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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_V3_ENTRY_IMPL_V3_H_ | |
6 #define NET_DISK_CACHE_V3_ENTRY_IMPL_V3_H_ | |
7 | |
8 #include <string> | |
9 | |
10 #include "base/memory/scoped_ptr.h" | |
11 #include "net/base/net_log.h" | |
12 #include "net/disk_cache/disk_cache.h" | |
13 #include "net/disk_cache/storage_block.h" | |
14 #include "net/disk_cache/v3/disk_format_v3.h" | |
15 | |
16 namespace disk_cache { | |
17 | |
18 class BackendImplV3; | |
19 class SparseControlV3; | |
20 | |
21 // This class implements the Entry interface. An object of this | |
22 // class represents a single entry on the cache. | |
23 class NET_EXPORT_PRIVATE EntryImplV3 | |
24 : public Entry, | |
25 public base::RefCounted<EntryImplV3> { | |
26 friend class base::RefCounted<EntryImplV3>; | |
27 // friend class SparseControlV3; | |
28 public: | |
29 enum Operation { | |
30 kRead, | |
31 kWrite, | |
32 kSparseRead, | |
33 kSparseWrite, | |
34 kAsyncIO, | |
35 kReadAsync1, | |
36 kWriteAsync1 | |
37 }; | |
38 | |
39 EntryImplV3(BackendImplV3* backend, Addr address, bool read_only); | |
40 | |
41 // Performs the initialization of a EntryImplV3 that will be added to the | |
42 // cache. | |
43 bool CreateEntry(Addr node_address, const std::string& key, uint32 hash); | |
44 | |
45 uint32 GetHash(); | |
46 | |
47 uint32 GetHash() const; | |
48 Addr GetAddress() const; | |
49 int GetReuseCounter() const; | |
50 void SetReuseCounter(int count); | |
51 int GetRefetchCounter() const; | |
52 void SetRefetchCounter(int count); | |
53 | |
54 // Returns true if this entry matches the lookup arguments. | |
55 bool IsSameEntry(const std::string& key, uint32 hash); | |
56 | |
57 // Permamently destroys this entry. | |
58 void InternalDoom(); | |
59 | |
60 // Returns false if the entry is clearly invalid. | |
61 bool SanityCheck(); | |
62 bool DataSanityCheck(); | |
63 | |
64 // Attempts to make this entry reachable though the key. | |
65 void FixForDelete(); | |
66 | |
67 // Set the access times for this entry. This method provides support for | |
68 // the upgrade tool. | |
69 void SetTimes(base::Time last_used, base::Time last_modified); | |
70 | |
71 // Logs a begin event and enables logging for the EntryImplV3. Will also cause | |
72 // an end event to be logged on destruction. The EntryImplV3 must have its key | |
73 // initialized before this is called. |created| is true if the Entry was | |
74 // created rather than opened. | |
75 void BeginLogging(net::NetLog* net_log, bool created); | |
76 | |
77 const net::BoundNetLog& net_log() const; | |
78 | |
79 // Entry interface. | |
80 virtual void Doom() OVERRIDE; | |
81 virtual void Close() OVERRIDE; | |
82 virtual std::string GetKey() const OVERRIDE; | |
83 virtual base::Time GetLastUsed() const OVERRIDE; | |
84 virtual base::Time GetLastModified() const OVERRIDE; | |
85 virtual int32 GetDataSize(int index) const OVERRIDE; | |
86 virtual int ReadData(int index, int offset, IOBuffer* buf, int buf_len, | |
87 const CompletionCallback& callback) OVERRIDE; | |
88 virtual int WriteData(int index, int offset, IOBuffer* buf, int buf_len, | |
89 const CompletionCallback& callback, | |
90 bool truncate) OVERRIDE; | |
91 virtual int ReadSparseData(int64 offset, IOBuffer* buf, int buf_len, | |
92 const CompletionCallback& callback) OVERRIDE; | |
93 virtual int WriteSparseData(int64 offset, IOBuffer* buf, int buf_len, | |
94 const CompletionCallback& callback) OVERRIDE; | |
95 virtual int GetAvailableRange(int64 offset, int len, int64* start, | |
96 const CompletionCallback& callback) OVERRIDE; | |
97 virtual bool CouldBeSparse() const OVERRIDE; | |
98 virtual void CancelSparseIO() OVERRIDE; | |
99 virtual int ReadyForSparseIO(const CompletionCallback& callback) OVERRIDE; | |
100 | |
101 private: | |
102 enum { | |
103 kNumStreams = 3 | |
104 }; | |
105 class UserBuffer; | |
106 | |
107 virtual ~EntryImplV3(); | |
108 | |
109 // Do all the work for ReadDataImpl and WriteDataImpl. Implemented as | |
110 // separate functions to make logging of results simpler. | |
111 int InternalReadData(int index, int offset, IOBuffer* buf, | |
112 int buf_len, const CompletionCallback& callback); | |
113 int InternalWriteData(int index, int offset, IOBuffer* buf, int buf_len, | |
114 const CompletionCallback& callback, bool truncate); | |
115 | |
116 // Initializes the storage for an internal or external data block. | |
