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 
CBC_ReedSolomonGF256Poly(CBC_ReedSolomonGF256 * field,int32_t coefficients)29 CBC_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 }
CBC_ReedSolomonGF256Poly()37 CBC_ReedSolomonGF256Poly::CBC_ReedSolomonGF256Poly() {
38   m_field = nullptr;
39 }
Init(CBC_ReedSolomonGF256 * field,CFX_Int32Array * coefficients,int32_t & e)40 void CBC_ReedSolomonGF256Poly::Init(CBC_ReedSolomonGF256* field,
41                                     CFX_Int32Array* coefficients,
42                                     int32_t& e) {
43   if (!coefficients || coefficients->GetSize() == 0) {
44     e = BCExceptionCoefficientsSizeIsNull;
45     BC_EXCEPTION_CHECK_ReturnVoid(e);
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 }
GetCoefficients()67 CFX_Int32Array* CBC_ReedSolomonGF256Poly::GetCoefficients() {
68   return &m_coefficients;
69 }
GetDegree()70 int32_t CBC_ReedSolomonGF256Poly::GetDegree() {
71   return m_coefficients.GetSize() - 1;
72 }
IsZero()73 FX_BOOL CBC_ReedSolomonGF256Poly::IsZero() {
74   return m_coefficients[0] == 0;
75 }
GetCoefficients(int32_t degree)76 int32_t CBC_ReedSolomonGF256Poly::GetCoefficients(int32_t degree) {
77   return m_coefficients[m_coefficients.GetSize() - 1 - degree];
78 }
EvaluateAt(int32_t a)79 int32_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 }
Clone(int32_t & e)98 CBC_ReedSolomonGF256Poly* CBC_ReedSolomonGF256Poly::Clone(int32_t& e) {
99   CBC_ReedSolomonGF256Poly* temp = new CBC_ReedSolomonGF256Poly();
100   temp->Init(m_field, &m_coefficients, e);
101   BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
102   return temp;
103 }
AddOrSubtract(CBC_ReedSolomonGF256Poly * other,int32_t & e)104 CBC_ReedSolomonGF256Poly* CBC_ReedSolomonGF256Poly::AddOrSubtract(
105     CBC_ReedSolomonGF256Poly* other,
106     int32_t& e) {
107   if (IsZero())
108     return other->Clone(e);
109   if (other->IsZero())
110     return Clone(e);
111 
112   CFX_Int32Array smallerCoefficients;
113   smallerCoefficients.Copy(m_coefficients);
114   CFX_Int32Array largerCoefficients;
115   largerCoefficients.Copy(*(other->GetCoefficients()));
116   if (smallerCoefficients.GetSize() > largerCoefficients.GetSize()) {
117     CFX_Int32Array temp;
118     temp.Copy(smallerCoefficients);
119     smallerCoefficients.Copy(largerCoefficients);
120     largerCoefficients.Copy(temp);
121   }
122   CFX_Int32Array sumDiff;
123   sumDiff.SetSize(largerCoefficients.GetSize());
124   int32_t lengthDiff =
125       largerCoefficients.GetSize() - smallerCoefficients.GetSize();
126   for (int32_t i = 0; i < lengthDiff; i++) {
127     sumDiff[i] = largerCoefficients[i];
128   }
129   for (int32_t j = lengthDiff; j < largerCoefficients.GetSize(); j++) {
130     sumDiff[j] = (CBC_ReedSolomonGF256::AddOrSubtract(
131         smallerCoefficients[j - lengthDiff], largerCoefficients[j]));
132   }
133   CBC_ReedSolomonGF256Poly* temp = new CBC_ReedSolomonGF256Poly();
134   temp->Init(m_field, &sumDiff, e);
135   BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
136   return temp;
137 }
Multiply(CBC_ReedSolomonGF256Poly * other,int32_t & e)138 CBC_ReedSolomonGF256Poly* CBC_ReedSolomonGF256Poly::Multiply(
139     CBC_ReedSolomonGF256Poly* other,
140     int32_t& e) {
141   if (IsZero() || other->IsZero())
142     return m_field->GetZero()->Clone(e);
143 
144   CFX_Int32Array aCoefficients;
145   aCoefficients.Copy(m_coefficients);
146   int32_t aLength = m_coefficients.GetSize();
147   CFX_Int32Array bCoefficients;
148   bCoefficients.Copy(*(other->GetCoefficients()));
149   int32_t bLength = other->GetCoefficients()->GetSize();
150   CFX_Int32Array product;
151   product.SetSize(aLength + bLength - 1);
152   for (int32_t i = 0; i < aLength; i++) {
153     int32_t aCoeff = m_coefficients[i];
154     for (int32_t j = 0; j < bLength; j++) {
155       product[i + j] = CBC_ReedSolomonGF256::AddOrSubtract(
156           product[i + j],
157           m_field->Multiply(aCoeff, other->GetCoefficients()->operator[](j)));
