1// Copyright (c) 2012 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5#ifndef NET_DISK_CACHE_ENTRY_IMPL_H_ 6#define NET_DISK_CACHE_ENTRY_IMPL_H_ 7 8#include "base/memory/scoped_ptr.h" 9#include "net/base/net_log.h" 10#include "net/disk_cache/disk_cache.h" 11#include "net/disk_cache/storage_block.h" 12#include "net/disk_cache/storage_block-inl.h" 13 14namespace disk_cache { 15 16class BackendImpl; 17class InFlightBackendIO; 18class SparseControl; 19 20// This class implements the Entry interface. An object of this 21// class represents a single entry on the cache. 22class NET_EXPORT_PRIVATE EntryImpl 23 : public Entry, 24 public base::RefCounted<EntryImpl> { 25 friend class base::RefCounted<EntryImpl>; 26 friend class SparseControl; 27 public: 28 enum Operation { 29 kRead, 30 kWrite, 31 kSparseRead, 32 kSparseWrite, 33 kAsyncIO, 34 kReadAsync1, 35 kWriteAsync1 36 }; 37 38 EntryImpl(BackendImpl* backend, Addr address, bool read_only); 39 40 // Background implementation of the Entry interface. 41 void DoomImpl(); 42 int ReadDataImpl(int index, int offset, IOBuffer* buf, int buf_len, 43 const CompletionCallback& callback); 44 int WriteDataImpl(int index, int offset, IOBuffer* buf, int buf_len, 45 const CompletionCallback& callback, bool truncate); 46 int ReadSparseDataImpl(int64 offset, IOBuffer* buf, int buf_len, 47 const CompletionCallback& callback); 48 int WriteSparseDataImpl(int64 offset, IOBuffer* buf, int buf_len, 49 const CompletionCallback& callback); 50 int GetAvailableRangeImpl(int64 offset, int len, int64* start); 51 void CancelSparseIOImpl(); 52 int ReadyForSparseIOImpl(const CompletionCallback& callback); 53 54 // Performs the initialization of a EntryImpl that will be added to the 55 // cache. 56 bool CreateEntry(Addr node_address, const std::string& key, uint32 hash); 57 58 uint32 GetHash(); 59 60 // Returns true if this entry matches the lookup arguments. 61 bool IsSameEntry(const std::string& key, uint32 hash); 62 63 // Permamently destroys this entry. 64 void InternalDoom(); 65 66 bool dirty() { 67 return dirty_; 68 } 69 70 bool doomed() { 71 return doomed_; 72 } 73 74 // Returns false if the entry is clearly invalid. 75 bool SanityCheck(); 76 bool DataSanityCheck(); 77 78 // Attempts to make this entry reachable though the key. 79 void FixForDelete(); 80 81 // Set the access times for this entry. This method provides support for 82 // the upgrade tool. 83 void SetTimes(base::Time last_used, base::Time last_modified); 84 85 // Logs a begin event and enables logging for the EntryImpl. Will also cause 86 // an end event to be logged on destruction. The EntryImpl must have its key 87 // initialized before this is called. |created| is true if the Entry was 88 // created rather than opened. 89 void BeginLogging(net::NetLog* net_log, bool created); 90 91 const net::BoundNetLog& net_log() const; 92 93 // Entry interface. 94 virtual void Doom() OVERRIDE; 95 virtual void Close() OVERRIDE; 96 virtual std::string GetKey() const OVERRIDE; 97 virtual base::Time GetLastUsed() const OVERRIDE; 98 virtual base::Time GetLastModified() const OVERRIDE; 99 virtual int32 GetDataSize(int index) const OVERRIDE; 100 virtual int ReadData(int index, int offset, IOBuffer* buf, int buf_len, 101 const CompletionCallback& callback) OVERRIDE; 102 virtual int WriteData(int index, int offset, IOBuffer* buf, int buf_len, 103 const CompletionCallback& callback, 104 bool truncate) OVERRIDE; 105 virtual int ReadSparseData(int64 offset, IOBuffer* buf, int buf_len, 106 const CompletionCallback& callback) OVERRIDE; 107 virtual int WriteSparseData(int64 offset, IOBuffer* buf, int buf_len, 108 const CompletionCallback& callback) OVERRIDE; 109 virtual int GetAvailableRange(int64 offset, int len, int64* start, 110 const CompletionCallback& callback) OVERRIDE; 111 virtual bool CouldBeSparse() const OVERRIDE; 112 virtual void CancelSparseIO() OVERRIDE; 113 virtual int ReadyForSparseIO(const CompletionCallback& callback) OVERRIDE; 114 115 private: 116 enum { 117 kNumStreams = 3 118 }; 119 class UserBuffer; 120 121 virtual ~EntryImpl(); 122 123 // Do all the work for ReadDataImpl and WriteDataImpl. Implemented as 124 // separate functions to make logging of results simpler. 