BC_ReedSolomonGF256Poly.cpp revision 5ae9d0c6fd838a2967cca72aa5751b51dadc2769 
1// Copyright 2014 PDFium 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// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
6// Original code is licensed as follows:
7/*
8 * Copyright 2007 ZXing authors
9 *
10 * Licensed under the Apache License, Version 2.0 (the "License");
11 * you may not use this file except in compliance with the License.
12 * You may obtain a copy of the License at
13 *
14 *      http://www.apache.org/licenses/LICENSE-2.0
15 *
16 * Unless required by applicable law or agreed to in writing, software
17 * distributed under the License is distributed on an "AS IS" BASIS,
18 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
19 * See the License for the specific language governing permissions and
20 * limitations under the License.
21 */
22
23#include "xfa/fxbarcode/common/reedsolomon/BC_ReedSolomonGF256Poly.h"
24
25#include <memory>
26
27#include "xfa/fxbarcode/common/reedsolomon/BC_ReedSolomonGF256.h"
28
29CBC_ReedSolomonGF256Poly::CBC_ReedSolomonGF256Poly(CBC_ReedSolomonGF256* field,
30                                                   int32_t coefficients) {
31  if (!field)
32    return;
33
34  m_field = field;
35  m_coefficients.Add(coefficients);
36}
37CBC_ReedSolomonGF256Poly::CBC_ReedSolomonGF256Poly() {
38  m_field = nullptr;
39}
40void CBC_ReedSolomonGF256Poly::Init(CBC_ReedSolomonGF256* field,
41                                    CFX_ArrayTemplate<int32_t>* coefficients,
42                                    int32_t& e) {
43  if (!coefficients || coefficients->GetSize() == 0) {
44    e = BCExceptionCoefficientsSizeIsNull;
45    return;
46  }
47  m_field = field;
48  int32_t coefficientsLength = coefficients->GetSize();
49  if ((coefficientsLength > 1 && (*coefficients)[0] == 0)) {
50    int32_t firstNonZero = 1;
51    while ((firstNonZero < coefficientsLength) &&
52           ((*coefficients)[firstNonZero] == 0)) {
53      firstNonZero++;
54    }
55    if (firstNonZero == coefficientsLength) {
56      m_coefficients.Copy(*(m_field->GetZero()->GetCoefficients()));
57    } else {
58      m_coefficients.SetSize(coefficientsLength - firstNonZero);
59      for (int32_t i = firstNonZero, j = 0; i < coefficientsLength; i++, j++) {
60        m_coefficients[j] = coefficients->operator[](i);
61      }
62    }
63  } else {
64    m_coefficients.Copy(*coefficients);
65  }
66}
67CFX_ArrayTemplate<int32_t>* CBC_ReedSolomonGF256Poly::GetCoefficients() {
68  return &m_coefficients;
69}
70int32_t CBC_ReedSolomonGF256Poly::GetDegree() {
71  return m_coefficients.GetSize() - 1;
72}
73bool CBC_ReedSolomonGF256Poly::IsZero() {
74  return m_coefficients[0] == 0;
75}
76int32_t CBC_ReedSolomonGF256Poly::GetCoefficients(int32_t degree) {
77  return m_coefficients[m_coefficients.GetSize() - 1 - degree];
78}
79int32_t CBC_ReedSolomonGF256Poly::EvaluateAt(int32_t a) {
80  if (a == 0) {
81    return GetCoefficients(0);
82  }
83  int32_t size = m_coefficients.GetSize();
84  if (a == 1) {
85    int32_t result = 0;
86    for (int32_t i = 0; i < size; i++) {
87      result = CBC_ReedSolomonGF256::AddOrSubtract(result, m_coefficients[i]);
88    }
89    return result;
90  }
