1 files changed, 98 insertions, 0 deletions
diff --git a/chrome/browser/chromeos/external_metrics.h b/chrome/browser/chromeos/external_metrics.h
new file mode 100644
index 0000000..2721939
--- /dev/null
+++ b/chrome/browser/chromeos/external_metrics.h
@@ -0,0 +1,98 @@
+// Copyright (c) 2009 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 CHROME_BROWSER_CHROMEOS_EXTERNAL_METRICS_H_
+#define CHROME_BROWSER_CHROMEOS_EXTERNAL_METRICS_H_
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/task.h"
+#include "testing/gtest/include/gtest/gtest_prod.h"  // For FRIEND_TEST
+
+class Profile;
+
+namespace chromeos {
+
+// ExternalMetrics is a service that Chrome offers to Chrome OS to upload
+// metrics to the UMA server on its behalf.  Chrome periodically reads the
+// content of a well-know file, and parses it into name-value pairs, each
+// representing a Chrome OS metrics event. The events are logged using the
+// normal UMA mechanism. The file is then truncated to zero size. Chrome uses
+// flock() to synchronize accesses to the file.
+class ExternalMetrics : public base::RefCountedThreadSafe<ExternalMetrics> {
+  FRIEND_TEST(ExternalMetricsTest, ParseExternalMetricsFile);
+  friend class base::RefCountedThreadSafe<ExternalMetrics>;
+
+ public:
+  ExternalMetrics() {}
+
+  // Begins the external data collection.  Profile is passed through to
+  // UserMetrics::RecordAction.  The lifetime of profile must exceed that of
+  // the external metrics object.
+  void Start(Profile* profile);
+
+ private:
+  // There is one function with this type for each action or histogram.
+  typedef void (*RecordFunctionType)(const char*);
+  // The type of event associated with each name.
+  typedef enum {
+    EVENT_TYPE_ACTION,
+    EVENT_TYPE_HISTOGRAM
+  } MetricsEventType;
+  // Used in mapping names (C strings) into event-recording functions.
+  typedef struct {
+    const char* name;
+    RecordFunctionType function;
+    MetricsEventType type;
+  } RecordFunctionTableEntry;
+  typedef void (*RecorderType)(const char*, const char*);  // See SetRecorder.
+
+  // The max length of a message (name-value pair, plus header)
+  static const int kMetricsMessageMaxLength = 4096;
+
+  ~ExternalMetrics();
+
+  // Protect action recorders from being called when external_metrics_profile is
+  // null.  This could happen when testing, or in the unlikely case that the
+  // order of object deletion at shutdown changes.
+  static void RecordActionWrapper(RecordFunctionType);
+
+  // Maps a name to an entry in the record function table.  Return NULL on
+  // failure.
+  static const ExternalMetrics::RecordFunctionTableEntry* FindRecordEntry(
+      const char* name);
+
+  // Initializes a table that maps a metric name to a function that logs that
+  // metric.
+  void InitializeFunctionTable();
+
+  // Passes an event, either an ACTION or HISTOGRAM depending on |name|, to the
+  // UMA service.  For a histogram, |value| contains the numeric value, in a
+  // format that depends on |name|.
+  static void RecordEvent(const char* name, const char* value);
+
+  // Collects external events from metrics log file.  This is run at periodic
+  // intervals.
+  void CollectEvents();
+
+  // Calls CollectEvents and reschedules a future collection.
+  void CollectEventsAndReschedule();
+
+  // Schedules a metrics event collection in the future.
+  void ScheduleCollector();
+
+  // Sets the event logging function.  Exists only because of testing.
+  void SetRecorder(RecorderType recorder) {
+    recorder_ = recorder;
+  }
+
+  // This table maps event names to event recording functions.
+  static RecordFunctionTableEntry function_table_[];
+  RecorderType recorder_;  // See SetRecorder.
+  DISALLOW_COPY_AND_ASSIGN(ExternalMetrics);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_EXTERNAL_METRICS_H_