net/disk_cache/simple/simple_index_file_unittest.cc - chromium/src - Git at Google

 // Copyright (c) 2011 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/file.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/hash.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/pickle.h"
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/stringprintf.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/threading/thread.h"
 #include "base/time/time.h"
 #include "net/base/cache_type.h"
 #include "net/base/test_completion_callback.h"
 #include "net/disk_cache/disk_cache_test_util.h"
 #include "net/disk_cache/simple/simple_backend_impl.h"
 #include "net/disk_cache/simple/simple_backend_version.h"
 #include "net/disk_cache/simple/simple_entry_format.h"
 #include "net/disk_cache/simple/simple_index.h"
 #include "net/disk_cache/simple/simple_index_file.h"
 #include "net/disk_cache/simple/simple_util.h"
 #include "net/disk_cache/simple/simple_version_upgrade.h"
 #include "testing/gtest/include/gtest/gtest.h"

 using base::Time;
 using disk_cache::SimpleIndexFile;
 using disk_cache::SimpleIndex;

 namespace disk_cache {

 // The Simple Cache backend requires a few guarantees from the filesystem like
 // atomic renaming of recently open files. Those guarantees are not provided in
 // general on Windows.
 #if defined(OS_POSIX)

 TEST(IndexMetadataTest, Basics) {
   SimpleIndexFile::IndexMetadata index_metadata;

   EXPECT_EQ(disk_cache::kSimpleIndexMagicNumber, index_metadata.magic_number_);
   EXPECT_EQ(disk_cache::kSimpleVersion, index_metadata.version_);
   EXPECT_EQ(0U, index_metadata.GetNumberOfEntries());
   EXPECT_EQ(0U, index_metadata.cache_size_);

   EXPECT_TRUE(index_metadata.CheckIndexMetadata());
 }

 TEST(IndexMetadataTest, Serialize) {
   SimpleIndexFile::IndexMetadata index_metadata(123, 456);
   base::Pickle pickle;
   index_metadata.Serialize(&pickle);
   base::PickleIterator it(pickle);
   SimpleIndexFile::IndexMetadata new_index_metadata;
   new_index_metadata.Deserialize(&it);

   EXPECT_EQ(new_index_metadata.magic_number_, index_metadata.magic_number_);
   EXPECT_EQ(new_index_metadata.version_, index_metadata.version_);
   EXPECT_EQ(new_index_metadata.GetNumberOfEntries(),
             index_metadata.GetNumberOfEntries());
   EXPECT_EQ(new_index_metadata.cache_size_, index_metadata.cache_size_);

   EXPECT_TRUE(new_index_metadata.CheckIndexMetadata());
 }

 // This friend derived class is able to reexport its ancestors private methods
 // as public, for use in tests.
 class WrappedSimpleIndexFile : public SimpleIndexFile {
  public:
   using SimpleIndexFile::Deserialize;
   using SimpleIndexFile::LegacyIsIndexFileStale;
   using SimpleIndexFile::Serialize;
   using SimpleIndexFile::SerializeFinalData;

   explicit WrappedSimpleIndexFile(const base::FilePath& index_file_directory)
       : SimpleIndexFile(base::ThreadTaskRunnerHandle::Get(),
                         base::ThreadTaskRunnerHandle::Get(),
                         net::DISK_CACHE,
                         index_file_directory) {}
   ~WrappedSimpleIndexFile() override {}

   const base::FilePath& GetIndexFilePath() const {
     return index_file_;
   }

   const base::FilePath& GetTempIndexFilePath() const {
     return temp_index_file_;
   }

   bool CreateIndexFileDirectory() const {
     return base::CreateDirectory(index_file_.DirName());
   }
 };

 class SimpleIndexFileTest : public testing::Test {
  public:
   bool CompareTwoEntryMetadata(const EntryMetadata& a, const EntryMetadata& b) {
     return
         a.last_used_time_seconds_since_epoch_ ==
             b.last_used_time_seconds_since_epoch_ &&
         a.entry_size_ == b.entry_size_;
   }
 };

