/// <summary>
/// Creates a new CH edge data source.
/// </summary>
public CHEdgeDataDataSource(Stream stream, CHEdgeDataDataSourceSerializer serializer,
int startOfRegions, CHVertexRegionIndex regionIndex, int zoom,
int startOfBlocks, CHBlockIndex blockIndex, uint blockSize,
ITagsCollectionIndexReadonly tagsIndex)
{
_stream = stream;
_serializer = serializer;
this.InitializeRegions(startOfRegions, regionIndex, zoom);
this.InitializeBlocks(startOfBlocks, blockIndex, blockSize);
_blocks = new LRUCache <uint, CHBlock>(1000);
_regions = new LRUCache <ulong, CHVertexRegion>(1000);
_tagsIndex = tagsIndex;
}
/// <summary>
/// Initializes the blocks stuff.
/// </summary>
/// <param name="startOfBlocks"></param>
/// <param name="blocksIndex"></param>
/// <param name="blockSize"></param>
private void InitializeBlocks(int startOfBlocks, CHBlockIndex blocksIndex, uint blockSize)
{
_startOfBlocks = startOfBlocks;
_blocksIndex = blocksIndex;
_blockSize = blockSize;
}
/// <summary>
/// Does the v2 serialization.
/// </summary>
/// <param name="stream"></param>
/// <param name="graph"></param>
/// <returns></returns>
protected override void DoSerialize(LimitedStream stream,
DynamicGraphRouterDataSource <CHEdgeData> graph)
{
// sort the graph.
IDynamicGraph <CHEdgeData> sortedGraph = this.SortGraph(graph);
// create the regions.
SortedDictionary <ulong, List <uint> > regions = new SortedDictionary <ulong, List <uint> >();
for (uint newVertexId = 1; newVertexId < sortedGraph.VertexCount + 1; newVertexId++)
{
// add to the CHRegions.
float latitude, longitude;
sortedGraph.GetVertex(newVertexId, out latitude, out longitude);
Tile tile = Tile.CreateAroundLocation(new GeoCoordinate(
latitude, longitude), _regionZoom);
List <uint> regionVertices;
if (!regions.TryGetValue(tile.Id, out regionVertices))
{
regionVertices = new List <uint>();
regions.Add(tile.Id, regionVertices);
}
regionVertices.Add(newVertexId);
}
// serialize the sorted graph.
// [START_OF_BLOCKS][START_OF_TAGS][[SIZE_OF_REGION_INDEX][REGION_INDEX][REGIONS]][[SIZE_OF_BLOCK_INDEX][BLOCK_INDEX][BLOCKS]][TAGS]
// STRART_OF_BLOCKS: 4bytes
// START_OF_STAGS: 4bytes
// SIZE_OF_REGION_INDEX: 4bytes
// REGION_INDEX: see SIZE_OF_REGION_INDEX
// REGIONS: see START_OF_BLOCKS - 4bytes
// SIZE_OF_BLOCK_INDEX: 4bytes
// BLOCK_INDEX: see SIZE_OF_BLOCK_INDEX.
// BLOCKS: from START_OF_BLOCKS + 4bytes + SIZE_OF_BLOCKS_INDEX until END.
// serialize regions and build their index.
CHVertexRegionIndex chRegionIndex = new CHVertexRegionIndex();
chRegionIndex.LocationIndex = new int[regions.Count];
chRegionIndex.RegionIds = new ulong[regions.Count];
var memoryStream = new MemoryStream();
int regionIdx = 0;
foreach (KeyValuePair <ulong, List <uint> > region in regions)
{
// serialize.
