   150→    auto f_remap_ways = std::async(std::launch::async, [&]() {
   151→        std::vector<uint32_t> sorted_ids(used_way_ids.begin(), used_way_ids.end());
   152→        std::sort(sorted_ids.begin(), sorted_ids.end());
   153→        std::vector<WayHeader> ways;
   154→        std::vector<NodeCoord> nodes;
   155→        ways.reserve(sorted_ids.size());
   156→        nodes.reserve(sorted_ids.size() * 5);
   157→        std::unordered_map<uint32_t, uint32_t> remap;
   158→        remap.reserve(sorted_ids.size());
   159→        for (uint32_t old_id : sorted_ids) {
   160→            remap[old_id] = static_cast<uint32_t>(ways.size());
   161→            const auto& w = full.ways[old_id];
   162→            WayHeader nw = w;
   163→            nw.node_offset = static_cast<uint32_t>(nodes.size());
   164→            ways.push_back(nw);
   165→            for (uint8_t n = 0; n < w.node_count; n++)
   166→                nodes.push_back(full.street_nodes[w.node_offset + n]);
   167→        }
   168→        return std::make_tuple(std::move(remap), std::move(ways), std::move(nodes));
   169→    });
   170→
   171→    // Addrs
   172→    auto f_remap_addrs = std::async(std::launch::async, [&]() {
   173→        std::vector<uint32_t> sorted_ids(used_addr_ids.begin(), used_addr_ids.end());
   174→        std::sort(sorted_ids.begin(), sorted_ids.end());
   175→        std::vector<AddrPoint> addrs;
   176→        addrs.reserve(sorted_ids.size());
   177→        std::unordered_map<uint32_t, uint32_t> remap;
   178→        remap.reserve(sorted_ids.size());
   179→        for (uint32_t old_id : sorted_ids) {
   180→            remap[old_id] = static_cast<uint32_t>(addrs.size());
   181→            addrs.push_back(full.addr_points[old_id]);
   182→        }
   183→        return std::make_tuple(std::move(remap), std::move(addrs));
   184→    });
   185→
   186→    // Interps
   187→    auto f_remap_interps = std::async(std::launch::async, [&]() {
   188→        std::vector<uint32_t> sorted_ids(used_interp_ids.begin(), used_interp_ids.end());
   189→        std::sort(sorted_ids.begin(), sorted_ids.end());
   190→        std::vector<InterpWay> iways;
   191→        std::vector<NodeCoord> inodes;
   192→        iways.reserve(sorted_ids.size());
   193→        std::unordered_map<uint32_t, uint32_t> remap;
   194→        remap.reserve(sorted_ids.size());
   195→        for (uint32_t old_id : sorted_ids) {
   196→            remap[old_id] = static_cast<uint32_t>(iways.size());
   197→            const auto& iw = full.interp_ways[old_id];
   198→            InterpWay niw = iw;
   199→            niw.node_offset = static_cast<uint32_t>(inodes.size());
   200→            iways.push_back(niw);
   201→            for (uint8_t n = 0; n < iw.node_count; n++)
   202→                inodes.push_back(full.interp_nodes[iw.node_offset + n]);
   203→        }
   204→        return std::make_tuple(std::move(remap), std::move(iways), std::move(inodes));
   205→    });
   206→
   207→    // Admins
   208→    auto f_remap_admins = std::async(std::launch::async, [&]() {
   209→        std::vector<uint32_t> sorted_ids(used_admin_ids.begin(), used_admin_ids.end());
   210→        std::sort(sorted_ids.begin(), sorted_ids.end());
   211→        std::vector<AdminPolygon> polys;
   212→        std::vector<NodeCoord> verts;
   213→        polys.reserve(sorted_ids.size());
   214→        std::unordered_map<uint32_t, uint32_t> remap;
   215→        remap.reserve(sorted_ids.size());
   216→        for (uint32_t old_id : sorted_ids) {
   217→            remap[old_id] = static_cast<uint32_t>(polys.size());
   218→            const auto& ap = full.admin_polygons[old_id];
   219→            AdminPolygon nap = ap;
   220→            nap.vertex_offset = static_cast<uint32_t>(verts.size());
   221→            polys.push_back(nap);
   222→            for (uint32_t v = 0; v < ap.vertex_count; v++)
   223→                verts.push_back(full.admin_vertices[ap.vertex_offset + v]);
   224→        }
   225→        return std::make_tuple(std::move(remap), std::move(polys), std::move(verts));
   226→    });
   227→
   228→    // Collect results
   229→    {
   230→        auto [wr, ways, nodes] = f_remap_ways.get();
   231→        way_remap = std::move(wr);
   232→        out.ways = std::move(ways);
   233→        out.street_nodes = std::move(nodes);
   234→    }
   235→    {
   236→        auto [ar, addrs] = f_remap_addrs.get();
   237→        addr_remap = std::move(ar);
   238→        out.addr_points = std::move(addrs);
   239→    }
   240→    {
   241→        auto [ir, iways, inodes] = f_remap_interps.get();
   242→        interp_remap = std::move(ir);
   243→        out.interp_ways = std::move(iways);
   244→        out.interp_nodes = std::move(inodes);
   245→    }
   246→    {
   247→        auto [ar, polys, verts] = f_remap_admins.get();
   248→        admin_remap = std::move(ar);
   249→        out.admin_polygons = std::move(polys);
   250→        out.admin_vertices = std::move(verts);
   251→    }
   252→    log_phase("      filter: data remap", _ft, _fc);
   253→
   254→    // Remap cell maps — use sorted pairs where available (parallel), hash maps otherwise
   255→    auto remap_cells_map = [&](const std::unordered_map<uint64_t, std::vector<uint32_t>>& src,
   256→                               const std::unordered_map<uint32_t, uint32_t>& remap,
   257→                               std::unordered_map<uint64_t, std::vector<uint32_t>>& dst,
   258→                               bool handle_flags = false) {
   259→        for (const auto& [cell_id, ids] : src) {
   260→            if (!cell_in_bbox(cell_id, bbox)) continue;
   261→            std::vector<uint32_t> new_ids;
   262→            for (uint32_t id : ids) {
   263→                uint32_t raw_id = handle_flags ? (id & ID_MASK) : id;
   264→                uint32_t flags = handle_flags ? (id & INTERIOR_FLAG) : 0;
   265→                auto it = remap.find(raw_id);
   266→                if (it != remap.end()) new_ids.push_back(it->second | flags);
   267→            }
   268→            if (!new_ids.empty()) dst[cell_id] = std::move(new_ids);
   269→        }
   270→    };
   271→
   272→    // Remap from sorted pairs — builds output cell map by scanning sorted pairs.
   273→    // Uses same parallel chunked pattern as filter_cells_sorted.
   274→    auto remap_cells_sorted = [&](const std::vector<CellItemPair>& sorted,
   275→                                   const std::unordered_map<uint32_t, uint32_t>& remap,
   276→                                   std::unordered_map<uint64_t, std::vector<uint32_t>>& dst) {
   277→        if (sorted.empty()) return;
   278→        auto _rt = std::chrono::steady_clock::now();
   279→        auto _rc = CpuTicks::now();
   280→
   281→        unsigned nthreads = std::max(1u, std::thread::hardware_concurrency() / 4);
   282→        size_t chunk = (sorted.size() + nthreads - 1) / nthreads;
   283→
   284→        // Find chunk boundaries at cell_id transitions
   285→        std::vector<size_t> bounds = {0};
   286→        for (unsigned t = 1; t < nthreads; t++) {
   287→            size_t target = t * chunk;
   288→            if (target >= sorted.size()) break;
   289→            while (target < sorted.size() && sorted[target].cell_id == sorted[target-1].cell_id)
   290→                target++;
   291→            if (target < sorted.size()) bounds.push_back(target);
   292→        }
   293→        bounds.push_back(sorted.size());
   294→
   295→        std::cerr << "        remap_sorted: " << sorted.size() << " pairs, "
   296→                  << bounds.size()-1 << " chunks, " << nthreads << " threads" << std::endl;
   297→
   298→        // Each thread builds its own partial map
   299→        std::vector<std::unordered_map<uint64_t, std::vector<uint32_t>>> partial(bounds.size() - 1);
   300→        std::vector<std::thread> threads;
   301→        for (size_t t = 0; t + 1 < bounds.size(); t++) {
   302→            threads.emplace_back([&, t]() {
   303→                auto& local = partial[t];
   304→                for (size_t i = bounds[t]; i < bounds[t+1]; ) {
   305→                    uint64_t cell_id = sorted[i].cell_id;
   306→                    bool match = cell_in_bbox(cell_id, bbox);
   307→                    std::vector<uint32_t> new_ids;
   308→                    while (i < bounds[t+1] && sorted[i].cell_id == cell_id) {
   309→                        if (match) {
   310→                            auto it = remap.find(sorted[i].item_id);
   311→                            if (it != remap.end()) new_ids.push_back(it->second);
   312→                        }
   313→                        i++;
   314→                    }
   315→                    if (!new_ids.empty()) local[cell_id] = std::move(new_ids);
   316→                }
   317→            });
   318→        }
   319→        for (auto& t : threads) t.join();
   320→        log_phase("        remap_sorted: scan", _rt, _rc);
   321→
   322→        // Merge partial maps (no conflicts — cell boundaries are clean splits)
   323→        size_t total = 0;
   324→        for (auto& p : partial) total += p.size();
   325→        dst.reserve(total);
   326→        for (auto& p : partial) {
   327→            for (auto& [k, v] : p) dst[k] = std::move(v);
   328→        }
   329→        log_phase("        remap_sorted: merge", _rt, _rc);
   330→    };
   331→
   332→    // Build sorted pairs for continent by filtering + remapping in one pass.
   333→    // Much faster than building hash maps — write_index uses sorted pairs directly.
   334→    auto filter_and_remap_sorted = [&](const std::vector<CellItemPair>& sorted,
   335→                                        const std::unordered_map<uint32_t, uint32_t>& remap,
   336→                                        std::vector<CellItemPair>& dst) {
   337→        if (sorted.empty()) return;
   338→        auto _rt = std::chrono::steady_clock::now();
   339→        auto _rc = CpuTicks::now();
   340→
   341→        unsigned nthreads = std::max(1u, std::thread::hardware_concurrency() / 4);
   342→        size_t chunk = (sorted.size() + nthreads - 1) / nthreads;
   343→
   344→        std::vector<size_t> bounds = {0};
   345→        for (unsigned t = 1; t < nthreads; t++) {
   346→            size_t target = t * chunk;
   347→            if (target >= sorted.size()) break;
   348→            while (target < sorted.size() && sorted[target].cell_id == sorted[target-1].cell_id)
   349→                target++;
   350→            if (target < sorted.size()) bounds.push_back(target);
   351→        }
   352→        bounds.push_back(sorted.size());
   353→
   354→        // Each thread produces a local vector of filtered+remapped pairs
   355→        std::vector<std::vector<CellItemPair>> thread_pairs(bounds.size() - 1);
   356→        std::vector<std::thread> threads;
   357→        for (size_t t = 0; t + 1 < bounds.size(); t++) {
   358→            threads.emplace_back([&, t]() {
   359→                auto& local = thread_pairs[t];
   360→                for (size_t i = bounds[t]; i < bounds[t+1]; ) {
   361→                    uint64_t cell_id = sorted[i].cell_id;
   362→                    bool match = cell_in_bbox(cell_id, bbox);
   363→                    while (i < bounds[t+1] && sorted[i].cell_id == cell_id) {
   364→                        if (match) {
   365→                            auto it = remap.find(sorted[i].item_id);
   366→                            if (it != remap.end())
   367→                                local.push_back({cell_id, it->second});
   368→                        }
   369→                        i++;
   370→                    }
   371→                }
   372→            });
   373→        }
   374→        for (auto& t : threads) t.join();
   375→        log_phase("        sorted remap: scan", _rt, _rc);
   376→
   377→        // Concatenate (already in sorted cell_id order since chunks are at cell boundaries)
   378→        size_t total = 0;
   379→        for (auto& v : thread_pairs) total += v.size();
   380→        dst.reserve(total);
   381→        for (auto& v : thread_pairs) dst.insert(dst.end(), v.begin(), v.end());
   382→        log_phase("        sorted remap: concat", _rt, _rc);
   383→    };
   384→
   385→    {
   386→        // Build sorted pairs for ways/addrs/interps (write_index uses these directly)
   387→        auto f1 = std::async(std::launch::async, [&]{ filter_and_remap_sorted(full.sorted_way_cells, way_remap, out.sorted_way_cells); });
   388→        auto f2 = std::async(std::launch::async, [&]{ filter_and_remap_sorted(full.sorted_addr_cells, addr_remap, out.sorted_addr_cells); });
   389→        auto f3 = std::async(std::launch::async, [&]{ filter_and_remap_sorted(full.sorted_interp_cells, interp_remap, out.sorted_interp_cells); });
   390→        // Admin still uses hash map (has interior flags)
   391→        auto f4 = std::async(std::launch::async, [&]{ remap_cells_map(full.cell_to_admin, admin_remap, out.cell_to_admin, true); });
   392→        f1.get(); f2.get(); f3.get(); f4.get();
   393→    }
   394→    log_phase("      filter: cell map remap", _ft, _fc);
   395→
   396→    // Rebuild compact string pool
   397→    std::unordered_set<uint32_t> used_offsets;
   398→    for (const auto& w : out.ways) used_offsets.insert(w.name_id);
   399→    for (const auto& a : out.addr_points) { used_offsets.insert(a.housenumber_id); used_offsets.insert(a.street_id); }


