1 // Copyright (c) 2006-2008 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_STATS_H_ 6 #define NET_DISK_CACHE_STATS_H_ 7 8 #include <string> 9 #include <vector> 10 11 #include "base/basictypes.h" 12 #include "base/scoped_ptr.h" 13 #include "net/disk_cache/stats_histogram.h" 14 15 namespace disk_cache { 16 17 class BackendImpl; 18 19 typedef std::vector<std::pair<std::string, std::string> > StatsItems; 20 21 // This class stores cache-specific usage information, for tunning purposes. 22 class Stats { 23 public: 24 static const int kDataSizesLength = 28; 25 enum Counters { 26 MIN_COUNTER = 0, 27 OPEN_MISS = MIN_COUNTER, 28 OPEN_HIT, 29 CREATE_MISS, 30 CREATE_HIT, 31 RESURRECT_HIT, 32 CREATE_ERROR, 33 TRIM_ENTRY, 34 DOOM_ENTRY, 35 DOOM_CACHE, 36 INVALID_ENTRY, 37 OPEN_ENTRIES, // Average number of open entries. 38 MAX_ENTRIES, // Maximum number of open entries. 39 TIMER, 40 READ_DATA, 41 WRITE_DATA, 42 OPEN_RANKINGS, // An entry has to be read just to modify rankings. 43 GET_RANKINGS, // We got the ranking info without reading the whole entry. 44 FATAL_ERROR, 45 LAST_REPORT, // Time of the last time we sent a report. 46 LAST_REPORT_TIMER, // Timer count of the last time we sent a report. 47 MAX_COUNTER 48 }; 49 Stats()50 Stats() : backend_(NULL) {} 51 ~Stats(); 52 53 bool Init(BackendImpl* backend, uint32* storage_addr); 54 55 // Tracks changes to the stoage space used by an entry. 56 void ModifyStorageStats(int32 old_size, int32 new_size); 57 58 // Tracks general events. 59 void OnEvent(Counters an_event); 60 void SetCounter(Counters counter, int64 value); 61 int64 GetCounter(Counters counter) const; 62 63 void GetItems(StatsItems* items); 64 int GetHitRatio() const; 65 int GetResurrectRatio() const; 66 void ResetRatios(); 67 68 // Returns the lower bound of the space used by entries bigger than 512 KB. 69 int GetLargeEntriesSize(); 70 71 // Saves the stats to disk. 72 void Store(); 73 74 // Support for StatsHistograms. Together, these methods allow StatsHistograms 75 // to take a snapshot of the data_sizes_ as the histogram data. 76 int GetBucketRange(size_t i) const; 77 void Snapshot(StatsHistogram::StatsSamples* samples) const; 78 79 private: 80 int GetStatsBucket(int32 size); 81 int GetRatio(Counters hit, Counters miss) const; 82 83 BackendImpl* backend_; 84 uint32 storage_addr_; 85 int data_sizes_[kDataSizesLength]; 86 int64 counters_[MAX_COUNTER]; 87 scoped_refptr<StatsHistogram> size_histogram_; 88 89 DISALLOW_COPY_AND_ASSIGN(Stats); 90 }; 91 92 } // namespace disk_cache 93 94 #endif // NET_DISK_CACHE_STATS_H_ 95