tangrams · rwrx · Dec 18, 2019
diff --git a/core/include/tangram/data/clientDataSource.h b/core/include/tangram/data/clientDataSource.h
@@ -50,11 +50,17 @@ class ClientDataSource : public TileSource {
 
     void addPointFeature(Properties&& properties, LngLat coordinates);
 
-    void addPolylineFeature(Properties&& properties, PolylineBuilder&& polyline);
+    uint64_t addPolylineFeature(Properties&& properties, PolylineBuilder&& polyline);
 
     void addPolygonFeature(Properties&& properties, PolygonBuilder
         && polygon);
 
+    void updatePolylineFeature(uint64_t id, const Coordinates& coordinates);
+
+    void updatePolylineFeature(uint64_t id, const Properties&& properties);
+
+    void removePolylineFeature(uint64_t id);
+
     // Transform added feature data into tiles.
     void generateTiles();
 

diff --git a/core/include/tangram/data/tileSource.h b/core/include/tangram/data/tileSource.h
@@ -54,6 +54,8 @@ class TileSource : public std::enable_shared_from_this<TileSource> {
     struct DataSource {
         virtual ~DataSource() {}
 
+        virtual TileID getFallbackTileID(const TileID& _tileID, int32_t _maxZoom, int32_t _zoomBias) = 0;
+
         virtual bool loadTileData(std::shared_ptr<TileTask> _task, TileTaskCb _cb) = 0;
 
         /* Stops any running I/O tasks pertaining to @_tile */
@@ -92,6 +94,8 @@ class TileSource : public std::enable_shared_from_this<TileSource> {
      */
     virtual const char* mimeType() const;
 
+    TileID getFallbackTileID(const TileID& _tileID);
+
     /* Fetches data for the map tile specified by @_tileID
      *
      * LoadTile starts an asynchronous I/O task to retrieve the data for a tile. When

diff --git a/core/src/data/clientDataSource.cpp b/core/src/data/clientDataSource.cpp
@@ -38,6 +38,7 @@ struct ClientDataSource::Storage {
     std::unique_ptr<geojsonvt::GeoJSONVT> tiles;
     geometry::feature_collection<double> features;
     std::vector<Properties> properties;
+    std::map<uint64_t, uint64_t> polylineIds;
 };
 
 struct ClientDataSource::PolylineBuilderData : mapbox::geometry::line_string<double> {
@@ -260,14 +261,21 @@ void ClientDataSource::addPointFeature(Properties&& properties, LngLat coordinat
     m_store->properties.emplace_back(properties);
 }
 
-void ClientDataSource::addPolylineFeature(Properties&& properties, PolylineBuilder&& polyline) {
+uint64_t ClientDataSource::addPolylineFeature(Properties&& properties, PolylineBuilder&& polyline) {
 
     std::lock_guard<std::mutex> lock(m_mutexStore);
 
-    uint64_t id = m_store->features.size();
+    uint64_t i = m_store->features.size();
+    uint64_t id = m_store->polylineIds.size();
+
+    properties.set("id", std::to_string(id));
+
     auto geom = std::move(polyline.data);
-    m_store->features.emplace_back(*geom, id);
+    m_store->features.emplace_back(*geom, i);
     m_store->properties.emplace_back(properties);
+    m_store->polylineIds.insert(std::pair<uint64_t, uint64_t>(id, i));
+
+    return id;
 }
 
 void ClientDataSource::addPolygonFeature(Properties&& properties, PolygonBuilder&& polygon) {
@@ -280,6 +288,61 @@ void ClientDataSource::addPolygonFeature(Properties&& properties, PolygonBuilder
     m_store->properties.emplace_back(properties);
 }
 