CHVertexRegion chRegion = new CHVertexRegion();
chRegion.Vertices = region.Value.ToArray();
_runtimeTypeModel.Serialize(memoryStream, chRegion);
// set index.
chRegionIndex.LocationIndex[regionIdx] = (int)memoryStream.Position;
chRegionIndex.RegionIds[regionIdx] = region.Key;
regionIdx++;
}
stream.Seek(12, SeekOrigin.Begin); // move to beginning of [REGION_INDEX]
_runtimeTypeModel.Serialize(stream, chRegionIndex); // write region index.
int sizeRegionIndex = (int)(stream.Position - 12); // now at beginning of [REGIONS]
memoryStream.Seek(0, SeekOrigin.Begin);
memoryStream.WriteTo(stream); // write regions.
memoryStream.Dispose();
int startOfBlocks = (int)stream.Position; // now at beginning of [SIZE_OF_BLOCK_INDEX]
// serialize the blocks and build their index.
memoryStream = new MemoryStream();
List <int> blockLocations = new List <int>();
uint vertexId = 1;
while (vertexId < sortedGraph.VertexCount)
{
uint blockId = vertexId;
List <CHArc> blockArcs = new List <CHArc>();
List <CHVertex> blockVertices = new List <CHVertex>();
while (vertexId < blockId + _blockVertexSize &&
vertexId < sortedGraph.VertexCount + 1)
{ // create this block.
CHVertex chVertex = new CHVertex();
float latitude, longitude;
sortedGraph.GetVertex(vertexId, out latitude, out longitude);
chVertex.Latitude = latitude;
chVertex.Longitude = longitude;
chVertex.ArcIndex = (ushort)(blockArcs.Count);
foreach (KeyValuePair <uint, CHEdgeData> sortedArc in sortedGraph.GetArcs(vertexId))
{
CHArc chArc = new CHArc();
chArc.TargetId = sortedArc.Key;
chArc.ShortcutId = sortedArc.Value.ContractedVertexId;
chArc.Weight = sortedArc.Value.Weight;
chArc.Direction = sortedArc.Value.Direction;
chArc.TagsId = sortedArc.Value.Tags;
blockArcs.Add(chArc);
}
chVertex.ArcCount = (ushort)(blockArcs.Count - chVertex.ArcIndex);
blockVertices.Add(chVertex);
vertexId++; // move to the next vertex.
}
// create block.
CHBlock block = new CHBlock();
block.Arcs = blockArcs.ToArray();
block.Vertices = blockVertices.ToArray(); // TODO: get rid of the list and create an array to begin with.
// write blocks.
MemoryStream blockStream = new MemoryStream();
_runtimeTypeModel.Serialize(blockStream, block);
byte[] compressed = GZipStream.CompressBuffer(blockStream.ToArray());
blockStream.Dispose();
memoryStream.Write(compressed, 0, compressed.Length);
blockLocations.Add((int)memoryStream.Position);
}
CHBlockIndex blockIndex = new CHBlockIndex();
blockIndex.LocationIndex = blockLocations.ToArray();
stream.Seek(startOfBlocks + 4, SeekOrigin.Begin); // move to beginning of [BLOCK_INDEX]
_runtimeTypeModel.Serialize(stream, blockIndex); // write region index.
int sizeBlockIndex = (int)(stream.Position - (startOfBlocks + 4)); // now at beginning of [BLOCKS]
memoryStream.Seek(0, SeekOrigin.Begin);
memoryStream.WriteTo(stream); // write blocks.
memoryStream.Dispose();
// write tags after blocks.
int tagsPosition = (int)stream.Position;
TagIndexSerializer.SerializeBlocks(stream, graph.TagsIndex, 100);
stream.Seek(startOfBlocks, SeekOrigin.Begin); // move to [SIZE_OF_BLOCK_INDEX]
stream.Write(BitConverter.GetBytes(sizeBlockIndex), 0, 4); // write start position of blocks. Now at [SIZE_OF_REGION_INDEX]
// write index.
stream.Seek(0, SeekOrigin.Begin); // move to beginning
stream.Write(BitConverter.GetBytes(startOfBlocks), 0, 4); // write start position of blocks. Now at [SIZE_OF_REGION_INDEX]
stream.Write(BitConverter.GetBytes(tagsPosition), 0, 4);
stream.Write(BitConverter.GetBytes(sizeRegionIndex), 0, 4); // write size of region index.
stream.Flush();
}