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 CHROME_TEST_LOGGING_WIN_MOF_DATA_PARSER_H_ 6 #define CHROME_TEST_LOGGING_WIN_MOF_DATA_PARSER_H_ 7 8 #include <stddef.h> 9 #include <windows.h> 10 #include <wmistr.h> 11 #include <evntrace.h> 12 13 #include "base/basictypes.h" 14 #include "base/strings/string_piece.h" 15 16 namespace logging_win { 17 18 // A parser for Mof data found in an EVENT_TRACE object as formatted by 19 // Chromium-related classes. Instances have an implicit cursor that scans the 20 // data. Callers invoke Read* methods to extract primitive data types values or 21 // pointers to complex data types (arrays and strings). In the latter case, the 22 // pointers are only valid for the lifetime of the underlying event. 23 class MofDataParser { 24 public: 25 explicit MofDataParser(const EVENT_TRACE* event); 26 27 bool ReadDWORD(DWORD* value) { 28 return ReadPrimitive(value); 29 } 30 31 bool ReadInt(int* value) { 32 return ReadPrimitive(value); 33 } 34 35 bool ReadPointer(intptr_t* value) { 36 return ReadPrimitive(value); 37 } 38 39 // Populates |values| with a pointer to an array of |size| pointer-sized 40 // values in the data. 41 bool ReadPointerArray(DWORD size, const intptr_t** values) { 42 return ReadPrimitiveArray(size, values); 43 } 44 45 // Populates |value| with a pointer to an arbitrary data structure at the 46 // current position. 47 template<typename T> bool ReadStructure(const T** value) { 48 if (length_ < sizeof(**value)) 49 return false; 50 *value = reinterpret_cast<const T*>(scan_); 51 Advance(sizeof(**value)); 52 return true; 53 } 54 55 // Sets |value| such that it points to the string in the data at the current 56 // position. A trailing newline, if present, is not included in the returned 57 // piece. The returned piece is not null-terminated. 58 bool ReadString(base::StringPiece* value); 59 60 bool empty() { return length_ == 0; } 61 62 private: 63 void Advance(size_t num_bytes) { 64 scan_ += num_bytes; 65 length_ -= num_bytes; 66 } 67 68 template<typename T> bool ReadPrimitive(T* value) { 69 if (length_ < sizeof(*value)) 70 return false; 71 *value = *reinterpret_cast<const T*>(scan_); 72 Advance(sizeof(*value)); 73 return true; 74 } 75 76 template<typename T> bool ReadPrimitiveArray(DWORD size, const T** values) { 77 if (length_ < sizeof(**values) * size) 78 return false; 79 *values = reinterpret_cast<const T*>(scan_); 80 Advance(sizeof(**values) * size); 81 return true; 82 } 83 84 const uint8* scan_; 85 uint32 length_; 86 }; 87 88 } // namespace logging_win 89 90 #endif // CHROME_TEST_LOGGING_WIN_MOF_DATA_PARSER_H_ 91
