// 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. #ifndef NET_DISK_CACHE_ENTRY_IMPL_H__ #define NET_DISK_CACHE_ENTRY_IMPL_H__ #include "net/disk_cache/disk_cache.h" #include "net/disk_cache/storage_block.h" #include "net/disk_cache/storage_block-inl.h" namespace disk_cache { class BackendImpl; // This class implements the Entry interface. An object of this // class represents a single entry on the cache. class EntryImpl : public Entry, public base::RefCounted { friend class base::RefCounted; public: EntryImpl(BackendImpl* backend, Addr address); // Entry interface. virtual void Doom(); virtual void Close(); virtual std::string GetKey() const; virtual Time GetLastUsed() const; virtual Time GetLastModified() const; virtual int32 GetDataSize(int index) const; virtual int ReadData(int index, int offset, char* buf, int buf_len, net::CompletionCallback* completion_callback); virtual int WriteData(int index, int offset, const char* buf, int buf_len, net::CompletionCallback* completion_callback, bool truncate); inline CacheEntryBlock* entry() { return &entry_; } inline CacheRankingsBlock* rankings() { return &node_; } uint32 GetHash(); // Performs the initialization of a EntryImpl that will be added to the // cache. bool CreateEntry(Addr node_address, const std::string& key, uint32 hash); // Returns true if this entry matches the lookup arguments. bool IsSameEntry(const std::string& key, uint32 hash); // Permamently destroys this entry void InternalDoom(); // Returns the address of the next entry on the list of entries with the same // hash. CacheAddr GetNextAddress(); // Sets the address of the next entry on the list of entries with the same // hash. void SetNextAddress(Addr address); // Reloads the rankings node information. bool LoadNodeAddress(); // Reloads the data for this entry. If there is already an object in memory // for the entry, the returned value is a pointer to that entry, otherwise // it is the passed in entry. On failure returns NULL. static EntryImpl* Update(EntryImpl* entry); // Returns true if this entry is marked as dirty on disk. bool IsDirty(int32 current_id); void ClearDirtyFlag(); // Fixes this entry so it can be treated as valid (to delete it). void SetPointerForInvalidEntry(int32 new_id); // Returns false if the entry is clearly invalid. bool SanityCheck(); // Handle the pending asynchronous IO count. void IncrementIoCount(); void DecrementIoCount(); private: ~EntryImpl(); // Index for the file used to store the key, if any (files_[kKeyFileIndex]). static const int kKeyFileIndex = 2; // Initializes the storage for an internal or external data block. bool CreateDataBlock(int index, int size); // Initializes the storage for an internal or external generic block. bool CreateBlock(int size, Addr* address); // Deletes the data pointed by address, maybe backed by files_[index]. void DeleteData(Addr address, int index); // Updates ranking information. void UpdateRank(bool modified); // Returns a pointer to the file that stores the given address. File* GetBackingFile(Addr address, int index); // Returns a pointer to the file that stores external data. File* GetExternalFile(Addr address, int index); // Prepares the target file or buffer for a write of buf_len bytes at the // given offset. bool PrepareTarget(int index, int offset, int buf_len, bool truncate); // Grows the size of the storage used to store user data, if needed. bool GrowUserBuffer(int index, int offset, int buf_len, bool truncate); // Reads from a block data file to this object's memory buffer. bool MoveToLocalBuffer(int index); // Loads the external file to this object's memory buffer. bool ImportSeparateFile(int index, int offset, int buf_len); // Flush the in-memory data to the backing storage. bool Flush(int index, int size, bool async); // Logs this entry to the internal trace buffer. void Log(const char* msg); CacheEntryBlock entry_; // Key related information for this entry. CacheRankingsBlock node_; // Rankings related information for this entry. BackendImpl* backend_; // Back pointer to the cache. scoped_array user_buffers_[2]; // Store user data. scoped_refptr files_[3]; // Files to store external user data and key. int unreported_size_[2]; // Bytes not reported yet to the backend. bool doomed_; // True if this entry was removed from the cache. DISALLOW_EVIL_CONSTRUCTORS(EntryImpl); }; } // namespace disk_cache #endif // NET_DISK_CACHE_ENTRY_IMPL_H__