52:        std::cerr << "  --continents           Also generate per-continent indexes" << std::endl;
71:    bool generate_continents = false;
98:        } else if (arg == "--continents") {
99:            generate_continents = true;
1464:            auto wf1 = std::async(std::launch::async, [&]{ write_index(d, base_dir + "/full", IndexMode::Full); });
1465:            auto wf2 = std::async(std::launch::async, [&]{ write_index(d, base_dir + "/no-addresses", IndexMode::NoAddresses); });
1466:            auto wf3 = std::async(std::launch::async, [&]{ write_index(d, base_dir + "/admin", IndexMode::AdminOnly); });
1469:            write_index(d, base_dir, mode);
1485:    // Process continents with bounded concurrency, largest first.
1486:    if (generate_continents) {
1550:        // Sort by bbox area descending — largest continents first
1562:        std::cerr << "Processing " << kContinentCount << " continents ("
1637:        if (generate_continents) {


Let me now check the end of build_index.cpp to see how files are finalized, and look for any manifest or indexing information:


1736 /root/traccar-geocoder/builder/src/build_index.cpp


  1600→    log_phase("All index writing (total)", _pt, _cpu);
  1601→
  1602→    // --- Generate manifest.json ---
  1603→    {
  1604→        auto file_size = [](const std::string& path) -> int64_t {
  1605→            struct stat st;
  1606→            if (stat(path.c_str(), &st) == 0) return st.st_size;
  1607→            return -1;
  1608→        };
  1609→
  1610→        auto dir_size = [&](const std::string& dir, const std::vector<std::string>& files) -> int64_t {
  1611→            int64_t total = 0;
  1612→            for (const auto& f : files) {
  1613→                int64_t s = file_size(dir + "/" + f);
  1614→                if (s > 0) total += s;
  1615→            }
  1616→            return total;
  1617→        };
  1618→
  1619→        std::vector<std::string> admin_base_files = {
  1620→            "admin_cells.bin", "admin_entries.bin", "strings.bin"
  1621→        };
  1622→        std::vector<std::string> admin_quality_files = {
  1623→            "admin_polygons.bin", "admin_vertices.bin"
  1624→        };
  1625→        std::vector<std::string> street_files = {
  1626→            "street_ways.bin", "street_nodes.bin", "street_entries.bin"
  1627→        };
  1628→        std::vector<std::string> address_files = {
  1629→            "addr_points.bin", "addr_entries.bin",
  1630→            "interp_ways.bin", "interp_nodes.bin", "interp_entries.bin"
  1631→        };
  1632→        std::vector<std::string> geo_files = {"geo_cells.bin"};
  1633→
  1634→        // Build list of regions
  1635→        std::vector<std::pair<std::string, std::string>> regions; // (name, path)
  1636→        regions.push_back({"planet", output_dir});
  1637→        if (generate_continents) {
  1638→            for (size_t ci = 0; ci < kContinentCount; ci++) {
  1639→                regions.push_back({kContinents[ci].name,
  1640→                    output_dir + "/" + kContinents[ci].name});
  1641→            }
  1642→        }
  1643→
  1644→        // Quality level names
  1645→        auto quality_dir_name = [](double scale) -> std::string {
  1646→            if (scale == 0) return "uncapped";
  1647→            char buf[32]; snprintf(buf, sizeof(buf), "q%.4g", scale);
  1648→            return buf;
  1649→        };
  1650→
  1651→        std::ofstream mf(output_dir + "/manifest.json");
  1652→        mf << "{\n";
  1653→        mf << "  \"version\": 1,\n";
  1654→        mf << "  \"regions\": [\n";
  1655→
  1656→        for (size_t ri = 0; ri < regions.size(); ri++) {
  1657→            const auto& [rname, rpath] = regions[ri];
  1658→            mf << "    {\n";
  1659→            mf << "      \"name\": \"" << rname << "\",\n";
  1660→
  1661→            // Modes
  1662→            mf << "      \"modes\": {\n";
  1663→            if (multi_output) {
  1664→                // Full
  1665→                std::string full_dir = rpath + "/full";
  1666→                int64_t full_sz = dir_size(full_dir, geo_files) +
  1667→                    dir_size(full_dir, street_files) +
  1668→                    dir_size(full_dir, address_files) +
  1669→                    dir_size(full_dir, admin_base_files) +
  1670→                    dir_size(full_dir, admin_quality_files);
  1671→                mf << "        \"full\": {\"size\": " << full_sz << "},\n";
  1672→
  1673→                // Streets (no addresses)
  1674→                std::string na_dir = rpath + "/no-addresses";
  1675→                int64_t na_sz = dir_size(na_dir, geo_files) +
  1676→                    dir_size(na_dir, street_files) +
  1677→                    dir_size(na_dir, admin_base_files) +
  1678→                    dir_size(na_dir, admin_quality_files);
  1679→                mf << "        \"no-addresses\": {\"size\": " << na_sz << "},\n";
  1680→
  1681→                // Admin base (shared files)
  1682→                std::string admin_dir = rpath + "/admin";
  1683→                int64_t admin_base_sz = dir_size(admin_dir, admin_base_files);
  1684→                mf << "        \"admin\": {\"base_size\": " << admin_base_sz << "}\n";
  1685→            } else {
  1686→                int64_t sz = 0;
  1687→                for (const auto& lists : {geo_files, street_files, address_files,
  1688→                                          admin_base_files, admin_quality_files}) {
  1689→                    sz += dir_size(rpath, lists);
  1690→                }
  1691→                mf << "        \"" << (mode == IndexMode::Full ? "full" :
  1692→                    mode == IndexMode::NoAddresses ? "no-addresses" : "admin") << "\": {\"size\": " << sz << "}\n";
  1693→            }
  1694→            mf << "      },\n";
  1695→
  1696→            // Quality variants
  1697→            if (multi_quality) {
  1698→                std::string admin_dir = multi_output ? rpath + "/admin" : rpath;
  1699→                mf << "      \"qualities\": [\n";
  1700→                for (size_t qi = 0; qi < quality_scales.size(); qi++) {
  1701→                    double scale = quality_scales[qi];
  1702→                    std::string qname = quality_dir_name(scale);
  1703→                    std::string qdir = admin_dir + "/" + qname;
  1704→                    int64_t qsz = dir_size(qdir, admin_quality_files);
  1705→
  1706→                    // Compute epsilon values for this scale
  1707→                    double eps_l2 = (scale == 0) ? 0 : 500.0 * scale * kEpsilonScale;
  1708→                    double eps_l8 = (scale == 0) ? 0 : 15.0 * scale * kEpsilonScale;
  1709→
  1710→                    mf << "        {\"name\": \"" << qname << "\", \"scale\": " << scale
  1711→                       << ", \"size\": " << qsz
  1712→                       << ", \"epsilon_l2_m\": " << eps_l2
  1713→                       << ", \"epsilon_l8_m\": " << eps_l8
  1714→                       << "}";
  1715→                    if (qi + 1 < quality_scales.size()) mf << ",";
  1716→                    mf << "\n";
  1717→                }
  1718→                mf << "      ]\n";
  1719→            } else {
  1720→                mf << "      \"qualities\": []\n";
  1721→            }
  1722→
  1723→            mf << "    }";
  1724→            if (ri + 1 < regions.size()) mf << ",";
  1725→            mf << "\n";
  1726→        }
  1727→
  1728→        mf << "  ]\n";
  1729→        mf << "}\n";
  1730→
  1731→        std::cerr << "Wrote " << output_dir << "/manifest.json" << std::endl;
  1732→    }
  1733→
  1734→    std::cerr << "Done." << std::endl;
  1735→    return 0;


Perfect! Now let me look at the continent processing section more carefully:


  1485→    // Process continents with bounded concurrency, largest first.
  1486→    if (generate_continents) {
  1487→        // Pre-compute continent membership for each unique cell in sorted pairs.
  1488→        // One parallel scan replaces 8 × cell_in_bbox per cell during filtering.
  1489→        auto _pct = std::chrono::steady_clock::now();
  1490→        auto _pcc = CpuTicks::now();
  1491→
  1492→        // Load continent polygons for boundary-based filtering
  1493→        auto continent_polys = get_continent_polygons();
  1494→        std::cerr << "  Loaded " << continent_polys.size() << " continent boundary polygons" << std::endl;
  1495→
  1496→        // For each sorted pair array, build a parallel array of continent bitmasks.
  1497→        // Since pairs are sorted by cell_id, consecutive entries share the same mask.
  1498→        auto precompute_masks = [&continent_polys](const std::vector<CellItemPair>& sorted) -> std::vector<uint8_t> {
  1499→            if (sorted.empty()) return {};
  1500→            std::vector<uint8_t> masks(sorted.size(), 0);
  1501→
  1502→            unsigned nthreads = std::max(1u, std::thread::hardware_concurrency());
  1503→            size_t chunk = (sorted.size() + nthreads - 1) / nthreads;
  1504→            std::vector<size_t> bounds = {0};
  1505→            for (unsigned t = 1; t < nthreads; t++) {
  1506→                size_t target = t * chunk;
  1507→                if (target >= sorted.size()) break;
  1508→                while (target < sorted.size() && sorted[target].cell_id == sorted[target-1].cell_id)
  1509→                    target++;
  1510→                if (target < sorted.size()) bounds.push_back(target);
  1511→            }
  1512→            bounds.push_back(sorted.size());
  1513→
  1514→            std::vector<std::thread> threads;
  1515→            for (size_t th = 0; th + 1 < bounds.size(); th++) {
  1516→                threads.emplace_back([&, th]() {
  1517→                    for (size_t i = bounds[th]; i < bounds[th+1]; ) {
  1518→                        uint64_t cell_id = sorted[i].cell_id;
  1519→                        S2CellId cell(cell_id);
  1520→                        S2LatLng center = cell.ToLatLng();
  1521→                        double lat = center.lat().degrees();
  1522→                        double lng = center.lng().degrees();
  1523→                        uint8_t mask = 0;
  1524→                        // Test against continent polygons (not bboxes)
  1525→                        for (size_t ci = 0; ci < continent_polys.size() && ci < 8; ci++) {
  1526→                            if (point_in_polygon(lat, lng, continent_polys[ci].vertices))
  1527→                                mask |= (1u << ci);
  1528→                        }
  1529→                        while (i < bounds[th+1] && sorted[i].cell_id == cell_id) {
  1530→                            masks[i] = mask;
  1531→                            i++;
  1532→                        }
  1533→                    }
  1534→                });
  1535→            }
  1536→            for (auto& t : threads) t.join();
  1537→            return masks;
  1538→        };
  1539→
  1540→        // Precompute for all three sorted pair arrays
  1541→        auto way_masks = std::async(std::launch::async, [&]{ return precompute_masks(data.sorted_way_cells); });
  1542→        auto addr_masks = std::async(std::launch::async, [&]{ return precompute_masks(data.sorted_addr_cells); });
  1543→        auto interp_masks = std::async(std::launch::async, [&]{ return precompute_masks(data.sorted_interp_cells); });
  1544→        auto way_continent_masks = way_masks.get();
  1545→        auto addr_continent_masks = addr_masks.get();
  1546→        auto interp_continent_masks = interp_masks.get();
  1547→
  1548→        log_phase("Pre-compute continent masks", _pct, _pcc);
  1549→
  1550→        // Sort by bbox area descending — largest continents first
  1551→        std::vector<size_t> continent_order(kContinentCount);
  1552→        std::iota(continent_order.begin(), continent_order.end(), 0u);
  1553→        std::sort(continent_order.begin(), continent_order.end(), [](size_t a, size_t b) {
  1554→            auto area = [](const ContinentBBox& c) {
  1555→                return (c.max_lat - c.min_lat) * (c.max_lng - c.min_lng);
  1556→            };
  1557→            return area(kContinents[a]) > area(kContinents[b]);
  1558→        });
  1559→
  1560→        unsigned max_concurrent = std::max(1u, std::min(4u,
  1561→            std::thread::hardware_concurrency() / 8));
  1562→        std::cerr << "Processing " << kContinentCount << " continents ("
  1563→                  << max_concurrent << " concurrent, largest first)..." << std::endl;
  1564→
  1565→        std::atomic<unsigned> active{0};
  1566→        std::mutex cv_mutex;
  1567→        std::condition_variable cv;
  1568→        std::vector<std::future<void>> futures;
  1569→
  1570→        for (size_t i = 0; i < kContinentCount; i++) {
  1571→            {
  1572→                std::unique_lock<std::mutex> lock(cv_mutex);
  1573→                cv.wait(lock, [&]{ return active.load() < max_concurrent; });
  1574→            }
  1575→            active.fetch_add(1);
  1576→
  1577→            futures.push_back(std::async(std::launch::async, [&, i]() {
  1578→                const auto& continent = kContinents[continent_order[i]];
  1579→                auto _ct = std::chrono::steady_clock::now();
  1580→                auto _cc = CpuTicks::now();
  1581→                std::cerr << "Continent: " << continent.name << " (start)..." << std::endl;
  1582→                uint8_t cbit = 1u << continent_order[i];
  1583→                const auto* poly = (continent_order[i] < continent_polys.size() && !continent_polys[continent_order[i]].vertices.empty())
  1584→                    ? &continent_polys[continent_order[i]].vertices : nullptr;
  1585→                auto subset = filter_by_bbox_masked(data, continent, cbit,
  1586→                    way_continent_masks, addr_continent_masks, interp_continent_masks, poly);
  1587→                log_phase(("  " + std::string(continent.name) + ": filter").c_str(), _ct, _cc);
  1588→                write_region(subset, output_dir + "/" + continent.name);
  1589→                log_phase(("  " + std::string(continent.name) + ": total").c_str(), _ct, _cc);
  1590→
  1591→                active.fetch_sub(1);
  1592→                cv.notify_one();
  1593→            }));
  1594→        }


