leveldb_database.cc revision 6e8cce623b6e4fe0c9e4af605d675dd9d0338c38 
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/slice.h"
29
30using base::StringPiece;
31
32namespace content {
33
34// Forcing flushes to disk at the end of a transaction guarantees that the
35// data hit disk, but drastically impacts throughput when the filesystem is
36// busy with background compactions. Not syncing trades off reliability for
37// performance. Note that background compactions which move data from the
38// log to SSTs are always done with reliable writes.
39//
40// Sync writes are necessary on Windows for quota calculations; POSIX
41// calculates file sizes correctly even when not synced to disk.
42#if defined(OS_WIN)
43static const bool kSyncWrites = true;
44#else
45// TODO(dgrogan): Either remove the #if block or change this back to false.
46// See http://crbug.com/338385.
47static const bool kSyncWrites = true;
48#endif
49
50static leveldb::Slice MakeSlice(const StringPiece& s) {
51  return leveldb::Slice(s.begin(), s.size());
52}
53
54static StringPiece MakeStringPiece(const leveldb::Slice& s) {
55  return StringPiece(s.data(), s.size());
56}
57
58LevelDBDatabase::ComparatorAdapter::ComparatorAdapter(
59    const LevelDBComparator* comparator)
60    : comparator_(comparator) {}
61
62int LevelDBDatabase::ComparatorAdapter::Compare(const leveldb::Slice& a,
63                                                const leveldb::Slice& b) const {
64  return comparator_->Compare(MakeStringPiece(a), MakeStringPiece(b));
65}
66
67const char* LevelDBDatabase::ComparatorAdapter::Name() const {
68  return comparator_->Name();
69}
70
71// TODO(jsbell): Support the methods below in the future.
72void LevelDBDatabase::ComparatorAdapter::FindShortestSeparator(
73    std::string* start,
74    const leveldb::Slice& limit) const {}
75
76void LevelDBDatabase::ComparatorAdapter::FindShortSuccessor(
77    std::string* key) const {}
78
79LevelDBSnapshot::LevelDBSnapshot(LevelDBDatabase* db)
80    : db_(db->db_.get()), snapshot_(db_->GetSnapshot()) {}
81
82LevelDBSnapshot::~LevelDBSnapshot() { db_->ReleaseSnapshot(snapshot_); }
83
84LevelDBDatabase::LevelDBDatabase() {}
85
86LevelDBDatabase::~LevelDBDatabase() {
87  // db_'s destructor uses comparator_adapter_; order of deletion is important.
88  db_.reset();
89  comparator_adapter_.reset();
90  env_.reset();
91}
92
93static leveldb::Status OpenDB(leveldb::Comparator* comparator,
94                              leveldb::Env* env,
95                              const base::FilePath& path,
96                              leveldb::DB** db) {
97  leveldb::Options options;
98  options.comparator = comparator;
99  options.create_if_missing = true;
100  options.paranoid_checks = true;
101  options.compression = leveldb::kSnappyCompression;
102
103  // For info about the troubles we've run into with this parameter, see:
104  // https://code.google.com/p/chromium/issues/detail?id=227313#c11
105  options.max_open_files = 80;
106  options.env = env;
107
108  // ChromiumEnv assumes UTF8, converts back to FilePath before using.
109  return leveldb::DB::Open(options, path.AsUTF8Unsafe(), db);
110}
111
112leveldb::Status LevelDBDatabase::Destroy(const base::FilePath& file_name) {
113  leveldb::Options options;
114  options.env = leveldb::IDBEnv();
115  // ChromiumEnv assumes UTF8, converts back to FilePath before using.
