blob: 5a83f12e171b3da1b9327df28b28929fef4bbe0a [file] [log] [blame]
// Copyright (c) 2012 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.
#ifndef NET_DISK_CACHE_EVICTION_H_
#define NET_DISK_CACHE_EVICTION_H_
#pragma once
#include "base/basictypes.h"
#include "base/memory/weak_ptr.h"
#include "net/disk_cache/disk_format.h"
#include "net/disk_cache/rankings.h"
namespace disk_cache {
class BackendImpl;
class EntryImpl;
// This class implements the eviction algorithm for the cache and it is tightly
// integrated with BackendImpl.
class Eviction {
public:
Eviction();
~Eviction();
void Init(BackendImpl* backend);
void Stop();
// Deletes entries from the cache until the current size is below the limit.
// If empty is true, the whole cache will be trimmed, regardless of being in
// use.
void TrimCache(bool empty);
// Updates the ranking information for an entry.
void UpdateRank(EntryImpl* entry, bool modified);
// Notifications of interesting events for a given entry.
void OnOpenEntry(EntryImpl* entry);
void OnCreateEntry(EntryImpl* entry);
void OnDoomEntry(EntryImpl* entry);
void OnDestroyEntry(EntryImpl* entry);
// Testing interface.
void SetTestMode();
void TrimDeletedList(bool empty);
private:
void PostDelayedTrim();
void DelayedTrim();
bool ShouldTrim();
bool ShouldTrimDeleted();
void ReportTrimTimes(EntryImpl* entry);
Rankings::List GetListForEntry(EntryImpl* entry);
bool EvictEntry(CacheRankingsBlock* node, bool empty, Rankings::List list);
// We'll just keep for a while a separate set of methods that implement the
// new eviction algorithm. This code will replace the original methods when
// finished.
void TrimCacheV2(bool empty);
void UpdateRankV2(EntryImpl* entry, bool modified);
void OnOpenEntryV2(EntryImpl* entry);
void OnCreateEntryV2(EntryImpl* entry);
void OnDoomEntryV2(EntryImpl* entry);
void OnDestroyEntryV2(EntryImpl* entry);
Rankings::List GetListForEntryV2(EntryImpl* entry);
void TrimDeleted(bool empty);
bool RemoveDeletedNode(CacheRankingsBlock* node);
bool NodeIsOldEnough(CacheRankingsBlock* node, int list);
int SelectListByLength(Rankings::ScopedRankingsBlock* next);
void ReportListStats();
BackendImpl* backend_;
Rankings* rankings_;
IndexHeader* header_;
int max_size_;
int trim_delays_;
int index_size_;
bool new_eviction_;
bool first_trim_;
bool trimming_;
bool delay_trim_;
bool init_;
bool test_mode_;
base::WeakPtrFactory<Eviction> ptr_factory_;
DISALLOW_COPY_AND_ASSIGN(Eviction);
};
} // namespace disk_cache
#endif // NET_DISK_CACHE_EVICTION_H_