     1→#pragma once
     2→
     3→#include "parsed_data.h"
     4→
     5→struct ContinentBBox {
     6→    const char* name;
     7→    double min_lat, max_lat, min_lng, max_lng;
     8→};
     9→
    10→extern const ContinentBBox kContinents[];
    11→extern const size_t kContinentCount;
    12→
    13→ParsedData filter_by_bbox(const ParsedData& full, const ContinentBBox& bbox);
    14→
    15→// Fast version using precomputed continent bitmasks (avoids cell_in_bbox per cell)
    16→// If polygon is provided, items are additionally tested at the coordinate level.
    17→ParsedData filter_by_bbox_masked(const ParsedData& full, const ContinentBBox& bbox,
    18→    uint8_t continent_bit,
    19→    const std::vector<uint8_t>& way_masks,
    20→    const std::vector<uint8_t>& addr_masks,
    21→    const std::vector<uint8_t>& interp_masks,
    22→    const std::vector<std::pair<double,double>>* polygon = nullptr);
    23→


Excellent! Now let me check for the write_region function and look at what happens during multi-quality processing:


Bash

grep -n "write_region\|filter_by_bbox_masked\|get_continent_polygons" /root/traccar-geocoder/builder/src/build_index.cpp | head -20


1459:    auto write_region = [&](const ParsedData& d, const std::string& base_dir) {
1482:        write_region(data, output_dir);
1493:        auto continent_polys = get_continent_polygons();
1585:                auto subset = filter_by_bbox_masked(data, continent, cbit,
1588:                write_region(subset, output_dir + "/" + continent.name);


Let me look at the write_region function more carefully:


  1459→    auto write_region = [&](const ParsedData& d, const std::string& base_dir) {
  1460→        ensure_dir(base_dir);
  1461→
  1462→        if (multi_output) {
  1463→            // Write all 3 modes in parallel (they read shared data, write to separate dirs)
  1464→            auto wf1 = std::async(std::launch::async, [&]{ write_index(d, base_dir + "/full", IndexMode::Full); });
  1465→            auto wf2 = std::async(std::launch::async, [&]{ write_index(d, base_dir + "/no-addresses", IndexMode::NoAddresses); });
  1466→            auto wf3 = std::async(std::launch::async, [&]{ write_index(d, base_dir + "/admin", IndexMode::AdminOnly); });
  1467→            wf1.get(); wf2.get(); wf3.get();
  1468→        } else {
  1469→            write_index(d, base_dir, mode);
  1470→        }
  1471→
  1472→        // Write quality variants under admin/ (or base_dir if not multi_output)
  1473→        if (multi_quality) {
  1474→            std::string admin_dir = multi_output ? base_dir + "/admin" : base_dir;
  1475→            std::cerr << "  Writing quality variants for " << base_dir << "..." << std::endl;
  1476→            write_qualities(d, admin_dir);
  1477→        }
  1478→    };
  1479→
  1480→    // Write planet (async — overlaps with continent filtering start)
  1481→    auto planet_future = std::async(std::launch::async, [&]() {
  1482→        write_region(data, output_dir);
  1483→    });


grep -n "get_continent_polygons\|filter_by_bbox_masked" /root/traccar-geocoder/builder/src/*.h /root/traccar-geocoder/builder/src/*.cpp 2>/dev/null | grep -v "Binary"


/root/traccar-geocoder/builder/src/continent_boundaries.h:19:std::vector<ContinentPolygon> get_continent_polygons();
/root/traccar-geocoder/builder/src/continent_filter.h:17:ParsedData filter_by_bbox_masked(const ParsedData& full, const ContinentBBox& bbox,
/root/traccar-geocoder/builder/src/build_index.cpp:1493:        auto continent_polys = get_continent_polygons();
/root/traccar-geocoder/builder/src/build_index.cpp:1585:                auto subset = filter_by_bbox_masked(data, continent, cbit,
/root/traccar-geocoder/builder/src/continent_boundaries.cpp:53:std::vector<ContinentPolygon> get_continent_polygons() {
/root/traccar-geocoder/builder/src/continent_filter.cpp:427:ParsedData filter_by_bbox_masked(const ParsedData& full, const ContinentBBox& bbox,


Let me look at the filter_by_bbox_masked implementation:


