xfa/src/fxbarcode/src/BC_ReedSolomon.cpp

// 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

#include "barcode.h"
#include "include/BC_ReedSolomonGF256.h"
#include "include/BC_ReedSolomonGF256Poly.h"
#include "include/BC_ReedSolomon.h"
CBC_ReedSolomonEncoder::CBC_ReedSolomonEncoder(CBC_ReedSolomonGF256* field)
{
    m_field = field;
}
void CBC_ReedSolomonEncoder::Init()
{
    m_cachedGenerators.Add(FX_NEW CBC_ReedSolomonGF256Poly(m_field, 1));
}
CBC_ReedSolomonGF256Poly* CBC_ReedSolomonEncoder::BuildGenerator(FX_INT32 degree, FX_INT32 &e)
{
    if(degree >= m_cachedGenerators.GetSize()) {
        CBC_ReedSolomonGF256Poly* lastGenerator = (CBC_ReedSolomonGF256Poly*)(m_cachedGenerators[m_cachedGenerators.GetSize() - 1]);
        for(FX_INT32 d = m_cachedGenerators.GetSize(); d <= degree; d++) {
            CFX_Int32Array temp;
            temp.Add(1);
            temp.Add(m_field->Exp(d - 1));
            CBC_ReedSolomonGF256Poly temp_poly;
            temp_poly.Init(m_field, &temp, e);
            BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
            CBC_ReedSolomonGF256Poly* nextGenerator = lastGenerator->Multiply(&temp_poly, e);
            BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
            m_cachedGenerators.Add(nextGenerator);
            lastGenerator = nextGenerator;
        }
    }
    return (CBC_ReedSolomonGF256Poly*)(m_cachedGenerators[degree]);
}
void CBC_ReedSolomonEncoder::Encode(CFX_Int32Array *toEncode, FX_INT32 ecBytes, FX_INT32 &e)
{
    if(ecBytes == 0) {
        e = BCExceptionNoCorrectionBytes;
        BC_EXCEPTION_CHECK_ReturnVoid(e);
    }
    FX_INT32 dataBytes = toEncode->GetSize() - ecBytes;
    if(dataBytes <= 0) {
        e = BCExceptionNoDataBytesProvided;
        BC_EXCEPTION_CHECK_ReturnVoid(e);
    }
    CBC_ReedSolomonGF256Poly* generator = BuildGenerator(ecBytes, e);
    BC_EXCEPTION_CHECK_ReturnVoid(e);
    CFX_Int32Array infoCoefficients;
    infoCoefficients.SetSize(dataBytes);
    for(FX_INT32 x = 0; x < dataBytes; x++) {
        infoCoefficients[x] = toEncode->operator [](x);
    }
    CBC_ReedSolomonGF256Poly info;
    info.Init(m_field, &infoCoefficients, e);
    BC_EXCEPTION_CHECK_ReturnVoid(e);
    CBC_ReedSolomonGF256Poly* rsg = info.MultiplyByMonomial(ecBytes, 1, e);
    BC_EXCEPTION_CHECK_ReturnVoid(e);
    CBC_AutoPtr<CBC_ReedSolomonGF256Poly> infoTemp(rsg);
    CFX_PtrArray *pa = infoTemp->Divide(generator, e);
    BC_EXCEPTION_CHECK_ReturnVoid(e);
    CBC_AutoPtr<CFX_PtrArray > temp(pa);
    CBC_ReedSolomonGF256Poly* remainder = (CBC_ReedSolomonGF256Poly*)(temp->operator [](1));
    CFX_Int32Array* coefficients = remainder->GetCoefficients();
    FX_INT32 numZeroCoefficients = ecBytes - coefficients->GetSize();
    for(FX_INT32 i = 0; i < numZeroCoefficients; i++) {
        (*toEncode)[dataBytes + i] = 0;
    }
    for(FX_INT32 y = 0; y < coefficients->GetSize(); y++) {
        (*toEncode)[dataBytes + numZeroCoefficients + y] =
            coefficients->operator [](y);
    }
    for (FX_INT32 k = 0; k < temp->GetSize(); k++) {
        delete (CBC_ReedSolomonGF256Poly*)(*temp)[k];
    }
}
CBC_ReedSolomonEncoder::~CBC_ReedSolomonEncoder()
{
    for (FX_INT32 i = 0; i < m_cachedGenerators.GetSize(); i++) {
        delete (CBC_ReedSolomonGF256Poly*)m_cachedGenerators[i];
    }
}