chromium/components/search_provider_logos/logo_cache.h

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_SEARCH_PROVIDER_LOGOS_LOGO_CACHE_H_
#define COMPONENTS_SEARCH_PROVIDER_LOGOS_LOGO_CACHE_H_

#include <memory>
#include <string>

#include "base/files/file_path.h"
#include "base/functional/callback.h"
#include "base/gtest_prod_util.h"
#include "base/memory/ref_counted.h"
#include "base/memory/ref_counted_memory.h"
#include "base/threading/thread_checker.h"
#include "components/search_provider_logos/logo_common.h"

namespace search_provider_logos {

// A file-based cache for the search provider's logo. This allows clients to
// store and retrieve a logo (of type EncodedLogo) and its associated metadata
// (of type LogoMetadata). Metadata can be updated independently from the logo
// to handle cases where, e.g. the expiration date changes, but the logo stays
// the same. If corruption is detected in the metadata or logo, the cache will
// be cleared.
//
// Note: this class must only be used on a single thread. All methods are
// are blocking, so this should not be used on the UI thread.
//
// The logo and its metadata are stored in files, so they persist even when
// Chrome is closed. Once loaded from disk, the metadata is kept in memory to
// enable quick retrieval. The logo is not kept around in memory because of its
// size.
class LogoCache { … };

}  // namespace search_provider_logos

#endif  // COMPONENTS_SEARCH_PROVIDER_LOGOS_LOGO_CACHE_H_