1// Copyright (c) 2012 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 "sync/syncable/on_disk_directory_backing_store.h"
6
7#include "base/logging.h"
8#include "base/stl_util.h"
9#include "base/metrics/histogram.h"
10#include "sync/syncable/syncable-inl.h"
11
12namespace syncer {
13namespace syncable {
14
15namespace {
16
17enum HistogramResultEnum {
18  FIRST_TRY_SUCCESS,
19  SECOND_TRY_SUCCESS,
20  SECOND_TRY_FAILURE,
21  RESULT_COUNT
22};
23
24}  // namespace
25
26OnDiskDirectoryBackingStore::OnDiskDirectoryBackingStore(
27    const std::string& dir_name, const base::FilePath& backing_filepath)
28    : DirectoryBackingStore(dir_name),
29      allow_failure_for_test_(false),
30      backing_filepath_(backing_filepath) {
31  db_->set_exclusive_locking();
32  db_->set_page_size(4096);
33}
34
35OnDiskDirectoryBackingStore::~OnDiskDirectoryBackingStore() { }
36
37DirOpenResult OnDiskDirectoryBackingStore::TryLoad(
38    Directory::MetahandlesMap* handles_map,
39    JournalIndex* delete_journals,
40    Directory::KernelLoadInfo* kernel_load_info) {
41  DCHECK(CalledOnValidThread());
42  if (!db_->is_open()) {
43    if (!db_->Open(backing_filepath_))
44      return FAILED_OPEN_DATABASE;
45  }
46
47  if (!InitializeTables())
48    return FAILED_OPEN_DATABASE;
49
50  if (!DropDeletedEntries())
51    return FAILED_DATABASE_CORRUPT;
52  if (!LoadEntries(handles_map))
53    return FAILED_DATABASE_CORRUPT;
54  if (!LoadDeleteJournals(delete_journals))
55    return FAILED_DATABASE_CORRUPT;
56  if (!LoadInfo(kernel_load_info))
57    return FAILED_DATABASE_CORRUPT;
58  if (!VerifyReferenceIntegrity(handles_map))
59    return FAILED_DATABASE_CORRUPT;
60
61  return OPENED;
62
63}
64
65DirOpenResult OnDiskDirectoryBackingStore::Load(
66    Directory::MetahandlesMap* handles_map,
67    JournalIndex* delete_journals,
68    Directory::KernelLoadInfo* kernel_load_info) {
69  DirOpenResult result = TryLoad(handles_map, delete_journals,
70                                 kernel_load_info);
71  if (result == OPENED) {
72    UMA_HISTOGRAM_ENUMERATION(
73        "Sync.DirectoryOpenResult", FIRST_TRY_SUCCESS, RESULT_COUNT);
74    return OPENED;
75  }
76
77  ReportFirstTryOpenFailure();
78
79  // The fallback: delete the current database and return a fresh one.  We can
80  // fetch the user's data from the cloud.
81  STLDeleteValues(handles_map);
82  STLDeleteElements(delete_journals);
83  db_.reset(new sql::Connection);
84  // TODO: Manually propagating the default database settings is
85  // brittle.  Either have a helper to set these up (or generate a new
86  // connection), or add something like Reset() to sql::Connection.
87  db_->set_exclusive_locking();
88  db_->set_page_size(4096);
89  db_->set_histogram_tag("SyncDirectory");
90  base::DeleteFile(backing_filepath_, false);
91
92  result = TryLoad(handles_map, delete_journals, kernel_load_info);
93  if (result == OPENED) {
94    UMA_HISTOGRAM_ENUMERATION(
95        "Sync.DirectoryOpenResult", SECOND_TRY_SUCCESS, RESULT_COUNT);
96  } else {
97    UMA_HISTOGRAM_ENUMERATION(
98        "Sync.DirectoryOpenResult", SECOND_TRY_FAILURE, RESULT_COUNT);
99  }
100
101  return result;
102}
103
104void OnDiskDirectoryBackingStore::ReportFirstTryOpenFailure() {
105  // In debug builds, the last thing we want is to silently clear the database.
106  // It's full of evidence that might help us determine what went wrong.  It
107  // might be sqlite's fault, but it could also be a bug in sync.  We crash
108  // immediately so a developer can investigate.
109  //
110  // Developers: If you're not interested in debugging this right now, just move
111  // aside the 'Sync Data' directory in your profile.  This is similar to what
112  // the code would do if this DCHECK were disabled.
113  NOTREACHED() << "Crashing to preserve corrupt sync database";
114}
115
116}  // namespace syncable
117}  // namespace syncer
118