leveldb_database.cc revision f8ee788a64d60abd8f2d742a5fdedde054ecd910
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/leveldb/leveldb_comparator.h"
20#include "content/browser/indexed_db/leveldb/leveldb_iterator.h"
21#include "content/browser/indexed_db/leveldb/leveldb_write_batch.h"
22#include "third_party/leveldatabase/env_chromium.h"
23#include "third_party/leveldatabase/env_idb.h"
24#include "third_party/leveldatabase/src/helpers/memenv/memenv.h"
25#include "third_party/leveldatabase/src/include/leveldb/db.h"
26#include "third_party/leveldatabase/src/include/leveldb/env.h"
27#include "third_party/leveldatabase/src/include/leveldb/slice.h"
28
29using base::StringPiece;
30
31namespace content {
32
33// Forcing flushes to disk at the end of a transaction guarantees that the
34// data hit disk, but drastically impacts throughput when the filesystem is
35// busy with background compactions. Not syncing trades off reliability for
36// performance. Note that background compactions which move data from the
37// log to SSTs are always done with reliable writes.
38//
39// Sync writes are necessary on Windows for quota calculations; POSIX
40// calculates file sizes correctly even when not synced to disk.
41#if defined(OS_WIN)
42static const bool kSyncWrites = true;
43#else
44// TODO(dgrogan): Either remove the #if block or change this back to false.
45// See http://crbug.com/338385.
46static const bool kSyncWrites = true;
47#endif
48
49static leveldb::Slice MakeSlice(const StringPiece& s) {
50  return leveldb::Slice(s.begin(), s.size());
51}
52
53static StringPiece MakeStringPiece(const leveldb::Slice& s) {
54  return StringPiece(s.data(), s.size());
55}
56
57LevelDBDatabase::ComparatorAdapter::ComparatorAdapter(
58    const LevelDBComparator* comparator)
59    : comparator_(comparator) {}
60
61int LevelDBDatabase::ComparatorAdapter::Compare(const leveldb::Slice& a,
62                                                const leveldb::Slice& b) const {
63  return comparator_->Compare(MakeStringPiece(a), MakeStringPiece(b));
64}
65
66const char* LevelDBDatabase::ComparatorAdapter::Name() const {
67  return comparator_->Name();
68}
69
70// TODO(jsbell): Support the methods below in the future.
71void LevelDBDatabase::ComparatorAdapter::FindShortestSeparator(
72    std::string* start,
73    const leveldb::Slice& limit) const {}
74
75void LevelDBDatabase::ComparatorAdapter::FindShortSuccessor(
76    std::string* key) const {}
77
78LevelDBSnapshot::LevelDBSnapshot(LevelDBDatabase* db)
79    : db_(db->db_.get()), snapshot_(db_->GetSnapshot()) {}
80
81LevelDBSnapshot::~LevelDBSnapshot() { db_->ReleaseSnapshot(snapshot_); }
82
83LevelDBDatabase::LevelDBDatabase() {}
84
85LevelDBDatabase::~LevelDBDatabase() {
86  // db_'s destructor uses comparator_adapter_; order of deletion is important.
87  db_.reset();
88  comparator_adapter_.reset();
89  env_.reset();
90}
91
92static leveldb::Status OpenDB(leveldb::Comparator* comparator,
93                              leveldb::Env* env,
94                              const base::FilePath& path,
95                              leveldb::DB** db) {
96  leveldb::Options options;
97  options.comparator = comparator;
98  options.create_if_missing = true;
99  options.paranoid_checks = true;
100  options.compression = leveldb::kSnappyCompression;
101
102  // For info about the troubles we've run into with this parameter, see:
103  // https://code.google.com/p/chromium/issues/detail?id=227313#c11
104  options.max_open_files = 80;
105  options.env = env;
106
107  // ChromiumEnv assumes UTF8, converts back to FilePath before using.
108  return leveldb::DB::Open(options, path.AsUTF8Unsafe(), db);
109}
110
111leveldb::Status LevelDBDatabase::Destroy(const base::FilePath& file_name) {
112  leveldb::Options options;
113  options.env = leveldb::IDBEnv();
114  // ChromiumEnv assumes UTF8, converts back to FilePath before using.
