public override DataRecord Construct()
{
TableRecord record = new TableRecord(_tableColumnNames, _tableColumnSeparator);
record.KeyColumnNos = _keyColumnNos;
return record;
}
// for wrapping table records for table conversion
public ColumnWrapper(TableRecord record)
{
_separator = record.TableColumnSeparator;
_columnNames = ((TableRecord)record).ColumnNames;
_keyColumnNos = ((TableRecord)record).KeyColumnNos;
_isTableRecord = true;
return;
}
public override void ProcessRecord(DataRecord record, RecordAccepter accepter)
{
// caseNum 0: null conversion (key expression == incoming key)
// caseNum 1: table record
// caseNum 2: everything else
// So, the thing is a null conversion is costly, potentially super
// costly. Instead of trying to rebuild the whole tree without
// conversion (which brought with it potential sorting nodes as
// well) we will error and message the user to remove the null
// conversion.
// initialize the wrapper
if (_wrapper == null) {
bool hasHeaders = false;
int caseNum = 0;
HintMessageToConsole();
// case 1: table record.
if (record is TableRecord) {
TableRecord t = record as TableRecord;
_wrapper = new ColumnWrapper(t);
caseNum = 1; // table record
}
else {
caseNum = 2; // everything else
hasHeaders = ColumnWrapper.HasHeaders(KeyExpression);
_wrapper = new ColumnWrapper(record, _sourceName, _columnSeparator, hasHeaders);
// if columnNames provided by filter user
if (_columnNames != null) {
if (_columnNames.Length != _wrapper.ColumnNames.Length) {
Console.WriteLine("too few column names provided");
Environment.Exit(1);
}
}
else {
_columnNames = _wrapper.ColumnNames; // use default
}
}
// making table records is costly. If the key columns have not
// changed there is no reason to do the conversion. (since
// sorting and joining work the same for all records).
_keyColumnNos = _wrapper.GetColumnNos(KeyExpression);
int[] currentKeyColumnNos = _wrapper.KeyColumnNos;
// _keyColumnNos == the requested new key columns
if (_keyColumnNos.Length == currentKeyColumnNos.Length) {
for (int i = 0; i < _keyColumnNos.Length; i++) {
if (_keyColumnNos[i] != currentKeyColumnNos[i])
_caseNum = caseNum;
}
}
else _caseNum = caseNum;
// we special case flat files converting to tables allowing null conversions
// since when they define headers ToTable is evaluating and dropping them
// from the input.
if (hasHeaders) {
_caseNum = 2;
return; // eat up this record containing headers
}
}
switch (_caseNum) {
case 0: // null conversion see comments above
Console.WriteLine("Null-table conversions are costly (i.e. key expression equal to incoming key).");
Console.WriteLine("Remove unnecessary 'ToTable(" + KeyExpression + ")' from expression.");
Environment.Exit(1);
break;
case 1: // table record
TableRecord outRecord = record as TableRecord;
outRecord.KeyColumnNos = _keyColumnNos;
accepter.AddRecord(outRecord);
break;
case 2: // everything else
_wrapper.SetRecord(record);
// ignore null records: no key no data
if (record.Key.Length == 0 && record.Data == null)
return;
outRecord = new TableRecord(_columnNames, _columnSeparator);
//if (_outRecord == null) {
// _outRecord = new TableRecord(_columnNames, _columnSeparator);
//}
outRecord.KeyColumnNos = _keyColumnNos;
_stringBuilder.Length = 0;
for (int i = 0; i < _wrapper.ColumnNames.Length; i++) {
if (i != 0) _stringBuilder.Append('\t');
_wrapper.AppendColumn(i, _stringBuilder);
}
outRecord.DelimitedColumns = _stringBuilder.ToString();
accepter.AddRecord(outRecord);
break;
}
}
public TableRecord Join(DataRecord left, DataRecord right, bool match)
{
_leftWrapper.SetRecord(left);
_rightWrapper.SetRecord(right);
TableRecord outRecord = new TableRecord(_outputColumnNames, _separator);
outRecord.KeyColumnNos = _leftWrapper.KeyColumnNos;
_delimitedColumns.Length = 0; // reset
// add the left columns
for (int i = 0; i < _leftWrapper.ColumnNames.Length; i++) {
if (i != 0) _delimitedColumns.Append(_separator);
_leftWrapper.AppendColumn(i, _delimitedColumns);
}
if (!match) {
_delimitedColumns.Append(_emptyRightColumns);
outRecord.DelimitedColumns = _delimitedColumns.ToString();
return outRecord;
}
// we matched.
// add the right columns
int j = 0;
for (int i = 0; i < _rightWrapper.ColumnNames.Length; i++) {
if (i == _rightWrapper.KeyColumnNos[j]) { // don't add keys
if (_rightWrapper.KeyColumnNos.Length > j + 1) j++;
}
else {
_delimitedColumns.Append(_separator);
_rightWrapper.AppendColumn(i, _delimitedColumns);
}
}
outRecord.DelimitedColumns = _delimitedColumns.ToString();
return outRecord;
}