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      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_ReedSolomonGF256.h"
     24 
     25 #include "third_party/base/ptr_util.h"
     26 #include "xfa/fxbarcode/common/reedsolomon/BC_ReedSolomonGF256Poly.h"
     27 
     28 CBC_ReedSolomonGF256* CBC_ReedSolomonGF256::QRCodeField = nullptr;
     29 CBC_ReedSolomonGF256* CBC_ReedSolomonGF256::DataMatrixField = nullptr;
     30 
     31 void CBC_ReedSolomonGF256::Initialize() {
     32   QRCodeField = new CBC_ReedSolomonGF256(0x011D);
     33   QRCodeField->Init();
     34   DataMatrixField = new CBC_ReedSolomonGF256(0x012D);
     35   DataMatrixField->Init();
     36 }
     37 
     38 void CBC_ReedSolomonGF256::Finalize() {
     39   delete QRCodeField;
     40   QRCodeField = nullptr;
     41   delete DataMatrixField;
     42   DataMatrixField = nullptr;
     43 }
     44 
     45 CBC_ReedSolomonGF256::CBC_ReedSolomonGF256(int32_t primitive) {
     46   int32_t x = 1;
     47   for (int32_t j = 0; j < 256; j++) {
     48     m_expTable[j] = x;
     49     x <<= 1;
     50     if (x >= 0x100) {
     51       x ^= primitive;
     52     }
     53   }
     54   for (int32_t i = 0; i < 255; i++) {
     55     m_logTable[m_expTable[i]] = i;
     56   }
     57   m_logTable[0] = 0;
     58 }
     59 
     60 void CBC_ReedSolomonGF256::Init() {
     61   m_zero = pdfium::MakeUnique<CBC_ReedSolomonGF256Poly>(this, 0);
     62   m_one = pdfium::MakeUnique<CBC_ReedSolomonGF256Poly>(this, 1);
     63 }
     64 
     65 CBC_ReedSolomonGF256::~CBC_ReedSolomonGF256() {}
     66 
     67 CBC_ReedSolomonGF256Poly* CBC_ReedSolomonGF256::GetZero() const {
     68   return m_zero.get();
     69 }
     70 
     71 CBC_ReedSolomonGF256Poly* CBC_ReedSolomonGF256::GetOne() const {
     72   return m_one.get();
     73 }
     74 
     75 CBC_ReedSolomonGF256Poly* CBC_ReedSolomonGF256::BuildMonomial(
     76     int32_t degree,
     77     int32_t coefficient,
     78     int32_t& e) {
     79   if (degree < 0) {
     80     e = BCExceptionDegreeIsNegative;
     81     return nullptr;
     82   }
     83   if (coefficient == 0) {
     84     CBC_ReedSolomonGF256Poly* temp = m_zero->Clone(e);
     85     if (e != BCExceptionNO)
     86       return nullptr;
     87     return temp;
     88   }
     89   CFX_ArrayTemplate<int32_t> coefficients;
     90   coefficients.SetSize(degree + 1);
     91   coefficients[0] = coefficient;
     92   CBC_ReedSolomonGF256Poly* temp = new CBC_ReedSolomonGF256Poly();
     93   temp->Init(this, &coefficients, e);
     94   if (e != BCExceptionNO)
     95     return nullptr;
     96   return temp;
     97 }
     98 
     99 int32_t CBC_ReedSolomonGF256::AddOrSubtract(int32_t a, int32_t b) {
    100   return a ^ b;
    101 }
    102 
    103 int32_t CBC_ReedSolomonGF256::Exp(int32_t a) {
    104   return m_expTable[a];
    105 }
    106 
    107 int32_t CBC_ReedSolomonGF256::Log(int32_t a, int32_t& e) {
    108   if (a == 0) {
    109     e = BCExceptionAIsZero;
    110     return 0;
    111   }
    112   return m_logTable[a];
    113 }
    114 
    115 int32_t CBC_ReedSolomonGF256::Inverse(int32_t a, int32_t& e) {
    116   if (a == 0) {
    117     e = BCExceptionAIsZero;
    118     return 0;
    119   }
    120   return m_expTable[255 - m_logTable[a]];
    121 }
    122 
    123 int32_t CBC_ReedSolomonGF256::Multiply(int32_t a, int32_t b) {
    124   if (a == 0 || b == 0) {
    125     return 0;
    126   }
    127   if (a == 1) {
    128     return b;
    129   }
    130   if (b == 1) {
    131     return a;
    132   }
    133   return m_expTable[(m_logTable[a] + m_logTable[b]) % 255];
    134 }
    135