/// <summary>
/// The primary factory method to produce the BridgeDataReader; given a store data
/// reader and a column map, create the BridgeDataReader, hooking up the IteratorSources
/// and ResultColumn Hierarchy. All construction of top level data readers go through
/// this method.
/// </summary>
/// <param name="storeDataReader"></param>
/// <param name="columnMap">column map of the first result set</param>
/// <param name="nextResultColumnMaps">enumerable of the column maps for NextResult() calls.</param>
/// <returns></returns>
static internal DbDataReader Create(DbDataReader storeDataReader, ColumnMap columnMap, MetadataWorkspace workspace, IEnumerable <ColumnMap> nextResultColumnMaps)
{
Debug.Assert(storeDataReader != null, "null storeDataReaders?");
Debug.Assert(columnMap != null, "null columnMap?");
Debug.Assert(workspace != null, "null workspace?");
var shaperInfo = CreateShaperInfo(storeDataReader, columnMap, workspace);
DbDataReader result = new BridgeDataReader(shaperInfo.Key, shaperInfo.Value, /*depth:*/ 0, GetNextResultShaperInfo(storeDataReader, workspace, nextResultColumnMaps).GetEnumerator());
return(result);
}
/// <summary>
/// The primary factory method to produce the BridgeDataReader; given a store data
/// reader and a column map, create the BridgeDataReader, hooking up the IteratorSources
/// and ResultColumn Hierarchy. All construction of top level data readers go through
/// this method.
/// </summary>
/// <param name="storeDataReader"></param>
/// <param name="columnMap">column map of the first result set</param>
/// <param name="nextResultColumnMaps">enumerable of the column maps for NextResult() calls.</param>
/// <returns></returns>
public virtual DbDataReader Create(
DbDataReader storeDataReader, ColumnMap columnMap, MetadataWorkspace workspace, IEnumerable<ColumnMap> nextResultColumnMaps)
{
//Contract.Requires(storeDataReader != null);
//Contract.Requires(columnMap != null);
//Contract.Requires(workspace != null);
//Contract.Requires(nextResultColumnMaps != null);
var shaperInfo = CreateShaperInfo(storeDataReader, columnMap, workspace);
DbDataReader result = new BridgeDataReader(
shaperInfo.Key, shaperInfo.Value, /*depth:*/ 0,
GetNextResultShaperInfo(storeDataReader, workspace, nextResultColumnMaps).GetEnumerator());
return result;
}
/// <summary>
/// Ensure that whatever column we're currently processing is implicitly closed;
/// </summary>
private void CloseNestedObjectImplicitly()
{
// it would be nice to use Interlocked.Exchange to avoid multi-thread `race condition risk
// when the the bridge is being misused by the user accessing it with multiple threads.
// but this is called frequently enough to have a performance impact
BridgeDataRecord currentNestedRecord = _currentNestedRecord;
if (null != currentNestedRecord)
{
_currentNestedRecord = null;
currentNestedRecord.CloseImplicitly();
}
BridgeDataReader currentNestedReader = _currentNestedReader;
if (null != currentNestedReader)
{
_currentNestedReader = null;
currentNestedReader.CloseImplicitly();
}
}
/// <summary>
/// For nested objects (records/readers) we have a bit more work to do; this
/// method extracts it all out from the main GetValue method so it doesn't
/// have to be so big.
