1 files changed, 100 insertions, 0 deletions
diff --git a/chromium/net/disk_cache/blockfile/stats.h b/chromium/net/disk_cache/blockfile/stats.h
new file mode 100644
index 00000000000..8e1293d61d4
--- /dev/null
+++ b/chromium/net/disk_cache/blockfile/stats.h
@@ -0,0 +1,100 @@
+// 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_BLOCKFILE_STATS_H_
+#define NET_DISK_CACHE_BLOCKFILE_STATS_H_
+
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "net/disk_cache/blockfile/addr.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);
+
+ private:
+  // Supports generation of SizeStats histogram data.
+  int GetBucketRange(size_t i) const;
+  int GetStatsBucket(int32 size);
+  int GetRatio(Counters hit, Counters miss) const;
+
+  Addr storage_addr_;
+  int data_sizes_[kDataSizesLength];
+  int64 counters_[MAX_COUNTER];
+
+  DISALLOW_COPY_AND_ASSIGN(Stats);
+};
+
+}  // namespace disk_cache
+
+#endif  // NET_DISK_CACHE_BLOCKFILE_STATS_H_