   400→    for (const auto& iw : out.interp_ways) used_offsets.insert(iw.street_id);
   401→    for (const auto& ap : out.admin_polygons) used_offsets.insert(ap.name_id);
   402→
   403→    const auto& old_sp = full.string_pool.data();
   404→    std::unordered_map<uint32_t, uint32_t> string_remap;
   405→    auto& new_sp = out.string_pool.mutable_data();
   406→    new_sp.clear();
   407→
   408→    std::vector<uint32_t> sorted_offsets(used_offsets.begin(), used_offsets.end());
   409→    std::sort(sorted_offsets.begin(), sorted_offsets.end());
   410→    for (uint32_t old_off : sorted_offsets) {
   411→        uint32_t new_off = static_cast<uint32_t>(new_sp.size());
   412→        string_remap[old_off] = new_off;
   413→        const char* str = old_sp.data() + old_off;
   414→        size_t len = std::strlen(str);
   415→        new_sp.insert(new_sp.end(), str, str + len + 1);
   416→    }
   417→
   418→    for (auto& w : out.ways) w.name_id = string_remap[w.name_id];
   419→    for (auto& a : out.addr_points) { a.housenumber_id = string_remap[a.housenumber_id]; a.street_id = string_remap[a.street_id]; }
   420→    for (auto& iw : out.interp_ways) iw.street_id = string_remap[iw.street_id];
   421→    for (auto& ap : out.admin_polygons) ap.name_id = string_remap[ap.name_id];
   422→    log_phase("      filter: string pool rebuild", _ft, _fc);
   423→
   424→    return out;
   425→}
   426→
   427→ParsedData filter_by_bbox_masked(const ParsedData& full, const ContinentBBox& bbox,
   428→    uint8_t continent_bit,
   429→    const std::vector<uint8_t>& way_masks,
   430→    const std::vector<uint8_t>& addr_masks,
   431→    const std::vector<uint8_t>& interp_masks,
   432→    const std::vector<std::pair<double,double>>* polygon) {
   433→
   434→    ParsedData out;
   435→    auto _ft = std::chrono::steady_clock::now();
   436→    auto _fc = CpuTicks::now();
   437→
   438→    // Fast mask-based filter using bitset → sorted vector directly
   439→    // Eliminates hash set entirely. O(1) bit set, O(n) scan to extract sorted IDs.
   440→    auto filter_sorted_masked = [&](const std::vector<CellItemPair>& sorted,
   441→                                     const std::vector<uint8_t>& masks,
   442→                                     uint32_t max_id) {
   443→        std::vector<uint32_t> result;
   444→        if (sorted.empty()) return result;
   445→
   446→        unsigned nthreads = std::max(1u, std::thread::hardware_concurrency() / 4);
   447→        size_t bitset_bytes = (max_id + 8) / 8;
   448→        size_t chunk = (sorted.size() + nthreads - 1) / nthreads;
   449→        std::vector<size_t> bounds = {0};
   450→        for (unsigned t = 1; t < nthreads; t++) {
   451→            size_t target = t * chunk;
   452→            if (target >= sorted.size()) break;
   453→            while (target < sorted.size() && sorted[target].cell_id == sorted[target-1].cell_id) target++;
   454→            if (target < sorted.size()) bounds.push_back(target);
   455→        }
   456→        bounds.push_back(sorted.size());
   457→
   458→        // Per-thread bitsets to avoid race conditions on concurrent byte writes
   459→        std::vector<std::vector<uint8_t>> thread_bitsets(bounds.size() - 1);
   460→        std::vector<std::thread> threads;
   461→        for (size_t t = 0; t + 1 < bounds.size(); t++) {
   462→            threads.emplace_back([&, t]() {
   463→                auto& bs = thread_bitsets[t];
   464→                bs.resize(bitset_bytes, 0);
   465→                for (size_t i = bounds[t]; i < bounds[t+1]; i++) {
   466→                    if (masks[i] & continent_bit) {
   467→                        uint32_t id = sorted[i].item_id;
   468→                        if (id < max_id)
   469→                            bs[id / 8] |= (1 << (id % 8));
   470→                    }
   471→                }
   472→            });
   473→        }
   474→        for (auto& t : threads) t.join();
   475→
   476→        // Merge with OR
   477→        std::vector<uint8_t> bitset(bitset_bytes, 0);
   478→        for (auto& bs : thread_bitsets) {
   479→            for (size_t i = 0; i < bitset_bytes; i++) bitset[i] |= bs[i];
   480→        }
   481→
   482→        // Extract sorted IDs from bitset (already in ascending order)
   483→        for (uint32_t id = 0; id < max_id; id++) {
   484→            if (bitset[id / 8] & (1 << (id % 8))) result.push_back(id);
   485→        }
   486→        return result;
   487→    };
   488→
   489→    // Filter from hash map (admin only — no precomputed masks)
   490→    auto filter_cells_map = [&](const std::unordered_map<uint64_t, std::vector<uint32_t>>& cell_map,
   491→                                bool mask_interior = false) {
   492→        std::unordered_set<uint32_t> ids;
   493→        for (const auto& [cell_id, cell_ids] : cell_map) {
   494→            if (cell_in_bbox(cell_id, bbox)) {
   495→                for (uint32_t id : cell_ids)
   496→                    ids.insert(mask_interior ? (id & ID_MASK) : id);
   497→            }
   498→        }
   499→        return ids;
   500→    };
   501→
   502→    // Pass max_id for each data type to size the bitset
   503→    uint32_t max_way_id = static_cast<uint32_t>(full.ways.size());
   504→    uint32_t max_addr_id = static_cast<uint32_t>(full.addr_points.size());
   505→    uint32_t max_interp_id = static_cast<uint32_t>(full.interp_ways.size());
   506→
   507→    auto f_ways = std::async(std::launch::async, [&]{ return filter_sorted_masked(full.sorted_way_cells, way_masks, max_way_id); });
   508→    auto f_addrs = std::async(std::launch::async, [&]{ return filter_sorted_masked(full.sorted_addr_cells, addr_masks, max_addr_id); });
   509→    auto f_interps = std::async(std::launch::async, [&]{ return filter_sorted_masked(full.sorted_interp_cells, interp_masks, max_interp_id); });
   510→    auto f_admin = std::async(std::launch::async, [&]{ return filter_cells_map(full.cell_to_admin, true); });
   511→
   512→    auto used_way_ids = f_ways.get();     // sorted vector<uint32_t>
   513→    auto used_addr_ids = f_addrs.get();   // sorted vector<uint32_t>
   514→    auto used_interp_ids = f_interps.get(); // sorted vector<uint32_t>
   515→    auto used_admin_ids = f_admin.get();  // unordered_set<uint32_t> (admin still uses hash map)
   516→    log_phase("      filter: ID collection (masked)", _ft, _fc);
   517→
   518→    // Reuse the same remap + cell remap + string pool logic from filter_by_bbox
   519→    // (inline the rest — same as filter_by_bbox from the remap section onwards)
   520→    std::unordered_map<uint32_t, uint32_t> way_remap, addr_remap, interp_remap, admin_remap;
   521→
   522→    auto f_remap_ways = std::async(std::launch::async, [&]() {
   523→        auto& sorted_ids = used_way_ids;
   524→        std::vector<WayHeader> ways; std::vector<NodeCoord> nodes;
   525→        ways.reserve(sorted_ids.size()); nodes.reserve(sorted_ids.size() * 5);
   526→        std::unordered_map<uint32_t, uint32_t> remap; remap.reserve(sorted_ids.size());
   527→        for (uint32_t old_id : sorted_ids) {
   528→            const auto& w = full.ways[old_id];
   529→            // Coordinate-level polygon test — include way if ANY node is inside
   530→            if (polygon && w.node_count > 0) {
   531→                bool any_inside = false;
   532→                for (uint8_t n = 0; n < w.node_count; n++) {
   533→                    const auto& nd = full.street_nodes[w.node_offset + n];
   534→                    if (point_in_polygon(nd.lat, nd.lng, *polygon)) { any_inside = true; break; }
   535→                }
