sync/syncable/on_disk_directory_backing_store.cc

   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
  12 namespace syncer {
  13 namespace syncable {
  14
  15 namespace {
  16
  17 enum HistogramResultEnum {
  18   FIRST_TRY_SUCCESS,
  19   SECOND_TRY_SUCCESS,
  20   SECOND_TRY_FAILURE,
  21   RESULT_COUNT
  22 };
  23
  24 }  // namespace
  25
  26 OnDiskDirectoryBackingStore::OnDiskDirectoryBackingStore(
  27     const std::string& dir_name, const 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
  35 OnDiskDirectoryBackingStore::~OnDiskDirectoryBackingStore() { }
  36
  37 DirOpenResult OnDiskDirectoryBackingStore::TryLoad(
  38     MetahandlesIndex* entry_bucket,
  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(entry_bucket))
  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(*entry_bucket))
  59     return FAILED_DATABASE_CORRUPT;
  60
  61   return OPENED;
  62
  63 }
  64
  65 DirOpenResult OnDiskDirectoryBackingStore::Load(
  66     MetahandlesIndex* entry_bucket,
  67     JournalIndex* delete_journals,
  68     Directory::KernelLoadInfo* kernel_load_info) {
  69   DirOpenResult result = TryLoad(entry_bucket, 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   STLDeleteElements(entry_bucket);
  82   STLDeleteElements(delete_journals);
  83   db_.reset(new sql::Connection);
  84   file_util::Delete(backing_filepath_, false);
  85
  86   result = TryLoad(entry_bucket, delete_journals, kernel_load_info);
  87   if (result == OPENED) {
  88     UMA_HISTOGRAM_ENUMERATION(
  89         "Sync.DirectoryOpenResult", SECOND_TRY_SUCCESS, RESULT_COUNT);
  90   } else {
  91     UMA_HISTOGRAM_ENUMERATION(
  92         "Sync.DirectoryOpenResult", SECOND_TRY_FAILURE, RESULT_COUNT);
  93   }
  94
  95   return result;
  96 }
  97
  98 void OnDiskDirectoryBackingStore::ReportFirstTryOpenFailure() {
  99   // In debug builds, the last thing we want is to silently clear the database.
 100   // It's full of evidence that might help us determine what went wrong.  It
 101   // might be sqlite's fault, but it could also be a bug in sync.  We crash
 102   // immediately so a developer can investigate.
 103   //
 104   // Developers: If you're not interested in debugging this right now, just move
 105   // aside the 'Sync Data' directory in your profile.  This is similar to what
 106   // the code would do if this DCHECK were disabled.
 107   NOTREACHED() << "Crashing to preserve corrupt sync database";
 108 }
 109
 110 }  // namespace syncable
 111 }  // namespace syncer