91  int32_t result = m_coefficients[0];
92  for (int32_t j = 1; j < size; j++) {
93    result = CBC_ReedSolomonGF256::AddOrSubtract(m_field->Multiply(a, result),
94                                                 m_coefficients[j]);
95  }
96  return result;
97}
98CBC_ReedSolomonGF256Poly* CBC_ReedSolomonGF256Poly::Clone(int32_t& e) {
99  CBC_ReedSolomonGF256Poly* temp = new CBC_ReedSolomonGF256Poly();
100  temp->Init(m_field, &m_coefficients, e);
101  if (e != BCExceptionNO)
102    return nullptr;
103  return temp;
104}
105CBC_ReedSolomonGF256Poly* CBC_ReedSolomonGF256Poly::AddOrSubtract(
106    CBC_ReedSolomonGF256Poly* other,
107    int32_t& e) {
108  if (IsZero())
109    return other->Clone(e);
110  if (other->IsZero())
111    return Clone(e);
112
113  CFX_ArrayTemplate<int32_t> smallerCoefficients;
114  smallerCoefficients.Copy(m_coefficients);
115  CFX_ArrayTemplate<int32_t> largerCoefficients;
116  largerCoefficients.Copy(*(other->GetCoefficients()));
117  if (smallerCoefficients.GetSize() > largerCoefficients.GetSize()) {
118    CFX_ArrayTemplate<int32_t> temp;
119    temp.Copy(smallerCoefficients);
120    smallerCoefficients.Copy(largerCoefficients);
121    largerCoefficients.Copy(temp);
122  }
123  CFX_ArrayTemplate<int32_t> sumDiff;
124  sumDiff.SetSize(largerCoefficients.GetSize());
125  int32_t lengthDiff =
126      largerCoefficients.GetSize() - smallerCoefficients.GetSize();
127  for (int32_t i = 0; i < lengthDiff; i++) {
128    sumDiff[i] = largerCoefficients[i];
129  }
130  for (int32_t j = lengthDiff; j < largerCoefficients.GetSize(); j++) {
131    sumDiff[j] = (CBC_ReedSolomonGF256::AddOrSubtract(
132        smallerCoefficients[j - lengthDiff], largerCoefficients[j]));
133  }
134  CBC_ReedSolomonGF256Poly* temp = new CBC_ReedSolomonGF256Poly();
135  temp->Init(m_field, &sumDiff, e);
136  if (e != BCExceptionNO)
137    return nullptr;
138  return temp;
139}
140CBC_ReedSolomonGF256Poly* CBC_ReedSolomonGF256Poly::Multiply(
141    CBC_ReedSolomonGF256Poly* other,
142    int32_t& e) {
143  if (IsZero() || other->IsZero())
144    return m_field->GetZero()->Clone(e);
145
146  CFX_ArrayTemplate<int32_t> aCoefficients;
147  aCoefficients.Copy(m_coefficients);
148  int32_t aLength = m_coefficients.GetSize();
149  CFX_ArrayTemplate<int32_t> bCoefficients;
150  bCoefficients.Copy(*(other->GetCoefficients()));
151  int32_t bLength = other->GetCoefficients()->GetSize();
152  CFX_ArrayTemplate<int32_t> product;
153  product.SetSize(aLength + bLength - 1);
154  for (int32_t i = 0; i < aLength; i++) {
155    int32_t aCoeff = m_coefficients[i];
156    for (int32_t j = 0; j < bLength; j++) {
157      product[i + j] = CBC_ReedSolomonGF256::AddOrSubtract(
158          product[i + j],
159          m_field->Multiply(aCoeff, other->GetCoefficients()->operator[](j)));
160    }
161  }
162  CBC_ReedSolomonGF256Poly* temp = new CBC_ReedSolomonGF256Poly();
163  temp->Init(m_field, &product, e);
164  if (e != BCExceptionNO)
165    return nullptr;
166  return temp;
167}
168CBC_ReedSolomonGF256Poly* CBC_ReedSolomonGF256Poly::Multiply(int32_t scalar,
169                                                             int32_t& e) {
170  if (scalar == 0)
171    return m_field->GetZero()->Clone(e);
