// retrieve the next image
public RemoteSessionImage GetNextUpdate(int imageIdx, int?waitDuration = null)
{
RemoteSessionImage image = null;
lock (_imageEventLock)
{
try
{
// retrieve the next available image from cache, up to the latest received
if (imageIdx < _lastReceivedImageIdx)
{
for (var idx = imageIdx + 1; idx <= _lastReceivedImageIdx; idx++)
{
image = GetCachedUpdate(idx);
if (image != null)
{
break;
}
}
}
// if no image is available and a wait duration is specified, wait for a new image
if (image == null && waitDuration.HasValue)
{
Trace.TraceInformation("Waiting for new image, remote session {0}", RemoteSession.Id);
_imageEventPending = true;
if (waitDuration.Value > 0)
{
// wait for the specified time
if (Monitor.Wait(_imageEventLock, waitDuration.Value))
{
image = GetCachedUpdate(_lastReceivedImageIdx);
}
}
else
{
// wait indefinitely
if (Monitor.Wait(_imageEventLock))
{
image = GetCachedUpdate(_lastReceivedImageIdx);
}
}
_imageEventPending = false;
Monitor.Pulse(_imageEventLock);
}
}
catch (Exception exc)
{
Trace.TraceError("Failed to retrieve next update from index {0}, remote session {1} ({2})", imageIdx, RemoteSession.Id, exc);
}
}
return(image);
}
public void SendImage(RemoteSessionImage image)
{
if (!BinaryMode)
{
Send(GetImageText(image) + ";");
}
else
{
Send(GetImageBytes(image));
}
}
private string GetImageText(RemoteSessionImage image)
{
return
(image.Idx + "," +
image.PosX + "," +
image.PosY + "," +
image.Width + "," +
image.Height + "," +
image.Format.ToString().ToLower() + "," +
image.Quality + "," +
image.Fullscreen.ToString().ToLower() + "," +
Convert.ToBase64String(image.Data));
}
public byte[] TakeScreenshot(Guid connectionId)
{
try
{
HttpContext.Current.Application.Lock();
var remoteSessions = (IDictionary <Guid, RemoteSession>)HttpContext.Current.Application[HttpApplicationStateVariables.RemoteSessions.ToString()];
if (!remoteSessions.ContainsKey(connectionId))
{
throw new Exception(string.Format("connection {0} not found", connectionId));
}
else
{
var remoteSession = remoteSessions[connectionId];
RemoteSessionImage screenshot = null;
// one screenshot at a time
if (remoteSession.Manager.ScreenshotEventLock == null)
{
remoteSession.Manager.ScreenshotEventLock = new object();
// request a screenshot (async) and wait it (up to 10 seconds)
lock (remoteSession.Manager.ScreenshotEventLock)
{
remoteSession.Manager.SendCommand(RemoteSessionCommand.TakeScreenshot);
remoteSession.Manager.ScreenshotEventPending = true;
if (Monitor.Wait(remoteSession.Manager.ScreenshotEventLock, 10000))
{
screenshot = remoteSession.Manager.GetCachedUpdate(remoteSession.Manager.ScreenshotImageIdx);
}
remoteSession.Manager.ScreenshotEventPending = false;
Monitor.Pulse(remoteSession.Manager.ScreenshotEventLock);
}
remoteSession.Manager.ScreenshotEventLock = null;
}
return(screenshot?.Data);
}
}
catch (Exception exc)
{
Trace.TraceError("Failed to take screenshot for connection {0} ({1})", connectionId, exc);
throw;
}
finally
{
HttpContext.Current.Application.UnLock();
}
}
public void ProcessImage(RemoteSessionImage image)
{
if (!BinaryMode)
{
Send(GetImageText(image) + ";");
}
else
{
using (var memoryStream = new MemoryStream())
{
var bytes = GetImageBytes(image);
memoryStream.Write(BitConverter.GetBytes(bytes.Length), 0, 4);
