private IEnumerable <mwc.Incumbent> GetIncumbentsFromTable(string tableName, string partitionKey, IncumbentType incumbentType)
{
// Todo: this is a temporary method provided until the backend supports retriving incumbents of type "tv_us"
Microsoft.WhiteSpaces.AzureTableAccess.AzureTableOperation azureTableOperations = new Microsoft.WhiteSpaces.AzureTableAccess.AzureTableOperation();
string tableQuery = TableQuery.GenerateFilterCondition("PartitionKey", QueryComparisons.Equal, partitionKey);
if (incumbentType != IncumbentType.None)
{
tableQuery = TableQuery.CombineFilters(tableQuery, TableOperators.And, TableQuery.GenerateFilterConditionForInt("Type", QueryComparisons.Equal, (int)incumbentType));
}
IEnumerable <mwc.Incumbent> tvEngDataList = azureTableOperations.GetAllEntities <CDBSTvEngData>(tableName, tableQuery)
.Select(cdbsTvEndData =>
{
List <Position> contourPoints = WhitespacesManager.GetContourPointsSpaceSeperator(cdbsTvEndData.Contour);
mwc.Incumbent incumbent = new mwc.Incumbent(
cdbsTvEndData.CallSign,
cdbsTvEndData.Channel,
contourPoints,
null,
incumbentType,
null,
new Location(cdbsTvEndData.Latitude, cdbsTvEndData.Longitude));
return(incumbent);
});
return(tvEngDataList);
}
/// <summary>
/// Gets all the incumbents based on either channel numbers or position (if channels value is not null, then it will
/// retrieve based on Channel number; otherwise it will retrieve incumbents based on location).
/// </summary>
/// <param name="channels">Retrieves incumbents that match the specified channels (if null, then it will use the latitude and longitude field)</param>
/// <param name="incumbentType">Retrieves incumbents that match the specified type</param>
/// <param name="latitude">Retrieves incumbents that are near the specified latitude (only used if channels parameter is null).</param>
/// <param name="longitude">Retrieves incumbents that are near the specified longitude (only used if channels parameter is null).</param>
/// <returns>List of incumbents that match the passed in parameters</returns>
private List <mwc.Incumbent> GetIncumbentsFromTable(IEnumerable <int> channels, IncumbentType incumbentType = IncumbentType.None, double latitude = 0, double longitude = 0)
{
// Todo: this is a temporary method provided until the back-end supports retrieving incumbents of type "tv_us"
Microsoft.WhiteSpaces.AzureTableAccess.AzureTableOperation azureTableOperations = new Microsoft.WhiteSpaces.AzureTableAccess.AzureTableOperation();
List <mwc.Incumbent> incumbents = new List <mwc.Incumbent>();
if (channels == null)
{
// Just get the TV Towers that are located around the specified latitude or longitude.
string partitionKey = string.Format("RGN1-Lat{0}Long{1}", (int)latitude, (int)longitude);
IEnumerable <mwc.Incumbent> tvEngDataList = this.GetIncumbentsFromTable("PortalSummary", partitionKey, incumbentType);
incumbents.AddRange(tvEngDataList);
}
else
{
// Get all incumbents associated with the specified channels.
// NB: Creating multiple queries and executing them in parallel will get the results faster, rather scanning through entire table.
// For more reference refer http://msdn.microsoft.com/en-us/magazine/ff796231.aspx
try
{
Parallel.ForEach <int>(
channels,
channel =>
{
System.Diagnostics.Stopwatch watch = new System.Diagnostics.Stopwatch();
watch.Start();
System.Diagnostics.Trace.TraceError(string.Format("***PERF: Retrieving {0} channel elements", channel));
int elementsCount = 0;
IEnumerable <mwc.Incumbent> tvEngDataList = GetIncumbentsFromTable("PortalContours", "RGN1-" + channel, incumbentType);
if (tvEngDataList != null)
{
lock (lockObject)
{
elementsCount = incumbents.Count;
incumbents.AddRange(tvEngDataList);
elementsCount = incumbents.Count - elementsCount;
}
}
watch.Stop();
System.Diagnostics.Trace.TraceError(string.Format("***PERF: Retrieved {0} elements in {1} seconds ({2})", tvEngDataList != null ? elementsCount : 0, watch.Elapsed.ToString(), channel));
});
}
catch (AggregateException)
{
throw;
}
}
return(incumbents);
}
