| // 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_ReedSolomonGF256Poly.h" |
| |
| #include <memory> |
| #include <utility> |
| |
| #include "fxbarcode/common/reedsolomon/BC_ReedSolomonGF256.h" |
| #include "third_party/base/stl_util.h" |
| |
| CBC_ReedSolomonGF256Poly::CBC_ReedSolomonGF256Poly(CBC_ReedSolomonGF256* field, |
| int32_t coefficients) { |
| if (!field) |
| return; |
| |
| m_field = field; |
| m_coefficients.push_back(coefficients); |
| } |
| |
| CBC_ReedSolomonGF256Poly::CBC_ReedSolomonGF256Poly() { |
| m_field = nullptr; |
| } |
| |
| void CBC_ReedSolomonGF256Poly::Init(CBC_ReedSolomonGF256* field, |
| std::vector<int32_t>* coefficients, |
| int32_t& e) { |
| if (!coefficients || coefficients->empty()) { |
| e = BCExceptionCoefficientsSizeIsNull; |
| return; |
| } |
| m_field = field; |
| size_t coefficientsLength = coefficients->size(); |
| if (coefficientsLength > 1 && coefficients->front() == 0) { |
| size_t firstNonZero = 1; |
| while (firstNonZero < coefficientsLength && |
| (*coefficients)[firstNonZero] == 0) { |
| firstNonZero++; |
| } |
| if (firstNonZero == coefficientsLength) { |
| m_coefficients = *(m_field->GetZero()->GetCoefficients()); |
| } else { |
| m_coefficients.resize(coefficientsLength - firstNonZero); |
| for (size_t i = firstNonZero, j = 0; i < coefficientsLength; i++, j++) |
| m_coefficients[j] = (*coefficients)[i]; |
| } |
| } else { |
| m_coefficients = *coefficients; |
| } |
| } |
| |
| std::vector<int32_t>* CBC_ReedSolomonGF256Poly::GetCoefficients() { |
| return &m_coefficients; |
| } |
| |
| int32_t CBC_ReedSolomonGF256Poly::GetDegree() { |
| return pdfium::CollectionSize<int32_t>(m_coefficients) - 1; |
| } |
| |
| bool CBC_ReedSolomonGF256Poly::IsZero() { |
| return m_coefficients.front() == 0; |
| } |
| |
| int32_t CBC_ReedSolomonGF256Poly::GetCoefficients(int32_t degree) { |
| return m_coefficients[m_coefficients.size() - 1 - degree]; |
| } |
| |
| int32_t CBC_ReedSolomonGF256Poly::EvaluateAt(int32_t a) { |
| if (a == 0) { |
| return GetCoefficients(0); |
| } |
| size_t size = m_coefficients.size(); |
| if (a == 1) { |
| int32_t result = 0; |
| for (size_t i = 0; i < size; i++) |
| result = CBC_ReedSolomonGF256::AddOrSubtract(result, m_coefficients[i]); |
| return result; |
| } |
| int32_t result = m_coefficients[0]; |
| for (size_t j = 1; j < size; j++) { |
| result = CBC_ReedSolomonGF256::AddOrSubtract(m_field->Multiply(a, result), |
| m_coefficients[j]); |
| } |
| return result; |
| } |
| |
| CBC_ReedSolomonGF256Poly* CBC_ReedSolomonGF256Poly::Clone(int32_t& e) { |
| CBC_ReedSolomonGF256Poly* temp = new CBC_ReedSolomonGF256Poly(); |
| temp->Init(m_field, &m_coefficients, e); |
| if (e != BCExceptionNO) |
| return nullptr; |
| return temp; |
| } |
| CBC_ReedSolomonGF256Poly* CBC_ReedSolomonGF256Poly::AddOrSubtract( |
| CBC_ReedSolomonGF256Poly* other, |
| int32_t& e) { |
| if (IsZero()) |
| return other->Clone(e); |
| if (other->IsZero()) |
| return Clone(e); |
| |
| std::vector<int32_t> smallerCoefficients = m_coefficients; |
| std::vector<int32_t> largerCoefficients = *(other->GetCoefficients()); |
| if (smallerCoefficients.size() > largerCoefficients.size()) { |
| std::swap(smallerCoefficients, largerCoefficients); |
| } |
| std::vector<int32_t> sumDiff(largerCoefficients.size()); |
| size_t lengthDiff = largerCoefficients.size() - smallerCoefficients.size(); |
| for (size_t i = 0; i < lengthDiff; i++) { |
| sumDiff[i] = largerCoefficients[i]; |
| } |
| for (size_t j = lengthDiff; j < largerCoefficients.size(); j++) { |
| sumDiff[j] = CBC_ReedSolomonGF256::AddOrSubtract( |
| smallerCoefficients[j - lengthDiff], largerCoefficients[j]); |
| } |
| CBC_ReedSolomonGF256Poly* temp = new CBC_ReedSolomonGF256Poly(); |
| temp->Init(m_field, &sumDiff, e); |
| if (e != BCExceptionNO) |
| return nullptr; |
| return temp; |
| } |
| CBC_ReedSolomonGF256Poly* CBC_ReedSolomonGF256Poly::Multiply( |
| CBC_ReedSolomonGF256Poly* other, |
