Refactor WebRtcLoggingHandlerHost in preparation of automatic upload of WebRtcEventLogs.

chrome/browser/media/webrtc_text_log_handler.h

Index: chrome/browser/media/webrtc_text_log_handler.h
diff --git a/chrome/browser/media/webrtc_text_log_handler.h b/chrome/browser/media/webrtc_text_log_handler.h
new file mode 100644
index 0000000000000000000000000000000000000000..bd612a071e50ebe738f27ec537ed9f7f818aa56e
--- /dev/null
+++ b/chrome/browser/media/webrtc_text_log_handler.h
@@ -0,0 +1,166 @@
+// Copyright 2016 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_MEDIA_WEBRTC_TEXT_LOG_HANDLER_H_
+#define CHROME_BROWSER_MEDIA_WEBRTC_TEXT_LOG_HANDLER_H_
+
+#include <map>
+#include <string>
+
+#include "base/callback.h"
+#include "base/threading/thread_checker.h"
+#include "chrome/common/media/webrtc_logging_message_data.h"
+#include "chrome/common/partial_circular_buffer.h"
+#include "net/base/network_interfaces.h"
+
+#if defined(OS_ANDROID)
+const size_t kWebRtcLogSize = 1 * 1024 * 1024;  // 1 MB
+#else
+const size_t kWebRtcLogSize = 6 * 1024 * 1024;  // 6 MB
+#endif
+
+typedef std::map<std::string, std::string> MetaDataMap;
+
+class WebRtcLogUploader;
+
+class WebRtcLogBuffer {
+ public:
+  WebRtcLogBuffer();
+  ~WebRtcLogBuffer();
+
+  void Log(const std::string& message);
+
+  // Returns a circular buffer instance for reading the internal log buffer.
+  // Must only be called after the log has been marked as complete
+  // (see SetComplete) and the caller must ensure that the WebRtcLogBuffer
+  // instance remains in scope for the lifetime of the returned circular buffer.
+  PartialCircularBuffer Read();
+
+  // Switches the buffer to read-only mode, where access to the internal
+  // buffer is allowed from different threads than were used to contribute
+  // to the log.  Calls to Log() won't be allowed after calling
+  // SetComplete() and the call to SetComplete() must be done on the same
+  // thread as constructed the buffer and calls Log().
+  void SetComplete();
+
+ private:
+  base::ThreadChecker thread_checker_;
+  uint8_t buffer_[kWebRtcLogSize];
+  PartialCircularBuffer circular_;
+  bool read_only_;
+};
+
+class WebRtcTextLogHandler
+    : public base::RefCountedThreadSafe<WebRtcTextLogHandler> {
+ public:
+  // States used for protecting from function calls made at non-allowed points
+  // in time. For example, StartLogging() is only allowed in CLOSED state.
+  // Transitions: SetMetaData():  CLOSED -> CLOSED.
+  //              StartLogging(): CLOSED -> STARTING.
+  //              StartDone():    STARTING -> STARTED.
+  //              StopLogging():  STARTED -> STOPPING.
+  //              StopDone():     STOPPING -> STOPPED.
+  //              DiscardLog():   STOPPED -> CLOSED.
+  //              ReleaseLog():   STOPPED -> CLOSED.
+  //              RendererDying():    ANY -> DYING.

[magjed_chromium, 2016/07/19 14:53:17]

Is DYING == CHANNEL_CLOSING?

[terelius-chromium, 2016/07/21 16:25:14]

Yes. Forgot to update the comment. Fixed now.

+  enum LoggingState {
+    CLOSED,           // Logging not started, no log in memory.
+    STARTING,         // Start logging is in progress.
+    STARTED,          // Logging started.
+    STOPPING,         // Stop logging is in progress.
+    STOPPED,          // Logging has been stopped, log still open in memory.
+    CHANNEL_CLOSING,  // Renderer is closing. TODO

[magjed_chromium, 2016/07/19 14:53:16]

TODO what?

[terelius-chromium, 2016/07/21 16:25:14]

Improve comment. Done.

+  };
+
+ public:

[magjed_chromium, 2016/07/19 14:53:17]

Remove this extra 'public:'.

[terelius-chromium, 2016/07/21 16:25:14]

Done.

