diff --git a/Telegram/SourceFiles/app.h b/Telegram/SourceFiles/app.h
index 0f4414b78..4f7292618 100644
--- a/Telegram/SourceFiles/app.h
+++ b/Telegram/SourceFiles/app.h
@@ -7,7 +7,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 */
 #pragma once
 
-#include "core/basic_types.h"
 #include "data/data_types.h"
 #include "data/data_peer.h"
 
diff --git a/Telegram/SourceFiles/core/basic_types.h b/Telegram/SourceFiles/base/basic_types.h
similarity index 92%
rename from Telegram/SourceFiles/core/basic_types.h
rename to Telegram/SourceFiles/base/basic_types.h
index af380719a..6a12ede99 100644
--- a/Telegram/SourceFiles/core/basic_types.h
+++ b/Telegram/SourceFiles/base/basic_types.h
@@ -7,6 +7,13 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 */
 #pragma once
 
+#include "base/build_config.h"
+#include "base/ordered_set.h"
+#include "base/unique_function.h"
+#include "base/functors.h"
+
+#include <QtGlobal>
+
 #include <string>
 #include <exception>
 #include <memory>
@@ -14,11 +21,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include <functional>
 #include <gsl/gsl>
 
-#include "base/build_config.h"
-#include "base/ordered_set.h"
-#include "base/unique_function.h"
-#include "base/functors.h"
-
 namespace func = base::functors;
 
 using gsl::not_null;
@@ -45,6 +47,3 @@ using float64 = double;
 
 using TimeMs = int64;
 using TimeId = int32;
-
-#define qsl(s) QStringLiteral(s)
-#define qstr(s) QLatin1String((s), sizeof(s) - 1)
diff --git a/Telegram/SourceFiles/base/binary_guard.h b/Telegram/SourceFiles/base/binary_guard.h
new file mode 100644
index 000000000..d48857f60
--- /dev/null
+++ b/Telegram/SourceFiles/base/binary_guard.h
@@ -0,0 +1,71 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#pragma once
+
+#include "base/algorithm.h"
+
+#include <atomic>
+
+namespace base {
+
+class binary_guard {
+public:
+	binary_guard() = default;
+	binary_guard(binary_guard &&other);
+	binary_guard &operator=(binary_guard &&other);
+	~binary_guard();
+
+	bool alive() const;
+
+private:
+	void destroy();
+
+	std::atomic<bool> *_bothAlive = nullptr;
+
+	friend std::pair<binary_guard, binary_guard> make_binary_guard();
+
+};
+
+inline binary_guard::binary_guard(binary_guard &&other)
+: _bothAlive(base::take(other._bothAlive)) {
+}
+
+inline binary_guard &binary_guard::operator=(binary_guard &&other) {
+	if (this != &other) {
+		destroy();
+		_bothAlive = base::take(other._bothAlive);
+	}
+	return *this;
+}
+
+inline binary_guard::~binary_guard() {
+	destroy();
+}
+
+inline bool binary_guard::alive() const {
+	return _bothAlive && _bothAlive->load();
+}
+
+inline void binary_guard::destroy() {
+	if (_bothAlive) {
+		auto old = true;
+		if (!_bothAlive->compare_exchange_strong(old, false)) {
+			delete _bothAlive;
+		}
+	}
+}
+
+inline std::pair<binary_guard, binary_guard> make_binary_guard() {
+	auto result = std::pair<binary_guard, binary_guard>();
+	result.first._bothAlive
+		= result.second._bothAlive
+		= new std::atomic<bool>(true);
+	return result;
+}
+
+} // namespace base
diff --git a/Telegram/SourceFiles/base/openssl_help.h b/Telegram/SourceFiles/base/openssl_help.h
index 9d776b3da..2af1ba65c 100644
--- a/Telegram/SourceFiles/base/openssl_help.h
+++ b/Telegram/SourceFiles/base/openssl_help.h
@@ -9,7 +9,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 
 #include "base/bytes.h"
 #include "base/algorithm.h"
-#include "core/basic_types.h"
+#include "base/basic_types.h"
 
 extern "C" {
 #include <openssl/bn.h>
diff --git a/Telegram/SourceFiles/core/single_timer.h b/Telegram/SourceFiles/core/single_timer.h
index c031b170d..6b72b2fee 100644
--- a/Telegram/SourceFiles/core/single_timer.h
+++ b/Telegram/SourceFiles/core/single_timer.h
@@ -7,8 +7,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 */
 #pragma once
 
