/// <summary>
/// Read the next unread record from the stream. Will return <see cref="QueueStreamRecord.Empty"/> if there is no next record in the stream.
/// </summary>
/// <returns></returns>
public QueueStreamRecord ReadNextRecord()
{
EnsureInstanceNotDisposed();
if (_recordQueue.Count == 0)
{
return(QueueStreamRecord.Empty);
}
var next = _recordQueue.Dequeue();
var streamInfo = GetStreamInfoFromHandle(next);
if (streamInfo == null)
{
EnsureInstanceNotDisposed();
throw new InvalidOperationException("unable to access stream for head file");
}
streamInfo.Stream.Seek(next.Position + HEADER_SIZE, SeekOrigin.Begin);
var data = new ChunkedMemoryStream();
var copied = streamInfo.Stream.CopyTo(data, next.Length);
if (copied != next.Length)
{
_log.WarnFormat("reached EOF in the middle of the record");
return(QueueStreamRecord.Empty);
}
data.Seek(0, SeekOrigin.Begin);
return(new QueueStreamRecord(data, next));
}
//--- Methods ---
/// <summary>
/// Serialize an <see cref="XDoc"/> to a <see cref="Stream"/>
/// </summary>
/// <param name="doc">An <see cref="XDoc"/> document</param>
/// <returns>A <see cref="Stream"/></returns>
public Stream ToStream(XDoc doc)
{
var data = new ChunkedMemoryStream();
doc.WriteTo(data);
data.Position = 0;
return(data);
}
/// <summary>
/// WARNING: This method is thread-blocking. Please avoid using it if possible.
/// </summary>
public static Result <ChunkedMemoryStream> ToChunkedMemoryStream(this Stream stream, long length, Result <ChunkedMemoryStream> result)
{
var copy = new ChunkedMemoryStream();
stream.CopyTo(copy, length, new Result <long>(TimeSpan.MaxValue)).WhenDone(
v => {
copy.Position = 0;
result.Return(copy);
},
result.Throw
);
return(result);
}
/// <summary>
/// Read the next unread record from the stream. Will return <see cref="QueueStreamRecord.Empty"/> if there is no next record in the stream.
/// </summary>
/// <returns></returns>
public QueueStreamRecord ReadNextRecord()
{
if (_recordQueue.Count == 0)
{
return(QueueStreamRecord.Empty);
}
var next = _recordQueue.Dequeue();
var recordLength = _recordMap[next];
_stream.Seek(next + HEADER_SIZE, SeekOrigin.Begin);
var data = new ChunkedMemoryStream();
var copied = _stream.CopyTo(data, recordLength);
if (copied != recordLength)
{
_log.WarnFormat("reached EOF in the middle of the record");
return(QueueStreamRecord.Empty);
}
data.Position = 0;
return(new QueueStreamRecord(data, new QueueStreamHandle(next, _generation)));
}
