| // Copyright 2016 PDFium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com |
| |
| #include "core/fpdfapi/parser/cpdf_linearized_header.h" |
| |
| #include <algorithm> |
| #include <utility> |
| |
| #include "core/fpdfapi/parser/cpdf_array.h" |
| #include "core/fpdfapi/parser/cpdf_dictionary.h" |
| #include "core/fpdfapi/parser/cpdf_number.h" |
| #include "third_party/base/ptr_util.h" |
| |
| namespace { |
| |
| template <class T> |
| bool IsValidNumericDictionaryValue(const CPDF_Dictionary* pDict, |
| const char* key, |
| T min_value, |
| bool must_exist = true) { |
| if (!pDict->KeyExist(key)) |
| return !must_exist; |
| const CPDF_Number* pNum = ToNumber(pDict->GetObjectFor(key)); |
| if (!pNum || !pNum->IsInteger()) |
| return false; |
| const int raw_value = pNum->GetInteger(); |
| if (!pdfium::base::IsValueInRangeForNumericType<T>(raw_value)) |
| return false; |
| return static_cast<T>(raw_value) >= min_value; |
| } |
| |
| } // namespace |
| |
| // static |
| std::unique_ptr<CPDF_LinearizedHeader> CPDF_LinearizedHeader::CreateForObject( |
| std::unique_ptr<CPDF_Object> pObj) { |
| auto pDict = ToDictionary(std::move(pObj)); |
| if (!pDict || !pDict->KeyExist("Linearized") || |
| !IsValidNumericDictionaryValue<FX_FILESIZE>(pDict.get(), "L", 1) || |
| !IsValidNumericDictionaryValue<uint32_t>(pDict.get(), "P", 0, false) || |
| !IsValidNumericDictionaryValue<FX_FILESIZE>(pDict.get(), "T", 1) || |
| !IsValidNumericDictionaryValue<uint32_t>(pDict.get(), "N", 0) || |
| !IsValidNumericDictionaryValue<FX_FILESIZE>(pDict.get(), "E", 1) || |
| !IsValidNumericDictionaryValue<uint32_t>(pDict.get(), "O", 1)) |
| return nullptr; |
| return pdfium::WrapUnique(new CPDF_LinearizedHeader(pDict.get())); |
| } |
| |
| CPDF_LinearizedHeader::CPDF_LinearizedHeader(const CPDF_Dictionary* pDict) { |
| m_szFileSize = pDict->GetIntegerFor("L"); |
| m_dwFirstPageNo = pDict->GetIntegerFor("P"); |
| m_szLastXRefOffset = pDict->GetIntegerFor("T"); |
| m_PageCount = pDict->GetIntegerFor("N"); |
| m_szFirstPageEndOffset = pDict->GetIntegerFor("E"); |
| m_FirstPageObjNum = pDict->GetIntegerFor("O"); |
| const CPDF_Array* pHintStreamRange = pDict->GetArrayFor("H"); |
| const size_t nHintStreamSize = |
| pHintStreamRange ? pHintStreamRange->GetCount() : 0; |
| if (nHintStreamSize == 2 || nHintStreamSize == 4) { |
| m_szHintStart = std::max(pHintStreamRange->GetIntegerAt(0), 0); |
| m_szHintLength = std::max(pHintStreamRange->GetIntegerAt(1), 0); |
| } |
| } |
| |
| CPDF_LinearizedHeader::~CPDF_LinearizedHeader() {} |
| |
| bool CPDF_LinearizedHeader::HasHintTable() const { |
| return GetPageCount() > 1 && GetHintStart() > 0 && GetHintLength() > 0; |
| } |