-#include "core/basic_types.h"
-
 class SingleTimer : public QTimer { // single shot timer with check
 	Q_OBJECT
 
diff --git a/Telegram/SourceFiles/core/utils.h b/Telegram/SourceFiles/core/utils.h
index a3466e38f..77740370a 100644
--- a/Telegram/SourceFiles/core/utils.h
+++ b/Telegram/SourceFiles/core/utils.h
@@ -8,7 +8,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #pragma once
 
 #include "logs.h"
-#include "core/basic_types.h"
+#include "base/basic_types.h"
 #include "base/flags.h"
 #include "base/algorithm.h"
 #include "base/assertion.h"
@@ -21,6 +21,9 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include <cmath>
 #include <set>
 
+#define qsl(s) QStringLiteral(s)
+#define qstr(s) QLatin1String((s), sizeof(s) - 1)
+
 // Define specializations for QByteArray for Qt 5.3.2, because
 // QByteArray in Qt 5.3.2 doesn't declare "pointer" subtype.
 #ifdef OS_MAC_OLD
diff --git a/Telegram/SourceFiles/export/data/export_data_types.cpp b/Telegram/SourceFiles/export/data/export_data_types.cpp
index 7361f7a23..5f2e3aa19 100644
--- a/Telegram/SourceFiles/export/data/export_data_types.cpp
+++ b/Telegram/SourceFiles/export/data/export_data_types.cpp
@@ -10,7 +10,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "export/export_settings.h"
 #include "export/output/export_output_file.h"
 #include "core/mime_type.h"
-
+#include "core/utils.h"
 #include <QtCore/QDateTime>
 #include <QtCore/QRegularExpression>
 #include <QtGui/QImageReader>
diff --git a/Telegram/SourceFiles/export/export_api_wrap.cpp b/Telegram/SourceFiles/export/export_api_wrap.cpp
index 3cceb5064..c882ba8fe 100644
--- a/Telegram/SourceFiles/export/export_api_wrap.cpp
+++ b/Telegram/SourceFiles/export/export_api_wrap.cpp
@@ -14,7 +14,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "mtproto/rpc_sender.h"
 #include "base/value_ordering.h"
 #include "base/bytes.h"
-
 #include <set>
 #include <deque>
 
diff --git a/Telegram/SourceFiles/inline_bots/inline_bot_result.h b/Telegram/SourceFiles/inline_bots/inline_bot_result.h
index c6478ade0..346bc1ac4 100644
--- a/Telegram/SourceFiles/inline_bots/inline_bot_result.h
+++ b/Telegram/SourceFiles/inline_bots/inline_bot_result.h
@@ -7,8 +7,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 */
 #pragma once
 
-#include "core/basic_types.h"
-
 class FileLoader;
 
 namespace InlineBots {
diff --git a/Telegram/SourceFiles/inline_bots/inline_bot_send_data.h b/Telegram/SourceFiles/inline_bots/inline_bot_send_data.h
index a6ece93a5..3e3ee1cd6 100644
--- a/Telegram/SourceFiles/inline_bots/inline_bot_send_data.h
+++ b/Telegram/SourceFiles/inline_bots/inline_bot_send_data.h
@@ -7,7 +7,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 */
 #pragma once
 
-#include "core/basic_types.h"
 #include "history/history_location_manager.h"
 
 namespace InlineBots {
diff --git a/Telegram/SourceFiles/logs.h b/Telegram/SourceFiles/logs.h
index fdb6a1222..e27b8ed6a 100644
--- a/Telegram/SourceFiles/logs.h
+++ b/Telegram/SourceFiles/logs.h
@@ -7,7 +7,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 */
 #pragma once
 