+  typedef base::Callback<void(bool, const std::string&)> GenericDoneCallback;
+
+  explicit WebRtcTextLogHandler(int render_process_id);
+
+  // Returns the current state of the log. Must be called on the IO thread.
+  LoggingState GetState() const { return logging_state_; }
+
+  void SetMetaData(std::unique_ptr<MetaDataMap> meta_data,
+                   const GenericDoneCallback& callback);
+
+  // Opens a log and starts logging if allowed by the LogUploader.
+  // Returns false if logging could not be started.
+  // Must be called on the IO thread.
+  bool StartLogging(WebRtcLogUploader* log_uploader,
+                    const GenericDoneCallback& callback);
+
+  // Called automatically after StartLogging(). Do not call directly.

[magjed_chromium, 2016/07/19 14:53:17]

Why not make it private if it shouldn't be called directly?

[terelius-chromium, 2016/07/21 16:25:14]

Done, but the symmetry with StopDone is lost.

+  // Must be called on the IO thread.
+  void StartDone(const GenericDoneCallback& callback);
+
+  // Stops logging. Log will remain open until UploadLog or DiscardLog is
+  // called. Must be called on the IO thread.
+  bool StopLogging(const GenericDoneCallback& callback);
+
+  // Called by the WebRtcLoggingHandlerHost when logging has stopped in the
+  // renderer. Do not call directly. Must be called on the IO thread.

[magjed_chromium, 2016/07/19 14:53:17]

What does "Do not call directly." mean? It is called directly from
WebRtcLoggingHandlerHost.

[terelius-chromium, 2016/07/21 16:25:14]

Updated comment. Wdyt?

[magjed_chromium, 2016/07/22 09:30:31]

Now I understand, thanks.

+  void StopDone();
+
+  // Signals that the renderer is closing, which de facto stops logging but
+  // keeps the log in memory.
+  // Can be called in any state except CLOSED. Must be called on the IO thread.
+  void ChannelClosing();
+
+  // Discards a stopped log. Must be called on the IO thread.
+  void DiscardLog();
+
+  // Releases a stopped log to the caller. Must be called on the IO thread.
+  void ReleaseLog(std::unique_ptr<WebRtcLogBuffer>* log_buffer,
+                  std::unique_ptr<MetaDataMap>* meta_data);
+
+  // Adds a message to the log. Must be called on the IO thread.
+  void LogMessage(const std::string& message);
+
+  // Adds a message to the log. Must be called on the IO thread.
+  void LogWebRtcLoggingMessageData(const WebRtcLoggingMessageData& message);
+
+  // Returns true if the logging state is CLOSED and fires an the callback
+  // with an error message otherwise. Must be called on the IO thread.
+  bool ExpectLoggingStateStopped(const GenericDoneCallback& callback);
+
+  void FireGenericDoneCallback(const GenericDoneCallback& callback,
+                               bool success,
+                               const std::string& error_message);
+
+ private:
+  friend class RefCountedThreadSafe<WebRtcTextLogHandler>;
+  ~WebRtcTextLogHandler();
+
+  void LogToCircularBuffer(const std::string& message);
+
+  void LogInitialInfoOnFileThread(const GenericDoneCallback& callback);
+  void LogInitialInfoOnIOThread(const net::NetworkInterfaceList& network_list,
+                                const GenericDoneCallback& callback);
+  void EnableBrowserProcessLoggingOnUIThread();
+  void DisableBrowserProcessLoggingOnUIThread();
+
+  // The render process ID this object belongs to.
+  int render_process_id_;

[magjed_chromium, 2016/07/19 14:53:17]

Make const.

[terelius-chromium, 2016/07/21 16:25:14]

Done.

+
+  std::unique_ptr<WebRtcLogBuffer> log_buffer_;
+
+  // These are only accessed on the IO thread, except when in STARTING state. In
+  // this state we are protected since entering any function that alters the
+  // state is not allowed.
+  std::unique_ptr<MetaDataMap> meta_data_;
+
+  // These are only accessed on the IO thread.
+  GenericDoneCallback stop_callback_;
+
+  // Only accessed on the IO thread.
+  LoggingState logging_state_;
+
+  // The system time in ms when logging is started. Reset when logging_state_
+  // changes to STOPPED.
+  base::Time logging_started_time_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebRtcTextLogHandler);
+};
+
+#endif  // CHROME_BROWSER_MEDIA_WEBRTC_TEXT_LOG_HANDLER_H_