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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 // See net/disk_cache/disk_cache.h for the public interface of the cache. | |
| 6 | |
| 7 #ifndef NET_DISK_CACHE_BLOCKFILE_BACKEND_IMPL_V3_H_ | |
| 8 #define NET_DISK_CACHE_BLOCKFILE_BACKEND_IMPL_V3_H_ | |
| 9 | |
| 10 #include "base/containers/hash_tables.h" | |
| 11 #include "base/files/file_path.h" | |
| 12 #include "base/memory/ref_counted.h" | |
| 13 #include "base/timer/timer.h" | |
| 14 #include "net/disk_cache/blockfile/block_bitmaps_v3.h" | |
| 15 #include "net/disk_cache/blockfile/block_files.h" | |
| 16 #include "net/disk_cache/blockfile/eviction_v3.h" | |
| 17 #include "net/disk_cache/blockfile/index_table_v3.h" | |
| 18 #include "net/disk_cache/blockfile/stats.h" | |
| 19 #include "net/disk_cache/blockfile/stress_support.h" | |
| 20 #include "net/disk_cache/blockfile/trace.h" | |
| 21 #include "net/disk_cache/disk_cache.h" | |
| 22 | |
| 23 namespace base { | |
| 24 class SingleThreadTaskRunner; | |
| 25 } // namespace base | |
| 26 | |
| 27 namespace net { | |
| 28 class NetLog; | |
| 29 } // namespace net | |
| 30 | |
| 31 namespace disk_cache { | |
| 32 | |
| 33 class EntryImplV3; | |
| 34 | |
| 35 // This class implements the Backend interface. An object of this | |
| 36 // class handles the operations of the cache for a particular profile. | |
| 37 class NET_EXPORT_PRIVATE BackendImplV3 : public Backend { | |
| 38 public: | |
| 39 enum BackendFlags { | |
| 40 MAX_SIZE = 1 << 1, // A maximum size was provided. | |
| 41 UNIT_TEST_MODE = 1 << 2, // We are modifying the behavior for testing. | |
| 42 UPGRADE_MODE = 1 << 3, // This is the upgrade tool (dump). | |
| 43 EVICTION_V2 = 1 << 4, // Use of new eviction was specified. | |
| 44 BASIC_UNIT_TEST = 1 << 5, // Identifies almost all unit tests. | |
| 45 NO_LOAD_PROTECTION = 1 << 6, // Don't act conservatively under load. | |
| 46 NO_BUFFERING = 1 << 7, // Disable extended IO buffering. | |
| 47 NO_CLEAN_ON_EXIT = 1 << 8 // Avoid saving data at exit time. | |
| 48 }; | |
| 49 | |
| 50 BackendImplV3(const base::FilePath& path, | |
| 51 const scoped_refptr<base::SingleThreadTaskRunner>& cache_thread, | |
| 52 net::NetLog* net_log); | |
| 53 ~BackendImplV3() override; | |
| 54 | |
| 55 // Performs general initialization for this current instance of the cache. | |
| 56 int Init(const CompletionCallback& callback); | |
| 57 | |
| 58 // Sets the maximum size for the total amount of data stored by this instance. | |
| 59 bool SetMaxSize(int max_bytes); | |
| 60 | |
| 61 // Sets the cache type for this backend. | |
| 62 void SetType(net::CacheType type); | |
| 63 | |
| 64 // Creates a new storage block of size block_count. | |
| 65 bool CreateBlock(FileType block_type, int block_count, | |
| 66 Addr* block_address); | |
| 67 | |
| 68 // Updates the ranking information for an entry. | |
| 69 void UpdateRank(EntryImplV3* entry, bool modified); | |
| 70 | |
| 71 // Permanently deletes an entry, but still keeps track of it. | |
| 72 void InternalDoomEntry(EntryImplV3* entry); | |
| 73 | |
| 74 // This method must be called when an entry is released for the last time, so | |
| 75 // the entry should not be used anymore. |address| is the cache address of the | |
| 76 // entry. | |
| 77 void OnEntryDestroyBegin(Addr address); | |
| 78 | |
| 79 // This method must be called after all resources for an entry have been | |
| 80 // released. | |
| 81 void OnEntryDestroyEnd(); | |
| 82 | |
| 83 // If the |address| corresponds to an open entry, returns a pointer to that | |
| 84 // entry, otherwise returns NULL. Note that this method does not increase the | |
| 85 // ref counter for the entry. | |
| 86 EntryImplV3* GetOpenEntry(Addr address) const; | |
| 87 | |
| 88 // Returns the id being used on this run of the cache. | |
| 89 int32 GetCurrentEntryId() const; | |
| 90 | |
| 91 // Returns the maximum size for a file to reside on the cache. | |
| 92 int MaxFileSize() const; | |
| 93 | |
