNumPatterns,
 236       kNumPatterns + 1,
 237       base::HistogramBase::kUmaTargetedHistogramFlag)->Add(error);
 238 }
 239
 240 static void HistogramLevelDBError(const std::string& histogram_name,
 241                                   const leveldb::Status& s) {
 242   if (s.ok()) {
 243     NOTREACHED();
 244     return;
 245   }
 246   enum {
 247     LEVEL_DB_NOT_FOUND,
 248     LEVEL_DB_CORRUPTION,
 249     LEVEL_DB_IO_ERROR,
 250     LEVEL_DB_OTHER,
 251     LEVEL_DB_MAX_ERROR
 252   };
 253   int leveldb_error = LEVEL_DB_OTHER;
 254   if (s.IsNotFound())
 255     leveldb_error = LEVEL_DB_NOT_FOUND;
 256   else if (s.IsCorruption())
 257     leveldb_error = LEVEL_DB_CORRUPTION;
 258   else if (s.IsIOError())
 259     leveldb_error = LEVEL_DB_IO_ERROR;
 260   base::Histogram::FactoryGet(histogram_name,
 261                               1,
 262                               LEVEL_DB_MAX_ERROR,
 263                               LEVEL_DB_MAX_ERROR + 1,
 264                               base::HistogramBase::kUmaTargetedHistogramFlag)
 265       ->Add(leveldb_error);
 266   if (s.IsIOError())
 267     ParseAndHistogramIOErrorDetails(histogram_name, s);
 268   else
 269     ParseAndHistogramCorruptionDetails(histogram_name, s);
 270 }
 271
 272 leveldb::Status LevelDBDatabase::Open(const base::FilePath& file_name,
 273                                       const LevelDBComparator* comparator,
 274                                       scoped_ptr<LevelDBDatabase>* result,
 275                                       bool* is_disk_full) {
 276   base::TimeTicks begin_time = base::TimeTicks::Now();
 277
 278   scoped_ptr<ComparatorAdapter> comparator_adapter(
 279       new ComparatorAdapter(comparator));
 280
 281   leveldb::DB* db;
 282   scoped_ptr<const leveldb::FilterPolicy> filter_policy;
 283   const leveldb::Status s = OpenDB(comparator_adapter.get(), LevelDBEnv::Get(),
 284                                    file_name, &db, &filter_policy);
 285
 286   if (!s.ok()) {
 287     HistogramLevelDBError("WebCore.IndexedDB.LevelDBOpenErrors", s);
 288     int free_space_k_bytes = CheckFreeSpace("Failure", file_name);
 289     // Disks with <100k of free space almost never succeed in opening a
 290     // leveldb database.
 291     if (is_disk_full)
 292       *is_disk_full = free_space_k_bytes >= 0 && free_space_k_bytes < 100;
 293
 294     LOG(ERROR) << "Failed to open LevelDB database from "
 295                << file_name.AsUTF8Unsafe() << "," << s.ToString();
 296     return s;
 297   }
 298
 299   UMA_HISTOGRAM_MEDIUM_TIMES("WebCore.IndexedDB.LevelDB.OpenTime",
 300                              base::TimeTicks::Now() - begin_time);
 301
 302   CheckFreeSpace("Success", file_name);
 303
 304   (*result).reset(new LevelDBDatabase);
 305   (*result)->db_ = make_scoped_ptr(db);
 306   (*result)->comparator_adapter_ = comparator_adapter.Pass();
 307   (*result)->comparator_ = comparator;
 308   (*result)->filter_policy_ = filter_policy.Pass();
 309
 310   return s;
 311 }
 312
 313 scoped_ptr<LevelDBDatabase> LevelDBDatabase::OpenInMemory(
 314     const LevelDBComparator* comparator) {
 315   scoped_ptr<ComparatorAdapter> comparator_adapter(
 316       new ComparatorAdapter(comparator));
 317   scoped_ptr<leveldb::Env> in_memory_env(leveldb::NewMemEnv(LevelDBEnv::Get()));
 318
 319   leveldb::DB* db;
 320   scoped_ptr<const leveldb::FilterPolicy> filter_policy;
 321   const leveldb::Status s = OpenDB(comparator_adapter.get(),
 322                                    in_memory_env.get(),
 323                                    base::FilePath(),
 324                                    &db,
 325                                    &filter_policy);
 326
 327   if (!s.ok()) {
 328     LOG(ERROR) << "Failed to open in-memory LevelDB database: " << s.ToString();
 329     return scoped_ptr<LevelDBDatabase>();
 330   }
 331
 332   scoped_ptr<LevelDBDatabase> result(new LevelDBDatabase);
 333   result->env_ = in_memory_env.Pass();
 334   result->db_ = make_scoped_ptr(db);
