File indexing completed on 2024-12-08 10:16:04

 /*
     SPDX-FileCopyrightText: 2020 Volker Krause <vkrause@kde.org>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #include "o5mparser.h"
 #include "datatypes.h"
 #include "datasetmergebuffer.h"
 
 #include <QDebug>
 
 #include <cstdlib>
 #include <cstring>
 
 using namespace OSM;
 
 enum : uint8_t {
     O5M_BLOCK_RESET = 0xff,
     O5M_BLOCK_NODE = 0x10,
     O5M_BLOCK_WAY = 0x11,
     O5M_BLOCK_RELATION = 0x12,
     O5M_BLOCK_BOUNDING_BOX = 0xdb,
     O5M_BLOCK_TIMESTAMP = 0xdc,
     O5M_BLOCK_HEADER = 0xe0,
 
     O5M_NUMBER_CONTINUATION = 0b1000'0000,
     O5M_NUMBER_MASK = 0b0111'1111,
     O5M_NUMBER_SIGNED_BIT = 0b1,
 
     O5M_MEMTYPE_NODE = 0x30,
     O5M_MEMTYPE_WAY = 0x31,
     O5M_MEMTYPE_RELATION = 0x32,
 };
 
 enum : uint16_t {
     O5M_STRING_TABLE_SIZE = 15000,
     O5M_STRING_TABLE_MAXLEN = 250,
 };
 
 O5mParser::O5mParser(DataSet *dataSet)
     : AbstractReader(dataSet)
 {
     m_stringLookupTable.resize(O5M_STRING_TABLE_SIZE);
 }
 
 void O5mParser::readFromData(const uint8_t* data, std::size_t len)
 {
     std::fill(m_stringLookupTable.begin(), m_stringLookupTable.end(), nullptr);
     resetDeltaCodingState();
 
     const auto endIt = data + len;
     for (auto it = data; it < endIt - 1;) {
         const auto blockType = (*it);
         if (blockType == O5M_BLOCK_RESET) {
             resetDeltaCodingState();
             ++it;
             continue;
         }
 
         auto blockSize = readUnsigned(++it, endIt);
         if (blockSize >= (uint64_t)(endIt - it)) {
             qWarning() << "premature end of file, or blocksize too large" << (endIt - it) << blockType << blockSize;
             break;
         }
         switch (blockType) {
             case O5M_BLOCK_HEADER:
                 if (blockSize != 4 || std::strncmp(reinterpret_cast<const char*>(it), "o5m2", 4) != 0) {
                     qWarning() << "Invalid file header";
                     return;
                 }
                 break;
             case O5M_BLOCK_BOUNDING_BOX:
             case O5M_BLOCK_TIMESTAMP:
                 // not of interest at the moment
                 break;
             case O5M_BLOCK_NODE:
                 readNode(it, it + blockSize);
                 break;
             case O5M_BLOCK_WAY:
                 readWay(it, it + blockSize);
                 break;
             case O5M_BLOCK_RELATION:
                 readRelation(it, it + blockSize);
                 break;
             default:
                 qDebug() << "unhandled o5m block type:" << (it - data) << blockType << blockSize;
         }
 
         it += blockSize;
     }
 }
 
 uint64_t O5mParser::readUnsigned(const uint8_t *&it, const uint8_t *endIt) const
 {
     uint64_t result = 0;
     int i = 0;
     for (; it < endIt && ((*it) & O5M_NUMBER_CONTINUATION); ++it, ++i) {
         result |= ((*it) & O5M_NUMBER_MASK) << (i * 7);
     }
     result |= ((uint64_t)(*it++) & O5M_NUMBER_MASK) << (i * 7);
     return result;
 }
 
 int64_t O5mParser::readSigned(const uint8_t *&it, const uint8_t *endIt) const
 {
     const uint64_t u = readUnsigned(it, endIt);
     return (u & O5M_NUMBER_SIGNED_BIT) ? (-(u >> 1) -1) : (u >> 1);
 }
 
 template <typename T>
 T O5mParser::readDelta(const uint8_t *&it, const uint8_t *endIt, T &deltaState)
 {
     deltaState += (T)readSigned(it, endIt);
     return deltaState;
 }
 
 const char* O5mParser::readString(const uint8_t *&it, const uint8_t *endIt)
 {
     auto ref = readUnsigned(it, endIt);
     if (ref) {
         return m_stringLookupTable[(m_stringLookupPosition + O5M_STRING_TABLE_SIZE - ref) % O5M_STRING_TABLE_SIZE];
     } else {
         const auto s = reinterpret_cast<const char*>(it);
         const auto len = std::strlen(s);
         if (len <= O5M_STRING_TABLE_MAXLEN) {
             m_stringLookupTable[m_stringLookupPosition] = s;
             m_stringLookupPosition = (m_stringLookupPosition + 1) % O5M_STRING_TABLE_SIZE;
         }
         it += len + 1;
         return s;
     }
 }
 
 std::pair<const char*, const char*> O5mParser::readStringPair(const uint8_t *&it, const uint8_t *endIt)
 {
     auto ref = readUnsigned(it, endIt);
     if (ref) {
         const auto s = m_stringLookupTable[(m_stringLookupPosition + O5M_STRING_TABLE_SIZE - ref) % O5M_STRING_TABLE_SIZE];
         if (!s) {
             return {};
         }
         const auto len1 = std::strlen(s);
         return std::make_pair(s, s + len1 + 1);
     } else {
         const auto s = reinterpret_cast<const char*>(it);
         const auto len1 = std::strlen(s);
         const auto len2 = std::strlen(s + len1 + 1);
 