| 94 // A user data block is being created, extended or truncated. | |
| 95 void ModifyStorageSize(int32 old_size, int32 new_size); | |
| 96 | |
| 97 // Logs requests that are denied due to being too big. | |
| 98 void TooMuchStorageRequested(int32 size); | |
| 99 | |
| 100 // Returns true if a temporary buffer is allowed to be extended. | |
| 101 bool IsAllocAllowed(int current_size, int new_size); | |
| 102 | |
| 103 // Tracks the release of |size| bytes by an entry buffer. | |
| 104 void BufferDeleted(int size); | |
| 105 | |
| 106 // Only intended for testing the two previous methods. | |
| 107 int GetTotalBuffersSize() const { | |
| 108 return buffer_bytes_; | |
| 109 } | |
| 110 | |
| 111 // Returns true if this instance seems to be under heavy load. | |
| 112 bool IsLoaded() const; | |
| 113 | |
| 114 // Returns the full histogram name, for the given base |name| and the current | |
| 115 // cache type. The name will be "DiskCache3.name_type". | |
| 116 std::string HistogramName(const char* name) const; | |
| 117 | |
| 118 net::CacheType cache_type() const { | |
| 119 return cache_type_; | |
| 120 } | |
| 121 | |
| 122 bool read_only() const { | |
| 123 return read_only_; | |
| 124 } | |
| 125 | |
| 126 // Returns a weak pointer to this object. | |
| 127 base::WeakPtr<BackendImplV3> GetWeakPtr(); | |
| 128 | |
| 129 // Returns true if we should send histograms for this user again. The caller | |
| 130 // must call this function only once per run (because it returns always the | |
| 131 // same thing on a given run). | |
| 132 bool ShouldReportAgain(); | |
| 133 | |
| 134 // Reports some data when we filled up the cache. | |
| 135 void FirstEviction(); | |
| 136 | |
| 137 // Called when an interesting event should be logged (counted). | |
| 138 void OnEvent(Stats::Counters an_event); | |
| 139 | |
| 140 // Keeps track of payload access (doesn't include metadata). | |
| 141 void OnRead(int bytes); | |
| 142 void OnWrite(int bytes); | |
| 143 | |
| 144 // Timer callback to calculate usage statistics and perform backups. | |
| 145 void OnTimerTick(); | |
| 146 | |
| 147 // Sets internal parameters to enable unit testing mode. | |
| 148 void SetUnitTestMode(); | |
| 149 | |
| 150 // Sets internal parameters to enable upgrade mode (for internal tools). | |
| 151 void SetUpgradeMode(); | |
| 152 | |
| 153 // Sets the eviction algorithm to version 2. | |
| 154 void SetNewEviction(); | |
| 155 | |
| 156 // Sets an explicit set of BackendFlags. | |
| 157 void SetFlags(uint32 flags); | |
| 158 | |
| 159 // Sends a dummy operation through the operation queue, for unit tests. | |
| 160 int FlushQueueForTest(const CompletionCallback& callback); | |
| 161 | |
| 162 // Trims an entry (all if |empty| is true) from the list of deleted | |
| 163 // entries. This method should be called directly on the cache thread. | |
| 164 void TrimForTest(bool empty); | |
| 165 | |
| 166 // Trims an entry (all if |empty| is true) from the list of deleted | |
| 167 // entries. This method should be called directly on the cache thread. | |
| 168 void TrimDeletedListForTest(bool empty); | |
| 169 | |
| 170 // Performs a simple self-check, and returns the number of dirty items | |
| 171 // or an error code (negative value). | |
| 172 int SelfCheck(); | |
| 173 | |
| 174 // Backend implementation. | |
| 175 net::CacheType GetCacheType() const override; | |
| 176 int32 GetEntryCount() const override; | |
| 177 int OpenEntry(const std::string& key, | |
| 178 Entry** entry, | |
| 179 const CompletionCallback& callback) override; | |
| 180 int CreateEntry(const std::string& key, | |
| 181 Entry** entry, | |
| 182 const CompletionCallback& callback) override; | |
| 183 int DoomEntry(const std::string& key, | |
| 184 const CompletionCallback& callback) override; | |
| 185 int DoomAllEntries(const CompletionCallback& callback) override; | |
| 186 int DoomEntriesBetween(base::Time initial_time, | |
| 187 base::Time end_time, | |
| 188 const CompletionCallback& callback) override; | |
| 189 int DoomEntriesSince(base::Time initial_time, | |
