Complete rewrite of XmlImporter.cs

Server/XmlImporter.cs

@@ -0,0 +1,171 @@
+using System.Globalization;
+using System.Xml;
+using OSMDatastructure;
+using OSMImporter;
+
+namespace Server;
+
+public static class XmlImporter
+{
+    private static readonly XmlReaderSettings readerSettings = new()
+    {
+        IgnoreWhitespace = true,
+        IgnoreComments = true
+    };
+
+    public static HashSet<OsmNode> ImportXml(string filePath)
+    {
+        if (!File.Exists(filePath))
+            throw new FileNotFoundException();
+        
+        Console.WriteLine(string.Format("[{0}] Getting highwayNodeIds...", DateTime.Now.ToLocalTime()));
+        FileStream xmlFileStream = new FileStream(filePath, FileMode.Open);
+        HashSet<ulong> requiredNodeIds = GetHighwayNodeIds(XmlReader.Create(xmlFileStream, readerSettings));
+        xmlFileStream.Position = 0;
+
+        Console.WriteLine(string.Format("[{0}] Importing Nodes...", DateTime.Now.ToLocalTime()));
+        Dictionary<ulong, OsmNode> nodes =
+            GetHighwayNodesFromIds(XmlReader.Create(xmlFileStream, readerSettings), requiredNodeIds);
+        requiredNodeIds.Clear();
+        xmlFileStream.Position = 0;
+        
+        Console.WriteLine(string.Format("[{0}] Importing Ways...", DateTime.Now.ToLocalTime()));
+        HashSet<OsmNode> retNodes = ConnectNodes(XmlReader.Create(xmlFileStream, readerSettings), nodes);
+        nodes.Clear();
+
+        return retNodes;
+    }
+
+    public static HashSet<Region> SplitIntoRegions(HashSet<OsmNode> nodes)
+    {
+        Console.WriteLine(string.Format("[{0}] Splitting into Regions...", DateTime.Now.ToLocalTime()));
+        Dictionary<ulong, Region> retRegions = new();
+        foreach (OsmNode node in nodes)
+        {
+            ulong regionHash = node.coordinates.GetRegionHash();
+            if(retRegions.ContainsKey(regionHash))
+            {
+                retRegions[regionHash].nodes.Add(node);
+            }
+            else
+            {
+                Region newRegion = new Region(regionHash);
+                newRegion.nodes.Add(node);
+                retRegions.Add(regionHash, newRegion);
+            }
+        }
+
+        return retRegions.Values.ToHashSet();
+    }
+
+    private static readonly NumberFormatInfo decimalInfo = new()
+    {
+        NumberDecimalSeparator = "."
+    };
+    private static HashSet<ulong> GetHighwayNodeIds(XmlReader xmlReader)
+    {
+        HashSet<ulong> retSet = new();
+        bool isHighway;
+        HashSet<ulong> currentIds = new();
+        while (xmlReader.ReadToFollowing("way"))
+        {
+            isHighway = false;
+            currentIds.Clear();
+            XmlReader wayReader = xmlReader.ReadSubtree();
+            while (wayReader.Read())
+            {
+                if (xmlReader.Name == "tag" && xmlReader.GetAttribute("k")!.Equals("highway"))
+                {
+                    isHighway = true;
+                }
+                else if (xmlReader.Name == "nd")
+                {
+                    try
+                    {
+                        currentIds.Add(Convert.ToUInt64(xmlReader.GetAttribute("ref")));
+                    }
+                    catch (FormatException) { };
+                }
+            }
+            if (isHighway)
+            {
+                retSet.UnionWith(currentIds);
+            }
+            wayReader.Close();
+        }
+        xmlReader.Close();
+
+        return retSet;
+    }
+
+    private static Dictionary<ulong, OsmNode> GetHighwayNodesFromIds(XmlReader xmlReader, HashSet<ulong> ids)
+    {
+        Dictionary<ulong, OsmNode> retDict = new();
+
+        while (xmlReader.ReadToFollowing("node"))
+        {
+            ulong id = Convert.ToUInt64(xmlReader.GetAttribute("id"));
+            if (ids.Contains(id))
+            {
+                float lat = Convert.ToSingle(xmlReader.GetAttribute("lat")!, decimalInfo);
+                float lon = Convert.ToSingle(xmlReader.GetAttribute("lon")!, decimalInfo);
+                retDict.Add(id, new OsmNode(lat, lon));
+            }
+        }
+        xmlReader.Close();
+        
+        return retDict;
+    }
+    
+    private static HashSet<OsmNode> ConnectNodes(XmlReader xmlReader, Dictionary<ulong, OsmNode> dict)
+    {
+        while (xmlReader.ReadToFollowing("way"))
+        {
+            Dictionary<OsmEdge.tagType, object> tags = new();
+            List<ulong> wayNodeIds = new();
+            XmlReader wayReader = xmlReader.ReadSubtree();
+            while (wayReader.Read())
+            {
+                if (xmlReader.Name == "tag")
+                {
+                    KeyValuePair<OsmEdge.tagType, object> tag =
+                        OsmEdge.ConvertToTag(wayReader.GetAttribute("k")!, wayReader.GetAttribute("v")!);
+                    tags.TryAdd(tag.Key, tag.Value);
+                }
+                else if (xmlReader.Name == "nd")
+                {
+                    wayNodeIds.Add(Convert.ToUInt64(xmlReader.GetAttribute("ref")));
+                }
+            }
+            if (tags.ContainsKey(OsmEdge.tagType.highway))
+            {
+                ulong[] ids = wayNodeIds.Where(dict.ContainsKey).ToArray();
+                for (int i = 0; i < ids.Length - 1; i++)
+                {
+                    OsmNode n1 = dict[ids[i]];
+                    OsmNode n2 = dict[ids[i + 1]];
+                    if (tags.ContainsKey(OsmEdge.tagType.oneway) && (bool)tags[OsmEdge.tagType.oneway])
+                    {
+                        if (tags.ContainsKey(OsmEdge.tagType.forward) && !(bool)tags[OsmEdge.tagType.forward])
+                        {
+                            n2.edges.Add(new OsmEdge(n1.coordinates, tags));
+                        }
+                        else
+                        {
+                            n1.edges.Add(new OsmEdge(n2.coordinates, tags));
+                        }
+                    }
+                    else
+                    {
+                        n1.edges.Add(new OsmEdge(n2.coordinates, tags));
+                        n2.edges.Add(new OsmEdge(n1.coordinates, tags));
+                    }
+                }
+            }
+            wayReader.Close();
+        }
+        xmlReader.Close();
+
+        return dict.Values.ToHashSet();
+    }
+}