chrome/test/logging/win/file_logger.h

   1 // Copyright (c) 2012 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 CHROME_TEST_LOGGING_WIN_FILE_LOGGER_H_
   6 #define CHROME_TEST_LOGGING_WIN_FILE_LOGGER_H_
   7
   8 #include <guiddef.h>
   9
  10 #include "base/basictypes.h"
  11 #include "base/strings/string16.h"
  12 #include "base/win/event_trace_controller.h"
  13
  14 namespace base {
  15 class FilePath;
  16 }
  17
  18 namespace logging_win {
  19
  20 // A file logger instance captures LOG messages and trace events emitted via
  21 // Event Tracing for Windows (ETW) and sends them to a file.  Events can be
  22 // pulled from the file sometime later with PrintLogFile or ReadLogFile
  23 // (currently in log_file_printer_win.h and log_file_reader_win.h,
  24 // respectively).
  25 //
  26 // Important usage notes (read this):
  27 // - Due to the nature of event generation, only one instance of this class may
  28 //   be initialized at a time.
  29 // - This class is not thread safe.
  30 // - This class uses facilities that require the process to run with admin
  31 //   rights; StartLogging() will return false if this is not the case.
  32 class FileLogger {
  33  public:
  34   enum EventProviderBits {
  35     // Log messages from chrome.exe.
  36     CHROME_LOG_PROVIDER         = 1 << 0,
  37     // Log messages from npchrome_frame.dll.
  38     CHROME_FRAME_LOG_PROVIDER   = 1 << 1,
  39     // Log messages from the current process.
  40     CHROME_TESTS_LOG_PROVIDER   = 1 << 2,
  41     // Trace events.
  42     CHROME_TRACE_EVENT_PROVIDER = 1 << 3,
  43   };
  44
  45   static const uint32 kAllEventProviders = (CHROME_LOG_PROVIDER |
  46                                             CHROME_FRAME_LOG_PROVIDER |
  47                                             CHROME_TESTS_LOG_PROVIDER |
  48                                             CHROME_TRACE_EVENT_PROVIDER);
  49
  50   FileLogger();
  51   ~FileLogger();
  52
  53   // Initializes the instance to collect logs from all supported providers.
  54   void Initialize();
  55
  56   // Initializes the instance to collect logs from the providers present in
  57   // the given mask; see EventProviderBits.
  58   void Initialize(uint32 event_provider_mask);
  59
  60   // Starts capturing logs from all providers into |log_file|.  The common file
  61   // extension for such files is .etl.  Returns false if the session could not
  62   // be started (e.g., if not running as admin) or if no providers could be
  63   // enabled.
  64   bool StartLogging(const base::FilePath& log_file);
  65
  66   // Stops capturing logs.
  67   void StopLogging();
  68
  69   // Returns true if logs are being captured.
  70   bool is_logging() const {
  71     return controller_.session_name() && *controller_.session_name();
  72   }
  73
  74  private:
  75   bool EnableProviders();
  76   void DisableProviders();
  77
  78   static bool is_initialized_;
  79
  80   base::win::EtwTraceController controller_;
  81   uint32 event_provider_mask_;
  82
  83   DISALLOW_COPY_AND_ASSIGN(FileLogger);
  84 };
  85
  86 }  // namespace logging_win
  87
  88 #endif  // CHROME_TEST_LOGGING_WIN_FILE_LOGGER_H_