 335   result->comparator_adapter_ = comparator_adapter.Pass();
 336   result->comparator_ = comparator;
 337   result->filter_policy_ = filter_policy.Pass();
 338
 339   return result.Pass();
 340 }
 341
 342 leveldb::Status LevelDBDatabase::Put(const StringPiece& key,
 343                                      std::string* value) {
 344   base::TimeTicks begin_time = base::TimeTicks::Now();
 345
 346   leveldb::WriteOptions write_options;
 347   write_options.sync = kSyncWrites;
 348
 349   const leveldb::Status s =
 350       db_->Put(write_options, MakeSlice(key), MakeSlice(*value));
 351   if (!s.ok())
 352     LOG(ERROR) << "LevelDB put failed: " << s.ToString();
 353   else
 354     UMA_HISTOGRAM_TIMES("WebCore.IndexedDB.LevelDB.PutTime",
 355                         base::TimeTicks::Now() - begin_time);
 356   return s;
 357 }
 358
 359 leveldb::Status LevelDBDatabase::Remove(const StringPiece& key) {
 360   leveldb::WriteOptions write_options;
 361   write_options.sync = kSyncWrites;
 362
 363   const leveldb::Status s = db_->Delete(write_options, MakeSlice(key));
 364   if (!s.IsNotFound())
 365     LOG(ERROR) << "LevelDB remove failed: " << s.ToString();
 366   return s;
 367 }
 368
 369 leveldb::Status LevelDBDatabase::Get(const StringPiece& key,
 370                                      std::string* value,
 371                                      bool* found,
 372                                      const LevelDBSnapshot* snapshot) {
 373   *found = false;
 374   leveldb::ReadOptions read_options;
 375   read_options.verify_checksums = true;  // TODO(jsbell): Disable this if the
 376                                          // performance impact is too great.
 377   read_options.snapshot = snapshot ? snapshot->snapshot_ : 0;
 378
 379   const leveldb::Status s = db_->Get(read_options, MakeSlice(key), value);
 380   if (s.ok()) {
 381     *found = true;
 382     return s;
 383   }
 384   if (s.IsNotFound())
 385     return leveldb::Status::OK();
 386   HistogramLevelDBError("WebCore.IndexedDB.LevelDBReadErrors", s);
 387   LOG(ERROR) << "LevelDB get failed: " << s.ToString();
 388   return s;
 389 }
 390
 391 leveldb::Status LevelDBDatabase::Write(const LevelDBWriteBatch& write_batch) {
 392   base::TimeTicks begin_time = base::TimeTicks::Now();
 393   leveldb::WriteOptions write_options;
 394   write_options.sync = kSyncWrites;
 395
 396   const leveldb::Status s =
 397       db_->Write(write_options, write_batch.write_batch_.get());
 398   if (!s.ok()) {
 399     HistogramLevelDBError("WebCore.IndexedDB.LevelDBWriteErrors", s);
 400     LOG(ERROR) << "LevelDB write failed: " << s.ToString();
 401   } else {
 402     UMA_HISTOGRAM_TIMES("WebCore.IndexedDB.LevelDB.WriteTime",
 403                         base::TimeTicks::Now() - begin_time);
 404   }
 405   return s;
 406 }
 407
 408 scoped_ptr<LevelDBIterator> LevelDBDatabase::CreateIterator(
 409     const LevelDBSnapshot* snapshot) {
 410   leveldb::ReadOptions read_options;
 411   read_options.verify_checksums = true;  // TODO(jsbell): Disable this if the
 412                                          // performance impact is too great.
 413   read_options.snapshot = snapshot ? snapshot->snapshot_ : 0;
 414
 415   scoped_ptr<leveldb::Iterator> i(db_->NewIterator(read_options));
 416   return scoped_ptr<LevelDBIterator>(
 417       IndexedDBClassFactory::Get()->CreateIteratorImpl(i.Pass()));
 418 }
 419
 420 const LevelDBComparator* LevelDBDatabase::Comparator() const {
 421   return comparator_;
 422 }
 423
 424 void LevelDBDatabase::Compact(const base::StringPiece& start,
 425                               const base::StringPiece& stop) {
 426   const leveldb::Slice start_slice = MakeSlice(start);
 427   const leveldb::Slice stop_slice = MakeSlice(stop);
 428   // NULL batch means just wait for earlier writes to be done
 429   db_->Write(leveldb::WriteOptions(), NULL);
 430   db_->CompactRange(&start_slice, &stop_slice);
 431 }
 432
 433 void LevelDBDatabase::CompactAll() { db_->CompactRange(NULL, NULL); }
 434
 435 }  // namespace content