-#include "core/basic_types.h"
+#include "base/basic_types.h"
 
 namespace Core {
 class Launcher;
diff --git a/Telegram/SourceFiles/mtproto/core_types.h b/Telegram/SourceFiles/mtproto/core_types.h
index 1658a26dd..527b1d556 100644
--- a/Telegram/SourceFiles/mtproto/core_types.h
+++ b/Telegram/SourceFiles/mtproto/core_types.h
@@ -12,7 +12,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include <QtCore/QString>
 #include <QtCore/QByteArray>
 #include <rpl/details/callable.h>
-#include "core/basic_types.h"
+#include "base/basic_types.h"
 #include "base/match_method.h"
 #include "base/flags.h"
 #include "base/bytes.h"
diff --git a/Telegram/SourceFiles/mtproto/rpc_sender.h b/Telegram/SourceFiles/mtproto/rpc_sender.h
index fc8ecffaa..f92a9a019 100644
--- a/Telegram/SourceFiles/mtproto/rpc_sender.h
+++ b/Telegram/SourceFiles/mtproto/rpc_sender.h
@@ -7,8 +7,9 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 */
 #pragma once
 
-#include <rpl/details/callable.h>
 #include "base/flat_set.h"
+#include "core/utils.h"
+#include <rpl/details/callable.h>
 
 class RPCError {
 public:
diff --git a/Telegram/SourceFiles/stdafx.h b/Telegram/SourceFiles/stdafx.h
index e609c3626..0a63d5110 100644
--- a/Telegram/SourceFiles/stdafx.h
+++ b/Telegram/SourceFiles/stdafx.h
@@ -78,7 +78,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "base/flat_map.h"
 #include "base/weak_ptr.h"
 
