/// <summary>
/// Reads a binary file from the mount service and writes it into a memory stream
/// </summary>
/// <param name="filename">Relative path to the file on the mount service</param>
/// <param name="readReaderPort">Response port</param>
/// <returns></returns>
private IEnumerator <ITask> ReadFileFromMountService(string filename, FileReaderPort readReaderPort)
{
if (string.IsNullOrEmpty(filename))
{
Exception exception = new ArgumentException(
"Cannot read file from mount service. No filename specified"
);
LogWarning(exception);
readReaderPort.Post(exception);
yield break;
}
// Construct URI to file
string fileUri = "http://localhost" + ServicePaths.MountPoint;
if (!filename.StartsWith("/"))
{
fileUri += "/";
}
fileUri += filename;
// Establish channel with mount service
mnt.MountServiceOperations mountPort = ServiceForwarder <mnt.MountServiceOperations>(fileUri);
// Set up byte query
mnt.QueryBytesRequest queryBytesRequest = new mnt.QueryBytesRequest();
mnt.QueryBytes queryBytes = new mnt.QueryBytes(queryBytesRequest);
queryBytesRequest.Offset = 0;
queryBytesRequest.Length = MountServiceReadBlockSize;
// Read file in blocks from mount service
MemoryStream memoryStream = new MemoryStream();
int bytesRead = (int)queryBytesRequest.Length;
while (bytesRead == queryBytesRequest.Length)
{
mountPort.Post(queryBytes);
yield return((Choice)queryBytes.ResponsePort);
Fault fault = (Fault)queryBytes.ResponsePort;
if (fault != null)
{
LogWarning(fault.ToException());
readReaderPort.Post(fault.ToException());
yield break;
}
mnt.QueryBytesResponse byteQueryResponse = (mnt.QueryBytesResponse)queryBytes.ResponsePort;
bytesRead = byteQueryResponse.Data.Length;
memoryStream.Write(byteQueryResponse.Data, 0, bytesRead);
queryBytesRequest.Offset += bytesRead;
}
memoryStream.Position = 0;
readReaderPort.Post(memoryStream);
}
/// <summary>
/// Writes a binary file from a stream to the mount service
/// </summary>
/// <param name="filename">Filename and path where the file shall be store on the mount service</param>
/// <param name="fileStream">Stream containing the file data</param>
/// <param name="responsePort">File writer response port</param>
/// <returns></returns>
private IEnumerator <ITask> WriteFileToMountService(
string filename,
Stream fileStream,
SuccessFailurePort responsePort)
{
// Stream needs to support seeking, otherwise we will never know when the end
// is reached
if (!fileStream.CanSeek)
{
throw new ArgumentException("File stream needs to support seeking");
}
// Construct URI to file
string fileUri = "http://localhost" + ServicePaths.MountPoint;
if (!filename.StartsWith("/"))
{
fileUri += "/";
}
fileUri += filename;
// Establish channel with mount service
mnt.MountServiceOperations mountPort = ServiceForwarder <mnt.MountServiceOperations>(fileUri);
// Set up byte update message
mnt.UpdateBytesRequest updateBytesRequest = new mnt.UpdateBytesRequest();
mnt.UpdateBytes updateBytes = new mnt.UpdateBytes(updateBytesRequest);
updateBytesRequest.Offset = 0;
updateBytesRequest.Truncate = false;
// Write file in blocks to mount service
updateBytesRequest.Data = new byte[MountServiceWriteBlockSize];
fileStream.Position = 0;
int writeOffset = 0;
while (fileStream.Position < fileStream.Length)
{
// Fill buffer
int offset = 0;
while (offset < MountServiceWriteBlockSize && fileStream.Position < fileStream.Length)
{
int bytesRead = fileStream.Read(
updateBytesRequest.Data,
offset,
MountServiceWriteBlockSize - offset
);
offset += bytesRead;
}
if (offset < MountServiceWriteBlockSize)
{
// Last message will most probably not contain a completely filled buffer
Array.Resize <byte>(ref updateBytesRequest.Data, offset);
}
if (fileStream.Position >= fileStream.Length)
{
// End of stream reached, truncate file on mount service
// to current position
updateBytesRequest.Truncate = true;
}
updateBytesRequest.Offset = writeOffset;
// Send message to mount service
mountPort.Post(updateBytes);
yield return((Choice)updateBytes.ResponsePort);
Fault fault = (Fault)updateBytes.ResponsePort;
if (fault != null)
{
Exception exception = fault.ToException();
LogWarning(exception);
responsePort.Post(exception);
yield break;
}
// Clear response port
DefaultUpdateResponseType success = (DefaultUpdateResponseType)updateBytes.ResponsePort;
writeOffset += updateBytesRequest.Data.Length;
}
responsePort.Post(SuccessResult.Instance);
}
