RAPPOR implementation

components/rappor/rappor_recorder.h

+// 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.
+
+// RapporRecorder holds all Histograms and BucketRanges that are used by
+// Histograms in the system. It provides a general place for
+// Histograms/BucketRanges to register, and supports a global API for accessing
+// (i.e., dumping, or graphing) the data.
+
+#ifndef CHROME_BROWSER_RAPPOR_RAPPOR_RECORDER_H_
+#define CHROME_BROWSER_RAPPOR_RAPPOR_RECORDER_H_
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/gtest_prod_util.h"
+#include "base/lazy_instance.h"
+#include "base/synchronization/lock.h"
+#include "components/rappor/rappor.h"
+
+#define RAPPOR_SAMPLE(name, sample) \
+  rappor::g_rappor_recorder.Get().GetRappor(name)->Add(sample);
+
+namespace rappor {
+
+class RapporRecorder {
+ public:
+  typedef std::vector<Rappor*> Rappors;
+
+  // Method for extracting rappors for use by UMA.
+  void GetRappors(Rappors* output);
+
+  // Clears all recorded rappors.
+  void ClearRappors();
+
+  // Find a rappor by name, and create it if it doesn't already exist. It
+  // matches the exact name. This method is thread safe.
+  Rappor* GetRappor(const std::string& name);
+
+  // The constructor just initializes static members. Usually client code should
+  // use Initialize to do this. But in test code, you can friend this class and
+  // call destructor/constructor to get a clean RapporRecorder.
+  RapporRecorder();
+  ~RapporRecorder();
+
+ private:
+  // We keep all registered histograms in a map, from name to histogram.
+  typedef std::map<std::string, Rappor*> RapporMap;
+
+  RapporMap rappors_;
+
+  // Lock protects access to above map.
+  base::Lock lock_;
+};
+
+extern base::LazyInstance<RapporRecorder>::Leaky g_rappor_recorder;
+
+}  // namespace rappor
+
+#endif  // CHROME_BROWSER_RAPPOR_RAPPOR_RECORDER_H_