172  if (scalar == 1)
173    return Clone(e);
174
175  int32_t size = m_coefficients.GetSize();
176  CFX_ArrayTemplate<int32_t> product;
177  product.SetSize(size);
178  for (int32_t i = 0; i < size; i++) {
179    product[i] = m_field->Multiply(m_coefficients[i], scalar);
180  }
181  CBC_ReedSolomonGF256Poly* temp = new CBC_ReedSolomonGF256Poly();
182  temp->Init(m_field, &product, e);
183  if (e != BCExceptionNO)
184    return nullptr;
185  return temp;
186}
187CBC_ReedSolomonGF256Poly* CBC_ReedSolomonGF256Poly::MultiplyByMonomial(
188    int32_t degree,
189    int32_t coefficient,
190    int32_t& e) {
191  if (degree < 0) {
192    e = BCExceptionDegreeIsNegative;
193    return nullptr;
194  }
195  if (coefficient == 0)
196    return m_field->GetZero()->Clone(e);
197
198  int32_t size = m_coefficients.GetSize();
199  CFX_ArrayTemplate<int32_t> product;
200  product.SetSize(size + degree);
201  for (int32_t i = 0; i < size; i++) {
202    product[i] = (m_field->Multiply(m_coefficients[i], coefficient));
203  }
204  CBC_ReedSolomonGF256Poly* temp = new CBC_ReedSolomonGF256Poly();
205  temp->Init(m_field, &product, e);
206  if (e != BCExceptionNO)
207    return nullptr;
208  return temp;
209}
210
211CFX_ArrayTemplate<CBC_ReedSolomonGF256Poly*>* CBC_ReedSolomonGF256Poly::Divide(
212    CBC_ReedSolomonGF256Poly* other,
213    int32_t& e) {
214  if (other->IsZero()) {
215    e = BCExceptionDivideByZero;
216    return nullptr;
217  }
218  std::unique_ptr<CBC_ReedSolomonGF256Poly> quotient(
219      m_field->GetZero()->Clone(e));
220  if (e != BCExceptionNO)
221    return nullptr;
222  std::unique_ptr<CBC_ReedSolomonGF256Poly> remainder(Clone(e));
223  if (e != BCExceptionNO)
224    return nullptr;
225  int32_t denominatorLeadingTerm = other->GetCoefficients(other->GetDegree());
226  int32_t inverseDenominatorLeadingTeam =
227      m_field->Inverse(denominatorLeadingTerm, e);
228  if (e != BCExceptionNO)
229    return nullptr;
230  while (remainder->GetDegree() >= other->GetDegree() && !remainder->IsZero()) {
231    int32_t degreeDifference = remainder->GetDegree() - other->GetDegree();
232    int32_t scale =
233        m_field->Multiply(remainder->GetCoefficients((remainder->GetDegree())),
234                          inverseDenominatorLeadingTeam);
235    std::unique_ptr<CBC_ReedSolomonGF256Poly> term(
236        other->MultiplyByMonomial(degreeDifference, scale, e));
237    if (e != BCExceptionNO)
238      return nullptr;
239    std::unique_ptr<CBC_ReedSolomonGF256Poly> iteratorQuotient(
240        m_field->BuildMonomial(degreeDifference, scale, e));
241    if (e != BCExceptionNO)
242      return nullptr;
243    quotient.reset(quotient->AddOrSubtract(iteratorQuotient.get(), e));
244    if (e != BCExceptionNO)
245      return nullptr;
246    remainder.reset(remainder->AddOrSubtract(term.get(), e));
247    if (e != BCExceptionNO)
248      return nullptr;
249  }
250  CFX_ArrayTemplate<CBC_ReedSolomonGF256Poly*>* tempPtrA =
251      new CFX_ArrayTemplate<CBC_ReedSolomonGF256Poly*>();
252  tempPtrA->Add(quotient.release());
253  tempPtrA->Add(remainder.release());
254  return tempPtrA;
255}
256
257CBC_ReedSolomonGF256Poly::~CBC_ReedSolomonGF256Poly() {
258  m_coefficients.RemoveAll();
259}
260