interest_group_permissions_cache.h | Explore in Territory

// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_INTEREST_GROUP_INTEREST_GROUP_PERMISSIONS_CACHE_H_
#define CONTENT_BROWSER_INTEREST_GROUP_INTEREST_GROUP_PERMISSIONS_CACHE_H_

#include "content/common/content_export.h"

#include <map>
#include <memory>
#include <tuple>

#include "base/containers/lru_cache.h"
#include "base/time/time.h"
#include "base/timer/timer.h"
#include "net/base/network_isolation_key.h"
#include "url/origin.h"

namespace content {

// Cache of per-origin join/leave interest group permissions, partitioned by
// NetworkIsolationKey and initiating frame origin. To minimize leaks across
// first party contexts, uses a separate LRU cache "shard" for each {frame
// origin, NetworkIsolationKey} pair. Each LRU cache has a maximum number of
// entries, but there's no global limit, to prevent leaks. The short entry
// lifetime and delay in creating entries, along with the LRU size cap, should
// keep memory usage low.
//
// In addition to the LRU-ness of the cache, individual entries are passively
// expired (i.e., no longer returned, but not proactively deleted) after
// `kCacheDuration` has passed since they were added to the cache. Cache shards
// are garbage collected on a timer, at some point after all their entries have
// expired. Expired entries and shards are also deleted on access, which isn't
// strictly necessary.
//
// Permissions are typically learned from .well-known fetches, and should be
// cached by the network process, depending on HTTP response headers, but
// caching it in the browser process results in much better performance for
// sites that want to join (or, more likely, leave) large numbers of
// cross-origin interest groups, due to the limit of outstanding joins/leaves in
// the renderer process, and overhead on accessing the network stack's HTTP
// cache.
class CONTENT_EXPORT InterestGroupPermissionsCache { … };

}  // namespace content

#endif  // CONTENT_BROWSER_INTEREST_GROUP_INTEREST_GROUP_PERMISSIONS_CACHE_H_
chromium/content/browser/interest_group/interest_group_permissions_cache.h
