/// <summary>
/// Reads records by blocks of specific size returning one after another.
/// </summary>
public IEnumerable <RecordsBuffer> ReadBlocks()
{
IsLastBlock = false;
RecordsBuffer recordsBuffer = new RecordsBuffer(_bufferSizeInBytes);
Record? recordToCompare = null;
IRecordFieldComparer comparer = _readWhileSameFieldValue != -1
? _recordComparer.CreateRecordFieldComparer(_readWhileSameFieldValue)
: null;
if (_hasRecordAhead)
{
recordToCompare = _recordAhead;
recordsBuffer.AddRecord(_recordAhead);
_hasRecordAhead = false;
}
string line = null;
while ((line = _streamReader.ReadLine()) != null)
{
Record record = _recordParser.Parse(line);
if (_readWhileSameFieldValue >= 0)
{
if (recordToCompare == null)
{
recordToCompare = record;
}
else if (comparer.Compare(record, recordToCompare.Value) != 0)
{
_recordAhead = record;
_hasRecordAhead = true;
break;
}
}
bool added = recordsBuffer.AddRecord(record);
if (!added)
{
if (recordsBuffer.Records.Count == 0)
{
throw new InvalidOperationException("Buffer is too small. Can't add even one record.");
}
yield return(recordsBuffer);
recordsBuffer = new RecordsBuffer(_bufferSizeInBytes);
recordsBuffer.AddRecord(record);
}
}
if (recordsBuffer.Records.Count > 0)
{
IsLastBlock = true;
yield return(recordsBuffer);
}
}
