Keep only base/extractor.[cc|h].

base/event_trace_consumer.h

-// Copyright 2010 Google Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-// ========================================================================
-//
-// Declaration of a Windows event trace consumer base class.
-#ifndef BASE_EVENT_TRACE_CONSUMER_H_
-#define BASE_EVENT_TRACE_CONSUMER_H_
-
-#include <windows.h>
-#include <wmistr.h>
-#include <evntrace.h>
-#include <vector>
-#include "base/basictypes.h"
-
-namespace omaha {
-
-// This class is a base class that makes it easier to consume events
-// from realtime or file sessions. Concrete consumers need to sublass
-// a specialization of this class and override the ProcessEvent and/or
-// the ProcessBuffer methods to implement the event consumption logic.
-// Usage might look like:
-// class MyConsumer: public EtwTraceConsumerBase<MyConsumer, 1> {
-//  protected:
-//    static VOID WINAPI ProcessEvent(PEVENT_TRACE event);
-// };
-//
-// MyConsumer consumer;
-// consumer.OpenFileSession(file_path);
-// consumer.Consume();
-template <class ImplClass>
-class EtwTraceConsumerBase {
- public:
-  // Constructs a closed consumer.
-  EtwTraceConsumerBase() {
-  }
-
-  ~EtwTraceConsumerBase() {
-    Close();
-  }
-
-  // Opens the named realtime session, which must be existent.
-  // Note: You can use OpenRealtimeSession or OpenFileSession
-  //    to open as many as MAXIMUM_WAIT_OBJECTS (63) sessions at
-  //    any one time, though only one of them may be a realtime
-  //    session.
-  HRESULT OpenRealtimeSession(const wchar_t* session_name);
-
-  // Opens the event trace log in "file_name", which must be a full or
-  // relative path to an existing event trace log file.
-  // Note: You can use OpenRealtimeSession or OpenFileSession
-  //    to open as many as kNumSessions at any one time.
-  HRESULT OpenFileSession(const wchar_t* file_name);
-
-  // Consume all open sessions from beginning to end.
-  HRESULT Consume();
-
-  // Close all open sessions.
-  HRESULT Close();
-
- protected:
-  // Override in subclasses to handle events.
-  static void ProcessEvent(EVENT_TRACE* event) {
-  }
-  // Override in subclasses to handle buffers.
-  static bool ProcessBuffer(EVENT_TRACE_LOGFILE* buffer) {
-    buffer;
-    return true;  // keep going
-  }
-
- protected:
-  // Currently open sessions.
-  std::vector<TRACEHANDLE> trace_handles_;
-
- private:
-  // These delegate to ImplClass callbacks with saner signatures.
-  static void WINAPI ProcessEventCallback(EVENT_TRACE* event) {
-    ImplClass::ProcessEvent(event);
-  }
-  static ULONG WINAPI ProcessBufferCallback(PEVENT_TRACE_LOGFILE buffer) {
-    return ImplClass::ProcessBuffer(buffer);
-  }
-
-  DISALLOW_COPY_AND_ASSIGN(EtwTraceConsumerBase);
-};
-
-template <class ImplClass> inline
-HRESULT EtwTraceConsumerBase<ImplClass>::OpenRealtimeSession(
-    const wchar_t* session_name) {
-  EVENT_TRACE_LOGFILE logfile = {};
-  logfile.LoggerName = const_cast<wchar_t*>(session_name);
-  logfile.LogFileMode = EVENT_TRACE_REAL_TIME_MODE;
-  logfile.BufferCallback = &ProcessBufferCallback;
-  logfile.EventCallback = &ProcessEventCallback;
-  logfile.Context = this;
-  TRACEHANDLE trace_handle = ::OpenTrace(&logfile);
-  if (reinterpret_cast<TRACEHANDLE>(INVALID_HANDLE_VALUE) == trace_handle)
-    return HRESULT_FROM_WIN32(::GetLastError());
-
-  trace_handles_.push_back(trace_handle);
-  return S_OK;
-}
-
-template <class ImplClass> inline
-HRESULT EtwTraceConsumerBase<ImplClass>::OpenFileSession(
-    const wchar_t* file_name) {
-  EVENT_TRACE_LOGFILE logfile = {};
-  logfile.LogFileName = const_cast<wchar_t*>(file_name);
-  logfile.BufferCallback = &ProcessBufferCallback;
-  logfile.EventCallback = &ProcessEventCallback;
-  logfile.Context = this;
-  TRACEHANDLE trace_handle = ::OpenTrace(&logfile);
-  if (reinterpret_cast<TRACEHANDLE>(INVALID_HANDLE_VALUE) == trace_handle)
-    return HRESULT_FROM_WIN32(::GetLastError());
-
-  trace_handles_.push_back(trace_handle);
-  return S_OK;
-}
-
-template <class ImplClass> inline
-HRESULT EtwTraceConsumerBase<ImplClass>::Consume() {
-  ULONG err = ::ProcessTrace(&trace_handles_[0],
-                             trace_handles_.size(),
-                             NULL,
-                             NULL);
-  return HRESULT_FROM_WIN32(err);
-}
-
-template <class ImplClass> inline
-HRESULT EtwTraceConsumerBase<ImplClass>::Close() {
-  HRESULT hr = S_OK;
-  for (size_t i = 0; i < trace_handles_.size(); ++i) {
-    if (NULL != trace_handles_[i]) {
-      ULONG ret = ::CloseTrace(trace_handles_[i]);
-      trace_handles_[i] = NULL;
-
-      if (FAILED(HRESULT_FROM_WIN32(ret)))
-        hr = HRESULT_FROM_WIN32(ret);
-    }
-
-    trace_handles_.clear();
-  }
-
-  return hr;
-}
-
-}  // namespace omaha
-
-#endif  // BASE_EVENT_TRACE_CONSUMER_H_