 TEST_F(SimpleIndexFileTest, Serialize) {
   SimpleIndex::EntrySet entries;
   static const uint64_t kHashes[] = {11, 22, 33};
   static const size_t kNumHashes = arraysize(kHashes);
   EntryMetadata metadata_entries[kNumHashes];

   SimpleIndexFile::IndexMetadata index_metadata(
       static_cast<uint64_t>(kNumHashes), 456);
   for (size_t i = 0; i < kNumHashes; ++i) {
     uint64_t hash = kHashes[i];
     metadata_entries[i] = EntryMetadata(Time(), hash);
     SimpleIndex::InsertInEntrySet(hash, metadata_entries[i], &entries);
   }

   scoped_ptr<base::Pickle> pickle =
       WrappedSimpleIndexFile::Serialize(index_metadata, entries);
   EXPECT_TRUE(pickle.get() != NULL);
   base::Time now = base::Time::Now();
   EXPECT_TRUE(WrappedSimpleIndexFile::SerializeFinalData(now, pickle.get()));
   base::Time when_index_last_saw_cache;
   SimpleIndexLoadResult deserialize_result;
   WrappedSimpleIndexFile::Deserialize(static_cast<const char*>(pickle->data()),
                                       pickle->size(),
                                       &when_index_last_saw_cache,
                                       &deserialize_result);
   EXPECT_TRUE(deserialize_result.did_load);
   EXPECT_EQ(now, when_index_last_saw_cache);
   const SimpleIndex::EntrySet& new_entries = deserialize_result.entries;
   EXPECT_EQ(entries.size(), new_entries.size());

   for (size_t i = 0; i < kNumHashes; ++i) {
     SimpleIndex::EntrySet::const_iterator it = new_entries.find(kHashes[i]);
     EXPECT_TRUE(new_entries.end() != it);
     EXPECT_TRUE(CompareTwoEntryMetadata(it->second, metadata_entries[i]));
   }
 }

 TEST_F(SimpleIndexFileTest, LegacyIsIndexFileStale) {
   base::ScopedTempDir cache_dir;
   ASSERT_TRUE(cache_dir.CreateUniqueTempDir());
   base::Time cache_mtime;
   const base::FilePath cache_path = cache_dir.path();

   ASSERT_TRUE(simple_util::GetMTime(cache_path, &cache_mtime));
   WrappedSimpleIndexFile simple_index_file(cache_path);
   ASSERT_TRUE(simple_index_file.CreateIndexFileDirectory());
   const base::FilePath& index_path = simple_index_file.GetIndexFilePath();
   EXPECT_TRUE(
       WrappedSimpleIndexFile::LegacyIsIndexFileStale(cache_mtime, index_path));
   const std::string kDummyData = "nothing to be seen here";
   EXPECT_EQ(static_cast<int>(kDummyData.size()),
             base::WriteFile(index_path,
                             kDummyData.data(), kDummyData.size()));
   ASSERT_TRUE(simple_util::GetMTime(cache_path, &cache_mtime));
   EXPECT_FALSE(
       WrappedSimpleIndexFile::LegacyIsIndexFileStale(cache_mtime, index_path));

   const base::Time past_time = base::Time::Now() -
       base::TimeDelta::FromSeconds(10);
   EXPECT_TRUE(base::TouchFile(index_path, past_time, past_time));
   EXPECT_TRUE(base::TouchFile(cache_path, past_time, past_time));
   ASSERT_TRUE(simple_util::GetMTime(cache_path, &cache_mtime));
   EXPECT_FALSE(
       WrappedSimpleIndexFile::LegacyIsIndexFileStale(cache_mtime, index_path));
   const base::Time even_older = past_time - base::TimeDelta::FromSeconds(10);
   EXPECT_TRUE(base::TouchFile(index_path, even_older, even_older));
   EXPECT_TRUE(
       WrappedSimpleIndexFile::LegacyIsIndexFileStale(cache_mtime, index_path));
 }

 TEST_F(SimpleIndexFileTest, WriteThenLoadIndex) {
   base::ScopedTempDir cache_dir;
   ASSERT_TRUE(cache_dir.CreateUniqueTempDir());