+void ClientDataSource::updatePolylineFeature(uint64_t id, const Coordinates& coordinates) {
+
+    std::lock_guard<std::mutex> lock(m_mutexStore);
+
+    std::map<uint64_t, uint64_t>::iterator findIt = m_store->polylineIds.find(id);
+
+    if (findIt != m_store->polylineIds.end() && findIt->second < m_store->features.size()) {
+        uint64_t i = findIt->second;
+
+        geometry::line_string<double> geom;
+        for (auto &p : coordinates) {
+            geom.emplace_back(p.longitude, p.latitude);
+        }
+
+        m_store->features[i] = mapbox::geometry::feature<double>(geom, i);
+    }
+}
+
+void ClientDataSource::updatePolylineFeature(uint64_t id, const Properties&& properties) {
+
+    std::lock_guard<std::mutex> lock(m_mutexStore);
+
+    std::map<uint64_t, uint64_t>::iterator findIt = m_store->polylineIds.find(id);
+
+    if (findIt != m_store->polylineIds.end() && findIt->second < m_store->properties.size()) {
+        uint64_t i = findIt->second;
+
+        for (int j = 0; j < properties.items().size(); ++j) {
+            m_store->properties[i].set(properties.items()[j].key,
+                properties.getString(properties.items()[j].key));
+        }
+    }
+}
+
+void ClientDataSource::removePolylineFeature(uint64_t id) {
+
+    std::lock_guard<std::mutex> lock(m_mutexStore);
+
+    std::map<uint64_t, uint64_t>::iterator findIt = m_store->polylineIds.find(id);
+
+    if (findIt != m_store->polylineIds.end() && findIt->second < m_store->features.size()) {
+        uint64_t i = findIt->second;
+
+        m_store->features.erase(std::next(m_store->features.begin(), i));
+        m_store->properties.erase(std::next(m_store->properties.begin(), i));
+
+        for (std::map<uint64_t, uint64_t>::iterator it = m_store->polylineIds.begin(); it != m_store->polylineIds.end(); ++it) {
+            if (it->second > i) {
+                it->second = it->second - 1;
+                m_store->features[it->second].id = it->second;
+            }
+        }
+    }
+}
+
 struct add_geometry {
 
     static constexpr double extent = 4096.0;

diff --git a/core/src/data/mbtilesDataSource.cpp b/core/src/data/mbtilesDataSource.cpp
@@ -132,6 +132,24 @@ MBTilesDataSource::MBTilesDataSource(Platform& _platform, std::string _name, std
 MBTilesDataSource::~MBTilesDataSource() {
 }
 
+TileID MBTilesDataSource::getFallbackTileID(const TileID& _tileID, int32_t _maxZoom, int32_t _zoomBias) {
+
+    TileID tileID(_tileID);
+
+    while (!hasTileData(tileID) && tileID.z > 0) {
+        tileID = tileID.getParent(_zoomBias);
+    }
+
+    if (tileID.z == _maxZoom) {
+        tileID = _tileID;
+    }
+    else {
+        tileID.s = _tileID.s;
+    }
+
+    return tileID;
+}
+
 bool MBTilesDataSource::loadTileData(std::shared_ptr<TileTask> _task, TileTaskCb _cb) {
 
     if (m_offlineMode) {
@@ -196,12 +214,12 @@ bool MBTilesDataSource::loadNextSource(std::shared_ptr<TileTask> _task, TileTask
             if (m_cacheMode) {
                 m_worker->enqueue([this, _task](){
 
-                        auto& task = static_cast<BinaryTileTask&>(*_task);
+                    auto& task = static_cast<BinaryTileTask&>(*_task);
 
-                        LOGW("store tile: %s, %d", _task->tileId().toString().c_str(), task.hasData());
+                    LOGW("store tile: %s, %d", _task->tileId().toString().c_str(), task.hasData());
 
-                        storeTileData(_task->tileId(), *task.rawTileData);
-                    });
+                    storeTileData(_task->tileId(), *task.rawTileData);
+                });
             }
 
             _cb.func(_task);
@@ -422,8 +440,50 @@ void MBTilesDataSource::initSchema(SQLite::Database& db, std::string _name, std:
     }
 }
 
