Move Windows-specific Event Tracing for Windows implementation to base/win. ...

base/event_trace_controller_win.h

-// 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.
-//
-// Declaration of a Windows event trace controller class.
-// The controller takes care of creating and manipulating event trace
-// sessions.
-//
-// Event tracing for Windows is a system-provided service that provides
-// logging control and high-performance transport for generic, binary trace
-// events. Event trace providers register with the system by their name,
-// which is a GUID, and can from that point forward receive callbacks that
-// start or end tracing and that change their trace level and enable mask.
-//
-// A trace controller can create an event tracing session, which either
-// sends events to a binary file, or to a realtime consumer, or both.
-//
-// A trace consumer consumes events from zero or one realtime session,
-// as well as potentially from multiple binary trace files.
-#ifndef BASE_EVENT_TRACE_CONTROLLER_WIN_H_
-#define BASE_EVENT_TRACE_CONTROLLER_WIN_H_
-#pragma once
-
-#include <windows.h>
-#include <wmistr.h>
-#include <evntrace.h>
-#include <string>
-#include "base/basictypes.h"
-
-// Utility class to make it easier to work with EVENT_TRACE_PROPERTIES.
-// The EVENT_TRACE_PROPERTIES structure contains information about an
-// event tracing session.
-class EtwTraceProperties {
- public:
-  EtwTraceProperties();
-
-  EVENT_TRACE_PROPERTIES* get() {
-    return &properties_;
-  }
-
-  const EVENT_TRACE_PROPERTIES* get() const {
-    return reinterpret_cast<const EVENT_TRACE_PROPERTIES*>(&properties_);
-  }
-
-  const wchar_t* GetLoggerName() const {
-    return reinterpret_cast<const wchar_t *>(buffer_ + get()->LoggerNameOffset);
-  }
-
-  // Copies logger_name to the properties structure.
-  HRESULT SetLoggerName(const wchar_t* logger_name);
-  const wchar_t* GetLoggerFileName() const {
-    return reinterpret_cast<const wchar_t*>(buffer_ + get()->LogFileNameOffset);
-  }
-
-  // Copies logger_file_name to the properties structure.
-  HRESULT SetLoggerFileName(const wchar_t* logger_file_name);
-
-  // Max string len for name and session name is 1024 per documentation.
-  static const size_t kMaxStringLen = 1024;
-  // Properties buffer allocates space for header and for
-  // max length for name and session name.
-  static const size_t kBufSize = sizeof(EVENT_TRACE_PROPERTIES)
-      + 2 * sizeof(wchar_t) * (kMaxStringLen);
-
- private:
-  // The EVENT_TRACE_PROPERTIES structure needs to be overlaid on a
-  // larger buffer to allow storing the logger name and logger file
-  // name contiguously with the structure.
-  union {
-   public:
-    // Our properties header.
-    EVENT_TRACE_PROPERTIES properties_;
-    // The actual size of the buffer is forced by this member.
-    char buffer_[kBufSize];
-  };
-
-  DISALLOW_COPY_AND_ASSIGN(EtwTraceProperties);
-};
-
-// This class implements an ETW controller, which knows how to start and
-// stop event tracing sessions, as well as controlling ETW provider
-// log levels and enable bit masks under the session.
-class EtwTraceController {
- public:
-  EtwTraceController();
-  ~EtwTraceController();
-
-  // Start a session with given name and properties.
-  HRESULT Start(const wchar_t* session_name, EtwTraceProperties* prop);
-
-  // Starts a session tracing to a file with some default properties.
-  HRESULT StartFileSession(const wchar_t* session_name,
-                           const wchar_t* logfile_path,
-                           bool realtime = false);
-
-  // Starts a realtime session with some default properties.
-  HRESULT StartRealtimeSession(const wchar_t* session_name,
-                               size_t buffer_size);
-
-  // Enables "provider" at "level" for this session.
-  // This will cause all providers registered with the GUID
-  // "provider" to start tracing at the new level, systemwide.
-  HRESULT EnableProvider(const GUID& provider, UCHAR level,
-                         ULONG flags = 0xFFFFFFFF);
-  // Disables "provider".
-  HRESULT DisableProvider(const GUID& provider);
-
-  // Stops our session and retrieve the new properties of the session,
-  // properties may be NULL.
-  HRESULT Stop(EtwTraceProperties* properties);
-
-  // Flushes our session and retrieve the current properties,
-  // properties may be NULL.
-  HRESULT Flush(EtwTraceProperties* properties);
-
-  // Static utility functions for controlling
-  // sessions we don't necessarily own.
-  static HRESULT Start(const wchar_t* session_name,
-                       EtwTraceProperties* properties,
-                       TRACEHANDLE* session_handle);
-
-  static HRESULT Query(const wchar_t* session_name,
-                       EtwTraceProperties* properties);
-
-  static HRESULT Update(const wchar_t* session_name,
-                        EtwTraceProperties* properties);
-
-  static HRESULT Stop(const wchar_t* session_name,
-                      EtwTraceProperties* properties);
-  static HRESULT Flush(const wchar_t* session_name,
-                       EtwTraceProperties* properties);
-
-  // Accessors.
-  TRACEHANDLE session() const { return session_; }
-  const wchar_t* session_name() const { return session_name_.c_str(); }
-
- private:
-  std::wstring session_name_;
-  TRACEHANDLE session_;
-
-  DISALLOW_COPY_AND_ASSIGN(EtwTraceController);
-};
-
-#endif  // BASE_EVENT_TRACE_CONTROLLER_WIN_H_