-#include "core/basic_types.h"
+#include "base/basic_types.h"
 #include "logs.h"
 #include "core/utils.h"
 #include "config.h"
diff --git a/Telegram/SourceFiles/storage/cache/storage_cache_cleaner.cpp b/Telegram/SourceFiles/storage/cache/storage_cache_cleaner.cpp
new file mode 100644
index 000000000..274185754
--- /dev/null
+++ b/Telegram/SourceFiles/storage/cache/storage_cache_cleaner.cpp
@@ -0,0 +1,113 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#include "storage/cache/storage_cache_cleaner.h"
+
+#include <crl/crl.h>
+#include <QtCore/QDir>
+#include <QtCore/QFile>
+#include <unordered_map>
+#include <set>
+
+namespace Storage {
+namespace Cache {
+namespace details {
+
+class CleanerObject {
+public:
+	using Wrapper = Cache::Cleaner;
+	CleanerObject(
+		crl::weak_on_queue<CleanerObject> weak,
+		const QString &base,
+		base::binary_guard &&guard,
+		FnMut<void(Error)> done);
+
+private:
+	void start();
+	void scheduleNext();
+	void cleanNext();
+	void done();
+
+	crl::weak_on_queue<CleanerObject> _weak;
+	QString _base, _errorPath;
+	std::vector<QString> _queue;
+	base::binary_guard _guard;
+	FnMut<void(Error)> _done;
+
+};
+
+CleanerObject::CleanerObject(
+	crl::weak_on_queue<CleanerObject> weak,
+	const QString &base,
+	base::binary_guard &&guard,
+	FnMut<void(Error)> done)
+: _weak(std::move(weak))
+, _base(base)
+, _guard(std::move(guard))
+, _done(std::move(done)) {
+	start();
+}
+
+void CleanerObject::start() {
+	const auto entries = QDir(_base).entryList(
+		QDir::Dirs | QDir::NoDotAndDotDot);
+	for (const auto entry : entries) {
+		_queue.push_back(entry);
+	}
+	if (const auto version = ReadVersionValue(_base)) {
+		_queue.erase(
+			ranges::remove(_queue, QString::number(*version)),
+			end(_queue));
+		scheduleNext();
+	} else {
+		_errorPath = VersionFilePath(_base);
+		done();
+	}
+}
+
+void CleanerObject::scheduleNext() {
+	if (_queue.empty()) {
+		done();
+		return;
+	}
+	_weak.with([](CleanerObject &that) {
+		if (that._guard.alive()) {
+			that.cleanNext();
+		}
+	});
+}
+
+void CleanerObject::cleanNext() {
+	const auto path = _base + _queue.back();
+	_queue.pop_back();
+	if (!QDir(path).removeRecursively()) {
+		_errorPath = path;
+	}
+	scheduleNext();
+}
+
+void CleanerObject::done() {
+	if (_done) {
+		_done(_errorPath.isEmpty()
+			? Error::NoError()
+			: Error{ Error::Type::IO, _errorPath });
+	}
+}
+
+} // namespace details
+
+Cleaner::Cleaner(
+	const QString &base,
+	base::binary_guard &&guard,
+	FnMut<void(Error)> done)
+: _wrapped(base, std::move(guard), std::move(done)) {
+}
+
+Cleaner::~Cleaner() = default;
+
+} // namespace Cache
+} // namespace Storage
diff --git a/Telegram/SourceFiles/storage/cache/storage_cache_cleaner.h b/Telegram/SourceFiles/storage/cache/storage_cache_cleaner.h
new file mode 100644
index 000000000..cc2d8441f
--- /dev/null
+++ b/Telegram/SourceFiles/storage/cache/storage_cache_cleaner.h
@@ -0,0 +1,35 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#pragma once
+
+#include "storage/cache/storage_cache_types.h"
+#include "base/binary_guard.h"
+
+namespace Storage {
+namespace Cache {
+namespace details {
+class CleanerObject;
+} // namespace details
+
+class Cleaner {
+public:
+	Cleaner(
+		const QString &base,
+		base::binary_guard &&guard,
+		FnMut<void(Error)> done);
+
+	~Cleaner();
+
+private:
+	using Implementation = details::CleanerObject;
+	crl::object_on_queue<Implementation> _wrapped;
+
+};
+
+} // namespace Cache
+} // namespace Storage
diff --git a/Telegram/SourceFiles/storage/cache/storage_cache_database.cpp b/Telegram/SourceFiles/storage/cache/storage_cache_database.cpp
index 0368dd267..ad558cc96 100644
--- a/Telegram/SourceFiles/storage/cache/storage_cache_database.cpp
+++ b/Telegram/SourceFiles/storage/cache/storage_cache_database.cpp
@@ -7,6 +7,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 */
 #include "storage/cache/storage_cache_database.h"
 
+#include "storage/cache/storage_cache_cleaner.h"
 #include "storage/storage_encryption.h"
 #include "storage/storage_encrypted_file.h"
 #include "base/flat_set.h"
@@ -160,9 +161,11 @@ class Database {
 public:
 	using Wrapper = Cache::Database;
 	using Settings = Wrapper::Settings;
-	Database(const QString &path, const Settings &settings);
+	Database(
+		crl::weak_on_queue<Database> weak,
+		const QString &path,
+		const Settings &settings);
 
-	using Error = Wrapper::Error;
 	void open(EncryptionKey key, FnMut<void(Error)> done);
 	void close(FnMut<void()> done);
 
@@ -173,7 +176,6 @@ public:
 	void clear(FnMut<void(Error)> done);
 
 private:
-	using Version = int32;
 	struct Entry {
 		Entry() = default;
 		Entry(PlaceId place, uint8 tag, uint32 checksum, size_type size);
@@ -183,6 +185,10 @@ private:
 		size_type size = 0;
 		PlaceId place = { { 0 } };
 	};
+	struct CleanerWrap {
+		std::unique_ptr<Cleaner> object;
+		base::binary_guard guard;
+	};
 
 	template <typename Callback, typename ...Args>
 	void invokeCallback(Callback &&callback, Args &&...args);
@@ -215,6 +221,10 @@ private:
 	QString writeKeyPlace(const Key &key, size_type size, uint32 checksum);
 	void writeMultiRemove();
 