   SimpleIndex::EntrySet entries;
   static const uint64_t kHashes[] = {11, 22, 33};
   static const size_t kNumHashes = arraysize(kHashes);
   EntryMetadata metadata_entries[kNumHashes];
   for (size_t i = 0; i < kNumHashes; ++i) {
     uint64_t hash = kHashes[i];
     metadata_entries[i] = EntryMetadata(Time(), hash);
     SimpleIndex::InsertInEntrySet(hash, metadata_entries[i], &entries);
   }

   const uint64_t kCacheSize = 456U;
   net::TestClosure closure;
   {
     WrappedSimpleIndexFile simple_index_file(cache_dir.path());
     simple_index_file.WriteToDisk(entries, kCacheSize, base::TimeTicks(),
                                   false, closure.closure());
     closure.WaitForResult();
     EXPECT_TRUE(base::PathExists(simple_index_file.GetIndexFilePath()));
   }

   WrappedSimpleIndexFile simple_index_file(cache_dir.path());
   base::Time fake_cache_mtime;
   ASSERT_TRUE(simple_util::GetMTime(cache_dir.path(), &fake_cache_mtime));
   SimpleIndexLoadResult load_index_result;
   simple_index_file.LoadIndexEntries(fake_cache_mtime, closure.closure(),
                                      &load_index_result);
   closure.WaitForResult();

   EXPECT_TRUE(base::PathExists(simple_index_file.GetIndexFilePath()));
   EXPECT_TRUE(load_index_result.did_load);
   EXPECT_FALSE(load_index_result.flush_required);

   EXPECT_EQ(kNumHashes, load_index_result.entries.size());
   for (size_t i = 0; i < kNumHashes; ++i)
     EXPECT_EQ(1U, load_index_result.entries.count(kHashes[i]));
 }

 TEST_F(SimpleIndexFileTest, LoadCorruptIndex) {
   base::ScopedTempDir cache_dir;
   ASSERT_TRUE(cache_dir.CreateUniqueTempDir());

   WrappedSimpleIndexFile simple_index_file(cache_dir.path());
   ASSERT_TRUE(simple_index_file.CreateIndexFileDirectory());
   const base::FilePath& index_path = simple_index_file.GetIndexFilePath();
   const std::string kDummyData = "nothing to be seen here";
   EXPECT_EQ(static_cast<int>(kDummyData.size()),
             base::WriteFile(index_path, kDummyData.data(), kDummyData.size()));
   base::Time fake_cache_mtime;
   ASSERT_TRUE(simple_util::GetMTime(simple_index_file.GetIndexFilePath(),
                                     &fake_cache_mtime));
   EXPECT_FALSE(WrappedSimpleIndexFile::LegacyIsIndexFileStale(fake_cache_mtime,
                                                               index_path));
   SimpleIndexLoadResult load_index_result;
   net::TestClosure closure;
   simple_index_file.LoadIndexEntries(fake_cache_mtime, closure.closure(),
                                      &load_index_result);
   closure.WaitForResult();

   EXPECT_FALSE(base::PathExists(index_path));
   EXPECT_TRUE(load_index_result.did_load);
   EXPECT_TRUE(load_index_result.flush_required);
 }

 // Tests that after an upgrade the backend has the index file put in place.
 TEST_F(SimpleIndexFileTest, SimpleCacheUpgrade) {
   base::ScopedTempDir cache_dir;
   ASSERT_TRUE(cache_dir.CreateUniqueTempDir());
   const base::FilePath cache_path = cache_dir.path();

   // Write an old fake index file.
   base::File file(cache_path.AppendASCII("index"),
                   base::File::FLAG_CREATE | base::File::FLAG_WRITE);
   ASSERT_TRUE(file.IsValid());
   disk_cache::FakeIndexData file_contents;
   file_contents.initial_magic_number = disk_cache::kSimpleInitialMagicNumber;
   file_contents.version = 5;
   int bytes_written = file.Write(0, reinterpret_cast<char*>(&file_contents),
                                  sizeof(file_contents));
   ASSERT_EQ((int)sizeof(file_contents), bytes_written);
   file.Close();