   536→                if (!any_inside) continue;
   537→            }
   538→            remap[old_id] = static_cast<uint32_t>(ways.size());
   539→            WayHeader nw = w;
   540→            nw.node_offset = static_cast<uint32_t>(nodes.size()); ways.push_back(nw);
   541→            for (uint8_t n = 0; n < w.node_count; n++) nodes.push_back(full.street_nodes[w.node_offset + n]);
   542→        }
   543→        return std::make_tuple(std::move(remap), std::move(ways), std::move(nodes));
   544→    });
   545→    auto f_remap_addrs = std::async(std::launch::async, [&]() {
   546→        auto& sorted_ids = used_addr_ids;
   547→        std::vector<AddrPoint> addrs; addrs.reserve(sorted_ids.size());
   548→        std::unordered_map<uint32_t, uint32_t> remap; remap.reserve(sorted_ids.size());
   549→        for (uint32_t old_id : sorted_ids) {
   550→            const auto& a = full.addr_points[old_id];
   551→            // Coordinate-level polygon test on address point
   552→            if (polygon && !point_in_polygon(a.lat, a.lng, *polygon)) continue;
   553→            remap[old_id] = static_cast<uint32_t>(addrs.size()); addrs.push_back(a);
   554→        }
   555→        return std::make_tuple(std::move(remap), std::move(addrs));
   556→    });
   557→    auto f_remap_interps = std::async(std::launch::async, [&]() {
   558→        auto& sorted_ids = used_interp_ids;
   559→        std::vector<InterpWay> iways; std::vector<NodeCoord> inodes;
   560→        iways.reserve(sorted_ids.size());
   561→        std::unordered_map<uint32_t, uint32_t> remap; remap.reserve(sorted_ids.size());
   562→        for (uint32_t old_id : sorted_ids) {
   563→            remap[old_id] = static_cast<uint32_t>(iways.size());
   564→            const auto& iw = full.interp_ways[old_id]; InterpWay niw = iw;
   565→            niw.node_offset = static_cast<uint32_t>(inodes.size()); iways.push_back(niw);
   566→            for (uint8_t n = 0; n < iw.node_count; n++) inodes.push_back(full.interp_nodes[iw.node_offset + n]);
   567→        }
   568→        return std::make_tuple(std::move(remap), std::move(iways), std::move(inodes));
   569→    });
   570→    auto f_remap_admins = std::async(std::launch::async, [&]() {
   571→        std::vector<uint32_t> sorted_ids(used_admin_ids.begin(), used_admin_ids.end());
   572→        std::sort(sorted_ids.begin(), sorted_ids.end());
   573→        std::vector<AdminPolygon> polys; std::vector<NodeCoord> verts;
   574→        polys.reserve(sorted_ids.size());
   575→        std::unordered_map<uint32_t, uint32_t> remap; remap.reserve(sorted_ids.size());
   576→        for (uint32_t old_id : sorted_ids) {
   577→            remap[old_id] = static_cast<uint32_t>(polys.size());
   578→            const auto& ap = full.admin_polygons[old_id]; AdminPolygon nap = ap;
   579→            nap.vertex_offset = static_cast<uint32_t>(verts.size()); polys.push_back(nap);
   580→            for (uint32_t v = 0; v < ap.vertex_count; v++) verts.push_back(full.admin_vertices[ap.vertex_offset + v]);
   581→        }
   582→        return std::make_tuple(std::move(remap), std::move(polys), std::move(verts));
   583→    });
   584→
   585→    { auto [wr, ways, nodes] = f_remap_ways.get(); way_remap = std::move(wr); out.ways = std::move(ways); out.street_nodes = std::move(nodes); }
   586→    { auto [ar, addrs] = f_remap_addrs.get(); addr_remap = std::move(ar); out.addr_points = std::move(addrs); }
   587→    { auto [ir, iways, inodes] = f_remap_interps.get(); interp_remap = std::move(ir); out.interp_ways = std::move(iways); out.interp_nodes = std::move(inodes); }
   588→    { auto [ar, polys, verts] = f_remap_admins.get(); admin_remap = std::move(ar); out.admin_polygons = std::move(polys); out.admin_vertices = std::move(verts); }
   589→    log_phase("      filter: data remap (masked)", _ft, _fc);
   590→
   591→    // Remap sorted pairs using mask for fast filtering
   592→    auto remap_sorted_masked = [&](const std::vector<CellItemPair>& sorted,
   593→                                    const std::vector<uint8_t>& masks,
   594→                                    const std::unordered_map<uint32_t, uint32_t>& remap,
   595→                                    std::vector<CellItemPair>& dst) {
   596→        if (sorted.empty()) return;
   597→        unsigned nthreads = std::max(1u, std::thread::hardware_concurrency() / 4);
   598→        size_t chunk = (sorted.size() + nthreads - 1) / nthreads;
   599→        std::vector<size_t> bounds = {0};
   600→        for (unsigned t = 1; t < nthreads; t++) {
   601→            size_t target = t * chunk;
   602→            if (target >= sorted.size()) break;
   603→            while (target < sorted.size() && sorted[target].cell_id == sorted[target-1].cell_id) target++;
   604→            if (target < sorted.size()) bounds.push_back(target);
   605→        }
   606→        bounds.push_back(sorted.size());
   607→        std::vector<std::vector<CellItemPair>> thread_pairs(bounds.size() - 1);
   608→        std::vector<std::thread> threads;
   609→        for (size_t t = 0; t + 1 < bounds.size(); t++) {
   610→            threads.emplace_back([&, t]() {
   611→                auto& local = thread_pairs[t];
   612→                for (size_t i = bounds[t]; i < bounds[t+1]; i++) {
   613→                    if (masks[i] & continent_bit) {
   614→                        auto it = remap.find(sorted[i].item_id);
   615→                        if (it != remap.end()) local.push_back({sorted[i].cell_id, it->second});
   616→                    }
   617→                }
   618→            });
   619→        }
   620→        for (auto& t : threads) t.join();
   621→        size_t total = 0;
   622→        for (auto& v : thread_pairs) total += v.size();
   623→        dst.reserve(total);
   624→        for (auto& v : thread_pairs) dst.insert(dst.end(), v.begin(), v.end());
   625→    };
   626→
   627→    // Admin remap still uses cell_in_bbox (no precomputed masks for admin hash map)
   628→    auto remap_cells_map = [&](const std::unordered_map<uint64_t, std::vector<uint32_t>>& src,
   629→                               const std::unordered_map<uint32_t, uint32_t>& remap,
   630→                               std::unordered_map<uint64_t, std::vector<uint32_t>>& dst,
   631→                               bool handle_flags = false) {
   632→        for (const auto& [cell_id, ids] : src) {
   633→            if (!cell_in_bbox(cell_id, bbox)) continue;
   634→            std::vector<uint32_t> new_ids;
   635→            for (uint32_t id : ids) {
   636→                uint32_t raw_id = handle_flags ? (id & ID_MASK) : id;
   637→                uint32_t flags = handle_flags ? (id & INTERIOR_FLAG) : 0;
   638→                auto it = remap.find(raw_id);
   639→                if (it != remap.end()) new_ids.push_back(it->second | flags);
   640→            }
   641→            if (!new_ids.empty()) dst[cell_id] = std::move(new_ids);
   642→        }
   643→    };
   644→
   645→    {
   646→        auto f1 = std::async(std::launch::async, [&]{ remap_sorted_masked(full.sorted_way_cells, way_masks, way_remap, out.sorted_way_cells); });
   647→        auto f2 = std::async(std::launch::async, [&]{ remap_sorted_masked(full.sorted_addr_cells, addr_masks, addr_remap, out.sorted_addr_cells); });
   648→        auto f3 = std::async(std::launch::async, [&]{ remap_sorted_masked(full.sorted_interp_cells, interp_masks, interp_remap, out.sorted_interp_cells); });
   649→        auto f4 = std::async(std::launch::async, [&]{ remap_cells_map(full.cell_to_admin, admin_remap, out.cell_to_admin, true); });