+	void createCleaner();
+	void cleanerDone(Error error);
+
+	crl::weak_on_queue<Database> _weak;
 	QString _base, _path;
 	Settings _settings;
 	EncryptionKey _key;
@@ -222,6 +232,8 @@ private:
 	std::unordered_map<Key, Entry> _map;
 	std::set<Key> _removing;
 
+	CleanerWrap _cleaner;
+
 };
 
 Database::Entry::Entry(
@@ -235,8 +247,12 @@ Database::Entry::Entry(
 , size(size) {
 }
 
-Database::Database(const QString &path, const Settings &settings)
-: _base(QDir(path).absolutePath() + '/')
+Database::Database(
+	crl::weak_on_queue<Database> weak,
+	const QString &path,
+	const Settings &settings)
+: _weak(std::move(weak))
+, _base(ComputeBasePath(path))
 , _settings(settings) {
 }
 
@@ -253,7 +269,7 @@ void Database::invokeCallback(Callback &&callback, Args &&...args) {
 	}
 }
 
-auto Database::ioError(const QString &path) const -> Error {
+Error Database::ioError(const QString &path) const {
 	return { Error::Type::IO, path };
 }
 
@@ -276,15 +292,15 @@ void Database::open(EncryptionKey key, FnMut<void(Error)> done) {
 		break;
 	case File::Result::Failed: {
 		const auto available = findAvailableVersion();
-		const auto retry = openBinlog(available, File::Mode::Write, key);
-		if (retry == File::Result::Success) {
-			if (writeVersion(available)) {
+		if (writeVersion(available)) {
+			const auto open = openBinlog(available, File::Mode::Write, key);
+			if (open == File::Result::Success) {
 				invokeCallback(done, Error::NoError());
 			} else {
-				invokeCallback(done, ioError(versionPath()));
+				invokeCallback(done, ioError(binlogPath(available)));
 			}
 		} else {
-			invokeCallback(done, ioError(binlogPath(available)));
+			invokeCallback(done, ioError(versionPath()));
 		}
 	} break;
 	default: Unexpected("Result from Database::openBinlog.");
@@ -296,7 +312,7 @@ QString Database::computePath(Version version) const {
 }
 
 QString Database::binlogFilename() const {
-	return qsl("binlog");
+	return QStringLiteral("binlog");
 }
 
 QString Database::binlogPath(Version version) const {
@@ -316,6 +332,7 @@ File::Result Database::openBinlog(
 	if (result == File::Result::Success) {
 		_path = computePath(version);
 		_key = std::move(key);
+		createCleaner();
 		readBinlog();
 	}
 	return result;
@@ -466,6 +483,7 @@ bool Database::readRecordMultiRemove(bytes::const_span data) {
 }
 
 void Database::close(FnMut<void()> done) {
+	_cleaner = CleanerWrap();
 	_binlog.close();
 	invokeCallback(done);
 }
@@ -604,6 +622,24 @@ void Database::writeMultiRemove() {
 	}
 }
 
+void Database::createCleaner() {
+	auto [left, right] = base::make_binary_guard();
+	_cleaner.guard = std::move(left);
+	auto done = [weak = _weak](Error error) {
+		weak.with([=](Database &that) {
+			that.cleanerDone(error);
+		});
+	};
+	_cleaner.object = std::make_unique<Cleaner>(
+		_base,
+		std::move(right),
+		std::move(done));
+}
+
+void Database::cleanerDone(Error error) {
+	_cleaner = CleanerWrap();
+}
+
 void Database::clear(FnMut<void(Error)> done) {
 	Expects(_key.empty());
 
@@ -631,36 +667,18 @@ auto Database::findAvailableVersion() const -> Version {
 }
 
