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Diffstat (limited to 'chromium/net/disk_cache/stats.h')
-rw-r--r-- | chromium/net/disk_cache/stats.h | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/chromium/net/disk_cache/stats.h b/chromium/net/disk_cache/stats.h new file mode 100644 index 00000000000..440334af207 --- /dev/null +++ b/chromium/net/disk_cache/stats.h @@ -0,0 +1,105 @@ +// Copyright (c) 2012 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_STATS_H_ +#define NET_DISK_CACHE_STATS_H_ + +#include <string> +#include <vector> + +#include "base/basictypes.h" +#include "net/disk_cache/addr.h" +#include "net/disk_cache/stats_histogram.h" + +namespace base { +class HistogramSamples; +} // namespace base + +namespace disk_cache { + +typedef std::vector<std::pair<std::string, std::string> > StatsItems; + +// This class stores cache-specific usage information, for tunning purposes. +class Stats { + public: + static const int kDataSizesLength = 28; + enum Counters { + MIN_COUNTER = 0, + OPEN_MISS = MIN_COUNTER, + OPEN_HIT, + CREATE_MISS, + CREATE_HIT, + RESURRECT_HIT, + CREATE_ERROR, + TRIM_ENTRY, + DOOM_ENTRY, + DOOM_CACHE, + INVALID_ENTRY, + OPEN_ENTRIES, // Average number of open entries. + MAX_ENTRIES, // Maximum number of open entries. + TIMER, + READ_DATA, + WRITE_DATA, + OPEN_RANKINGS, // An entry has to be read just to modify rankings. + GET_RANKINGS, // We got the ranking info without reading the whole entry. + FATAL_ERROR, + LAST_REPORT, // Time of the last time we sent a report. + LAST_REPORT_TIMER, // Timer count of the last time we sent a report. + DOOM_RECENT, // The cache was partially cleared. + UNUSED, // Was: ga.js was evicted from the cache. + MAX_COUNTER + }; + + Stats(); + ~Stats(); + + // Initializes this object with |data| from disk. + bool Init(void* data, int num_bytes, Addr address); + + // Generates a size distribution histogram. + void InitSizeHistogram(); + + // Returns the number of bytes needed to store the stats on disk. + int StorageSize(); + + // Tracks changes to the stoage space used by an entry. + void ModifyStorageStats(int32 old_size, int32 new_size); + + // Tracks general events. + void OnEvent(Counters an_event); + void SetCounter(Counters counter, int64 value); + int64 GetCounter(Counters counter) const; + + void GetItems(StatsItems* items); + int GetHitRatio() const; + int GetResurrectRatio() const; + void ResetRatios(); + + // Returns the lower bound of the space used by entries bigger than 512 KB. + int GetLargeEntriesSize(); + + // Writes the stats into |data|, to be stored at the given cache address. + // Returns the number of bytes copied. + int SerializeStats(void* data, int num_bytes, Addr* address); + + // Support for StatsHistograms. Together, these methods allow StatsHistograms + // to take a snapshot of the data_sizes_ as the histogram data. + int GetBucketRange(size_t i) const; + void Snapshot(base::HistogramSamples* samples) const; + + private: + int GetStatsBucket(int32 size); + int GetRatio(Counters hit, Counters miss) const; + + Addr storage_addr_; + int data_sizes_[kDataSizesLength]; + int64 counters_[MAX_COUNTER]; + StatsHistogram* size_histogram_; + + DISALLOW_COPY_AND_ASSIGN(Stats); +}; + +} // namespace disk_cache + +#endif // NET_DISK_CACHE_STATS_H_ |