Perfect! Now let me check the cell_index.h to see the data structures and write_quality_variant more closely:


     1→#pragma once
     2→
     3→#include <string>
     4→#include <unordered_map>
     5→#include <vector>
     6→
     7→#include "types.h"
     8→#include "parsed_data.h"
     9→
    10→std::vector<uint32_t> write_entries(
    11→    const std::string& path,
    12→    const std::vector<uint64_t>& sorted_cells,
    13→    const std::unordered_map<uint64_t, std::vector<uint32_t>>& cell_map);
    14→
    15→std::vector<uint32_t> write_entries_from_sorted(
    16→    const std::string& path,
    17→    const std::vector<uint64_t>& sorted_cells,
    18→    const std::vector<CellItemPair>& sorted_pairs);
    19→
    20→void write_cell_index(
    21→    const std::string& cells_path,
    22→    const std::string& entries_path,
    23→    const std::unordered_map<uint64_t, std::vector<uint32_t>>& cell_map);
    24→
    25→void write_index(const ParsedData& data, const std::string& output_dir, IndexMode mode);
    26→
    27→// Write admin polygon/vertex files with on-the-fly simplification at a given epsilon scale.
    28→// Scale 0 = uncapped (no simplification). Other files are symlinked/copied from source_dir.
    29→void write_quality_variant(const ParsedData& data, const std::string& source_dir,
    30→                           const std::string& output_dir, double epsilon_scale);
    31→


grep -n "write_qualities" /root/traccar-geocoder/builder/src/build_index.cpp | head -5


1433:    auto write_qualities = [&](const ParsedData& d, const std::string& admin_dir) {
1476:            write_qualities(d, admin_dir);


Let me read the write_qualities implementation:


  1433→    auto write_qualities = [&](const ParsedData& d, const std::string& admin_dir) {
  1434→        constexpr unsigned max_concurrent_qualities = 3;
  1435→        std::atomic<unsigned> active{0};
  1436→        std::mutex qmtx;
  1437→        std::condition_variable qcv;
  1438→        std::vector<std::future<void>> qfutures;
  1439→
  1440→        for (double scale : quality_scales) {
  1441→            {
  1442→                std::unique_lock<std::mutex> lock(qmtx);
  1443→                qcv.wait(lock, [&]{ return active.load() < max_concurrent_qualities; });
  1444→            }
  1445→            active.fetch_add(1);
  1446→
  1447→            std::string qname = quality_dir_name(scale);
  1448→            std::string qdir = admin_dir + "/" + qname;
  1449→            qfutures.push_back(std::async(std::launch::async, [&, qdir, scale]() {
  1450→                write_quality_variant(d, admin_dir, qdir, scale);
  1451→                active.fetch_sub(1);
  1452→                qcv.notify_one();
  1453→            }));
  1454→        }
  1455→        for (auto& f : qfutures) f.get();
  1456→    };
  1457→
  1458→    // Write one region: modes + quality variants


     1→#pragma once
     2→
     3→#include <cstdint>
     4→#include <vector>
     5→
     6→// --- Binary format structs (must match server's index reader) ---
     7→
     8→struct WayHeader {
     9→    uint32_t node_offset;
    10→    uint8_t node_count;
    11→    uint32_t name_id;
    12→};
    13→
    14→struct AddrPoint {
    15→    float lat;
    16→    float lng;
    17→    uint32_t housenumber_id;
    18→    uint32_t street_id;
    19→};
    20→
    21→struct InterpWay {
    22→    uint32_t node_offset;
    23→    uint8_t node_count;
    24→    uint32_t street_id;
    25→    uint32_t start_number;
    26→    uint32_t end_number;
    27→    uint8_t interpolation;
    28→};
    29→
    30→struct AdminPolygon {
    31→    uint32_t vertex_offset;
    32→    uint32_t vertex_count;
    33→    uint32_t name_id;
    34→    uint8_t admin_level;
    35→    float area;
    36→    uint16_t country_code;
    37→};
    38→
    39→struct NodeCoord {
    40→    float lat;
    41→    float lng;
    42→};
    43→
    44→// Sorted cell-item pair for direct entry writing (avoids hash map)
    45→struct CellItemPair {
    46→    uint64_t cell_id;
    47→    uint32_t item_id;
    48→};
    49→
    50→// --- Constants ---
    51→
    52→static const uint32_t INTERIOR_FLAG = 0x80000000u;
    53→static const uint32_t ID_MASK       = 0x7FFFFFFFu;
    54→static const uint32_t NO_DATA       = 0xFFFFFFFFu;
    55→
    56→// Simplification mode
    57→enum class SimplifyMode { MaxVertices, ErrorBounded };
    58→
    59→// Processing limits
    60→static constexpr size_t MAX_BLOCK_QUEUE         = 64;    // producer-consumer queue depth
    61→static constexpr int    MAX_NODE_COUNT          = 255;   // uint8_t node_count
    62→static constexpr int    MAX_VERTEX_COUNT        = 0x7FFFFFFF; // uint32_t vertex_count
    63→static constexpr int    MAX_S2_CELLS_PER_POLY   = 200;   // S2RegionCoverer max_cells
    64→static constexpr int    BACKTRACK_CALL_BUDGET   = 100000; // per-ring backtracking limit
    65→static constexpr int    BACKTRACK_TOTAL_BUDGET  = 500000; // per-relation backtracking limit
    66→static constexpr int    BACKTRACK_MAX_DEPTH     = 200;    // recursion depth limit
    67→static constexpr size_t MAX_SUBWAYS_FOR_RETRY   = 30;     // only retry small relations
    68→static constexpr size_t MAX_NODE_ID_DEFAULT     = 15000000000ULL; // dense index capacity
    69→
    70→// --- Index mode ---
    71→
    72→enum class IndexMode { Full, NoAddresses, AdminOnly };
    73→
    74→// --- Deferred S2 work items ---
    75→
    76→struct DeferredWay {
    77→    uint32_t way_id;
    78→    uint32_t node_offset;
    79→    uint8_t node_count;
    80→};
    81→
    82→struct DeferredInterp {
    83→    uint32_t interp_id;
    84→    uint32_t node_offset;
    85→    uint8_t node_count;
    86→};
    87→
    88→// Collected relation data for parallel admin assembly
    89→struct CollectedRelation {
    90→    int64_t id;
    91→    uint8_t admin_level;
    92→    std::string name;
    93→    std::string country_code;
    94→    bool is_postal;
    95→    std::vector<std::pair<int64_t, std::string>> members; // (way_id, role)
    96→};
    97→


