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 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(databasePageSize_);
  33 }
  34
  35 OnDiskDirectoryBackingStore::~OnDiskDirectoryBackingStore() { }
  36
  37 DirOpenResult OnDiskDirectoryBackingStore::TryLoad(
  38     Directory::MetahandlesMap* handles_map,
  39     JournalIndex* delete_journals,
  40     MetahandleSet* metahandles_to_purge,
  41     Directory::KernelLoadInfo* kernel_load_info) {
  42   DCHECK(CalledOnValidThread());
  43   if (!db_->is_open()) {
  44     if (!db_->Open(backing_filepath_))
  45       return FAILED_OPEN_DATABASE;
  46   }
  47
  48   if (!InitializeTables())
  49     return FAILED_OPEN_DATABASE;
  50
  51   if (!LoadEntries(handles_map, metahandles_to_purge))
  52     return FAILED_DATABASE_CORRUPT;
  53   if (!LoadDeleteJournals(delete_journals))
  54     return FAILED_DATABASE_CORRUPT;
  55   if (!LoadInfo(kernel_load_info))
  56     return FAILED_DATABASE_CORRUPT;
  57   if (!VerifyReferenceIntegrity(handles_map))
  58     return FAILED_DATABASE_CORRUPT;
  59
  60   return OPENED;
  61
  62 }
  63
  64 DirOpenResult OnDiskDirectoryBackingStore::Load(
  65     Directory::MetahandlesMap* handles_map,
  66     JournalIndex* delete_journals,
  67     MetahandleSet* metahandles_to_purge,
  68     Directory::KernelLoadInfo* kernel_load_info) {
  69   DirOpenResult result = TryLoad(handles_map, delete_journals,
  70                                  metahandles_to_purge, 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(databasePageSize_);
  89   db_->set_histogram_tag("SyncDirectory");
  90   base::DeleteFile(backing_filepath_, false);
  91
  92   result = TryLoad(handles_map, delete_journals, metahandles_to_purge,
  93                    kernel_load_info);
  94   if (result == OPENED) {
  95     UMA_HISTOGRAM_ENUMERATION(
  96         "Sync.DirectoryOpenResult", SECOND_TRY_SUCCESS, RESULT_COUNT);
  97   } else {
  98     UMA_HISTOGRAM_ENUMERATION(
  99         "Sync.DirectoryOpenResult", SECOND_TRY_FAILURE, RESULT_COUNT);
 100   }
 101
 102   return result;
 103 }
 104
 105 void OnDiskDirectoryBackingStore::ReportFirstTryOpenFailure() {
 106   // In debug builds, the last thing we want is to silently clear the database.
 107   // It's full of evidence that might help us determine what went wrong.  It
 108   // might be sqlite's fault, but it could also be a bug in sync.  We crash
 109   // immediately so a developer can investigate.
 110   //
 111   // Developers: If you're not interested in debugging this right now, just move
 112   // aside the 'Sync Data' directory in your profile.  This is similar to what
 113   // the code would do if this DCHECK were disabled.
 114   NOTREACHED() << "Crashing to preserve corrupt sync database";
 115 }
 116
 117 }  // namespace syncable
 118 }  // namespace syncer