125 int InternalReadData(int index, int offset, IOBuffer* buf, 126 int buf_len, const CompletionCallback& callback); 127 int InternalWriteData(int index, int offset, IOBuffer* buf, int buf_len, 128 const CompletionCallback& callback, bool truncate); 129 130 // Initializes the storage for an internal or external data block. 131 bool CreateDataBlock(int index, int size); 132 133 // Initializes the storage for an internal or external generic block. 134 bool CreateBlock(int size, Addr* address); 135 136 // Deletes the data pointed by address, maybe backed by files_[index]. 137 // Note that most likely the caller should delete (and store) the reference to 138 // |address| *before* calling this method because we don't want to have an 139 // entry using an address that is already free. 140 void DeleteData(Addr address, int index); 141 142 // Updates ranking information. 143 void UpdateRank(bool modified); 144 145 // Deletes this entry from disk. If |everything| is false, only the user data 146 // will be removed, leaving the key and control data intact. 147 void DeleteEntryData(bool everything); 148 149 // Prepares the target file or buffer for a write of buf_len bytes at the 150 // given offset. 151 bool PrepareTarget(int index, int offset, int buf_len, bool truncate); 152 153 // Adjusts the internal buffer and file handle for a write that truncates this 154 // stream. 155 bool HandleTruncation(int index, int offset, int buf_len); 156 157 // Copies data from disk to the internal buffer. 158 bool CopyToLocalBuffer(int index); 159 160 // Reads from a block data file to this object's memory buffer. 161 bool MoveToLocalBuffer(int index); 162 163 // Loads the external file to this object's memory buffer. 164 bool ImportSeparateFile(int index, int new_size); 165 166 // Makes sure that the internal buffer can handle the a write of |buf_len| 167 // bytes to |offset|. 168 bool PrepareBuffer(int index, int offset, int buf_len); 169 170 // Flushes the in-memory data to the backing storage. The data destination 171 // is determined based on the current data length and |min_len|. 172 bool Flush(int index, int min_len); 173 174 // Updates the size of a given data stream. 175 void UpdateSize(int index, int old_size, int new_size); 176 177 // Initializes the sparse control object. Returns a net error code. 178 int InitSparseData(); 179 180 // Adds the provided |flags| to the current EntryFlags for this entry. 181 void SetEntryFlags(uint32 flags); 182 183 // Returns the current EntryFlags for this entry. 184 uint32 GetEntryFlags(); 185 186 // Gets the data stored at the given index. If the information is in memory, 187 // a buffer will be allocated and the data will be copied to it (the caller 188 // can find out the size of the buffer before making this call). Otherwise, 189 // the cache address of the data will be returned, and that address will be 190 // removed from the regular book keeping of this entry so the caller is 191 // responsible for deleting the block (or file) from the backing store at some 192 // point; there is no need to report any storage-size change, only to do the 193 // actual cleanup. 194 void GetData(int index, char** buffer, Addr* address); 195 196 // Generates a histogram for the time spent working on this operation. 197 void ReportIOTime(Operation op, const base::TimeTicks& start); 198 199 // Logs this entry to the internal trace buffer. 200 void Log(const char* msg); 201 202 CacheEntryBlock entry_; // Key related information for this entry. 203 CacheRankingsBlock node_; // Rankings related information for this entry. 204 base::WeakPtr<BackendImpl> backend_; // Back pointer to the cache. 205 base::WeakPtr<InFlightBackendIO> background_queue_; // In-progress queue. 206 scoped_ptr<UserBuffer> user_buffers_[kNumStreams]; // Stores user data. 207 // Files to store external user data and key. 208 scoped_refptr<File> files_[kNumStreams + 1]; 209 mutable std::string key_; // Copy of the key. 210 int unreported_size_[kNumStreams]; // Bytes not reported yet to the backend. 211 bool doomed_; // True if this entry was removed from the cache. 212 bool read_only_; // True if not yet writing. 213 bool dirty_; // True if we detected that this is a dirty entry. 214 scoped_ptr<SparseControl> sparse_; // Support for sparse entries. 215 216 net::BoundNetLog net_log_; 217 218 DISALLOW_COPY_AND_ASSIGN(EntryImpl); 219}; 220 221} // namespace disk_cache 222 223#endif // NET_DISK_CACHE_ENTRY_IMPL_H_ 224