blob: 865206ffe5e5ae920c19130ab99c96c5190b5a2a [file] [log] [blame]
// Copyright 2015 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 <stddef.h>
#include <time.h>
#include <memory>
#include <string>
#include "base/bind.h"
#include "base/containers/mru_cache.h"
#include "base/macros.h"
#include "base/memory/memory_coordinator_client.h"
#include "base/memory/memory_pressure_monitor.h"
#include "base/synchronization/lock.h"
#include "base/threading/thread_checker.h"
#include "base/time/time.h"
#include "net/base/net_export.h"
#include "third_party/boringssl/src/include/openssl/base.h"
namespace base {
class Clock;
namespace trace_event {
class ProcessMemoryDump;
namespace net {
class NET_EXPORT SSLClientSessionCache : public base::MemoryCoordinatorClient {
struct Config {
// The maximum number of entries in the cache.
size_t max_entries = 1024;
// The number of calls to Lookup before a new check for expired sessions.
size_t expiration_check_count = 256;
explicit SSLClientSessionCache(const Config& config);
~SSLClientSessionCache() override;
// Returns true if |entry| is expired as of |now|.
static bool IsExpired(SSL_SESSION* session, time_t now);
size_t size() const;
// Returns the session associated with |cache_key| and moves it to the front
// of the MRU list. Returns nullptr if there is none.
bssl::UniquePtr<SSL_SESSION> Lookup(const std::string& cache_key);
// Resets the count returned by Lookup to 0 for the session associated with
// |cache_key|.
void ResetLookupCount(const std::string& cache_key);
// Inserts |session| into the cache at |cache_key|. If there is an existing
// one, it is released. Every |expiration_check_count| calls, the cache is
// checked for stale entries.
void Insert(const std::string& cache_key, SSL_SESSION* session);
// Removes all entries from the cache.
void Flush();
void SetClockForTesting(std::unique_ptr<base::Clock> clock);
// Dumps memory allocation stats. |pmd| is the ProcessMemoryDump of the
// browser process.
void DumpMemoryStats(base::trace_event::ProcessMemoryDump* pmd);
struct Entry {
// Adds a new session onto this entry, dropping the oldest one if two are
// already stored.
void Push(bssl::UniquePtr<SSL_SESSION> session);
// Retrieves the latest session from the entry, removing it if its
// single-use.
bssl::UniquePtr<SSL_SESSION> Pop();
// Removes any expired sessions, returning true if this entry can be
// deleted.
bool ExpireSessions(time_t now);
bssl::UniquePtr<SSL_SESSION> sessions[2] = {nullptr};
// base::MemoryCoordinatorClient implementation:
void OnPurgeMemory() override;
// Removes all expired sessions from the cache.
void FlushExpiredSessions();
// Clear cache on low memory notifications callback.
void OnMemoryPressure(
base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level);
std::unique_ptr<base::Clock> clock_;
Config config_;
base::HashingMRUCache<std::string, Entry> cache_;
size_t lookups_since_flush_;
// TODO(davidben): After is fixed, replace this with
// a ThreadChecker. The session cache should be single-threaded like other
// classes in net.
base::Lock lock_;
std::unique_ptr<base::MemoryPressureListener> memory_pressure_listener_;
} // namespace net