 QString Database::versionPath() const {
-	return _base + "version";
+	return VersionFilePath(_base);
 }
 
 bool Database::writeVersion(Version version) {
-	const auto bytes = QByteArray::fromRawData(
-		reinterpret_cast<const char*>(&version),
-		sizeof(version));
-
-	if (!QDir().mkpath(_base)) {
-		return false;
-	}
-	QFile file(versionPath());
-	if (!file.open(QIODevice::WriteOnly)) {
-		return false;
-	} else if (file.write(bytes) != bytes.size()) {
-		return false;
-	}
-	return file.flush();
+	return WriteVersionValue(_base, version);
 }
 
 auto Database::readVersion() const -> Version {
-	QFile file(versionPath());
-	if (!file.open(QIODevice::ReadOnly)) {
-		return Version();
+	if (const auto result = ReadVersionValue(_base)) {
+		return *result;
 	}
-	const auto bytes = file.read(sizeof(Version));
-	if (bytes.size() != sizeof(Version)) {
-		return Version();
-	}
-	return *reinterpret_cast<const Version*>(bytes.data());
+	return Version();
 }
 
 QString Database::placePath(PlaceId place) const {
diff --git a/Telegram/SourceFiles/storage/cache/storage_cache_database.h b/Telegram/SourceFiles/storage/cache/storage_cache_database.h
index ca1e7a854..f1b76dcf9 100644
--- a/Telegram/SourceFiles/storage/cache/storage_cache_database.h
+++ b/Telegram/SourceFiles/storage/cache/storage_cache_database.h
@@ -7,7 +7,8 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 */
 #pragma once
 
-#include "core/basic_types.h"
+#include "storage/cache/storage_cache_types.h"
+#include "base/basic_types.h"
 #include <crl/crl_object_on_queue.h>
 #include <QtCore/QString>
 
@@ -42,20 +43,6 @@ public:
 	};
 	Database(const QString &path, const Settings &settings);
 
-	struct Error {
-		enum class Type {
-			None,
-			IO,
-			WrongKey,
-			LockFailed,
-		};
-		Type type = Type::None;
-		QString path;
-
-		static Error NoError() {
-			return Error();
-		}
-	};
 	void open(EncryptionKey key, FnMut<void(Error)> done);
 	void close(FnMut<void()> done);
 
diff --git a/Telegram/SourceFiles/storage/cache/storage_cache_database_tests.cpp b/Telegram/SourceFiles/storage/cache/storage_cache_database_tests.cpp
index 8aa49f68e..51f2bcdbf 100644
--- a/Telegram/SourceFiles/storage/cache/storage_cache_database_tests.cpp
+++ b/Telegram/SourceFiles/storage/cache/storage_cache_database_tests.cpp
@@ -9,8 +9,8 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 
 #include "storage/cache/storage_cache_database.h"
 #include "storage/storage_encryption.h"
-
 #include <crl/crl.h>
+#include <thread>
 
 using namespace Storage::Cache;
 
@@ -29,8 +29,8 @@ const auto TestValue2 = QByteArray("bytetestbytetestb");
 
 crl::semaphore Semaphore;
 
-auto Result = Database::Error();
-const auto GetResult = [](Database::Error error) {
+auto Result = Error();
+const auto GetResult = [](Error error) {
 	Result = error;
 	Semaphore.release();
 };
@@ -49,15 +49,15 @@ TEST_CASE("encrypted cache db", "[storage_cache_database]") {
 
 		db.clear(GetResult);
 		Semaphore.acquire();
-		REQUIRE(Result.type == Database::Error::Type::None);
+		REQUIRE(Result.type == Error::Type::None);
 
 		db.open(key, GetResult);
 		Semaphore.acquire();
-		REQUIRE(Result.type == Database::Error::Type::None);
+		REQUIRE(Result.type == Error::Type::None);
 
 		db.put(Key{ 0, 1 }, TestValue1, GetResult);
 		Semaphore.acquire();
-		REQUIRE(Result.type == Database::Error::Type::None);
+		REQUIRE(Result.type == Error::Type::None);
 