116  return leveldb::DestroyDB(file_name.AsUTF8Unsafe(), options);
117}
118
119namespace {
120class LockImpl : public LevelDBLock {
121 public:
122  explicit LockImpl(leveldb::Env* env, leveldb::FileLock* lock)
123      : env_(env), lock_(lock) {}
124  virtual ~LockImpl() { env_->UnlockFile(lock_); }
125 private:
126  leveldb::Env* env_;
127  leveldb::FileLock* lock_;
128
129  DISALLOW_COPY_AND_ASSIGN(LockImpl);
130};
131}  // namespace
132
133scoped_ptr<LevelDBLock> LevelDBDatabase::LockForTesting(
134    const base::FilePath& file_name) {
135  leveldb::Env* env = leveldb::IDBEnv();
136  base::FilePath lock_path = file_name.AppendASCII("LOCK");
137  leveldb::FileLock* lock = NULL;
138  leveldb::Status status = env->LockFile(lock_path.AsUTF8Unsafe(), &lock);
139  if (!status.ok())
140    return scoped_ptr<LevelDBLock>();
141  DCHECK(lock);
142  return scoped_ptr<LevelDBLock>(new LockImpl(env, lock));
143}
144
145static int CheckFreeSpace(const char* const type,
146                          const base::FilePath& file_name) {
147  std::string name =
148      std::string("WebCore.IndexedDB.LevelDB.Open") + type + "FreeDiskSpace";
149  int64 free_disk_space_in_k_bytes =
150      base::SysInfo::AmountOfFreeDiskSpace(file_name) / 1024;
151  if (free_disk_space_in_k_bytes < 0) {
152    base::Histogram::FactoryGet(
153        "WebCore.IndexedDB.LevelDB.FreeDiskSpaceFailure",
154        1,
155        2 /*boundary*/,
156        2 /*boundary*/ + 1,
157        base::HistogramBase::kUmaTargetedHistogramFlag)->Add(1 /*sample*/);
158    return -1;
159  }
160  int clamped_disk_space_k_bytes = free_disk_space_in_k_bytes > INT_MAX
161                                       ? INT_MAX
162                                       : free_disk_space_in_k_bytes;
163  const uint64 histogram_max = static_cast<uint64>(1e9);
164  COMPILE_ASSERT(histogram_max <= INT_MAX, histogram_max_too_big);
165  base::Histogram::FactoryGet(name,
166                              1,
167                              histogram_max,
168                              11 /*buckets*/,
169                              base::HistogramBase::kUmaTargetedHistogramFlag)
170      ->Add(clamped_disk_space_k_bytes);
171  return clamped_disk_space_k_bytes;
172}
173
174static void ParseAndHistogramIOErrorDetails(const std::string& histogram_name,
175                                            const leveldb::Status& s) {
176  leveldb_env::MethodID method;
177  int error = -1;
178  leveldb_env::ErrorParsingResult result =
179      leveldb_env::ParseMethodAndError(s.ToString().c_str(), &method, &error);
180  if (result == leveldb_env::NONE)
181    return;
182  std::string method_histogram_name(histogram_name);
183  method_histogram_name.append(".EnvMethod");
184  base::LinearHistogram::FactoryGet(
185      method_histogram_name,
186      1,
187      leveldb_env::kNumEntries,
188      leveldb_env::kNumEntries + 1,
189      base::HistogramBase::kUmaTargetedHistogramFlag)->Add(method);
190
191  std::string error_histogram_name(histogram_name);
192
193  if (result == leveldb_env::METHOD_AND_PFE) {
194    DCHECK_LT(error, 0);
195    error_histogram_name.append(std::string(".PFE.") +
196                                leveldb_env::MethodIDToString(method));
197    base::LinearHistogram::FactoryGet(
198        error_histogram_name,
199        1,
200        -base::File::FILE_ERROR_MAX,
201        -base::File::FILE_ERROR_MAX + 1,
202        base::HistogramBase::kUmaTargetedHistogramFlag)->Add(-error);
203  } else if (result == leveldb_env::METHOD_AND_ERRNO) {
204    error_histogram_name.append(std::string(".Errno.") +
205                                leveldb_env::MethodIDToString(method));
206    base::LinearHistogram::FactoryGet(
207        error_histogram_name,
208        1,
209        ERANGE + 1,
210        ERANGE + 2,
211        base::HistogramBase::kUmaTargetedHistogramFlag)->Add(error);
212  }
213}
214
215static 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
231static 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
263leveldb::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  const leveldb::Status s =
274      OpenDB(comparator_adapter.get(), leveldb::IDBEnv(), file_name, &db);
275
276  if (!s.ok()) {
277    HistogramLevelDBError("WebCore.IndexedDB.LevelDBOpenErrors", s);
278    int free_space_k_bytes = CheckFreeSpace("Failure", file_name);
279    // Disks with <100k of free space almost never succeed in opening a
280    // leveldb database.