   // Write the index file. The format is incorrect, but for transitioning from
   // v5 it does not matter.
   const std::string index_file_contents("incorrectly serialized data");
   const base::FilePath old_index_file =
       cache_path.AppendASCII("the-real-index");
   ASSERT_EQ(static_cast<int>(index_file_contents.size()),
             base::WriteFile(old_index_file, index_file_contents.data(),
                             index_file_contents.size()));

   // Upgrade the cache.
   ASSERT_TRUE(disk_cache::UpgradeSimpleCacheOnDisk(cache_path));

   // Create the backend and initiate index flush by destroying the backend.
   base::Thread cache_thread("CacheThread");
   ASSERT_TRUE(cache_thread.StartWithOptions(
       base::Thread::Options(base::MessageLoop::TYPE_IO, 0)));
   disk_cache::SimpleBackendImpl* simple_cache =
       new disk_cache::SimpleBackendImpl(cache_path, 0, net::DISK_CACHE,
                                         cache_thread.task_runner().get(), NULL);
   net::TestCompletionCallback cb;
   int rv = simple_cache->Init(cb.callback());
   EXPECT_EQ(net::OK, cb.GetResult(rv));
   rv = simple_cache->index()->ExecuteWhenReady(cb.callback());
   EXPECT_EQ(net::OK, cb.GetResult(rv));
   delete simple_cache;

   // The backend flushes the index on destruction and does so on the cache
   // thread, wait for the flushing to finish by posting a callback to the cache
   // thread after that.
   MessageLoopHelper helper;
   CallbackTest cb_shutdown(&helper, false);
   cache_thread.task_runner()->PostTaskAndReply(
       FROM_HERE, base::Bind(&base::DoNothing),
       base::Bind(&CallbackTest::Run, base::Unretained(&cb_shutdown), net::OK));
   helper.WaitUntilCacheIoFinished(1);

   // Verify that the index file exists.
   const base::FilePath& index_file_path =
       cache_path.AppendASCII("index-dir").AppendASCII("the-real-index");
   EXPECT_TRUE(base::PathExists(index_file_path));

   // Verify that the version of the index file is correct.
   std::string contents;
   EXPECT_TRUE(base::ReadFileToString(index_file_path, &contents));
   base::Time when_index_last_saw_cache;
   SimpleIndexLoadResult deserialize_result;
   WrappedSimpleIndexFile::Deserialize(contents.data(),
                                       contents.size(),
                                       &when_index_last_saw_cache,
                                       &deserialize_result);
   EXPECT_TRUE(deserialize_result.did_load);
 }

 TEST_F(SimpleIndexFileTest, OverwritesStaleTempFile) {
   base::ScopedTempDir cache_dir;
   ASSERT_TRUE(cache_dir.CreateUniqueTempDir());
   const base::FilePath cache_path = cache_dir.path();
   WrappedSimpleIndexFile simple_index_file(cache_path);
   ASSERT_TRUE(simple_index_file.CreateIndexFileDirectory());

   // Create an temporary index file.
   const base::FilePath& temp_index_path =
       simple_index_file.GetTempIndexFilePath();
   const std::string kDummyData = "nothing to be seen here";
   EXPECT_EQ(
       static_cast<int>(kDummyData.size()),
       base::WriteFile(temp_index_path, kDummyData.data(), kDummyData.size()));
   ASSERT_TRUE(base::PathExists(simple_index_file.GetTempIndexFilePath()));

   // Write the index file.
   SimpleIndex::EntrySet entries;
   SimpleIndex::InsertInEntrySet(11, EntryMetadata(Time(), 11), &entries);
   net::TestClosure closure;
   simple_index_file.WriteToDisk(entries, 120U, base::TimeTicks(), false,
                                 closure.closure());
   closure.WaitForResult();

   // Check that the temporary file was deleted and the index file was created.
   EXPECT_FALSE(base::PathExists(simple_index_file.GetTempIndexFilePath()));
   EXPECT_TRUE(base::PathExists(simple_index_file.GetIndexFilePath()));
 }

 #endif  // defined(OS_POSIX)

