net/disk_cache/blockfile/trace.h

   1 // Copyright (c) 2011 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 // This file provides support for basic in-memory tracing of short events. We
   6 // keep a static circular buffer where we store the last traced events, so we
   7 // can review the cache recent behavior should we need it.
   8
   9 #ifndef NET_DISK_CACHE_BLOCKFILE_TRACE_H_
  10 #define NET_DISK_CACHE_BLOCKFILE_TRACE_H_
  11
  12 #include "base/basictypes.h"
  13 #include "base/memory/ref_counted.h"
  14 #include "net/base/net_export.h"
  15
  16 namespace disk_cache {
  17
  18 // Create and destroy the tracing buffer.
  19 void InitTrace(void);
  20 void DestroyTrace(void);
  21
  22 // Simple class to handle the trace buffer lifetime. Any object interested in
  23 // tracing should keep a reference to the object returned by GetTraceObject().
  24 class TraceObject : public base::RefCounted<TraceObject> {
  25   friend class base::RefCounted<TraceObject>;
  26  public:
  27   static TraceObject* GetTraceObject();
  28   void EnableTracing(bool enable);
  29
  30  private:
  31   TraceObject();
  32   ~TraceObject();
  33   DISALLOW_COPY_AND_ASSIGN(TraceObject);
  34 };
  35
  36 // Traces to the internal buffer.
  37 NET_EXPORT_PRIVATE void Trace(const char* format, ...);
  38
  39 }  // namespace disk_cache
  40
  41 #endif  // NET_DISK_CACHE_BLOCKFILE_TRACE_H_