[Sync] Update DirectoryBackingStore to detect Sync DB corruption

sync/syncable/directory_backing_store_unittest.cc

 // Copyright 2012 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.
 
 #include "testing/gtest/include/gtest/gtest.h"
 
 #include <string>
 
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "sql/connection.h"
 #include "sql/statement.h"
+#include "sql/test/scoped_error_ignorer.h"
+#include "sql/test/test_helpers.h"
 #include "sync/base/sync_export.h"
 #include "sync/internal_api/public/base/node_ordinal.h"
 #include "sync/protocol/bookmark_specifics.pb.h"
 #include "sync/protocol/sync.pb.h"
 #include "sync/syncable/directory.h"
 #include "sync/syncable/directory_backing_store.h"
 #include "sync/syncable/on_disk_directory_backing_store.h"
 #include "sync/syncable/syncable-inl.h"
 #include "sync/test/test_directory_backing_store.h"
 #include "sync/util/time.h"
 #include "testing/gtest/include/gtest/gtest-param-test.h"
 
+namespace {
+
+// A handler that simply sets |catastrophic_error_handler_was_called| to true.
+void CatastrophicErrorHandler(bool* catastrophic_error_handler_was_called) {
+  *catastrophic_error_handler_was_called = true;
+}
+
+}  // namespace
+
 namespace syncer {
 namespace syncable {
 
 SYNC_EXPORT_PRIVATE extern const int32 kCurrentDBVersion;
 
 class MigrationTest : public testing::TestWithParam<int> {
  public:
   void SetUp() override { ASSERT_TRUE(temp_dir_.CreateUniqueTempDir()); }
 
  protected:
@@ skipping 43 matching lines @@
     SetUpVersion89Database(connection);  // Prepopulates data.
     scoped_ptr<TestDirectoryBackingStore> dbs(
         new TestDirectoryBackingStore(GetUsername(), connection));
     ASSERT_EQ(kCurrentDBVersion, dbs->GetVersion());
 
     ASSERT_TRUE(LoadAndIgnoreReturnedData(dbs.get()));
     ASSERT_FALSE(dbs->needs_column_refresh());
   }
 
  private:
+  base::MessageLoop message_loop_;
   base::ScopedTempDir temp_dir_;
 };
 
 class DirectoryBackingStoreTest : public MigrationTest {};
 
 #if defined(OS_WIN)
 
 // On Windows, we used to store timestamps in FILETIME format.
 #define LEGACY_META_PROTO_TIMES_1 129079956640320000LL
 #define LEGACY_META_PROTO_TIMES_2 128976886618480000LL
@@ skipping 3886 matching lines @@
   int pageSize = 0;
   dbs->GetDatabasePageSize(&pageSize);
   EXPECT_TRUE(32768 != pageSize);
   dbs->db_->set_page_size(32768);
   dbs->IncreasePageSizeTo32K();
   pageSize = 0;
   dbs->GetDatabasePageSize(&pageSize);
   EXPECT_EQ(32768, pageSize);
 }
 
+// See that a catastrophic error handler remains set across instances of the
+// underlying sql:Connection.
+TEST_F(DirectoryBackingStoreTest, CatastrophicErrorHandler_KeptAcrossReset) {
+  scoped_ptr<OnDiskDirectoryBackingStoreForTest> dbs(
+      new OnDiskDirectoryBackingStoreForTest(GetUsername(), GetDatabasePath()));
+  // See that by default there is no catastrophic error handler.
+  ASSERT_FALSE(dbs->db_->has_error_callback());
+  // Set one and see that it was set.
+  dbs->SetCatastrophicErrorHandler(
+      base::Bind(&CatastrophicErrorHandler, nullptr));
+  ASSERT_TRUE(dbs->db_->has_error_callback());
+  // Recreate the Connection and see that the handler remains set.
+  dbs->ResetAndCreateConnection();
+  ASSERT_TRUE(dbs->db_->has_error_callback());
+}
+
+// Verify that database corruption will trigger the catastrohpic error handler.
+TEST_F(DirectoryBackingStoreTest, CatastrophicErrorHandler_Invocation) {
+  bool was_called = false;
+  const base::Closure handler =

[Nicolas Zea, 2015/04/13 20:16:33]

nit: const vars should be of form kVariableName.

[maniscalco, 2015/04/14 17:44:14]

Definitely when they are global or class scoped.  For local variables I believe
it can be done either way.

http://google-styleguide.googlecode.com/svn/trunk/cppguide.html#Constant_Names

So far it seems like underscore_naming_scheme is more common for const locals so
I figured I'd keep doing that.

+      base::Bind(&CatastrophicErrorHandler, &was_called);
+  {
+    scoped_ptr<OnDiskDirectoryBackingStoreForTest> dbs(
+        new OnDiskDirectoryBackingStoreForTest(GetUsername(),
+                                               GetDatabasePath()));
+    dbs->SetCatastrophicErrorHandler(handler);
+    ASSERT_TRUE(dbs->db_->has_error_callback());
+    // Load the DB, and save one entry.
+    ASSERT_TRUE(LoadAndIgnoreReturnedData(dbs.get()));
+    ASSERT_FALSE(dbs->DidFailFirstOpenAttempt());
+    Directory::SaveChangesSnapshot snapshot;
+    scoped_ptr<EntryKernel> entry(new EntryKernel());
+    entry->put(ID, Id::CreateFromClientString("test_entry"));
+    entry->put(META_HANDLE, 2);
+    entry->mark_dirty(NULL);
+    snapshot.dirty_metas.insert(entry.release());
+    ASSERT_TRUE(dbs->SaveChanges(snapshot));
+  }
+
+  base::RunLoop().RunUntilIdle();
+  // No catastrophic errors have happened. See that it hasn't be called yet.
+  ASSERT_FALSE(was_called);
+
+  // Corrupt the DB. Some forms of corruption (like this one) will be detected
+  // upon loading the Sync DB.
+  ASSERT_TRUE(sql::test::CorruptSizeInHeader(GetDatabasePath()));
+
+  {
+    scoped_ptr<OnDiskDirectoryBackingStoreForTest> dbs(
+        new OnDiskDirectoryBackingStoreForTest(GetUsername(),
+                                               GetDatabasePath()));
+    dbs->SetCatastrophicErrorHandler(handler);
+    ASSERT_TRUE(dbs->db_->has_error_callback());
+    {
+      // The corruption will be detected when we attempt to load the data. Use a
+      // ScopedErrorIgnorer to ensure we don't crash in debug builds.
+      sql::ScopedErrorIgnorer error_ignorer;
+      error_ignorer.IgnoreError(SQLITE_CORRUPT);
+      ASSERT_TRUE(LoadAndIgnoreReturnedData(dbs.get()));
+      ASSERT_TRUE(error_ignorer.CheckIgnoredErrors());
+    }
+    // See that the first open failed as expected.
+    ASSERT_TRUE(dbs->DidFailFirstOpenAttempt());
+  }
+
+  // At this point the handler has been posted but not executed.
+  ASSERT_FALSE(was_called);
+  // Pump the message loop and see that it is executed.
+  base::RunLoop().RunUntilIdle();
+  ASSERT_TRUE(was_called);
+}
+
 }  // namespace syncable
 }  // namespace syncer