117 bool CreateDataBlock(int index, int size); | |
118 | |
119 // Initializes the storage for an internal or external generic block. | |
120 bool CreateBlock(int size, Addr* address); | |
121 | |
122 // Deletes the data pointed by address, maybe backed by files_[index]. | |
123 // Note that most likely the caller should delete (and store) the reference to | |
124 // |address| *before* calling this method because we don't want to have an | |
125 // entry using an address that is already free. | |
126 void DeleteData(Addr address, int index); | |
127 | |
128 // Updates ranking information. | |
129 void UpdateRank(bool modified); | |
130 | |
131 // Deletes this entry from disk. If |everything| is false, only the user data | |
132 // will be removed, leaving the key and control data intact. | |
133 void DeleteEntryData(bool everything); | |
134 | |
135 // Prepares the target file or buffer for a write of buf_len bytes at the | |
136 // given offset. | |
137 bool PrepareTarget(int index, int offset, int buf_len, bool truncate); | |
138 | |
139 // Adjusts the internal buffer and file handle for a write that truncates this | |
140 // stream. | |
141 bool HandleTruncation(int index, int offset, int buf_len); | |
142 | |
143 // Copies data from disk to the internal buffer. | |
144 bool CopyToLocalBuffer(int index); | |
145 | |
146 // Reads from a block data file to this object's memory buffer. | |
147 bool MoveToLocalBuffer(int index); | |
148 | |
149 // Loads the external file to this object's memory buffer. | |
150 bool ImportSeparateFile(int index, int new_size); | |
151 | |
152 // Makes sure that the internal buffer can handle the a write of |buf_len| | |
153 // bytes to |offset|. | |
154 bool PrepareBuffer(int index, int offset, int buf_len); | |
155 | |
156 // Flushes the in-memory data to the backing storage. The data destination | |
157 // is determined based on the current data length and |min_len|. | |
158 bool Flush(int index, int min_len); | |
159 | |
160 // Updates the size of a given data stream. | |
161 void UpdateSize(int index, int old_size, int new_size); | |
162 | |
163 // Initializes the sparse control object. Returns a net error code. | |
164 int InitSparseData(); | |
165 | |
166 // Adds the provided |flags| to the current EntryFlags for this entry. | |
167 void SetEntryFlags(uint32 flags); | |
168 | |
169 // Returns the current EntryFlags for this entry. | |
170 uint32 GetEntryFlags(); | |
171 | |
172 // Gets the data stored at the given index. If the information is in memory, | |
173 // a buffer will be allocated and the data will be copied to it (the caller | |
174 // can find out the size of the buffer before making this call). Otherwise, | |
175 // the cache address of the data will be returned, and that address will be | |
176 // removed from the regular book keeping of this entry so the caller is | |
177 // responsible for deleting the block (or file) from the backing store at some | |
178 // point; there is no need to report any storage-size change, only to do the | |
179 // actual cleanup. | |
180 void GetData(int index, char** buffer, Addr* address); | |
181 | |
182 // Generates a histogram for the time spent working on this operation. | |
183 void ReportIOTime(Operation op, const base::TimeTicks& start); | |
184 | |
185 // Logs this entry to the internal trace buffer. | |
186 void Log(const char* msg); | |
187 | |
188 scoped_ptr<EntryRecord> entry_; // Basic record for this entry. | |
189 scoped_ptr<ShortEntryRecord> short_entry_; // Valid for evicted entries. | |
190 base::WeakPtr<BackendImplV3> backend_; // Back pointer to the cache. | |
191 scoped_ptr<UserBuffer> user_buffers_[kNumStreams]; // Stores user data. | |
192 mutable std::string key_; // Copy of the key. | |
193 Addr address_; | |
194 int unreported_size_[kNumStreams]; // Bytes not reported yet to the backend. | |
195 bool doomed_; // True if this entry was removed from the cache. | |
196 bool read_only_; | |
197 bool dirty_; // True if there is something to write. | |
198 bool modified_; | |
199 // scoped_ptr<SparseControlV3> sparse_; // Support for sparse entries. | |
200 | |
201 net::BoundNetLog net_log_; | |
202 | |
203 DISALLOW_COPY_AND_ASSIGN(EntryImplV3); | |
204 }; | |
205 | |
206 } // namespace disk_cache | |
207 | |
208 #endif // NET_DISK_CACHE_V3_ENTRY_IMPL_V3_H_ | |
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