+bool MBTilesDataSource::hasTileData(const TileID& _tileId) {
+
+    TileID tileId = TileID(_tileId);
+    tileId.s = 0;
+
+    auto search = m_HasTileDataCache.find(tileId);
+
+    if (search != m_HasTileDataCache.end()) {
+        return search->second;
+    }
+
+    auto& stmt = m_queries->getTileData;
+    try {
+        // Google TMS to WMTS
+        // https://github.com/mapbox/node-mbtiles/blob/
+        // 4bbfaf991969ce01c31b95184c4f6d5485f717c3/lib/mbtiles.js#L149
+        int z = _tileId.z;
+        int y = (1 << z) - 1 - _tileId.y;
+
+        stmt.bind(1, z);
+        stmt.bind(2, _tileId.x);
+        stmt.bind(3, y);
+
+        if (stmt.executeStep()) {
+            stmt.reset();
+            m_HasTileDataCache[tileId] = true;
+            return true;
+        }
+
+    } catch (std::exception& e) {
+        LOGE("MBTiles SQLite get tile_data statement failed: %s", e.what());
+    }
+    try {
+        stmt.reset();
+    } catch (...) {}
+
+    m_HasTileDataCache[tileId] = false;
+    return false;
+}
+
 bool MBTilesDataSource::getTileData(const TileID& _tileId, std::vector<char>& _data) {
 
+    int largestLength = 0;
+
     auto& stmt = m_queries->getTileData;
     try {
         // Google TMS to WMTS
@@ -441,20 +501,24 @@ bool MBTilesDataSource::getTileData(const TileID& _tileId, std::vector<char>& _d
             const char* blob = (const char*) column.getBlob();
             const int length = column.getBytes();
 
-            if ((m_schemaOptions.compression == Compression::undefined) ||
-                (m_schemaOptions.compression == Compression::deflate)) {
-
-                if (zlib::inflate(blob, length, _data) != 0) {
-                    if (m_schemaOptions.compression == Compression::undefined) {
-                        _data.resize(length);
-                        memcpy(_data.data(), blob, length);
-                    } else {
-                        LOGW("Invalid deflate compression");
+            if (length > largestLength) {
+                if ((m_schemaOptions.compression == Compression::undefined) ||
+                    (m_schemaOptions.compression == Compression::deflate)) {
+
+                    if (zlib::inflate(blob, length, _data) != 0) {
+                        if (m_schemaOptions.compression == Compression::undefined) {
+                            _data.resize(length);
+                            memcpy(_data.data(), blob, length);
+                        } else {
+                            LOGW("Invalid deflate compression");
+                        }
                     }
+                } else {
+                    _data.resize(length);
+                    memcpy(_data.data(), blob, length);
                 }
-            } else {
-                _data.resize(length);
-                memcpy(_data.data(), blob, length);
+
+                largestLength = length;
             }
 
             stmt.reset();

diff --git a/core/src/data/mbtilesDataSource.h b/core/src/data/mbtilesDataSource.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <map>
 #include "data/tileSource.h"
 
 namespace SQLite {
@@ -22,11 +23,14 @@ class MBTilesDataSource : public TileSource::DataSource {
 
     ~MBTilesDataSource();
 
+    TileID getFallbackTileID(const TileID& _tileID, int32_t _maxZoom, int32_t _zoomBias) override;
+
     bool loadTileData(std::shared_ptr<TileTask> _task, TileTaskCb _cb) override;
 
     void clear() override {}
 
 private:
+    bool hasTileData(const TileID& _tileId);
     bool getTileData(const TileID& _tileId, std::vector<char>& _data);
     void storeTileData(const TileID& _tileId, const std::vector<char>& _data);
     bool loadNextSource(std::shared_ptr<TileTask> _task, TileTaskCb _cb);
@@ -52,6 +56,9 @@ class MBTilesDataSource : public TileSource::DataSource {
     std::unique_ptr<MBTilesQueries> m_queries;
     std::unique_ptr<AsyncWorker> m_worker;
 
+    // Cached has tile data
+    std::map<TileID, bool> m_HasTileDataCache;
+
     // Platform reference
     Platform& m_platform;
 

diff --git a/core/src/data/memoryCacheDataSource.cpp b/core/src/data/memoryCacheDataSource.cpp
@@ -22,8 +22,17 @@ struct RawCache {
 