115  return leveldb::DestroyDB(file_name.AsUTF8Unsafe(), options);
116}
117
118namespace {
119class LockImpl : public LevelDBLock {
120 public:
121  explicit LockImpl(leveldb::Env* env, leveldb::FileLock* lock)
122      : env_(env), lock_(lock) {}
123  virtual ~LockImpl() { env_->UnlockFile(lock_); }
124 private:
125  leveldb::Env* env_;
126  leveldb::FileLock* lock_;
127
128  DISALLOW_COPY_AND_ASSIGN(LockImpl);
129};
130}  // namespace
131
132scoped_ptr<LevelDBLock> LevelDBDatabase::LockForTesting(
133    const base::FilePath& file_name) {
134  leveldb::Env* env = leveldb::IDBEnv();
135  base::FilePath lock_path = file_name.AppendASCII("LOCK");
136  leveldb::FileLock* lock = NULL;
137  leveldb::Status status = env->LockFile(lock_path.AsUTF8Unsafe(), &lock);
138  if (!status.ok())
139    return scoped_ptr<LevelDBLock>();
140  DCHECK(lock);
141  return scoped_ptr<LevelDBLock>(new LockImpl(env, lock));
142}
143
144static int CheckFreeSpace(const char* const type,
145                          const base::FilePath& file_name) {
146  std::string name =
147      std::string("WebCore.IndexedDB.LevelDB.Open") + type + "FreeDiskSpace";
148  int64 free_disk_space_in_k_bytes =
149      base::SysInfo::AmountOfFreeDiskSpace(file_name) / 1024;
150  if (free_disk_space_in_k_bytes < 0) {
151    base::Histogram::FactoryGet(
152        "WebCore.IndexedDB.LevelDB.FreeDiskSpaceFailure",
153        1,
154        2 /*boundary*/,
155        2 /*boundary*/ + 1,
156        base::HistogramBase::kUmaTargetedHistogramFlag)->Add(1 /*sample*/);
157    return -1;
158  }
159  int clamped_disk_space_k_bytes = free_disk_space_in_k_bytes > INT_MAX
160                                       ? INT_MAX
161                                       : free_disk_space_in_k_bytes;
162  const uint64 histogram_max = static_cast<uint64>(1e9);
163  COMPILE_ASSERT(histogram_max <= INT_MAX, histogram_max_too_big);
164  base::Histogram::FactoryGet(name,
165                              1,
166                              histogram_max,
167                              11 /*buckets*/,
168                              base::HistogramBase::kUmaTargetedHistogramFlag)
169      ->Add(clamped_disk_space_k_bytes);
170  return clamped_disk_space_k_bytes;
171}
172
173static void ParseAndHistogramIOErrorDetails(const std::string& histogram_name,
174                                            const leveldb::Status& s) {
175  leveldb_env::MethodID method;
176  int error = -1;
177  leveldb_env::ErrorParsingResult result =
178      leveldb_env::ParseMethodAndError(s.ToString().c_str(), &method, &error);
179  if (result == leveldb_env::NONE)
180    return;
181  std::string method_histogram_name(histogram_name);
182  method_histogram_name.append(".EnvMethod");
183  base::LinearHistogram::FactoryGet(
184      method_histogram_name,
185      1,
186      leveldb_env::kNumEntries,
187      leveldb_env::kNumEntries + 1,
188      base::HistogramBase::kUmaTargetedHistogramFlag)->Add(method);
189
190  std::string error_histogram_name(histogram_name);
191
192  if (result == leveldb_env::METHOD_AND_PFE) {
193    DCHECK_LT(error, 0);
194    error_histogram_name.append(std::string(".PFE.") +
195                                leveldb_env::MethodIDToString(method));
196    base::LinearHistogram::FactoryGet(
197        error_histogram_name,
198        1,
199        -base::File::FILE_ERROR_MAX,
200        -base::File::FILE_ERROR_MAX + 1,
201        base::HistogramBase::kUmaTargetedHistogramFlag)->Add(-error);
202  } else if (result == leveldb_env::METHOD_AND_ERRNO) {
203    error_histogram_name.append(std::string(".Errno.") +
204                                leveldb_env::MethodIDToString(method));
205    base::LinearHistogram::FactoryGet(
206        error_histogram_name,
207        1,
208        ERANGE + 1,
209        ERANGE + 2,
210        base::HistogramBase::kUmaTargetedHistogramFlag)->Add(error);
211  }
212}
213
214static void ParseAndHistogramCorruptionDetails(
215    const std::string& histogram_name,
216    const leveldb::Status& status) {
217  int error = leveldb_env::GetCorruptionCode(status);
218  DCHECK_GE(error, 0);
219  std::string corruption_histogram_name(histogram_name);
220  corruption_histogram_name.append(".Corruption");
221  const int kNumPatterns = leveldb_env::GetNumCorruptionCodes();
222  base::LinearHistogram::FactoryGet(
223      corruption_histogram_name,
224      1,
225      kNumPatterns,
226      kNumPatterns + 1,
227      base::HistogramBase::kUmaTargetedHistogramFlag)->Add(error);
228}
229
