/// <summary>
/// Deserializes a graph from the given stream.
/// </summary>
/// <returns></returns>
public static Graph Deserialize(System.IO.Stream stream, GraphProfile profile)
{
var initialPosition = stream.Position;
// read sizes.
long size = 1;
var version = stream.ReadByte();
if (version != 1)
{
throw new Exception(string.Format("Cannot deserialize graph: Invalid version #: {0}.", version));
}
var bytes = new byte[8];
stream.Read(bytes, 0, 8);
size = size + 8;
var vertexLength = BitConverter.ToInt64(bytes, 0);
stream.Read(bytes, 0, 8);
size = size + 8;
var edgeLength = BitConverter.ToInt64(bytes, 0);
stream.Read(bytes, 0, 4);
size = size + 4;
var vertexSize = BitConverter.ToInt32(bytes, 0);
stream.Read(bytes, 0, 4);
size = size + 4;
var edgeSize = BitConverter.ToInt32(bytes, 0);
ArrayBase <uint> vertices;
ArrayBase <uint> edges;
if (profile == null)
{ // just create arrays and read the data.
vertices = new MemoryArray <uint>(vertexLength * vertexSize);
vertices.CopyFrom(stream);
size += vertexLength * vertexSize * 4;
edges = new MemoryArray <uint>(edgeLength * edgeSize);
edges.CopyFrom(stream);
size += edgeLength * edgeSize * 4;
}
else
{ // create accessors over the exact part of the stream that represents vertices/edges.
var position = stream.Position;
var map1 = new MemoryMapStream(new CappedStream(stream, position, vertexLength * vertexSize * 4));
vertices = new Array <uint>(map1.CreateUInt32(vertexLength * vertexSize), profile.VertexProfile);
size += vertexLength * vertexSize * 4;
var map2 = new MemoryMapStream(new CappedStream(stream, position + vertexLength * vertexSize * 4,
edgeLength * edgeSize * 4));
edges = new Array <uint>(map2.CreateUInt32(edgeLength * edgeSize), profile.EdgeProfile);
size += edgeLength * edgeSize * 4;
}
// make sure stream is positioned at the correct location.
stream.Seek(initialPosition + size, System.IO.SeekOrigin.Begin);
return(new Graph(edgeSize - MINIMUM_EDGE_SIZE, vertices, edges));
}
/// <summary>
/// Creates a new using the given file.
/// </summary>
public Graph(MemoryMap map, GraphProfile profile, int edgeDataSize, long estimatedSize)
{
_edgeDataSize = edgeDataSize;
_edgeSize = MINIMUM_EDGE_SIZE + edgeDataSize;
_vertices = new Array <uint>(map, estimatedSize, profile.VertexProfile);
for (int i = 0; i < _vertices.Length; i++)
{
_vertices[i] = Constants.NO_VERTEX;
}
_edges = new Array <uint>(map, estimatedSize * 3 * _edgeSize, profile.EdgeProfile);
for (int i = 0; i < _edges.Length; i++)
{
_edges[i] = Constants.NO_EDGE;
}
}