281    if (is_disk_full)
282      *is_disk_full = free_space_k_bytes >= 0 && free_space_k_bytes < 100;
283
284    LOG(ERROR) << "Failed to open LevelDB database from "
285               << file_name.AsUTF8Unsafe() << "," << s.ToString();
286    return s;
287  }
288
289  UMA_HISTOGRAM_MEDIUM_TIMES("WebCore.IndexedDB.LevelDB.OpenTime",
290                             base::TimeTicks::Now() - begin_time);
291
292  CheckFreeSpace("Success", file_name);
293
294  (*result).reset(new LevelDBDatabase);
295  (*result)->db_ = make_scoped_ptr(db);
296  (*result)->comparator_adapter_ = comparator_adapter.Pass();
297  (*result)->comparator_ = comparator;
298
299  return s;
300}
301
302scoped_ptr<LevelDBDatabase> LevelDBDatabase::OpenInMemory(
303    const LevelDBComparator* comparator) {
304  scoped_ptr<ComparatorAdapter> comparator_adapter(
305      new ComparatorAdapter(comparator));
306  scoped_ptr<leveldb::Env> in_memory_env(leveldb::NewMemEnv(leveldb::IDBEnv()));
307
308  leveldb::DB* db;
309  const leveldb::Status s = OpenDB(
310      comparator_adapter.get(), in_memory_env.get(), base::FilePath(), &db);
311
312  if (!s.ok()) {
313    LOG(ERROR) << "Failed to open in-memory LevelDB database: " << s.ToString();
314    return scoped_ptr<LevelDBDatabase>();
315  }
316
317  scoped_ptr<LevelDBDatabase> result(new LevelDBDatabase);
318  result->env_ = in_memory_env.Pass();
319  result->db_ = make_scoped_ptr(db);
320  result->comparator_adapter_ = comparator_adapter.Pass();
321  result->comparator_ = comparator;
322
323  return result.Pass();
324}
325
326leveldb::Status LevelDBDatabase::Put(const StringPiece& key,
327                                     std::string* value) {
328  base::TimeTicks begin_time = base::TimeTicks::Now();
329
330  leveldb::WriteOptions write_options;
331  write_options.sync = kSyncWrites;
332
333  const leveldb::Status s =
334      db_->Put(write_options, MakeSlice(key), MakeSlice(*value));
335  if (!s.ok())
336    LOG(ERROR) << "LevelDB put failed: " << s.ToString();
337  else
338    UMA_HISTOGRAM_TIMES("WebCore.IndexedDB.LevelDB.PutTime",
339                        base::TimeTicks::Now() - begin_time);
340  return s;
341}
342
343leveldb::Status LevelDBDatabase::Remove(const StringPiece& key) {
344  leveldb::WriteOptions write_options;
345  write_options.sync = kSyncWrites;
346
347  const leveldb::Status s = db_->Delete(write_options, MakeSlice(key));
348  if (!s.IsNotFound())
349    LOG(ERROR) << "LevelDB remove failed: " << s.ToString();
350  return s;
351}
352
353leveldb::Status LevelDBDatabase::Get(const StringPiece& key,
354                                     std::string* value,
355                                     bool* found,
356                                     const LevelDBSnapshot* snapshot) {
357  *found = false;
358  leveldb::ReadOptions read_options;
359  read_options.verify_checksums = true;  // TODO(jsbell): Disable this if the
360                                         // performance impact is too great.
361  read_options.snapshot = snapshot ? snapshot->snapshot_ : 0;
362
363  const leveldb::Status s = db_->Get(read_options, MakeSlice(key), value);
364  if (s.ok()) {
365    *found = true;
366    return s;
367  }
368  if (s.IsNotFound())
369    return leveldb::Status::OK();
370  HistogramLevelDBError("WebCore.IndexedDB.LevelDBReadErrors", s);
371  LOG(ERROR) << "LevelDB get failed: " << s.ToString();
372  return s;
373}
374
375leveldb::Status LevelDBDatabase::Write(const LevelDBWriteBatch& write_batch) {
376  base::TimeTicks begin_time = base::TimeTicks::Now();
377  leveldb::WriteOptions write_options;
378  write_options.sync = kSyncWrites;
379
380  const leveldb::Status s =
381      db_->Write(write_options, write_batch.write_batch_.get());
382  if (!s.ok()) {
383    HistogramLevelDBError("WebCore.IndexedDB.LevelDBWriteErrors", s);
384    LOG(ERROR) << "LevelDB write failed: " << s.ToString();
385  } else {
386    UMA_HISTOGRAM_TIMES("WebCore.IndexedDB.LevelDB.WriteTime",
387                        base::TimeTicks::Now() - begin_time);
388  }
389  return s;
390}
391
392scoped_ptr<LevelDBIterator> LevelDBDatabase::CreateIterator(
393    const LevelDBSnapshot* snapshot) {
394  leveldb::ReadOptions read_options;
395  read_options.verify_checksums = true;  // TODO(jsbell): Disable this if the
396                                         // performance impact is too great.
397  read_options.snapshot = snapshot ? snapshot->snapshot_ : 0;
398
399  scoped_ptr<leveldb::Iterator> i(db_->NewIterator(read_options));
400  return scoped_ptr<LevelDBIterator>(
401      IndexedDBClassFactory::Get()->CreateIteratorImpl(i.Pass()));
402}
403
404const LevelDBComparator* LevelDBDatabase::Comparator() const {
405  return comparator_;
406}
407
408void LevelDBDatabase::Compact(const base::StringPiece& start,
409                              const base::StringPiece& stop) {
410  const leveldb::Slice start_slice = MakeSlice(start);
411  const leveldb::Slice stop_slice = MakeSlice(stop);
412  // NULL batch means just wait for earlier writes to be done
413  db_->Write(leveldb::WriteOptions(), NULL);
414  db_->CompactRange(&start_slice, &stop_slice);
415}
416
417void LevelDBDatabase::CompactAll() { db_->CompactRange(NULL, NULL); }
418
419}  // namespace content
420