blob: 0590adf062f29a474e26c7a92831a8f7fea66c70 [file] [log] [blame]
// Copyright (c) 2012 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.
#pragma once
#include <stddef.h>
#include <windows.h>
#include <wmistr.h>
#include <evntrace.h>
#include "base/basictypes.h"
#include "base/string_piece.h"
namespace logging_win {
// A parser for Mof data found in an EVENT_TRACE object as formatted by
// Chromium-related classes. Instances have an implicit cursor that scans the
// data. Callers invoke Read* methods to extract primitive data types values or
// pointers to complex data types (arrays and strings). In the latter case, the
// pointers are only valid for the lifetime of the underlying event.
class MofDataParser {
explicit MofDataParser(const EVENT_TRACE* event);
bool ReadDWORD(DWORD* value) {
return ReadPrimitive(value);
bool ReadInt(int* value) {
return ReadPrimitive(value);
bool ReadPointer(intptr_t* value) {
return ReadPrimitive(value);
// Populates |values| with a pointer to an array of |size| pointer-sized
// values in the data.
bool ReadPointerArray(DWORD size, const intptr_t** values) {
return ReadPrimitiveArray(size, values);
// Populates |value| with a pointer to an arbitrary data structure at the
// current position.
template<typename T> bool ReadStructure(const T** value) {
if (length_ < sizeof(**value))
return false;
*value = reinterpret_cast<const T*>(scan_);
return true;
// Sets |value| such that it points to the string in the data at the current
// position. A trailing newline, if present, is not included in the returned
// piece. The returned piece is not null-terminated.
bool ReadString(base::StringPiece* value);
bool empty() { return length_ == 0; }
void Advance(size_t num_bytes) {
scan_ += num_bytes;
length_ -= num_bytes;
template<typename T> bool ReadPrimitive(T* value) {
if (length_ < sizeof(*value))
return false;
*value = *reinterpret_cast<const T*>(scan_);
return true;
template<typename T> bool ReadPrimitiveArray(DWORD size, const T** values) {
if (length_ < sizeof(**values) * size)
return false;
*values = reinterpret_cast<const T*>(scan_);
Advance(sizeof(**values) * size);
return true;
const uint8* scan_;
uint32 length_;
} // namespace logging_win