blob: 2c23a674ce336bf81a72b38f8fe2aaaf06100626 [file] [log] [blame]
// Copyright (c) 2006-2008 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.
// See net/disk_cache/disk_cache.h for the public interface of the cache.
#include "base/hash_tables.h"
#include "net/disk_cache/disk_cache.h"
#include "net/disk_cache/mem_rankings.h"
namespace disk_cache {
class MemEntryImpl;
// This class implements the Backend interface. An object of this class handles
// the operations of the cache without writting to disk.
class MemBackendImpl : public Backend {
MemBackendImpl() : max_size_(0), current_size_(0) {}
// Performs general initialization for this current instance of the cache.
bool Init();
// Backend interface.
virtual int32 GetEntryCount() const;
virtual bool OpenEntry(const std::string& key, Entry** entry);
virtual bool CreateEntry(const std::string& key, Entry** entry);
virtual bool DoomEntry(const std::string& key);
virtual bool DoomAllEntries();
virtual bool DoomEntriesBetween(const base::Time initial_time,
const base::Time end_time);
virtual bool DoomEntriesSince(const base::Time initial_time);
virtual bool OpenNextEntry(void** iter, Entry** next_entry);
virtual void EndEnumeration(void** iter);
virtual void GetStats(
std::vector<std::pair<std::string, std::string> >* stats) {}
// Sets the maximum size for the total amount of data stored by this instance.
bool SetMaxSize(int max_bytes);
// Permanently deletes an entry.
void InternalDoomEntry(MemEntryImpl* entry);
// Updates the ranking information for an entry.
void UpdateRank(MemEntryImpl* node);
// A user data block is being created, extended or truncated.
void ModifyStorageSize(int32 old_size, int32 new_size);
// Returns the maximum size for a file to reside on the cache.
int MaxFileSize() const;
// 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);
// Handles the used storage count.
void AddStorageSize(int32 bytes);
void SubstractStorageSize(int32 bytes);
typedef base::hash_map<std::string, MemEntryImpl*> EntryMap;
EntryMap entries_;
MemRankings rankings_; // Rankings to be able to trim the cache.
int32 max_size_; // Maximum data size for this instance.
int32 current_size_;
} // namespace disk_cache