Let SyncBackupManager keep backup data in memory until shutdown. Only persist

sync/syncable/deferred_on_disk_directory_backing_store_unittest.cc

Index: sync/syncable/deferred_on_disk_directory_backing_store_unittest.cc
diff --git a/sync/syncable/deferred_on_disk_directory_backing_store_unittest.cc b/sync/syncable/deferred_on_disk_directory_backing_store_unittest.cc
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index 0000000000000000000000000000000000000000..b562353af72193fd3cecc66b656f146fe4e2a474
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+++ b/sync/syncable/deferred_on_disk_directory_backing_store_unittest.cc
@@ -0,0 +1,114 @@
+// Copyright (c) 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.
+
+#include "base/files/scoped_temp_dir.h"
+#include "base/stl_util.h"
+#include "sync/syncable/deferred_on_disk_directory_backing_store.h"
+#include "sync/syncable/directory.h"
+#include "sync/syncable/entry_kernel.h"
+#include "sync/syncable/on_disk_directory_backing_store.h"
+#include "sync/syncable/syncable_delete_journal.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace syncer {
+namespace syncable {
+namespace {
+
+static const base::FilePath::CharType kSyncDataFolderName[] =
+    FILE_PATH_LITERAL("Sync Data");
+
+class DeferredOnDiskDirectoryBackingStoreTest : public testing::Test {
+ protected:
+  virtual void SetUp() OVERRIDE {
+    CHECK(temp_dir_.CreateUniqueTempDir());
+    db_path_ = temp_dir_.path().Append(kSyncDataFolderName);
+  }
+
+  virtual void TearDown() OVERRIDE {
+    STLDeleteValues(&handles_map_);
+  }
+
+  base::ScopedTempDir temp_dir_;
+  base::FilePath db_path_;
+  Directory::MetahandlesMap handles_map_;
+  JournalIndex delete_journals_;
+  Directory::KernelLoadInfo kernel_load_info_;
+};
+
+// Test initialization of root entry when calling Load().
+TEST_F(DeferredOnDiskDirectoryBackingStoreTest, Load) {
+  DeferredOnDiskDirectoryBackingStore store("test", db_path_);
+  EXPECT_EQ(OPENED, store.Load(&handles_map_, &delete_journals_,
+                               &kernel_load_info_));
+  EXPECT_TRUE(delete_journals_.empty());
+  ASSERT_EQ(1u, handles_map_.size());   // root node
+  ASSERT_TRUE(handles_map_.count(1));
+  EntryKernel* root = handles_map_[1];
+  EXPECT_TRUE(root->ref(ID).IsRoot());
+  EXPECT_EQ(1, root->ref(META_HANDLE));
+  EXPECT_TRUE(root->ref(IS_DIR));
+}
+
+// Test on-disk DB is not created if SaveChanges() is not called.
+TEST_F(DeferredOnDiskDirectoryBackingStoreTest,
+       DontPersistIfSavingChangesNotCalled) {
+  {
+    // Open and close.
+    DeferredOnDiskDirectoryBackingStore store("test", db_path_);
+    EXPECT_EQ(OPENED, store.Load(&handles_map_, &delete_journals_,
+                                 &kernel_load_info_));
+  }
+
+  EXPECT_FALSE(base::PathExists(db_path_));
+}
+
+// Test on-disk DB is not created when there are no changes.
+TEST_F(DeferredOnDiskDirectoryBackingStoreTest,
+       DontPersistWhenSavingNoChanges) {
+  {
+    // Open and close.
+    DeferredOnDiskDirectoryBackingStore store("test", db_path_);
+    EXPECT_EQ(OPENED, store.Load(&handles_map_, &delete_journals_,
+                                 &kernel_load_info_));
+
+    Directory::SaveChangesSnapshot snapshot;
+    store.SaveChanges(snapshot);
+  }
+
+  EXPECT_FALSE(base::PathExists(db_path_));
+}
+
+// Test changes are persisted to disk when SaveChanges() is called.
+TEST_F(DeferredOnDiskDirectoryBackingStoreTest, PersistWhenSavingValidChanges) {
+  {
+    // Open and close.
+    DeferredOnDiskDirectoryBackingStore store("test", db_path_);
+    EXPECT_EQ(OPENED, store.Load(&handles_map_, &delete_journals_,
+                                 &kernel_load_info_));
+
+    Directory::SaveChangesSnapshot snapshot;
+    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);
+    store.SaveChanges(snapshot);
+  }
+
+  STLDeleteValues(&handles_map_);
+
+  ASSERT_TRUE(base::PathExists(db_path_));
+  OnDiskDirectoryBackingStore read_store("test", db_path_);
+  EXPECT_EQ(OPENED, read_store.Load(&handles_map_, &delete_journals_,
+                                    &kernel_load_info_));
+  ASSERT_EQ(2u, handles_map_.size());
+  ASSERT_TRUE(handles_map_.count(1));     // root node
+  ASSERT_TRUE(handles_map_.count(2));
+  EntryKernel* entry = handles_map_[2];
+  EXPECT_EQ(Id::CreateFromClientString("test_entry"), entry->ref(ID));
+}
+
+}  // namespace
+}  // namespace syncable
+}  // namespace syncer