| 190 const CompletionCallback& callback) override; | |
| 191 scoped_ptr<Iterator> CreateIterator() override; | |
| 192 void GetStats(StatsItems* stats) override; | |
| 193 void OnExternalCacheHit(const std::string& key) override; | |
| 194 | |
| 195 private: | |
| 196 friend class EvictionV3; | |
| 197 typedef base::hash_map<CacheAddr, EntryImplV3*> EntriesMap; | |
| 198 class IteratorImpl; | |
| 199 class NotImplementedIterator; | |
| 200 class Worker; | |
| 201 | |
| 202 void AdjustMaxCacheSize(); | |
| 203 bool InitStats(void* stats_data); | |
| 204 void StoreStats(); | |
| 205 | |
| 206 // Deletes the cache and starts again. | |
| 207 void RestartCache(bool failure); | |
| 208 void PrepareForRestart(); | |
| 209 | |
| 210 // Performs final cleanup. | |
| 211 void CleanupCache(); | |
| 212 | |
| 213 // Creates a new entry object. Returns zero on success, or a disk_cache error | |
| 214 // on failure. | |
| 215 int NewEntry(Addr address, EntryImplV3** entry); | |
| 216 | |
| 217 // Handles the used storage count. | |
| 218 void AddStorageSize(int32 bytes); | |
| 219 void SubstractStorageSize(int32 bytes); | |
| 220 | |
| 221 // Update the number of referenced cache entries. | |
| 222 void IncreaseNumRefs(); | |
| 223 void DecreaseNumRefs(); | |
| 224 void IncreaseNumEntries(); | |
| 225 void DecreaseNumEntries(); | |
| 226 | |
| 227 // Dumps current cache statistics to the log. | |
| 228 void LogStats(); | |
| 229 | |
| 230 // Send UMA stats. | |
| 231 void ReportStats(); | |
| 232 | |
| 233 // Reports an uncommon, recoverable error. | |
| 234 void ReportError(int error); | |
| 235 | |
| 236 // Performs basic checks on the index file. Returns false on failure. | |
| 237 bool CheckIndex(); | |
| 238 | |
| 239 // Part of the self test. Returns the number or dirty entries, or an error. | |
| 240 int CheckAllEntries(); | |
| 241 | |
| 242 // Part of the self test. Returns false if the entry is corrupt. | |
| 243 bool CheckEntry(EntryImplV3* cache_entry); | |
| 244 | |
| 245 // Returns the maximum total memory for the memory buffers. | |
| 246 int MaxBuffersSize(); | |
| 247 | |
| 248 IndexTable index_; | |
| 249 base::FilePath path_; // Path to the folder used as backing storage. | |
| 250 BlockBitmaps block_files_; | |
| 251 int32 max_size_; // Maximum data size for this instance. | |
| 252 EvictionV3 eviction_; // Handler of the eviction algorithm. | |
| 253 EntriesMap open_entries_; | |
| 254 int num_refs_; // Number of referenced cache entries. | |
| 255 int max_refs_; // Max number of referenced cache entries. | |
| 256 int entry_count_; // Number of entries accessed lately. | |
| 257 int byte_count_; // Number of bytes read/written lately. | |
| 258 int buffer_bytes_; // Total size of the temporary entries' buffers. | |
| 259 int up_ticks_; // The number of timer ticks received (OnTimerTick). | |
| 260 net::CacheType cache_type_; | |
| 261 int uma_report_; // Controls transmission of UMA data. | |
| 262 uint32 user_flags_; // Flags set by the user. | |
| 263 bool init_; // controls the initialization of the system. | |
| 264 bool restarted_; | |
| 265 bool read_only_; // Prevents updates of the rankings data (used by tools). | |
| 266 bool disabled_; | |
| 267 bool lru_eviction_; // What eviction algorithm should be used. | |
| 268 bool first_timer_; // True if the timer has not been called. | |
| 269 bool user_load_; // True if we see a high load coming from the caller. | |
| 270 | |
| 271 net::NetLog* net_log_; | |
| 272 | |
| 273 Stats stats_; // Usage statistics. | |
| 274 scoped_ptr<base::RepeatingTimer<BackendImplV3> > timer_; // Usage timer. | |
| 275 scoped_refptr<TraceObject> trace_object_; // Initializes internal tracing. | |
| 276 base::WeakPtrFactory<BackendImplV3> ptr_factory_; | |
| 277 | |
| 278 DISALLOW_COPY_AND_ASSIGN(BackendImplV3); | |
| 279 }; | |
| 280 | |
| 281 } // namespace disk_cache | |
| 282 | |
| 283 #endif // NET_DISK_CACHE_BLOCKFILE_BACKEND_IMPL_V3_H_ | |
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