Perfect! Now let me create a comprehensive summary document of my findings. Let me do a final check on the tools directory and look at any documentation:


total 7783
drwxr-xr-x 2 root root        6 Mar 24 22:15 .
drwxr-xr-x 8 root root       10 Mar 26 20:19 ..
-rw-r--r-- 1 root root   154460 Mar 23 16:27 comparison.geojson
-rw-r--r-- 1 root root     5349 Mar 24 22:15 simplification_map.html
-rw-r--r-- 1 root root 14822689 Mar 23 23:22 simplification_viewer.html
-rw-r--r-- 1 root root    13274 Mar 23 23:04 simplify_compare.cpp


Now let me check the OPTIMIZATION_LOG for useful context:


     1→# Build Optimization Log
     2→
     3→## Final Result: 54m → 12m 22s (77% faster)
     4→
     5→Build: `--multi-output --continents --multi-quality`
     6→Output: 379 files, 91 GiB (planet + 8 continents × 3 modes × 7 quality levels)
     7→Machine: Node 3 — 32-core / 174 GiB RAM
     8→Validated: planet output identical to pre-optimization baseline
     9→
    10→## Phase Breakdown (Node 3)
    11→
    12→| Phase | Baseline (54m) | Final (12m 22s) | Speedup |
    13→|---|---|---|---|
    14→| Pass 1: relations | 46.6s | **3.9-7s** | 7-12x |
    15→| Pass 2: nodes | 184.4s | **80-106s** | 1.7-2.3x |
    16→| Pass 2b: ways | 132.3s | **88-115s** | 1.1-1.5x |
    17→| Admin S2 drain | 134.4s | 109-132s | ~same |
    18→| S2 street ways | 136.9s | 129-155s | ~same |
    19→| Rebuild cell maps | 224.2s | **0s** | eliminated |
    20→| Dedup | (in S2) | 38-55s | — |
    21→| Continent processing | 2087.5s | **60-131s** | 16-35x |
    22→| **Total** | **54m 1.7s** | **12m 22s** | **4.4x** |
    23→
    24→## All Optimizations (30+)
    25→
    26→### Custom PBF Reader (replaced osmium)
    27→1. Parallel PBF reader with per-thread fds and pread
    28→2. Streaming node decode — no PbfNode objects, inline callback
    29→3. Streaming way decode — no PbfWay objects, inline callback
    30→4. Zero-copy varint decode for dense nodes
    31→5. Binary search blob classification (32 decompressions vs 50K)
    32→6. Reusable decompression buffer + z_stream per thread
    33→7. Flat way_refs array (eliminates per-way vector allocation)
    34→8. PbfBlock reuse across iterations (keeps vector capacity)
    35→9. Zero-copy tag storage (string table indices, not copies)
    36→10. posix_fadvise WILLNEED for page cache warming
    37→11. Single-pass tag extraction + early exit for irrelevant ways
    38→12. Bitset admin way lookup (replaces hash set)
    39→13. First-character switch for highway/tag comparisons
    40→
    41→### Data Processing
    42→14. Parallel continents (4 concurrent, largest-first by bbox area)
    43→15. Eliminated planet cell map rebuild (filter from sorted pairs)
    44→16. Parallel remap in filter_by_bbox
    45→17. Parallel mode writes (full/no-addresses/admin simultaneously)
    46→18. Parallel quality variants (3 concurrent)
    47→19. Sorted pair filtering (cache-friendly linear scan)
    48→20. Parallel chunked scanning per continent
    49→21. Parallel per-cell dedup
    50→22. Admin polygon sorting (largest-first for work-stealing)
    51→23. Worker threads = N-1
    52→24. Deterministic interp resolution (lexicographic tiebreaker)
    53→25. Sorted pair remap for continents (fixes street_entries bug)
    54→26. Precomputed continent bitmasks (1 S2 lookup per cell instead of 8)
    55→27. Bitset ID collection for continent filtering (replaces hash set)
    56→28. Per-thread bitsets to avoid race conditions
    57→29. MADV_HUGEPAGE on dense node index
    58→
    59→### Continent Boundaries
    60→30. Geofabrik .poly files for continent boundaries
    61→31. Coordinate-level polygon filtering (point-in-polygon per item)
    62→32. Any-node-inside way matching (matches Geofabrik behavior)
    63→
    64→### Quality Variants
    65→33. Never drop polygons — binary search for minimum epsilon preserving ≥4 vertices
    66→
    67→### Profiling
    68→34. Per-phase CPU/memory profiling (getrusage + /proc/self/statm)
    69→35. Per-thread read/decode/callback timing in streaming readers
    70→
    71→## Bug Fixes
    72→- Continent street_entries.bin was empty (fixed by sorted pair remap)
    73→- Deterministic interp resolution (old code had nondeterministic last-wins)
    74→- PBF way callback used return instead of continue (skipped 50% of ways)
    75→- Race condition in continent bitset (per-thread bitsets fix)
    76→- Polygons dropped during quality simplification (min-vertex enforcement)
    77→
    78→## Multi-Machine Results
    79→
    80→| Machine | Cores | RAM | Build Time |
    81→|---|---|---|---|
    82→| Node 3 (Newer CPU) | 32 | 174 GiB | **12m 22s** |
    83→| Node 2b (E5-2699A v4) | 80 (cgroup) | 192 GiB | ~22-27m (I/O bound) |
    84→
    85→Node 2b is slower despite more cores due to older CPU, slower storage, and
    86→NUMA effects on the 111 GiB dense index. The fadvise optimization helps
    87→significantly (72% faster reads) but the machine's I/O subsystem limits
    88→parallel pread throughput.
    89→


Excellent! Now I have comprehensive information. Let me create a detailed summary of all the findings:

## Summary: Traccar Geocoder Codebase Analysis

### 1. **Patch Generation/Delta Tools**

No existing patch generation tools found in the codebase. However, there is a robust **comparison infrastructure**:

**Comparison Tools (builder/test/):**
- **`compare_indexes.cpp`** - Semantic comparison tool that:
  - Decodes all binary files (ways, addresses, admin, interpolations)
  - Creates canonical fingerprints for each item (name + sorted coordinates at 1e5 grid precision)
  - Compares collections as multisets (handles parallel/sequential ordering differences)
  - Two comparison modes:
    - **Exact**: Full coordinate precision fingerprinting
    - **Semantic**: Cross-version comparison using coarse grid (100m precision) and name/count only
  - Returns 0 if identical, 1 if different; reports missing/extra item counts

- **`deep_compare.cpp`** - Boundary analysis tool that:
  - Shows sample items only in directory A vs directory B
  - Reports first/last node coordinates for ways
  - Identifies edge differences for understanding filter boundaries
  - Customizable output (--ways, --addrs, --admins, --limit N)

**Fingerprint Strategy:**
```cpp
way_fingerprint: "name|node_count|sorted_grid_coords"
addr_fingerprint: "grid_lat,grid_lng|housenumber|street"
admin_fingerprint: "name|admin_level|country|sorted_grid_vertices"
interp_fingerprint: "street|start-end|interp_type|sorted_grid_nodes"
```

### 2. **Manifest.json Structure**

Generated at end of build process (`/root/traccar-geocoder/builder/src/build_index.cpp` lines 1602-1732):

```json
{
  "version": 1,
  "regions": [
    {
      "name": "planet|continent_name",
      "modes": {
        "full": { "size": <bytes> },
        "no-addresses": { "size": <bytes> },
        "admin": { "base_size": <bytes> }
      },
      "qualities": [
        {
          "name": "uncapped|q<scale>",
          "scale": <float>,
          "size": <bytes>,
          "epsilon_l2_m": <meters>,
          "epsilon_l8_m": <meters>
        }
      ]
    }
  ]
}
```