| int32_t& e) { |
| if (IsZero() || other->IsZero()) |
| return m_field->GetZero()->Clone(e); |
| |
| std::vector<int32_t> aCoefficients = m_coefficients; |
| std::vector<int32_t> bCoefficients = *(other->GetCoefficients()); |
| size_t aLength = aCoefficients.size(); |
| size_t bLength = bCoefficients.size(); |
| std::vector<int32_t> product(aLength + bLength - 1); |
| for (size_t i = 0; i < aLength; i++) { |
| int32_t aCoeff = m_coefficients[i]; |
| for (size_t j = 0; j < bLength; j++) { |
| product[i + j] = CBC_ReedSolomonGF256::AddOrSubtract( |
| product[i + j], |
| m_field->Multiply(aCoeff, (*other->GetCoefficients())[j])); |
| } |
| } |
| CBC_ReedSolomonGF256Poly* temp = new CBC_ReedSolomonGF256Poly(); |
| temp->Init(m_field, &product, e); |
| if (e != BCExceptionNO) |
| return nullptr; |
| return temp; |
| } |
| CBC_ReedSolomonGF256Poly* CBC_ReedSolomonGF256Poly::Multiply(int32_t scalar, |
| int32_t& e) { |
| if (scalar == 0) |
| return m_field->GetZero()->Clone(e); |
| if (scalar == 1) |
| return Clone(e); |
| |
| size_t size = m_coefficients.size(); |
| std::vector<int32_t> product(size); |
| for (size_t i = 0; i < size; i++) { |
| product[i] = m_field->Multiply(m_coefficients[i], scalar); |
| } |
| CBC_ReedSolomonGF256Poly* temp = new CBC_ReedSolomonGF256Poly(); |
| temp->Init(m_field, &product, e); |
| if (e != BCExceptionNO) |
| return nullptr; |
| return temp; |
| } |
| CBC_ReedSolomonGF256Poly* CBC_ReedSolomonGF256Poly::MultiplyByMonomial( |
| int32_t degree, |
| int32_t coefficient, |
| int32_t& e) { |
| if (degree < 0) { |
| e = BCExceptionDegreeIsNegative; |
| return nullptr; |
| } |
| if (coefficient == 0) |
| return m_field->GetZero()->Clone(e); |
| |
| size_t size = m_coefficients.size(); |
| std::vector<int32_t> product(size + degree); |
| for (size_t i = 0; i < size; i++) { |
| product[i] = m_field->Multiply(m_coefficients[i], coefficient); |
| } |
| CBC_ReedSolomonGF256Poly* temp = new CBC_ReedSolomonGF256Poly(); |
| temp->Init(m_field, &product, e); |
| if (e != BCExceptionNO) |
| return nullptr; |
| return temp; |
| } |
| |
| std::vector<CBC_ReedSolomonGF256Poly*>* CBC_ReedSolomonGF256Poly::Divide( |
| CBC_ReedSolomonGF256Poly* other, |
| int32_t& e) { |
| if (other->IsZero()) { |
| e = BCExceptionDivideByZero; |
| return nullptr; |
| } |
| std::unique_ptr<CBC_ReedSolomonGF256Poly> quotient( |
| m_field->GetZero()->Clone(e)); |
| if (e != BCExceptionNO) |
| return nullptr; |
| std::unique_ptr<CBC_ReedSolomonGF256Poly> remainder(Clone(e)); |
| if (e != BCExceptionNO) |
| return nullptr; |
| int32_t denominatorLeadingTerm = other->GetCoefficients(other->GetDegree()); |
| int32_t inverseDenominatorLeadingTeam = |
| m_field->Inverse(denominatorLeadingTerm, e); |
| if (e != BCExceptionNO) |
| return nullptr; |
| while (remainder->GetDegree() >= other->GetDegree() && !remainder->IsZero()) { |
| int32_t degreeDifference = remainder->GetDegree() - other->GetDegree(); |
| int32_t scale = |
| m_field->Multiply(remainder->GetCoefficients((remainder->GetDegree())), |
| inverseDenominatorLeadingTeam); |
| std::unique_ptr<CBC_ReedSolomonGF256Poly> term( |
| other->MultiplyByMonomial(degreeDifference, scale, e)); |
| if (e != BCExceptionNO) |
| return nullptr; |
| std::unique_ptr<CBC_ReedSolomonGF256Poly> iteratorQuotient( |
| m_field->BuildMonomial(degreeDifference, scale, e)); |
| if (e != BCExceptionNO) |
| return nullptr; |
| quotient.reset(quotient->AddOrSubtract(iteratorQuotient.get(), e)); |
| if (e != BCExceptionNO) |
| return nullptr; |
| remainder.reset(remainder->AddOrSubtract(term.get(), e)); |
| if (e != BCExceptionNO) |
| return nullptr; |
| } |
| std::vector<CBC_ReedSolomonGF256Poly*>* tempPtrA = |
| new std::vector<CBC_ReedSolomonGF256Poly*>(); |
| tempPtrA->push_back(quotient.release()); |
| tempPtrA->push_back(remainder.release()); |
| return tempPtrA; |
| } |
| |
| CBC_ReedSolomonGF256Poly::~CBC_ReedSolomonGF256Poly() {} |