 		db.close([&] { Semaphore.release(); });
 		Semaphore.acquire();
@@ -67,7 +67,7 @@ TEST_CASE("encrypted cache db", "[storage_cache_database]") {
 
 		db.open(key, GetResult);
 		Semaphore.acquire();
-		REQUIRE(Result.type == Database::Error::Type::None);
+		REQUIRE(Result.type == Error::Type::None);
 
 		db.get(Key{ 0, 1 }, GetValue);
 		Semaphore.acquire();
@@ -75,7 +75,7 @@ TEST_CASE("encrypted cache db", "[storage_cache_database]") {
 
 		db.put(Key{ 1, 0 }, TestValue2, GetResult);
 		Semaphore.acquire();
-		REQUIRE(Result.type == Database::Error::Type::None);
+		REQUIRE(Result.type == Error::Type::None);
 
 		db.get(Key{ 1, 0 }, GetValue);
 		Semaphore.acquire();
@@ -93,7 +93,7 @@ TEST_CASE("encrypted cache db", "[storage_cache_database]") {
 
 		db.open(key, GetResult);
 		Semaphore.acquire();
-		REQUIRE(Result.type == Database::Error::Type::None);
+		REQUIRE(Result.type == Error::Type::None);
 
 		db.get(Key{ 0, 1 }, GetValue);
 		Semaphore.acquire();
diff --git a/Telegram/SourceFiles/storage/cache/storage_cache_types.cpp b/Telegram/SourceFiles/storage/cache/storage_cache_types.cpp
new file mode 100644
index 000000000..d4f06a37d
--- /dev/null
+++ b/Telegram/SourceFiles/storage/cache/storage_cache_types.cpp
@@ -0,0 +1,55 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#include "storage/cache/storage_cache_types.h"
+
+#include <QtCore/QDir>
+
+namespace Storage {
+namespace Cache {
+
+QString ComputeBasePath(const QString &original) {
+	const auto result = QDir(original).absolutePath();
+	return result.endsWith('/') ? result : (result + '/');
+}
+
+QString VersionFilePath(const QString &base) {
+	Expects(base.endsWith('/'));
+
+	return base + QStringLiteral("version");
+}
+
+base::optional<Version> ReadVersionValue(const QString &base) {
+	QFile file(VersionFilePath(base));
+	if (!file.open(QIODevice::ReadOnly)) {
+		return base::none;
+	}
+	const auto bytes = file.read(sizeof(Version));
+	if (bytes.size() != sizeof(Version)) {
+		return base::none;
+	}
+	return *reinterpret_cast<const Version*>(bytes.data());
+}
+
+bool WriteVersionValue(const QString &base, Version value) {
+	if (!QDir().mkpath(base)) {
+		return false;
+	}
+	const auto bytes = QByteArray::fromRawData(
+		reinterpret_cast<const char*>(&value),
+		sizeof(value));
+	QFile file(VersionFilePath(base));
+	if (!file.open(QIODevice::WriteOnly)) {
+		return false;
+	} else if (file.write(bytes) != bytes.size()) {
+		return false;
+	}
+	return file.flush();
+}
+
+} // namespace Cache
+} // namespace Storage
diff --git a/Telegram/SourceFiles/storage/cache/storage_cache_types.h b/Telegram/SourceFiles/storage/cache/storage_cache_types.h
new file mode 100644
index 000000000..6e7acebe9
--- /dev/null
+++ b/Telegram/SourceFiles/storage/cache/storage_cache_types.h
@@ -0,0 +1,41 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#pragma once
+
+#include "base/basic_types.h"
+#include "base/optional.h"
+
+namespace Storage {
+namespace Cache {
+
+using Version = int32;
+
+QString ComputeBasePath(const QString &original);
+QString VersionFilePath(const QString &base);
+base::optional<Version> ReadVersionValue(const QString &base);
+bool WriteVersionValue(const QString &base, Version value);
+
+struct Error {
+	enum class Type {
+		None,
+		IO,
+		WrongKey,
+		LockFailed,
+	};
+	Type type = Type::None;
+	QString path;
+
+	static Error NoError();
+};
+
+inline Error Error::NoError() {
+	return Error();
+}
+
+} // namespace Cache
+} // namespace Storage
diff --git a/Telegram/SourceFiles/storage/localstorage.h b/Telegram/SourceFiles/storage/localstorage.h
index 9523dce68..f6a10f9b9 100644
--- a/Telegram/SourceFiles/storage/localstorage.h
+++ b/Telegram/SourceFiles/storage/localstorage.h
@@ -7,7 +7,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 */
 #pragma once
 
