trace.h revision a1401311d1ab56c4ed0a474bd38c108f75cb0cd9 
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
16namespace disk_cache {
17
18// Create and destroy the tracing buffer.
19void InitTrace(void);
20void 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().
24class 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.
37NET_EXPORT_PRIVATE void Trace(const char* format, ...);
38
39}  // namespace disk_cache
40
41#endif  // NET_DISK_CACHE_BLOCKFILE_TRACE_H_
42