/// <summary>
/// Writes the specified file reading from the given reader
/// </summary>
/// <param name="reader">A Data Reader with the data</param>
/// <param name="fileSetting">The source setting or the data that could be different than the setting for is writer</param>
/// <param name="cancellationToken">The cancellation token.</param>
/// <returns>
/// Number of records written
/// </returns>
protected override void Write(IDataReader reader, Stream output, CancellationToken cancellationToken)
{
Contract.Assume(!string.IsNullOrEmpty(m_CsvFile.FullPath));
using (var writer = new StreamWriter(output,
EncodingHelper.GetEncoding(m_CsvFile.CodePageId, m_CsvFile.ByteOrderMark), 8192))
{
DataReader2Stream(reader, writer, cancellationToken);
}
}
/// <summary>
/// Writes the specified file reading from the given reader
/// </summary>
/// <param name="reader">A Data Reader with the data</param>
/// <param name="output">The output.</param>
/// <param name="cancellationToken">The cancellation token.</param>
protected override async Task WriteReaderAsync([NotNull] IFileReader reader, [NotNull] Stream output,
CancellationToken cancellationToken)
{
using (var writer = new StreamWriter(output,
EncodingHelper.GetEncoding(m_CodePageId, m_ByteOrderMark), 8192))
{
SetColumns(reader);
if (Columns.Count == 0)
{
throw new FileWriterException("No columns defined to be written.");
}
HandleWriteStart();
var sb = new StringBuilder();
if (!string.IsNullOrEmpty(Header))
{
sb.Append(Header);
if (!Header.EndsWith(NewLine, StringComparison.Ordinal))
{
sb.Append(NewLine);
}
}
var lastCol = Columns[Columns.Count - 1];
if (ColumnHeader)
{
foreach (var columnInfo in Columns)
{
sb.Append(TextEncodeField(FileFormat, columnInfo.Name, columnInfo, true, null, QualifyText));
if (!FileFormat.IsFixedLength && !ReferenceEquals(columnInfo, lastCol))
{
sb.Append(FileFormat.FieldDelimiterChar);
}
}
sb.Append(NewLine);
}
while (await reader.ReadAsync(cancellationToken).ConfigureAwait(false) &&
!cancellationToken.IsCancellationRequested)
{
if (sb.Length > 32768)
{
await writer.WriteAsync(sb.ToString()).ConfigureAwait(false);
sb.Length = 0;
}
var emptyColumns = 0;
var row = new StringBuilder();
foreach (var columnInfo in Columns)
{
// Number of columns might be higher than number of reader columns
var col = reader.GetValue(columnInfo.ColumnOrdinal);
if (col == DBNull.Value || (col is string text && string.IsNullOrEmpty(text)))
{
emptyColumns++;
}