diff options
Diffstat (limited to 'fxbarcode/common/reedsolomon/BC_ReedSolomonGF256Poly.cpp')
| -rw-r--r-- | fxbarcode/common/reedsolomon/BC_ReedSolomonGF256Poly.cpp | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/fxbarcode/common/reedsolomon/BC_ReedSolomonGF256Poly.cpp b/fxbarcode/common/reedsolomon/BC_ReedSolomonGF256Poly.cpp new file mode 100644 index 0000000000..a062589218 --- /dev/null +++ b/fxbarcode/common/reedsolomon/BC_ReedSolomonGF256Poly.cpp @@ -0,0 +1,253 @@ +// 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() {} |