drive: Recover cache entries from trashed DB to filter out non-dirty cache files

chrome/browser/chromeos/drive/resource_metadata_storage_unittest.cc

 // Copyright 2013 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 "chrome/browser/chromeos/drive/resource_metadata_storage.h"
 
 #include <algorithm>
 
 #include "base/file_util.h"
 #include "base/files/scoped_temp_dir.h"
@@ skipping 422 matching lines @@
   // Create a file.
   base::FilePath path;
   ASSERT_TRUE(file_util::CreateTemporaryFileInDir(temp_dir_.path(), &path));
 
   storage_.reset(new ResourceMetadataStorage(
       path, base::MessageLoopProxy::current().get()));
   // Cannot initialize DB beacause the path does not point a directory.
   ASSERT_FALSE(storage_->Initialize());
 }
 
+TEST_F(ResourceMetadataStorageTest, RecoverCacheEntriesFromTrashedResourceMap) {
+  // Put some cache entries.
+  FileCacheEntry cache_entry;
+  cache_entry.set_md5("md5_foo");
+  EXPECT_TRUE(storage_->PutCacheEntry("id_foo", cache_entry));
+  cache_entry.set_md5("md5_bar");
+  EXPECT_TRUE(storage_->PutCacheEntry("id_bar", cache_entry));
+
+  // Put entry with id_foo.
+  ResourceEntry entry;
+  entry.set_local_id("id_foo");
+  entry.set_base_name("foo");
+  EXPECT_TRUE(storage_->PutEntry(entry));
+
+  // Put entry with id_bar as a id_foo's child.
+  entry.set_local_id("id_bar");
+  entry.set_parent_local_id("id_foo");
+  entry.set_base_name("bar");
+  EXPECT_TRUE(storage_->PutEntry(entry));
+
+  // Remove parent-child relationship to make the DB invalid.
+  RemoveChild("id_foo", "bar");
+  EXPECT_FALSE(CheckValidity());
+
+  // Reopen. This should result in trashing the DB.
+  storage_.reset(new ResourceMetadataStorage(
+      temp_dir_.path(), base::MessageLoopProxy::current().get()));
+  ASSERT_TRUE(storage_->Initialize());
+
+  // Recover cache entries from the trashed DB.
+  std::map<std::string, FileCacheEntry> recovered_cache_entries;
+  storage_->RecoverCacheEntriesFromTrashedResourceMap(&recovered_cache_entries);
+  EXPECT_EQ(2U, recovered_cache_entries.size());
+  EXPECT_EQ("md5_foo", recovered_cache_entries["id_foo"].md5());
+  EXPECT_EQ("md5_bar", recovered_cache_entries["id_bar"].md5());
+}
+
 TEST_F(ResourceMetadataStorageTest, CheckValidity) {
   const std::string key1 = "foo";
   const std::string name1 = "hoge";
   const std::string key2 = "bar";
   const std::string name2 = "fuga";
   const std::string key3 = "boo";
   const std::string name3 = "piyo";
 
   // Empty storage is valid.
   EXPECT_TRUE(CheckValidity());
@@ skipping 59 matching lines @@
   EXPECT_TRUE(storage_->RemoveEntry(key3));
   EXPECT_TRUE(CheckValidity());
 
   // Remove key1.
   EXPECT_TRUE(storage_->RemoveEntry(key1));
   EXPECT_TRUE(CheckValidity());
 }
 
 }  // namespace internal
 }  // namespace drive