public double GetEdgeWeight(Guid guid, int eid)
{
int pageIndex = NetworkObjectSerializer.Page(eid);
IWeightPage page = LoadWeightPage(guid, pageIndex);
if (page == null)
{
return(0.0);
}
// Page 0: Edge 1...512: weightIndex: 0..511 auf Page 1
// Page 1: Edge 512..1024: weightIndex: 0..511 auf Page 2
// ... ....
// Beispiele:
// 0-> weightIndex=( 1-1)-0*512=0
// 512-> weightIndex=( 512-1)-0*512=511
// 513-> weightIndex=( 513-1)-1*512=0
// 1024-> weightIndex=(1024-1)-1*512=511
// ...
int weightIndex = (eid - 1) - pageIndex * NetworkObjectSerializer.PageSize;
return(page.GetWeight(weightIndex));
}
private IWeightPage LoadWeightPage(Guid guid, int page)
{
lock (_thisLock)
{
if (!_weightPagesDict.ContainsKey(guid))
{
_weightPagesDict.Add(guid, new Dictionary <int, IWeightPage>());
}
Dictionary <int, IWeightPage> weightPages = _weightPagesDict[guid];
if (weightPages.ContainsKey(page))
{
return(weightPages[page]);
}
if (!_weightDataTypes.ContainsKey(guid) ||
!_weightTableNames.ContainsKey(guid))
{
return(null);
}
if (_dbfactory != null)
{
try
{
using (DbConnection connection = _dbfactory.CreateConnection())
{
connection.ConnectionString = _connectionString;
DbCommand command = _dbfactory.CreateCommand();
command.Connection = connection;
command.CommandText = "SELECT " + _dbNames.DbColName("Data") + " FROM " + _weightTableNames[guid] + " WHERE " + _dbNames.DbColName("Page") + "=" + page;
connection.Open();
DbDataReader reader = command.ExecuteReader();
if (reader.Read())
{
object obj = reader.GetValue(0);
connection.Close();
IWeightPage weightPage = null;
switch (_weightDataTypes[guid])
{
case GraphWeightDataType.Double:
weightPage = new DoubleWeightPage();
((DoubleWeightPage)weightPage).Deserialize((byte[])obj);
break;
case GraphWeightDataType.Integer:
weightPage = new IntWeightPage();
((IntWeightPage)weightPage).Deserialize((byte[])obj);
break;
}
return(weightPage);
}
connection.Close();
}
}
catch { }
}
return(null);
}
}