 }  // namespace disk_cache
	// Copyright (c) 2011 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/file.h"
	#include "base/files/file_util.h"
	#include "base/files/scoped_temp_dir.h"
	#include "base/hash.h"
	#include "base/location.h"
	#include "base/logging.h"
	#include "base/memory/scoped_ptr.h"
	#include "base/pickle.h"
	#include "base/run_loop.h"
	#include "base/single_thread_task_runner.h"
	#include "base/strings/stringprintf.h"
	#include "base/thread_task_runner_handle.h"
	#include "base/threading/thread.h"
	#include "base/time/time.h"
	#include "net/base/cache_type.h"
	#include "net/base/test_completion_callback.h"
	#include "net/disk_cache/disk_cache_test_util.h"
	#include "net/disk_cache/simple/simple_backend_impl.h"
	#include "net/disk_cache/simple/simple_backend_version.h"
	#include "net/disk_cache/simple/simple_entry_format.h"
	#include "net/disk_cache/simple/simple_index.h"
	#include "net/disk_cache/simple/simple_index_file.h"
	#include "net/disk_cache/simple/simple_util.h"
	#include "net/disk_cache/simple/simple_version_upgrade.h"
	#include "testing/gtest/include/gtest/gtest.h"

	using base::Time;
	using disk_cache::SimpleIndexFile;
	using disk_cache::SimpleIndex;

	namespace disk_cache {

	// The Simple Cache backend requires a few guarantees from the filesystem like
	// atomic renaming of recently open files. Those guarantees are not provided in
	// general on Windows.
	#if defined(OS_POSIX)

	TEST(IndexMetadataTest, Basics) {
	SimpleIndexFile::IndexMetadata index_metadata;

	EXPECT_EQ(disk_cache::kSimpleIndexMagicNumber, index_metadata.magic_number_);
	EXPECT_EQ(disk_cache::kSimpleVersion, index_metadata.version_);
	EXPECT_EQ(0U, index_metadata.GetNumberOfEntries());
	EXPECT_EQ(0U, index_metadata.cache_size_);

	EXPECT_TRUE(index_metadata.CheckIndexMetadata());
	}

	TEST(IndexMetadataTest, Serialize) {
	SimpleIndexFile::IndexMetadata index_metadata(123, 456);
	base::Pickle pickle;
	index_metadata.Serialize(&pickle);
	base::PickleIterator it(pickle);
	SimpleIndexFile::IndexMetadata new_index_metadata;
	new_index_metadata.Deserialize(&it);

	EXPECT_EQ(new_index_metadata.magic_number_, index_metadata.magic_number_);
	EXPECT_EQ(new_index_metadata.version_, index_metadata.version_);
	EXPECT_EQ(new_index_metadata.GetNumberOfEntries(),
	index_metadata.GetNumberOfEntries());
	EXPECT_EQ(new_index_metadata.cache_size_, index_metadata.cache_size_);

	EXPECT_TRUE(new_index_metadata.CheckIndexMetadata());
	}

	// This friend derived class is able to reexport its ancestors private methods
	// as public, for use in tests.
	class WrappedSimpleIndexFile : public SimpleIndexFile {
	public:
	using SimpleIndexFile::Deserialize;
	using SimpleIndexFile::LegacyIsIndexFileStale;
	using SimpleIndexFile::Serialize;
	using SimpleIndexFile::SerializeFinalData;

	explicit WrappedSimpleIndexFile(const base::FilePath& index_file_directory)
	: SimpleIndexFile(base::ThreadTaskRunnerHandle::Get(),
	base::ThreadTaskRunnerHandle::Get(),
	net::DISK_CACHE,
	index_file_directory) {}
	~WrappedSimpleIndexFile() override {}

	const base::FilePath& GetIndexFilePath() const {
	return index_file_;
	}

	const base::FilePath& GetTempIndexFilePath() const {
	return temp_index_file_;
	}

	bool CreateIndexFileDirectory() const {
	return base::CreateDirectory(index_file_.DirName());
	}
	};

	class SimpleIndexFileTest : public testing::Test {
	public:
	bool CompareTwoEntryMetadata(const EntryMetadata& a, const EntryMetadata& b) {
	return
	a.last_used_time_seconds_since_epoch_ ==
	b.last_used_time_seconds_since_epoch_ &&
	a.entry_size_ == b.entry_size_;
	}
	};