memoryStream.Write(bytes, 0, bytes.Length);
Send(memoryStream.ToArray());
}
}
}
// retrieve a cached image
public RemoteSessionImage GetCachedUpdate(int imageIdx)
{
RemoteSessionImage image = null;
try
{
var imageObj = _cache["remoteSessionImage_" + RemoteSession.Id + "_" + imageIdx];
if (imageObj != null)
{
image = (RemoteSessionImage)imageObj;
Trace.TraceInformation("Retrieved image {0} ({1}) from cache, remote session {2}", imageIdx, (image.Fullscreen ? "screen" : "region"), RemoteSession.Id);
}
}
catch (Exception exc)
{
Trace.TraceError("Failed to retrieve image {0} from cache, remote session {1} ({2})", imageIdx, RemoteSession.Id, exc);
}
return(image);
}
private byte[] GetImageBytes(RemoteSessionImage image)
{
using (var memoryStream = new MemoryStream())
{
// tag (4 bytes)
memoryStream.Write(BitConverter.GetBytes(0), 0, 4);
// info (32 bytes)
memoryStream.Write(BitConverter.GetBytes(image.Idx), 0, 4);
memoryStream.Write(BitConverter.GetBytes(image.PosX), 0, 4);
memoryStream.Write(BitConverter.GetBytes(image.PosY), 0, 4);
memoryStream.Write(BitConverter.GetBytes(image.Width), 0, 4);
memoryStream.Write(BitConverter.GetBytes(image.Height), 0, 4);
memoryStream.Write(BitConverter.GetBytes((int)image.Format), 0, 4);
memoryStream.Write(BitConverter.GetBytes(image.Quality), 0, 4);
memoryStream.Write(BitConverter.GetBytes(image.Fullscreen ? 1 : 0), 0, 4);
// data
memoryStream.Write(image.Data, 0, image.Data.Length);
return(memoryStream.ToArray());
}
}
// new image
private void ProcessUpdate(byte[] data)
{
try
{
if (data.Length <= 36)
{
throw new Exception("invalid image data");
}
// image info (8 items, 32 bits each => 8 * 4 = 32 bytes)
var imgInfo = new byte[32];
Array.Copy(data, 4, imgInfo, 0, 32);
// CAUTION! if the remote session is reconnected (i.e.: browser resize), a new instance of wfreerdp is spawned
// the image index can no longer be handled by wfreerdp, this must be done by the remote session manager
// the image index provided by wfreerdp is relative to its own instance, if needed
var image = new RemoteSessionImage
{
//Idx = BitConverter.ToInt32(imgInfo, 0),
Idx = ++_imageIdx,
PosX = BitConverter.ToInt32(imgInfo, 4),
PosY = BitConverter.ToInt32(imgInfo, 8),
Width = BitConverter.ToInt32(imgInfo, 12),
Height = BitConverter.ToInt32(imgInfo, 16),
Format = (ImageFormat)BitConverter.ToInt32(imgInfo, 20),
Quality = BitConverter.ToInt32(imgInfo, 24),
Fullscreen = BitConverter.ToInt32(imgInfo, 28) == 1,
Data = new byte[data.Length - 36]
};
Array.Copy(data, 36, image.Data, 0, data.Length - 36);
// cache the image, even if using websocket (used to retrieve the mouse cursor on IE)
_cache.Insert(
"remoteSessionImage_" + RemoteSession.Id + "_" + image.Idx,
image,
null,
DateTime.Now.AddMilliseconds(_imageCacheDuration),
Cache.NoSlidingExpiration);
Trace.TraceInformation("Received image {0} ({1}), remote session {2}", image.Idx, (image.Fullscreen ? "screen" : "region"), RemoteSession.Id);
// while a fullscreen update is pending, discard all updates; the fullscreen will replace all of them
if (FullscreenEventPending)
{
if (!image.Fullscreen)
{
Trace.TraceInformation("Discarding image {0} (region) as a fullscreen update is pending, remote session {1}", image.Idx, RemoteSession.Id);
return;
}
else
{