/// </summary>
/// <param name="result"></param>
/// <returns></returns>
private object GetNestedObjectValue(object result)
{
if (result != DBNull.Value)
{
RecordState recordState = result as RecordState;
if (null != recordState)
{
if (recordState.IsNull)
{
result = DBNull.Value;
}
else
{
BridgeDataRecord nestedRecord = new BridgeDataRecord(Shaper, Depth + 1);
nestedRecord.SetRecordSource(recordState, true);
result = nestedRecord;
_currentNestedRecord = nestedRecord;
_currentNestedReader = null;
}
}
else
{
Coordinator <RecordState> coordinator = result as Coordinator <RecordState>;
if (null != coordinator)
{
BridgeDataReader nestedReader = new BridgeDataReader(Shaper, coordinator.TypedCoordinatorFactory, Depth + 1, nextResultShaperInfos: null);
result = nestedReader;
_currentNestedRecord = null;
_currentNestedReader = nestedReader;
}
else
{
Debug.Fail("unexpected type of nested object result: " + result.GetType().ToString());
}
}
}
return(result);
}
/// <summary>
/// implementation of DbDataRecord.GetFieldType() method
/// </summary>
/// <param name="ordinal"></param>
/// <returns></returns>
override public Type GetFieldType(int ordinal)
{
AssertReaderIsOpenWithData();
return(BridgeDataReader.GetClrTypeFromTypeMetadata(GetTypeUsage(ordinal)));
}
/// <summary>
/// For nested objects (records/readers) we have a bit more work to do; this
/// method extracts it all out from the main GetValue method so it doesn't
/// have to be so big.
/// </summary>
/// <param name="result"></param>
/// <returns></returns>
private object GetNestedObjectValue(object result) {
if (result != DBNull.Value) {
RecordState recordState = result as RecordState;
if (null != recordState) {
if (recordState.IsNull) {
result = DBNull.Value;
}
else {
BridgeDataRecord nestedRecord = new BridgeDataRecord(Shaper, Depth + 1);
nestedRecord.SetRecordSource(recordState, true);
result = nestedRecord;
_currentNestedRecord = nestedRecord;
_currentNestedReader = null;
}
}
else {
Coordinator<RecordState> coordinator = result as Coordinator<RecordState>;
if (null != coordinator) {
BridgeDataReader nestedReader = new BridgeDataReader(Shaper, coordinator.TypedCoordinatorFactory, Depth + 1, nextResultShaperInfos: null);
result = nestedReader;
_currentNestedRecord = null;
_currentNestedReader = nestedReader;
}
else {
Debug.Fail("unexpected type of nested object result: " + result.GetType().ToString());
}
}
}
return result;
}
/// <summary>
/// Ensure that whatever column we're currently processing is implicitly closed;
/// </summary>
private void CloseNestedObjectImplicitly() {
// it would be nice to use Interlocked.Exchange to avoid multi-thread `race condition risk
// when the the bridge is being misused by the user accessing it with multiple threads.
// but this is called frequently enough to have a performance impact
BridgeDataRecord currentNestedRecord = _currentNestedRecord;
if (null != currentNestedRecord) {
_currentNestedRecord = null;
currentNestedRecord.CloseImplicitly();
}
BridgeDataReader currentNestedReader = _currentNestedReader;
if (null != currentNestedReader) {
_currentNestedReader = null;
currentNestedReader.CloseImplicitly();
}
}
/// <summary>
/// The primary factory method to produce the BridgeDataReader; given a store data
/// reader and a column map, create the BridgeDataReader, hooking up the IteratorSources
/// and ResultColumn Hierarchy. All construction of top level data readers go through
/// this method.
/// </summary>
/// <param name="storeDataReader"></param>
/// <param name="columnMap">column map of the first result set</param>
/// <param name="nextResultColumnMaps">enumerable of the column maps for NextResult() calls.</param>
/// <returns></returns>
static internal DbDataReader Create(DbDataReader storeDataReader, ColumnMap columnMap, MetadataWorkspace workspace, IEnumerable<ColumnMap> nextResultColumnMaps) {
Debug.Assert(storeDataReader != null, "null storeDataReaders?");
Debug.Assert(columnMap != null, "null columnMap?");
Debug.Assert(workspace != null, "null workspace?");
var shaperInfo = CreateShaperInfo(storeDataReader, columnMap, workspace);
DbDataReader result = new BridgeDataReader(shaperInfo.Key, shaperInfo.Value, /*depth:*/ 0, GetNextResultShaperInfo(storeDataReader, workspace, nextResultColumnMaps).GetEnumerator());
return result;
}
