Implementation of leveldb-backed PrefStore.

This is not hooked up yet, migration code from Json-backed stores is needed, among other things.

BUG=362814

Review URL: https://codereview.chromium.org/169323003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@271602 0039d316-1c4b-4281-b951-d872f2087c98

base/prefs/json_pref_store.cc

@@ -330,6 +330,11 @@ void JsonPrefStore::OnFileRead(scoped_ptr<base::Value> value,
         // operation itself.
         NOTREACHED();
         break;
+      case PREF_READ_ERROR_LEVELDB_IO:
+      case PREF_READ_ERROR_LEVELDB_CORRUPTION_READ_ONLY:
+      case PREF_READ_ERROR_LEVELDB_CORRUPTION:
+        // These are specific to LevelDBPrefStore.
+        NOTREACHED();
       case PREF_READ_ERROR_MAX_ENUM:
         NOTREACHED();
         break;

base/prefs/persistent_pref_store.h

@@ -33,6 +33,9 @@ class BASE_PREFS_EXPORT PersistentPrefStore : public WriteablePrefStore {
     // Indicates that ReadPrefs() couldn't complete synchronously and is waiting
     // for an asynchronous task to complete first.
     PREF_READ_ERROR_ASYNCHRONOUS_TASK_INCOMPLETE = 10,
+    PREF_READ_ERROR_LEVELDB_IO = 11,
+    PREF_READ_ERROR_LEVELDB_CORRUPTION_READ_ONLY = 12,
+    PREF_READ_ERROR_LEVELDB_CORRUPTION = 13,
     PREF_READ_ERROR_MAX_ENUM
   };
 

chrome/browser/prefs/chrome_pref_service_factory.cc

@@ -313,7 +313,8 @@ void HandleReadError(PersistentPrefStore::PrefReadError error) {
     // an example problem that this can cause.
     // Do some diagnosis and try to avoid losing data.
     int message_id = 0;
-    if (error <= PersistentPrefStore::PREF_READ_ERROR_JSON_TYPE) {
+    if (error <= PersistentPrefStore::PREF_READ_ERROR_JSON_TYPE ||
+        error == PersistentPrefStore::PREF_READ_ERROR_LEVELDB_CORRUPTION) {
       message_id = IDS_PREFERENCES_CORRUPT_ERROR;
     } else if (error != PersistentPrefStore::PREF_READ_ERROR_NO_FILE) {
       message_id = IDS_PREFERENCES_UNREADABLE_ERROR;

chrome/browser/prefs/leveldb_pref_store.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_PREFS_LEVELDB_PREF_STORE_H_
+#define CHROME_BROWSER_PREFS_LEVELDB_PREF_STORE_H_
+
+#include <set>
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/files/file_path.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/message_loop/message_loop_proxy.h"
+#include "base/observer_list.h"
+#include "base/prefs/persistent_pref_store.h"
+#include "base/prefs/pref_value_map.h"
+#include "base/timer/timer.h"
+
+namespace base {
+class DictionaryValue;
+class SequencedTaskRunner;
+class Value;
+}
+
+namespace leveldb {
+class DB;
+}
+
+// A writable PrefStore implementation that is used for user preferences.
+class LevelDBPrefStore : public PersistentPrefStore {
+ public:
+  // |sequenced_task_runner| is must be a shutdown-blocking task runner, ideally
+  // created by GetTaskRunnerForFile() method above.
+  LevelDBPrefStore(const base::FilePath& pref_filename,
+                   base::SequencedTaskRunner* sequenced_task_runner);
+
+  // PrefStore overrides:
+  virtual bool GetValue(const std::string& key,
+                        const base::Value** result) const OVERRIDE;
+  virtual void AddObserver(PrefStore::Observer* observer) OVERRIDE;
+  virtual void RemoveObserver(PrefStore::Observer* observer) OVERRIDE;
+  virtual bool HasObservers() const OVERRIDE;
+  virtual bool IsInitializationComplete() const OVERRIDE;
+
+  // PersistentPrefStore overrides:
+  virtual bool GetMutableValue(const std::string& key,
+                               base::Value** result) OVERRIDE;
+  // Takes ownership of value.
+  virtual void SetValue(const std::string& key, base::Value* value) OVERRIDE;
+  virtual void SetValueSilently(const std::string& key,
+                                base::Value* value) OVERRIDE;
+  virtual void RemoveValue(const std::string& key) OVERRIDE;
+  virtual bool ReadOnly() const OVERRIDE;
+  virtual PrefReadError GetReadError() const OVERRIDE;
+  virtual PrefReadError ReadPrefs() OVERRIDE;
+  virtual void ReadPrefsAsync(ReadErrorDelegate* error_delegate) OVERRIDE;
+  virtual void CommitPendingWrite() OVERRIDE;
+  virtual void ReportValueChanged(const std::string& key) OVERRIDE;
+
+ private:
+  struct ReadingResults;
+  class FileThreadSerializer;
+
+  virtual ~LevelDBPrefStore();
+
+  static scoped_ptr<ReadingResults> DoReading(const base::FilePath& path);
+  static void OpenDB(const base::FilePath& path,
+                     ReadingResults* reading_results);
+  void OnStorageRead(scoped_ptr<ReadingResults> reading_results);
+
+  void PersistFromUIThread();
+  void RemoveFromUIThread(const std::string& key);
+  void ScheduleWrite();
+
+  void SetValueInternal(const std::string& key,
+                        base::Value* value,
+                        bool notify);
+  void NotifyObservers(const std::string& key);
+  void MarkForInsertion(const std::string& key, const std::string& value);
+  void MarkForDeletion(const std::string& key);
+
+  base::FilePath path_;
+
+  const scoped_refptr<base::SequencedTaskRunner> sequenced_task_runner_;
+  const scoped_refptr<base::SequencedTaskRunner> original_task_runner_;
+
+  PrefValueMap prefs_;
+
+  bool read_only_;
+
+  ObserverList<PrefStore::Observer, true> observers_;
+
+  scoped_ptr<ReadErrorDelegate> error_delegate_;
+
+  bool initialized_;
+  PrefReadError read_error_;
+
+  // This object is created on the UI thread right after preferences are loaded
+  // from disk. A message to delete it is sent to the FILE thread by
+  // ~LevelDBPrefStore.
+  scoped_ptr<FileThreadSerializer> serializer_;
+
+  // Changes are accumulated in |keys_to_delete_| and |keys_to_set_| and are
+  // stored in the database according to |timer_|.
+  std::set<std::string> keys_to_delete_;
+  std::map<std::string, std::string> keys_to_set_;
+  base::OneShotTimer<LevelDBPrefStore> timer_;
+
+  base::WeakPtrFactory<LevelDBPrefStore> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(LevelDBPrefStore);
+};
+
+#endif  // CHROME_BROWSER_PREFS_LEVELDB_PREF_STORE_H_

