net/disk_cache/tracing_cache_backend.h

   1 // Copyright (c) 2013 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_TRACING_CACHE_BACKEND_H_
   6 #define NET_DISK_CACHE_TRACING_CACHE_BACKEND_H_
   7
   8 #include "base/memory/weak_ptr.h"
   9 #include "net/disk_cache/disk_cache.h"
  10 #include "net/disk_cache/stats.h"
  11
  12 namespace disk_cache {
  13
  14 class EntryProxy;
  15
  16 // The TracingCacheBackend implements the Cache Backend interface. It intercepts
  17 // all backend operations from the IO thread and records the time from the start
  18 // of the operation until the result is delivered.
  19 class NET_EXPORT TracingCacheBackend : public Backend,
  20     public base::SupportsWeakPtr<TracingCacheBackend> {
  21  public:
  22   explicit TracingCacheBackend(scoped_ptr<Backend> backend);
  23
  24   virtual net::CacheType GetCacheType() const OVERRIDE;
  25   virtual int32 GetEntryCount() const OVERRIDE;
  26   virtual int OpenEntry(const std::string& key, Entry** entry,
  27                         const CompletionCallback& callback) OVERRIDE;
  28   virtual int CreateEntry(const std::string& key, Entry** entry,
  29                           const CompletionCallback& callback) OVERRIDE;
  30   virtual int DoomEntry(const std::string& key,
  31                         const CompletionCallback& callback) OVERRIDE;
  32   virtual int DoomAllEntries(const CompletionCallback& callback) OVERRIDE;
  33   virtual int DoomEntriesBetween(base::Time initial_time,
  34                                  base::Time end_time,
  35                                  const CompletionCallback& callback) OVERRIDE;
  36   virtual int DoomEntriesSince(base::Time initial_time,
  37                                const CompletionCallback& callback) OVERRIDE;
  38   virtual int OpenNextEntry(void** iter, Entry** next_entry,
  39                             const CompletionCallback& callback) OVERRIDE;
  40   virtual void EndEnumeration(void** iter) OVERRIDE;
  41   virtual void GetStats(StatsItems* stats) OVERRIDE;
  42   virtual void OnExternalCacheHit(const std::string& key) OVERRIDE;
  43
  44  private:
  45   friend class EntryProxy;
  46   enum Operation {
  47     OP_OPEN,
  48     OP_CREATE,
  49     OP_DOOM_ENTRY,
  50     OP_READ,
  51     OP_WRITE
  52   };
  53
  54   virtual ~TracingCacheBackend();
  55
  56   EntryProxy* FindOrCreateEntryProxy(Entry* entry);
  57
  58   void OnDeleteEntry(Entry* e);
  59
  60   void RecordEvent(base::TimeTicks start_time, Operation op, std::string key,
  61                    Entry* entry, int result);
  62
  63   void BackendOpComplete(base::TimeTicks start_time, Operation op,
  64                          std::string key, Entry** entry,
  65                          const CompletionCallback& callback, int result);
  66
  67   net::CompletionCallback BindCompletion(Operation op,
  68                                          base::TimeTicks start_time,
  69                                          const std::string& key, Entry **entry,
  70                                          const net::CompletionCallback& cb);
  71
  72   scoped_ptr<Backend> backend_;
  73   typedef std::map<Entry*, EntryProxy*> EntryToProxyMap;
  74   EntryToProxyMap open_entries_;
  75
  76   DISALLOW_COPY_AND_ASSIGN(TracingCacheBackend);
  77 };
  78
  79 }  // namespace disk_cache
  80
  81 #endif  // NET_DISK_CACHE_TRACING_CACHE_BACKEND_H_