File indexing completed on 2024-12-29 04:51:01

 /*
     SPDX-FileCopyrightText: 2023 Volker Krause <vkrause@kde.org>
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #include "protobufstreamreader.h"
 
 #include <QDebug>
 
 using namespace KItinerary;
 
 ProtobufStreamReader::ProtobufStreamReader() = default;
 
 ProtobufStreamReader::ProtobufStreamReader(std::string_view data)
     : m_data(data)
 {
 }
 
 ProtobufStreamReader::ProtobufStreamReader(const QByteArray &data)
     : m_ownedData(data)
     , m_data(std::string_view(data.constData(), data.size()))
 {
 }
 
 ProtobufStreamReader::~ProtobufStreamReader() = default;
 
 uint64_t ProtobufStreamReader::readVarint()
 {
     uint64_t result = 0;
     int shift = 0;
     while (m_cursor < m_data.size()) {
         const uint64_t b = m_data[m_cursor++];
         result |= (b & 0b0111'1111) << shift;
         if ((b & 0b1000'0000) == 0) {
             break;
         }
         shift += 7;
     }
 
     return result;
 }
 
 uint64_t ProtobufStreamReader::peekVarint()
 {
     auto prevCursor = m_cursor;
     const auto result = readVarint();
     m_cursor = prevCursor;
     return result;
 }
 
 quint64 ProtobufStreamReader::fieldNumber()
 {
     return peekVarint() >> 3;
 }
 
 ProtobufStreamReader::WireType ProtobufStreamReader::wireType()
 {
     return static_cast<WireType>(peekVarint() & 0b111);
 }
 
 quint64 ProtobufStreamReader::readVarintField()
 {
     readVarint(); // skip field number and wire type
     return readVarint();
 }
 
 std::string_view ProtobufStreamReader::readLengthDelimitedRecord()
 {
     if (wireType() != LEN) {
         return {};
     }
     readVarint(); // skip field number and wire type
     const auto len = readVarint();
     if (m_cursor + len <= m_data.size()) {
         auto data = m_data.substr(m_cursor, len);
         m_cursor += len;
         return data;
     }
     return {};
 }
 
 QString ProtobufStreamReader::readString()
 {
     const auto data = readLengthDelimitedRecord();
     return QString::fromUtf8(data.data(), data.size());
 }
 
 ProtobufStreamReader ProtobufStreamReader::readSubMessage()
 {
     return ProtobufStreamReader(readLengthDelimitedRecord());
 }
 
 bool ProtobufStreamReader::atEnd() const
 {
     return m_cursor >= m_data.size();
 }
 
 void ProtobufStreamReader::skip()
 {
     switch (wireType()) {
         case VARINT:
             readVarintField();
             break;
         case LEN:
             readLengthDelimitedRecord();
             break;
         case I64:
         case I32:
         case SGROUP:
         case EGROUP:
             qWarning() << "encountered deprecated or unsupported protobuf wire type!" << wireType();
             m_cursor = m_data.size();
             break;
     }
 }
 
 #include "moc_protobufstreamreader.cpp"