230static void HistogramLevelDBError(const std::string& histogram_name,
231                                  const leveldb::Status& s) {
232  if (s.ok()) {
233    NOTREACHED();
234    return;
235  }
236  enum {
237    LEVEL_DB_NOT_FOUND,
238    LEVEL_DB_CORRUPTION,
239    LEVEL_DB_IO_ERROR,
240    LEVEL_DB_OTHER,
241    LEVEL_DB_MAX_ERROR
242  };
243  int leveldb_error = LEVEL_DB_OTHER;
244  if (s.IsNotFound())
245    leveldb_error = LEVEL_DB_NOT_FOUND;
246  else if (s.IsCorruption())
247    leveldb_error = LEVEL_DB_CORRUPTION;
248  else if (s.IsIOError())
249    leveldb_error = LEVEL_DB_IO_ERROR;
250  base::Histogram::FactoryGet(histogram_name,
251                              1,
252                              LEVEL_DB_MAX_ERROR,
253                              LEVEL_DB_MAX_ERROR + 1,
254                              base::HistogramBase::kUmaTargetedHistogramFlag)
255      ->Add(leveldb_error);
256  if (s.IsIOError())
257    ParseAndHistogramIOErrorDetails(histogram_name, s);
258  else
259    ParseAndHistogramCorruptionDetails(histogram_name, s);
260}
261
262leveldb::Status LevelDBDatabase::Open(const base::FilePath& file_name,
263                                      const LevelDBComparator* comparator,
264                                      scoped_ptr<LevelDBDatabase>* result,
265                                      bool* is_disk_full) {
266  scoped_ptr<ComparatorAdapter> comparator_adapter(
267      new ComparatorAdapter(comparator));
268
269  leveldb::DB* db;
270  const leveldb::Status s =
271      OpenDB(comparator_adapter.get(), leveldb::IDBEnv(), file_name, &db);
272
273  if (!s.ok()) {
274    HistogramLevelDBError("WebCore.IndexedDB.LevelDBOpenErrors", s);
275    int free_space_k_bytes = CheckFreeSpace("Failure", file_name);
276    // Disks with <100k of free space almost never succeed in opening a
277    // leveldb database.
278    if (is_disk_full)
279      *is_disk_full = free_space_k_bytes >= 0 && free_space_k_bytes < 100;
280
281    LOG(ERROR) << "Failed to open LevelDB database from "
282               << file_name.AsUTF8Unsafe() << "," << s.ToString();
283    return s;
284  }
285
286  CheckFreeSpace("Success", file_name);
287
288  (*result).reset(new LevelDBDatabase);
289  (*result)->db_ = make_scoped_ptr(db);
290  (*result)->comparator_adapter_ = comparator_adapter.Pass();
291  (*result)->comparator_ = comparator;
292
293  return s;
294}
295
296scoped_ptr<LevelDBDatabase> LevelDBDatabase::OpenInMemory(
297    const LevelDBComparator* comparator) {
298  scoped_ptr<ComparatorAdapter> comparator_adapter(
299      new ComparatorAdapter(comparator));
300  scoped_ptr<leveldb::Env> in_memory_env(leveldb::NewMemEnv(leveldb::IDBEnv()));
301
302  leveldb::DB* db;
303  const leveldb::Status s = OpenDB(
304      comparator_adapter.get(), in_memory_env.get(), base::FilePath(), &db);
305
306  if (!s.ok()) {
307    LOG(ERROR) << "Failed to open in-memory LevelDB database: " << s.ToString();
308    return scoped_ptr<LevelDBDatabase>();
309  }
310
311  scoped_ptr<LevelDBDatabase> result(new LevelDBDatabase);
312  result->env_ = in_memory_env.Pass();
313  result->db_ = make_scoped_ptr(db);
314  result->comparator_adapter_ = comparator_adapter.Pass();
315  result->comparator_ = comparator;
316
317  return result.Pass();
318}
319
320leveldb::Status LevelDBDatabase::Put(const StringPiece& key,
321                                     std::string* value) {
322  leveldb::WriteOptions write_options;
323  write_options.sync = kSyncWrites;
324
325  const leveldb::Status s =
326      db_->Put(write_options, MakeSlice(key), MakeSlice(*value));
327  if (!s.ok())
328    LOG(ERROR) << "LevelDB put failed: " << s.ToString();
329  return s;
330}
331
332leveldb::Status LevelDBDatabase::Remove(const StringPiece& key) {
333  leveldb::WriteOptions write_options;
334  write_options.sync = kSyncWrites;
335
336  const leveldb::Status s = db_->Delete(write_options, MakeSlice(key));
337  if (!s.IsNotFound())
338    LOG(ERROR) << "LevelDB remove failed: " << s.ToString();
339  return s;
340}
341
342leveldb::Status LevelDBDatabase::Get(const StringPiece& key,
343                                     std::string* value,
344                                     bool* found,
345                                     const LevelDBSnapshot* snapshot) {
346  *found = false;
347  leveldb::ReadOptions read_options;
348  read_options.verify_checksums = true;  // TODO(jsbell): Disable this if the
349                                         // performance impact is too great.