-#include "core/basic_types.h"
 #include "storage/file_download.h"
 #include "auth_session.h"
 
diff --git a/Telegram/SourceFiles/storage/storage_file_lock.h b/Telegram/SourceFiles/storage/storage_file_lock.h
index 3bc216cef..181b5bc06 100644
--- a/Telegram/SourceFiles/storage/storage_file_lock.h
+++ b/Telegram/SourceFiles/storage/storage_file_lock.h
@@ -7,7 +7,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 */
 #pragma once
 
-#include "core/basic_types.h"
+#include "base/basic_types.h"
 #include <QtCore/QFile>
 
 namespace Storage {
diff --git a/Telegram/SourceFiles/ui/animation.h b/Telegram/SourceFiles/ui/animation.h
index d3ec514d2..fb2e0be23 100644
--- a/Telegram/SourceFiles/ui/animation.h
+++ b/Telegram/SourceFiles/ui/animation.h
@@ -7,7 +7,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 */
 #pragma once
 
-#include "core/basic_types.h"
 #include <QtCore/QTimer>
 #include <QtGui/QColor>
 
diff --git a/Telegram/gyp/lib_storage.gyp b/Telegram/gyp/lib_storage.gyp
index 3de805d0c..a86f0ef63 100644
--- a/Telegram/gyp/lib_storage.gyp
+++ b/Telegram/gyp/lib_storage.gyp
@@ -52,8 +52,12 @@
       '<(src_loc)/storage/storage_file_lock_posix.cpp',
       '<(src_loc)/storage/storage_file_lock_win.cpp',
       '<(src_loc)/storage/storage_file_lock.h',
+      '<(src_loc)/storage/cache/storage_cache_cleaner.cpp',
+      '<(src_loc)/storage/cache/storage_cache_cleaner.h',
       '<(src_loc)/storage/cache/storage_cache_database.cpp',
       '<(src_loc)/storage/cache/storage_cache_database.h',
+      '<(src_loc)/storage/cache/storage_cache_types.cpp',
+      '<(src_loc)/storage/cache/storage_cache_types.h',
     ],
     'conditions': [[ 'build_macold', {
       'xcode_settings': {
diff --git a/Telegram/gyp/telegram_sources.txt b/Telegram/gyp/telegram_sources.txt
index 61dda8609..b7ed26ab0 100644
--- a/Telegram/gyp/telegram_sources.txt
+++ b/Telegram/gyp/telegram_sources.txt
@@ -1,5 +1,7 @@
 <(src_loc)/base/algorithm.h
 <(src_loc)/base/assertion.h
+<(src_loc)/base/basic_types.h
+<(src_loc)/base/binary_guard.h
 <(src_loc)/base/build_config.h
 <(src_loc)/base/bytes.h
 <(src_loc)/base/flags.h
@@ -136,7 +138,6 @@
 <(src_loc)/chat_helpers/tabbed_section.h
 <(src_loc)/chat_helpers/tabbed_selector.cpp
 <(src_loc)/chat_helpers/tabbed_selector.h
-<(src_loc)/core/basic_types.h
 <(src_loc)/core/changelogs.cpp
 <(src_loc)/core/changelogs.h
 <(src_loc)/core/click_handler.cpp