	TEST_F(SimpleIndexFileTest, Serialize) {
	SimpleIndex::EntrySet entries;
	static const uint64_t kHashes[] = {11, 22, 33};
	static const size_t kNumHashes = arraysize(kHashes);
	EntryMetadata metadata_entries[kNumHashes];

	SimpleIndexFile::IndexMetadata index_metadata(
	static_cast<uint64_t>(kNumHashes), 456);
	for (size_t i = 0; i < kNumHashes; ++i) {
	uint64_t hash = kHashes[i];
	metadata_entries[i] = EntryMetadata(Time(), hash);
	SimpleIndex::InsertInEntrySet(hash, metadata_entries[i], &entries);
	}

	scoped_ptr<base::Pickle> pickle =
	WrappedSimpleIndexFile::Serialize(index_metadata, entries);
	EXPECT_TRUE(pickle.get() != NULL);
	base::Time now = base::Time::Now();
	EXPECT_TRUE(WrappedSimpleIndexFile::SerializeFinalData(now, pickle.get()));
	base::Time when_index_last_saw_cache;
	SimpleIndexLoadResult deserialize_result;
	WrappedSimpleIndexFile::Deserialize(static_cast<const char*>(pickle->data()),
	pickle->size(),
	&when_index_last_saw_cache,
	&deserialize_result);
	EXPECT_TRUE(deserialize_result.did_load);
	EXPECT_EQ(now, when_index_last_saw_cache);
	const SimpleIndex::EntrySet& new_entries = deserialize_result.entries;
	EXPECT_EQ(entries.size(), new_entries.size());

	for (size_t i = 0; i < kNumHashes; ++i) {
	SimpleIndex::EntrySet::const_iterator it = new_entries.find(kHashes[i]);
	EXPECT_TRUE(new_entries.end() != it);
	EXPECT_TRUE(CompareTwoEntryMetadata(it->second, metadata_entries[i]));
	}
	}

	TEST_F(SimpleIndexFileTest, LegacyIsIndexFileStale) {
	base::ScopedTempDir cache_dir;
	ASSERT_TRUE(cache_dir.CreateUniqueTempDir());
	base::Time cache_mtime;
	const base::FilePath cache_path = cache_dir.path();

	ASSERT_TRUE(simple_util::GetMTime(cache_path, &cache_mtime));
	WrappedSimpleIndexFile simple_index_file(cache_path);
	ASSERT_TRUE(simple_index_file.CreateIndexFileDirectory());
	const base::FilePath& index_path = simple_index_file.GetIndexFilePath();
	EXPECT_TRUE(
	WrappedSimpleIndexFile::LegacyIsIndexFileStale(cache_mtime, index_path));
	const std::string kDummyData = "nothing to be seen here";
	EXPECT_EQ(static_cast<int>(kDummyData.size()),
	base::WriteFile(index_path,
	kDummyData.data(), kDummyData.size()));
	ASSERT_TRUE(simple_util::GetMTime(cache_path, &cache_mtime));
	EXPECT_FALSE(
	WrappedSimpleIndexFile::LegacyIsIndexFileStale(cache_mtime, index_path));

	const base::Time past_time = base::Time::Now() -
	base::TimeDelta::FromSeconds(10);
	EXPECT_TRUE(base::TouchFile(index_path, past_time, past_time));
	EXPECT_TRUE(base::TouchFile(cache_path, past_time, past_time));
	ASSERT_TRUE(simple_util::GetMTime(cache_path, &cache_mtime));
	EXPECT_FALSE(
	WrappedSimpleIndexFile::LegacyIsIndexFileStale(cache_mtime, index_path));
	const base::Time even_older = past_time - base::TimeDelta::FromSeconds(10);
	EXPECT_TRUE(base::TouchFile(index_path, even_older, even_older));
	EXPECT_TRUE(
	WrappedSimpleIndexFile::LegacyIsIndexFileStale(cache_mtime, index_path));
	}

	TEST_F(SimpleIndexFileTest, WriteThenLoadIndex) {
	base::ScopedTempDir cache_dir;
	ASSERT_TRUE(cache_dir.CreateUniqueTempDir());