350  read_options.snapshot = snapshot ? snapshot->snapshot_ : 0;
351
352  const leveldb::Status s = db_->Get(read_options, MakeSlice(key), value);
353  if (s.ok()) {
354    *found = true;
355    return s;
356  }
357  if (s.IsNotFound())
358    return leveldb::Status::OK();
359  HistogramLevelDBError("WebCore.IndexedDB.LevelDBReadErrors", s);
360  LOG(ERROR) << "LevelDB get failed: " << s.ToString();
361  return s;
362}
363
364leveldb::Status LevelDBDatabase::Write(const LevelDBWriteBatch& write_batch) {
365  leveldb::WriteOptions write_options;
366  write_options.sync = kSyncWrites;
367
368  const leveldb::Status s =
369      db_->Write(write_options, write_batch.write_batch_.get());
370  if (!s.ok()) {
371    HistogramLevelDBError("WebCore.IndexedDB.LevelDBWriteErrors", s);
372    LOG(ERROR) << "LevelDB write failed: " << s.ToString();
373  }
374  return s;
375}
376
377namespace {
378class IteratorImpl : public LevelDBIterator {
379 public:
380  virtual ~IteratorImpl() {}
381
382  virtual bool IsValid() const OVERRIDE;
383  virtual leveldb::Status SeekToLast() OVERRIDE;
384  virtual leveldb::Status Seek(const StringPiece& target) OVERRIDE;
385  virtual leveldb::Status Next() OVERRIDE;
386  virtual leveldb::Status Prev() OVERRIDE;
387  virtual StringPiece Key() const OVERRIDE;
388  virtual StringPiece Value() const OVERRIDE;
389
390 private:
391  friend class content::LevelDBDatabase;
392  explicit IteratorImpl(scoped_ptr<leveldb::Iterator> iterator);
393  void CheckStatus();
394
395  scoped_ptr<leveldb::Iterator> iterator_;
396
397  DISALLOW_COPY_AND_ASSIGN(IteratorImpl);
398};
399}  // namespace
400
401IteratorImpl::IteratorImpl(scoped_ptr<leveldb::Iterator> it)
402    : iterator_(it.Pass()) {}
403
404void IteratorImpl::CheckStatus() {
405  const leveldb::Status& s = iterator_->status();
406  if (!s.ok())
407    LOG(ERROR) << "LevelDB iterator error: " << s.ToString();
408}
409
410bool IteratorImpl::IsValid() const { return iterator_->Valid(); }
411
412leveldb::Status IteratorImpl::SeekToLast() {
413  iterator_->SeekToLast();
414  CheckStatus();
415  return iterator_->status();
416}
417
418leveldb::Status IteratorImpl::Seek(const StringPiece& target) {
419  iterator_->Seek(MakeSlice(target));
420  CheckStatus();
421  return iterator_->status();
422}
423
424leveldb::Status IteratorImpl::Next() {
425  DCHECK(IsValid());
426  iterator_->Next();
427  CheckStatus();
428  return iterator_->status();
429}
430
431leveldb::Status IteratorImpl::Prev() {
432  DCHECK(IsValid());
433  iterator_->Prev();
434  CheckStatus();
435  return iterator_->status();
436}
437
438StringPiece IteratorImpl::Key() const {
439  DCHECK(IsValid());
440  return MakeStringPiece(iterator_->key());
441}
442
443StringPiece IteratorImpl::Value() const {
444  DCHECK(IsValid());
445  return MakeStringPiece(iterator_->value());
446}
447
448scoped_ptr<LevelDBIterator> LevelDBDatabase::CreateIterator(
449    const LevelDBSnapshot* snapshot) {
450  leveldb::ReadOptions read_options;
451  read_options.verify_checksums = true;  // TODO(jsbell): Disable this if the
452                                         // performance impact is too great.
453  read_options.snapshot = snapshot ? snapshot->snapshot_ : 0;
454
455  scoped_ptr<leveldb::Iterator> i(db_->NewIterator(read_options));
456  return scoped_ptr<LevelDBIterator>(new IteratorImpl(i.Pass()));
457}
458
459const LevelDBComparator* LevelDBDatabase::Comparator() const {
460  return comparator_;
461}
462
463void LevelDBDatabase::Compact(const base::StringPiece& start,
464                              const base::StringPiece& stop) {
465  const leveldb::Slice start_slice = MakeSlice(start);
466  const leveldb::Slice stop_slice = MakeSlice(stop);
467  db_->CompactRange(&start_slice, &stop_slice);
468}
469
470void LevelDBDatabase::CompactAll() { db_->CompactRange(NULL, NULL); }
471
472}  // namespace content
473