| // Copyright 2014 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 |
| // Original code is licensed as follows: |
| /* |
| * Copyright 2007 ZXing authors |
| * |
| * 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. |
| */ |
| |
| #include "fxbarcode/common/reedsolomon/BC_ReedSolomon.h" |
| |
| #include <memory> |
| #include <utility> |
| |
| #include "fxbarcode/common/reedsolomon/BC_ReedSolomonGF256.h" |
| #include "fxbarcode/common/reedsolomon/BC_ReedSolomonGF256Poly.h" |
| #include "third_party/base/ptr_util.h" |
| |
| CBC_ReedSolomonEncoder::CBC_ReedSolomonEncoder(CBC_ReedSolomonGF256* field) |
| : m_field(field) { |
| m_cachedGenerators.push_back( |
| pdfium::MakeUnique<CBC_ReedSolomonGF256Poly>(m_field.Get(), 1)); |
| } |
| |
| CBC_ReedSolomonEncoder::~CBC_ReedSolomonEncoder() {} |
| |
| CBC_ReedSolomonGF256Poly* CBC_ReedSolomonEncoder::BuildGenerator( |
| size_t degree) { |
| if (degree >= m_cachedGenerators.size()) { |
| CBC_ReedSolomonGF256Poly* lastGenerator = m_cachedGenerators.back().get(); |
| for (size_t d = m_cachedGenerators.size(); d <= degree; ++d) { |
| std::vector<int32_t> temp = {1, m_field->Exp(d - 1)}; |
| CBC_ReedSolomonGF256Poly temp_poly; |
| if (!temp_poly.Init(m_field.Get(), &temp)) |
| return nullptr; |
| |
| auto nextGenerator = lastGenerator->Multiply(&temp_poly); |
| if (!nextGenerator) |
| return nullptr; |
| |
| lastGenerator = nextGenerator.get(); |
| m_cachedGenerators.push_back(std::move(nextGenerator)); |
| } |
| } |
| return m_cachedGenerators[degree].get(); |
| } |
| |
| bool CBC_ReedSolomonEncoder::Encode(std::vector<int32_t>* toEncode, |
| size_t ecBytes) { |
| if (ecBytes == 0) |
| return false; |
| |
| if (toEncode->size() <= ecBytes) |
| return false; |
| |
| CBC_ReedSolomonGF256Poly* generator = BuildGenerator(ecBytes); |
| if (!generator) |
| return false; |
| |
| size_t dataBytes = toEncode->size() - ecBytes; |
| std::vector<int32_t> infoCoefficients(dataBytes); |
| for (size_t x = 0; x < dataBytes; x++) |
| infoCoefficients[x] = (*toEncode)[x]; |
| |
| CBC_ReedSolomonGF256Poly info; |
| if (!info.Init(m_field.Get(), &infoCoefficients)) |
| return false; |
| |
| auto infoTemp = info.MultiplyByMonomial(ecBytes, 1); |
| if (!infoTemp) |
| return false; |
| |
| auto remainder = infoTemp->Divide(generator); |
| if (!remainder) |
| return false; |
| |
| const auto& coefficients = remainder->GetCoefficients(); |
| size_t numZeroCoefficients = |
| ecBytes > coefficients.size() ? ecBytes - coefficients.size() : 0; |
| for (size_t i = 0; i < numZeroCoefficients; i++) |
| (*toEncode)[dataBytes + i] = 0; |
| for (size_t y = 0; y < coefficients.size(); y++) |
| (*toEncode)[dataBytes + numZeroCoefficients + y] = coefficients[y]; |
| return true; |
| } |