	SimpleIndex::EntrySet entries;
	static const uint64_t kHashes[] = {11, 22, 33};
	static const size_t kNumHashes = arraysize(kHashes);
	EntryMetadata metadata_entries[kNumHashes];
	for (size_t i = 0; i < kNumHashes; ++i) {
	uint64_t hash = kHashes[i];
	metadata_entries[i] = EntryMetadata(Time(), hash);
	SimpleIndex::InsertInEntrySet(hash, metadata_entries[i], &entries);
	}

	const uint64_t kCacheSize = 456U;
	net::TestClosure closure;
	{
	WrappedSimpleIndexFile simple_index_file(cache_dir.path());
	simple_index_file.WriteToDisk(entries, kCacheSize, base::TimeTicks(),
	false, closure.closure());
	closure.WaitForResult();
	EXPECT_TRUE(base::PathExists(simple_index_file.GetIndexFilePath()));
	}

	WrappedSimpleIndexFile simple_index_file(cache_dir.path());
	base::Time fake_cache_mtime;
	ASSERT_TRUE(simple_util::GetMTime(cache_dir.path(), &fake_cache_mtime));
	SimpleIndexLoadResult load_index_result;
	simple_index_file.LoadIndexEntries(fake_cache_mtime, closure.closure(),
	&load_index_result);
	closure.WaitForResult();

	EXPECT_TRUE(base::PathExists(simple_index_file.GetIndexFilePath()));
	EXPECT_TRUE(load_index_result.did_load);
	EXPECT_FALSE(load_index_result.flush_required);

	EXPECT_EQ(kNumHashes, load_index_result.entries.size());
	for (size_t i = 0; i < kNumHashes; ++i)
	EXPECT_EQ(1U, load_index_result.entries.count(kHashes[i]));
	}

	TEST_F(SimpleIndexFileTest, LoadCorruptIndex) {
	base::ScopedTempDir cache_dir;
	ASSERT_TRUE(cache_dir.CreateUniqueTempDir());

	WrappedSimpleIndexFile simple_index_file(cache_dir.path());
	ASSERT_TRUE(simple_index_file.CreateIndexFileDirectory());
	const base::FilePath& index_path = simple_index_file.GetIndexFilePath();
	const std::string kDummyData = "nothing to be seen here";
	EXPECT_EQ(static_cast<int>(kDummyData.size()),
	base::WriteFile(index_path, kDummyData.data(), kDummyData.size()));
	base::Time fake_cache_mtime;
	ASSERT_TRUE(simple_util::GetMTime(simple_index_file.GetIndexFilePath(),
	&fake_cache_mtime));
	EXPECT_FALSE(WrappedSimpleIndexFile::LegacyIsIndexFileStale(fake_cache_mtime,
	index_path));
	SimpleIndexLoadResult load_index_result;
	net::TestClosure closure;
	simple_index_file.LoadIndexEntries(fake_cache_mtime, closure.closure(),
	&load_index_result);
	closure.WaitForResult();

	EXPECT_FALSE(base::PathExists(index_path));
	EXPECT_TRUE(load_index_result.did_load);
	EXPECT_TRUE(load_index_result.flush_required);
	}

	// Tests that after an upgrade the backend has the index file put in place.
	TEST_F(SimpleIndexFileTest, SimpleCacheUpgrade) {
	base::ScopedTempDir cache_dir;
	ASSERT_TRUE(cache_dir.CreateUniqueTempDir());
	const base::FilePath cache_path = cache_dir.path();

	// Write an old fake index file.
	base::File file(cache_path.AppendASCII("index"),
	base::File::FLAG_CREATE \| base::File::FLAG_WRITE);
	ASSERT_TRUE(file.IsValid());
	disk_cache::FakeIndexData file_contents;
	file_contents.initial_magic_number = disk_cache::kSimpleInitialMagicNumber;
	file_contents.version = 5;
	int bytes_written = file.Write(0, reinterpret_cast<char*>(&file_contents),
	sizeof(file_contents));
	ASSERT_EQ((int)sizeof(file_contents), bytes_written);
	file.Close();