158     }
159   }
160   CBC_ReedSolomonGF256Poly* temp = new CBC_ReedSolomonGF256Poly();
161   temp->Init(m_field, &product, e);
162   BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
163   return temp;
164 }
Multiply(int32_t scalar,int32_t & e)165 CBC_ReedSolomonGF256Poly* CBC_ReedSolomonGF256Poly::Multiply(int32_t scalar,
166                                                              int32_t& e) {
167   if (scalar == 0)
168     return m_field->GetZero()->Clone(e);
169   if (scalar == 1)
170     return Clone(e);
171 
172   int32_t size = m_coefficients.GetSize();
173   CFX_Int32Array product;
174   product.SetSize(size);
175   for (int32_t i = 0; i < size; i++) {
176     product[i] = m_field->Multiply(m_coefficients[i], scalar);
177   }
178   CBC_ReedSolomonGF256Poly* temp = new CBC_ReedSolomonGF256Poly();
179   temp->Init(m_field, &product, e);
180   BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
181   return temp;
182 }
MultiplyByMonomial(int32_t degree,int32_t coefficient,int32_t & e)183 CBC_ReedSolomonGF256Poly* CBC_ReedSolomonGF256Poly::MultiplyByMonomial(
184     int32_t degree,
185     int32_t coefficient,
186     int32_t& e) {
187   if (degree < 0) {
188     e = BCExceptionDegreeIsNegative;
189     return nullptr;
190   }
191   if (coefficient == 0)
192     return m_field->GetZero()->Clone(e);
193 
194   int32_t size = m_coefficients.GetSize();
195   CFX_Int32Array product;
196   product.SetSize(size + degree);
197   for (int32_t i = 0; i < size; i++) {
198     product[i] = (m_field->Multiply(m_coefficients[i], coefficient));
199   }
200   CBC_ReedSolomonGF256Poly* temp = new CBC_ReedSolomonGF256Poly();
201   temp->Init(m_field, &product, e);
202   BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
203   return temp;
204 }
205 
Divide(CBC_ReedSolomonGF256Poly * other,int32_t & e)206 CFX_ArrayTemplate<CBC_ReedSolomonGF256Poly*>* CBC_ReedSolomonGF256Poly::Divide(
207     CBC_ReedSolomonGF256Poly* other,
208     int32_t& e) {
209   if (other->IsZero()) {
210     e = BCExceptionDivideByZero;
211     return nullptr;
212   }
213   std::unique_ptr<CBC_ReedSolomonGF256Poly> quotient(
214       m_field->GetZero()->Clone(e));
215   BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
216   std::unique_ptr<CBC_ReedSolomonGF256Poly> remainder(Clone(e));
217   BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
218   int32_t denominatorLeadingTerm = other->GetCoefficients(other->GetDegree());
219   int32_t inverseDenominatorLeadingTeam =
220       m_field->Inverse(denominatorLeadingTerm, e);
221   BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
222   while (remainder->GetDegree() >= other->GetDegree() && !remainder->IsZero()) {
223     int32_t degreeDifference = remainder->GetDegree() - other->GetDegree();
224     int32_t scale =
225         m_field->Multiply(remainder->GetCoefficients((remainder->GetDegree())),
226                           inverseDenominatorLeadingTeam);
227     std::unique_ptr<CBC_ReedSolomonGF256Poly> term(
228         other->MultiplyByMonomial(degreeDifference, scale, e));
229     BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
230     std::unique_ptr<CBC_ReedSolomonGF256Poly> iteratorQuotient(
231         m_field->BuildMonomial(degreeDifference, scale, e));
232     BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
233     quotient.reset(quotient->AddOrSubtract(iteratorQuotient.get(), e));
234     BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
235     remainder.reset(remainder->AddOrSubtract(term.get(), e));
236     BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
237   }
238   CFX_ArrayTemplate<CBC_ReedSolomonGF256Poly*>* tempPtrA =
239       new CFX_ArrayTemplate<CBC_ReedSolomonGF256Poly*>();
240   tempPtrA->Add(quotient.release());
241   tempPtrA->Add(remainder.release());
242   return tempPtrA;
243 }
244 
~CBC_ReedSolomonGF256Poly()245 CBC_ReedSolomonGF256Poly::~CBC_ReedSolomonGF256Poly() {
246   m_coefficients.RemoveAll();
247 }
248