     CacheMap m_cacheMap;
     CacheList m_cacheList;
-    int m_usage = 0;
-    int m_maxUsage = 0;
+    size_t m_usage = 0;
+    size_t m_maxUsage = 0;
+
+    bool has(const TileID& _tileID) {
+
+        if (m_maxUsage <= 0) { return false; }
+
+        std::lock_guard<std::mutex> lock(m_mutex);
+
+        return m_cacheMap.find(_tileID) != m_cacheMap.end();
+    }
 
     bool get(BinaryTileTask& _task) {
 
@@ -93,6 +102,10 @@ void MemoryCacheDataSource::setCacheSize(size_t _cacheSize) {
     m_cache->m_maxUsage = _cacheSize;
 }
 
+bool MemoryCacheDataSource::hasCache(const TileID& _tileID) {
+    return m_cache->has(_tileID);
+}
+
 bool MemoryCacheDataSource::cacheGet(BinaryTileTask& _task) {
     return m_cache->get(_task);
 }
@@ -101,6 +114,43 @@ void MemoryCacheDataSource::cachePut(const TileID& _tileID, std::shared_ptr<std:
     m_cache->put(_tileID, _rawDataRef);
 }
 
+TileID MemoryCacheDataSource::getFallbackTileID(const TileID& _tileID, int32_t _maxZoom, int32_t _zoomBias) {
+
+    TileID tileID(_tileID);
+    bool isCached = false;
+
+    while (!(isCached = hasCache(tileID)) && tileID.z > 0) {
+        tileID = tileID.getParent(_zoomBias);
+    }
+
+    if (tileID.z == _maxZoom) {
+        tileID = _tileID;
+    }
+    else {
+        tileID.s = _tileID.s;
+    }
+
+    if (next) {
+        TileID nextTileID = next->getFallbackTileID(_tileID, _maxZoom, _zoomBias);
+
+        if (nextTileID.z == _maxZoom) {
+            nextTileID = _tileID;
+        }
+        else {
+            nextTileID.s = _tileID.s;
+        }
+
+        if (isCached) {
+            return (tileID.z > nextTileID.z) ? tileID : nextTileID;
+        }
+        else {
+            return nextTileID;
+        }
+    }
+
+    return tileID;
+}
+
 bool MemoryCacheDataSource::loadTileData(std::shared_ptr<TileTask> _task, TileTaskCb _cb) {
 
     auto& task = static_cast<BinaryTileTask&>(*_task);

diff --git a/core/src/data/memoryCacheDataSource.h b/core/src/data/memoryCacheDataSource.h
@@ -10,6 +10,8 @@ class MemoryCacheDataSource : public TileSource::DataSource {
     MemoryCacheDataSource();
     ~MemoryCacheDataSource();
 
+    TileID getFallbackTileID(const TileID& _tileID, int32_t _maxZoom, int32_t _zoomBias) override;
+
     bool loadTileData(std::shared_ptr<TileTask> _task, TileTaskCb _cb) override;
 
     void clear() override;
@@ -20,6 +22,7 @@ class MemoryCacheDataSource : public TileSource::DataSource {
     void setCacheSize(size_t _cacheSize);
 
 private:
+    bool hasCache(const TileID& _tileID);
     bool cacheGet(BinaryTileTask& _task);
 
     void cachePut(const TileID& _tileID, std::shared_ptr<std::vector<char>> _rawDataRef);

diff --git a/core/src/data/networkDataSource.h b/core/src/data/networkDataSource.h
@@ -15,6 +15,8 @@ class NetworkDataSource : public TileSource::DataSource {
     NetworkDataSource(Platform& _platform, const std::string& _urlTemplate,
                       std::vector<std::string>&& _urlSubdomains, bool _isTms);
 
+    TileID getFallbackTileID(const TileID& _tileID, int32_t _maxZoom, int32_t _zoomBias) override { return _tileID; }
+
     bool loadTileData(std::shared_ptr<TileTask> _task, TileTaskCb _cb) override;
 
     void cancelLoadingTile(TileTask& _task) override;