	// Write the index file. The format is incorrect, but for transitioning from
	// v5 it does not matter.
	const std::string index_file_contents("incorrectly serialized data");
	const base::FilePath old_index_file =
	cache_path.AppendASCII("the-real-index");
	ASSERT_EQ(static_cast<int>(index_file_contents.size()),
	base::WriteFile(old_index_file, index_file_contents.data(),
	index_file_contents.size()));

	// Upgrade the cache.
	ASSERT_TRUE(disk_cache::UpgradeSimpleCacheOnDisk(cache_path));

	// Create the backend and initiate index flush by destroying the backend.
	base::Thread cache_thread("CacheThread");
	ASSERT_TRUE(cache_thread.StartWithOptions(
	base::Thread::Options(base::MessageLoop::TYPE_IO, 0)));
	disk_cache::SimpleBackendImpl* simple_cache =
	new disk_cache::SimpleBackendImpl(cache_path, 0, net::DISK_CACHE,
	cache_thread.task_runner().get(), NULL);
	net::TestCompletionCallback cb;
	int rv = simple_cache->Init(cb.callback());
	EXPECT_EQ(net::OK, cb.GetResult(rv));
	rv = simple_cache->index()->ExecuteWhenReady(cb.callback());
	EXPECT_EQ(net::OK, cb.GetResult(rv));
	delete simple_cache;

	// The backend flushes the index on destruction and does so on the cache
	// thread, wait for the flushing to finish by posting a callback to the cache
	// thread after that.
	MessageLoopHelper helper;
	CallbackTest cb_shutdown(&helper, false);
	cache_thread.task_runner()->PostTaskAndReply(
	FROM_HERE, base::Bind(&base::DoNothing),
	base::Bind(&CallbackTest::Run, base::Unretained(&cb_shutdown), net::OK));
	helper.WaitUntilCacheIoFinished(1);

	// Verify that the index file exists.
	const base::FilePath& index_file_path =
	cache_path.AppendASCII("index-dir").AppendASCII("the-real-index");
	EXPECT_TRUE(base::PathExists(index_file_path));

	// Verify that the version of the index file is correct.
	std::string contents;
	EXPECT_TRUE(base::ReadFileToString(index_file_path, &contents));
	base::Time when_index_last_saw_cache;
	SimpleIndexLoadResult deserialize_result;
	WrappedSimpleIndexFile::Deserialize(contents.data(),
	contents.size(),
	&when_index_last_saw_cache,
	&deserialize_result);
	EXPECT_TRUE(deserialize_result.did_load);
	}

	TEST_F(SimpleIndexFileTest, OverwritesStaleTempFile) {
	base::ScopedTempDir cache_dir;
	ASSERT_TRUE(cache_dir.CreateUniqueTempDir());
	const base::FilePath cache_path = cache_dir.path();
	WrappedSimpleIndexFile simple_index_file(cache_path);
	ASSERT_TRUE(simple_index_file.CreateIndexFileDirectory());

	// Create an temporary index file.
	const base::FilePath& temp_index_path =
	simple_index_file.GetTempIndexFilePath();
	const std::string kDummyData = "nothing to be seen here";
	EXPECT_EQ(
	static_cast<int>(kDummyData.size()),
	base::WriteFile(temp_index_path, kDummyData.data(), kDummyData.size()));
	ASSERT_TRUE(base::PathExists(simple_index_file.GetTempIndexFilePath()));

	// Write the index file.
	SimpleIndex::EntrySet entries;
	SimpleIndex::InsertInEntrySet(11, EntryMetadata(Time(), 11), &entries);
	net::TestClosure closure;
	simple_index_file.WriteToDisk(entries, 120U, base::TimeTicks(), false,
	closure.closure());
	closure.WaitForResult();

	// Check that the temporary file was deleted and the index file was created.
	EXPECT_FALSE(base::PathExists(simple_index_file.GetTempIndexFilePath()));
	EXPECT_TRUE(base::PathExists(simple_index_file.GetIndexFilePath()));
	}

	#endif // defined(OS_POSIX)

	} // namespace disk_cache