         if (len1 + len2 <= O5M_STRING_TABLE_MAXLEN) {
             m_stringLookupTable[m_stringLookupPosition] = s;
             m_stringLookupPosition = (m_stringLookupPosition + 1) % O5M_STRING_TABLE_SIZE;
         }
 
         it += len1 + len2 + 2;
         return std::make_pair(s, s + len1 + 1);
     }
 }
 
 void O5mParser::skipVersionInformation(const uint8_t *&it, const uint8_t *end)
 {
     if (it >= end) { return; }
     const auto version = readUnsigned(it, end);
     if (version > 0) {
         qWarning() << "skipping changeset data not implemented yet!";
         //    timestamp (seconds since 1970, signed, delta-coded)
         //    author information – only if timestamp is not 0:
         //        changeset (signed, delta-coded)
         //        uid, user (string pair)
         it = end;
     }
 }
 
 template<typename Elem>
 void O5mParser::readTagOrBbox(Elem &e, const uint8_t *&it, const uint8_t *endIt)
 {
     const auto tagData = readStringPair(it, endIt);
     if (!tagData.first) {
         return;
     }
     if (std::strcmp(tagData.first, "bBox") == 0) {
         char *next = nullptr;
         const auto lon1 = std::strtod(tagData.second, &next);
         ++next;
         const auto lat1 = std::strtod(next, &next);
         ++next;
         const auto lon2 = std::strtod(next, &next);
         ++next;
         const auto lat2 = std::strtod(next, &next);
         e.bbox = OSM::BoundingBox(OSM::Coordinate(lat1, lon1), OSM::Coordinate(lat2, lon2));
         return;
     }
 
     OSM::Tag tag;
     tag.key = m_dataSet->makeTagKey(tagData.first, DataSet::StringIsTransient); // TODO make use of mmap'ed data for this
     tag.value = QByteArray(tagData.second);
     OSM::setTag(e, std::move(tag));
 }
 
 void O5mParser::readNode(const uint8_t *begin, const uint8_t *end)
 {
     OSM::Node node;
 
     auto it = begin;
     node.id = readDelta(it, end, m_nodeIdDelta);
     skipVersionInformation(it, end);
     if (it >= end) { return; }
 
     node.coordinate.longitude = (int64_t)readDelta(it, end, m_lonDelta) + 1'800'000'000ll;
     node.coordinate.latitude = (int64_t)readDelta(it, end, m_latDelata) + 900'000'000ll;
 
     while (it < end) {
         OSM::Tag tag;
         const auto tagData = readStringPair(it, end);
         if (tagData.first) {
             tag.key = m_dataSet->makeTagKey(tagData.first, DataSet::StringIsTransient); // TODO use the fact this is mmap'ed data here
             tag.value = QByteArray(tagData.second);
             OSM::setTag(node, std::move(tag));
         }
     }
 
     addNode(std::move(node));
 }
 
 void O5mParser::readWay(const uint8_t *begin, const uint8_t *end)
 {
     OSM::Way way;
 
     auto it = begin;
     way.id = readDelta(it, end, m_wayIdDelta);
     skipVersionInformation(it, end);
     if (it >= end) { return; }
 
     const auto nodesBlockSize = readUnsigned(it, end);
     if (it + nodesBlockSize > end) { return; }
 
     const auto nodesBlockEnd = it + nodesBlockSize;
     while(it < nodesBlockEnd) {
         way.nodes.push_back(readDelta(it, end, m_wayNodeIdDelta));
     }
 
     while (it < end) {
         readTagOrBbox(way, it, end);
     }
 
    addWay(std::move(way));
 }
 
 void O5mParser::readRelation(const uint8_t *begin, const uint8_t *end)
 {
     OSM::Relation rel;
 
     auto it = begin;
     rel.id = readDelta(it, end, m_relIdDelta);
     skipVersionInformation(it, end);
     if (it >= end) { return; }
 
     const auto relBlockSize = readUnsigned(it, end);
     if (it + relBlockSize > end) { return; }
 
     const auto relBlockEnd = it + relBlockSize;
     while (it < relBlockEnd) {
         const int64_t memId = readSigned(it, end);
         OSM::Member mem;
         const auto typeAndRole = readString(it, end);
         switch (typeAndRole[0]) {
             case O5M_MEMTYPE_NODE:
                 mem.id = m_relNodeMemberIdDelta += memId;
                 mem.setType(OSM::Type::Node);
                 break;
             case O5M_MEMTYPE_WAY:
                 mem.id = m_relWayMemberIdDelta += memId;
                 mem.setType(OSM::Type::Way);
                 break;
             case O5M_MEMTYPE_RELATION:
                 mem.id = m_relRelMemberIdDelta += memId;
                 mem.setType(OSM::Type::Relation);
                 break;
         }
         mem.setRole(m_dataSet->makeRole(typeAndRole + 1, DataSet::StringIsTransient));
 
         rel.members.push_back(std::move(mem));
     }
 
 
 
     while (it < end) {
         readTagOrBbox(rel, it, end);
     }
 
     addRelation(std::move(rel));
 }
 
 void O5mParser::resetDeltaCodingState()
 {
     m_nodeIdDelta = 0;
     m_latDelata = 0;
     m_lonDelta = 0;
 
     m_wayIdDelta = 0;
     m_wayNodeIdDelta = 0;
 
     m_relIdDelta = 0;
     m_relNodeMemberIdDelta = 0;
     m_relWayMemberIdDelta = 0;
     m_relRelMemberIdDelta = 0;
 }