**Key Characteristics:**
- Single manifest covers all regions (planet + 8 continents if `--continents` flag set)
- Multi-mode support: Full (streets+addresses), NoAddresses (streets only), AdminOnly
- Quality variants track simplification levels (0=uncapped, then scaled 0.2-2.5x)
- File sizes calculated from directory entries for download planning
- Regions fully independent — can be distributed separately

### 3. **Semantic Comparison Strategy**

The `compare_indexes.cpp` and `deep_compare.cpp` demonstrate a **multiset-based semantic comparison** rather than binary-exact:

**How Comparison Works (compare_indexes.cpp):**
1. Load all items from both directories
2. For each item type (ways, addresses, admin, interps):
   - Build fingerprint from canonical form (sorted coordinates + metadata)
   - Create frequency map of fingerprints
   - Compare as multisets: count missing/extra fingerprints
3. **Result**: Reports counts of matched items and differences

**Tolerances:**
- Exact mode: 1e5 precision (roughly 1m grid)
- Semantic mode: 1e3 precision (roughly 100m grid) for cross-version comparison
- Ways considered equal if: same name + same set of nodes (order-independent)
- Addresses considered equal if: same housenumber + street + coarse position
- Admin equal if: same name + level (vertices can differ slightly)

### 4. **Continent Filtering Pipeline**

The system produces region-specific indexes via **bbox + polygon filtering** with three optimization levels:

**Phase 1: Precompute Continent Bitmasks** (lines 1487-1548)
```
For each unique S2 cell_id in sorted pairs:
  - Compute S2LatLng center
  - Test against continent polygons (loaded from Geofabrik .poly files)
  - Set bit i if cell center is in continent i
  - Store as parallel uint8_t masks array (one entry per sorted pair)
```

**Phase 2: Fast Bitset-Based Filtering** (continent_filter.cpp lines 440-487)
```
filter_sorted_masked():
  - For each sorted pair, check if masks[i] & continent_bit
  - Use per-thread bitsets to collect matching item IDs (avoids hash set)
  - Merge bitsets with OR operation
  - Extract sorted ID vector (in ascending order)
```

**Phase 3: Parallel Chunked Remapping** (continent_filter.cpp lines 591-625)
```
remap_sorted_masked():
  - Scan sorted pairs at cell boundaries (parallel chunks)
  - Check mask, then remap old_id → new_id
  - Each thread builds local CellItemPair vector
  - Concatenate (already in sorted order)
```

**Key Optimization:**
- Precomputed masks: **eliminates 8 cell_in_bbox() calls per cell** → 16-35x speedup
- Coordinate-level polygon test as secondary filter (matches Geofabrik behavior)
- Any-node-inside matching for ways (if ANY node is inside polygon, include way)

**Output per Continent:**
- Compressed data structures (sorted pairs instead of hash maps)
- Rewritten cell indices pointing to new data offsets
- Deduplicated string pool (only strings referenced in filtered data)
- Parallel interior flag handling for admin boundaries

### 5. **Download/Distribution Mechanism**

**Distribution Structure:**
```
output_dir/
├── manifest.json              # Single manifest covering all regions
├── planet/                    # Full planet data
│   ├── full/                 # All modes written in parallel
│   │   ├── *_cells.bin
│   │   ├── *_entries.bin
│   │   ├── *_ways.bin, etc.
│   ├── no-addresses/
│   ├── admin/
│   │   ├── admin_polygons.bin (base shared)
│   │   ├── uncapped/, q0.2/, q0.5/, ... (quality variants)
├── africa/                    # Per-continent (if --continents flag)
│   ├── full/, no-addresses/, admin/
│   ├── admin/ (with quality subdirs)
├── asia/, europe/, ... (8 total continents)
```

**Distribution Strategy:**
1. Single `manifest.json` lists all available regions/modes
2. Client selects region (planet or continent) and mode
3. Downloads 14 binary files for selected combination
4. Quality variants optional (stored separately from base)

**File Sharing:**
- Admin base files (`admin_cells.bin`, `admin_entries.bin`, `strings.bin`) shared across quality levels
- Quality variants only contain changed files (`admin_polygons.bin`, `admin_vertices.bin`)
- Reduces storage: full build is ~91 GiB for planet + 8 continents × 3 modes × 7 qualities

**No Download Tool in Builder:** Distribution is expected to be handled externally (e.g., HTTP server, CDN). The builder only produces the files.

### 6. **Index File Production (write_index & write_entries_from_sorted)**

**Entry Production from In-Memory Data** (cell_index.cpp lines 56-133):

```cpp
write_entries_from_sorted():
  Input: sorted_cells (vector of unique uint64_t), sorted_pairs (CellItemPair array)

  1. Split sorted_pairs into N threads by cell boundaries (keep cell together)
  2. Each thread builds entry buffer for its chunk:
     - For each matching cell, write: [uint16_t count][uint32_t item_id ...]
     - Track offsets relative to thread start
  3. Merge thread offsets to global offsets
  4. Concatenate all thread buffers into single file
```

**Geographic Index Production** (cell_index.cpp lines 159-284):

```cpp
write_index():

  1. Extract unique cells from sorted_way/addr/interp_cells
  2. Merge into single sorted geo_cells list (with duplicates removed)
  3. Write geo_cells.bin: [uint64_t cell_id][uint32_t street_offset][uint32_t addr_offset][uint32_t interp_offset]
  4. Write entries in parallel:
     - street_entries.bin: per-cell street way IDs
     - addr_entries.bin: per-cell address point IDs
     - interp_entries.bin: per-cell interpolation way IDs
  5. Write data arrays:
     - street_ways.bin: WayHeader structs
     - street_nodes.bin: NodeCoord structs
     - addr_points.bin: AddrPoint structs (lat, lng, housenumber_id, street_id)
     - interp_ways.bin: InterpWay structs
     - interp_nodes.bin: NodeCoord structs
  6. Write admin in parallel:
     - admin_cells.bin: [uint64_t cell_id][uint32_t offset]
     - admin_entries.bin: [uint16_t count][uint32_t polygon_id ...]
     - admin_polygons.bin: AdminPolygon structs
     - admin_vertices.bin: NodeCoord structs
  7. Write strings.bin: deduplicated null-terminated strings
  8. Compact if needed (AdminOnly or NoAddresses modes)
```

**Quality Variant Production** (cell_index.cpp lines 387-469):

```cpp
write_quality_variant():
  Input: ParsedData, source_dir (admin files to read), output_dir, epsilon_scale

  1. For each admin polygon:
     - Extract vertices from source
     - Simplify using RDP with epsilon_scale × per-level defaults
     - Ensure ≥3 vertices (binary search for minimum epsilon preserving vertices)
  2. Build new vertex array (reindexed)
  3. Write admin_polygons.bin (reindexed), admin_vertices.bin
  4. Other files symlinked/copied from source_dir
```

**Parallelization:**
- Threads = hardware_concurrency - 1
- Entry writing uses per-thread buffering (no locks)
- Quality variants limited to 3 concurrent (CPU-bound simplification)
- Multi-output (full/no-addresses/admin) all 3 modes written simultaneously

### File Inventory (14 files per index mode)

| File | Content | Size Estimate |
|------|---------|----------------|
| `geo_cells.bin` | S2 cell index (merged ways+addrs+interps) | 5-50 MB |
| `street_entries.bin` | Way IDs per cell | 10-100 MB |
| `street_ways.bin` | WayHeader (offset, count, name_id) | 10-100 MB |
| `street_nodes.bin` | NodeCoord (lat, lng) for ways | 100 MB-1 GB |
| `addr_entries.bin` | Address point IDs per cell | 1-20 MB |
| `addr_points.bin` | AddrPoint (lat, lng, house#, street) | 50-500 MB |
| `interp_entries.bin` | Interpolation way IDs per cell | 1-10 MB |
| `interp_ways.bin` | InterpWay headers | 10-100 MB |
| `interp_nodes.bin` | NodeCoord for interpolations | 10-100 MB |
| `admin_cells.bin` | S2 cell index for boundaries | 1-10 MB |
| `admin_entries.bin` | Polygon IDs per cell | 1-10 MB |
| `admin_polygons.bin` | AdminPolygon metadata | 1-10 MB |
| `admin_vertices.bin` | NodeCoord for polygon boundaries | 50-500 MB |
| `strings.bin` | Deduplicated string pool (names, streets, etc.) | 10-100 MB |

---

**Key Files for Reference:**
- `/root/traccar-geocoder/builder/src/cell_index.cpp` - Write functions (lines 18-469)
- `/root/traccar-geocoder/builder/src/cell_index.h` - Function signatures
- `/root/traccar-geocoder/builder/src/build_index.cpp` - Main orchestration (lines 1459-1732 for manifest + continent processing)
- `/root/traccar-geocoder/builder/src/continent_filter.cpp` - Filter implementation (lines 35-650)
- `/root/traccar-geocoder/builder/test/compare_indexes.cpp` - Semantic comparison (full file)
- `/root/traccar-geocoder/README.md` - Distribution format documentation