media/base/media_log.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 MEDIA_BASE_MEDIA_LOG_H_
   6 #define MEDIA_BASE_MEDIA_LOG_H_
   7
   8 #include <sstream>
   9 #include <string>
  10
  11 #include "base/logging.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "media/base/media_export.h"
  15 #include "media/base/media_log_event.h"
  16 #include "media/base/pipeline.h"
  17 #include "media/base/pipeline_status.h"
  18
  19 namespace media {
  20
  21
  22 class MEDIA_EXPORT MediaLog : public base::RefCountedThreadSafe<MediaLog> {
  23  public:
  24   enum MediaLogLevel {
  25     MEDIALOG_ERROR,
  26     MEDIALOG_INFO,
  27     MEDIALOG_DEBUG,
  28   };
  29
  30   // Convert various enums to strings.
  31   static std::string MediaLogLevelToString(MediaLogLevel level);
  32   static MediaLogEvent::Type MediaLogLevelToEventType(MediaLogLevel level);
  33   static std::string EventTypeToString(MediaLogEvent::Type type);
  34   static std::string PipelineStatusToString(PipelineStatus status);
  35
  36   static std::string MediaEventToLogString(const MediaLogEvent& event);
  37
  38   MediaLog();
  39
  40   // Add an event to this log. Overriden by inheritors to actually do something
  41   // with it.
  42   virtual void AddEvent(scoped_ptr<MediaLogEvent> event);
  43
  44   // Helper methods to create events and their parameters.
  45   scoped_ptr<MediaLogEvent> CreateEvent(MediaLogEvent::Type type);
  46   scoped_ptr<MediaLogEvent> CreateBooleanEvent(
  47       MediaLogEvent::Type type, const std::string& property, bool value);
  48   scoped_ptr<MediaLogEvent> CreateStringEvent(MediaLogEvent::Type type,
  49                                               const std::string& property,
  50                                               const std::string& value);
  51   scoped_ptr<MediaLogEvent> CreateTimeEvent(MediaLogEvent::Type type,
  52                                             const std::string& property,
  53                                             base::TimeDelta value);
  54   scoped_ptr<MediaLogEvent> CreateLoadEvent(const std::string& url);
  55   scoped_ptr<MediaLogEvent> CreateSeekEvent(float seconds);
  56   scoped_ptr<MediaLogEvent> CreatePipelineStateChangedEvent(
  57       Pipeline::State state);
  58   scoped_ptr<MediaLogEvent> CreatePipelineErrorEvent(PipelineStatus error);
  59   scoped_ptr<MediaLogEvent> CreateVideoSizeSetEvent(
  60       size_t width, size_t height);
  61   scoped_ptr<MediaLogEvent> CreateBufferedExtentsChangedEvent(
  62       int64 start, int64 current, int64 end);
  63
  64   // Report a log message at the specified log level.
  65   void AddLogEvent(MediaLogLevel level, const std::string& message);
  66
  67   // Report a property change without an accompanying event.
  68   void SetStringProperty(const std::string& key, const std::string& value);
  69   void SetIntegerProperty(const std::string& key, int value);
  70   void SetDoubleProperty(const std::string& key, double value);
  71   void SetBooleanProperty(const std::string& key, bool value);
  72   void SetTimeProperty(const std::string& key, base::TimeDelta value);
  73
  74  protected:
  75   friend class base::RefCountedThreadSafe<MediaLog>;
  76   virtual ~MediaLog();
  77
  78  private:
  79   // A unique (to this process) id for this MediaLog.
  80   int32 id_;
  81
  82   DISALLOW_COPY_AND_ASSIGN(MediaLog);
  83 };
  84
  85 // Indicates a string should be added to the log.
  86 // First parameter - The log level for the string.
  87 // Second parameter - The string to add to the log.
  88 typedef base::Callback<void(MediaLog::MediaLogLevel, const std::string&)> LogCB;
  89
  90 // Helper class to make it easier to use log_cb like DVLOG().
  91 class LogHelper {
  92  public:
  93   LogHelper(MediaLog::MediaLogLevel level, const LogCB& log_cb);
  94   ~LogHelper();
  95
  96   std::ostream& stream() { return stream_; }
  97
  98  private:
  99   MediaLog::MediaLogLevel level_;
 100   LogCB log_cb_;
 101   std::stringstream stream_;
 102 };
 103
 104 // Provides a stringstream to collect a log entry to pass to the provided
 105 // LogCB at the requested level.
 106 #define MEDIA_LOG(level, log_cb) \
 107   LogHelper((MediaLog::MEDIALOG_##level), (log_cb)).stream()
 108
 109 // Logs only while count < max. Increments count for each log. Use LAZY_STREAM
 110 // to avoid wasteful evaluation of subsequent stream arguments.
 111 #define LIMITED_MEDIA_LOG(level, log_cb, count, max) \
 112   LAZY_STREAM(MEDIA_LOG(level, log_cb), (count) < (max) && ((count)++ || true))
 113
 114 }  // namespace media
 115
 116 #endif  // MEDIA_BASE_MEDIA_LOG_H_