chrome/chrome_browser.gypi

@@ -1549,6 +1549,8 @@
         'browser/prefs/incognito_mode_prefs.h',
         'browser/prefs/interceptable_pref_filter.cc',
         'browser/prefs/interceptable_pref_filter.h',
+        'browser/prefs/leveldb_pref_store.cc',
+        'browser/prefs/leveldb_pref_store.h',
         'browser/prefs/pref_hash_calculator.cc',
         'browser/prefs/pref_hash_calculator.h',
         'browser/prefs/pref_hash_filter.cc',

chrome/chrome_tests_unit.gypi

@@ -1154,6 +1154,7 @@
         'browser/prefs/chrome_pref_service_unittest.cc',
         'browser/prefs/command_line_pref_store_unittest.cc',
         'browser/prefs/incognito_mode_prefs_unittest.cc',
+        'browser/prefs/leveldb_pref_store_unittest.cc',
         'browser/prefs/pref_hash_calculator_unittest.cc',
         'browser/prefs/pref_hash_filter_unittest.cc',
         'browser/prefs/pref_hash_store_impl_unittest.cc',

chrome/test/data/prefs/corrupted_leveldb/CURRENT

+MANIFEST-000007
\ No newline at end of file

tools/metrics/histograms/histograms.xml

@@ -8989,6 +8989,14 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="LevelDBPrefStore.ReadErrors" enum="LevelDBPrefStoreErrorCodes">
+  <owner>dgrogan@chromium.org</owner>
+  <summary>
+    Bitfield that indicates errors and recovery that occurred when opening a
+    LevelDB preferences database.
+  </summary>
+</histogram>
+
 <histogram name="LibraryLoader.NativeLibraryHack" enum="BooleanUsage">
   <owner>feng@chromium.org</owner>
   <summary>
@@ -37275,6 +37283,36 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="20" label="GetChildren"/>
 </enum>
 
+<enum name="LevelDBPrefStoreErrorCodes" type="int">
+  <int value="1" label="OPENED"/>
+  <int value="5" label="REPAIRED | OPENED"/>
+  <int value="6" label="REPAIRED | DESTROYED"/>
+  <int value="7" label="REPAIRED | DESTROYED | OPENED"/>
+  <int value="12" label="REPAIRED | DESTROY_FAILED"/>
+  <int value="18" label="REPAIR_FAILED | DESTROYED"/>
+  <int value="19" label="REPAIR_FAILED | DESTROYED | OPENED"/>
+  <int value="24" label="REPAIR_FAILED | DESTROY_FAILED"/>
+  <int value="32" label="IO_ERROR"/>
+  <int value="36" label="REPAIRED | IO_ERROR"/>
+  <int value="38" label="REPAIRED | DESTROYED | IO_ERROR"/>
+  <int value="50" label="REPAIR_FAILED | DESTROYED | IO_ERROR"/>
+  <int value="65" label="OPENED | DATA_LOST"/>
+  <int value="69" label="REPAIRED | OPENED | DATA_LOST"/>
+  <int value="71" label="REPAIRED | DESTROYED | OPENED | DATA_LOST"/>
+  <int value="83" label="REPAIR_FAILED | DESTROYED | OPENED | DATA_LOST"/>
+  <int value="129" label="OPENED | ITER_NOT_OK"/>
+  <int value="133" label="REPAIRED | OPENED | ITER_NOT_OK"/>
+  <int value="135" label="REPAIRED | DESTROYED | OPENED | ITER_NOT_OK"/>
+  <int value="147" label="REPAIR_FAILED | DESTROYED | OPENED | ITER_NOT_OK"/>
+  <int value="193" label="OPENED | DATA_LOST | ITER_NOT_OK"/>
+  <int value="197" label="REPAIRED | OPENED | DATA_LOST | ITER_NOT_OK"/>
+  <int value="199"
+      label="REPAIRED | DESTROYED | OPENED | DATA_LOST | ITER_NOT_OK"/>
+  <int value="211"
+      label="REPAIR_FAILED | DESTROYED | OPENED | DATA_LOST | ITER_NOT_OK"/>
+  <int value="256" label="FILE_NOT_SPECIFIED"/>
+</enum>
+
 <enum name="LinkMonitorFailureType" type="int">
   <int value="0" label="Local MAC Address Not Found"/>
   <int value="1" label="Client Startup Failure"/>