Trace.TraceInformation("Fullscreen update received, resuming image(s) processing, remote session {0}", RemoteSession.Id);
FullscreenEventPending = false;
// screenshot request
if (ScreenshotEventLock != null)
{
lock (ScreenshotEventLock)
{
// screenshot image index
ScreenshotImageIdx = image.Idx;
// if waiting for a screenshot, signal the reception
if (ScreenshotEventPending)
{
ScreenshotEventPending = false;
Monitor.Pulse(ScreenshotEventLock);
}
}
}
}
}
// HTML5 client(s)
if (WebSockets.Count > 0)
{
Trace.TraceInformation("Sending image {0} ({1}) on websocket(s), remote session {2}", image.Idx, (image.Fullscreen ? "screen" : "region"), RemoteSession.Id);
foreach (var webSocket in WebSockets)
{
webSocket.SendImage(image);
}
}
// HTML4 client(s)
lock (_imageEventLock)
{
// last received image index
_lastReceivedImageIdx = image.Idx;
// if waiting for a new image, signal the reception
if (_imageEventPending)
{
_imageEventPending = false;
Monitor.Pulse(_imageEventLock);
}
}
}
catch (Exception exc)
{
Trace.TraceError("Failed to process update, remote session {0} ({1})", RemoteSession.Id, exc);
}
}
// new image
private void ProcessUpdate(byte[] data)
{
try
{
if (data.Length <= 36)
{
throw new Exception("invalid image data");
}
// image info (8 items, 32 bits each => 8 * 4 = 32 bytes)
var imgInfo = new byte[32];
Array.Copy(data, 4, imgInfo, 0, 32);
var image = new RemoteSessionImage
{
Idx = BitConverter.ToInt32(imgInfo, 0),
PosX = BitConverter.ToInt32(imgInfo, 4),
PosY = BitConverter.ToInt32(imgInfo, 8),
Width = BitConverter.ToInt32(imgInfo, 12),
Height = BitConverter.ToInt32(imgInfo, 16),
Format = (ImageFormat)BitConverter.ToInt32(imgInfo, 20),
Quality = BitConverter.ToInt32(imgInfo, 24),
Fullscreen = BitConverter.ToInt32(imgInfo, 28) == 1,
Data = new byte[data.Length - 36]
};
Array.Copy(data, 36, image.Data, 0, data.Length - 36);
// cache the image, even if using websocket (used to retrieve the mouse cursor on IE)
_imageCache.Insert(
"remoteSessionImage_" + RemoteSession.Id + "_" + image.Idx,
image,
null,
DateTime.Now.AddMilliseconds(_imageCacheDuration),
Cache.NoSlidingExpiration);
Trace.TraceInformation("Received image {0} ({1}), remote session {2}", image.Idx, (image.Fullscreen ? "screen" : "region"), RemoteSession.Id);
// while a fullscreen update is pending, discard all updates; the fullscreen will replace all of them
if (FullscreenEventPending)
{
if (!image.Fullscreen)
{
Trace.TraceInformation("Discarding image {0} (region) as a fullscreen update is pending, remote session {1}", image.Idx, RemoteSession.Id);
return;
}
else
{
Trace.TraceInformation("Fullscreen update received, resuming image(s) processing, remote session {0}", RemoteSession.Id);
FullscreenEventPending = false;
}
}
// if using websocket(s), send the image
if (WebSockets.Count > 0)
{
Trace.TraceInformation("Sending image {0} ({1}) on websocket(s), remote session {2}", image.Idx, (image.Fullscreen ? "screen" : "region"), RemoteSession.Id);
foreach (var webSocket in WebSockets)
{
if (!webSocket.BinaryMode)
{
webSocket.Send(
image.Idx + "," +
image.PosX + "," +
image.PosY + "," +
image.Width + "," +
image.Height + "," +
image.Format.ToString().ToLower() + "," +
image.Quality + "," +
image.Fullscreen.ToString().ToLower() + "," +
Convert.ToBase64String(image.Data));
}
else
{
webSocket.Send(data);
}
}
}
// otherwise, it will be retrieved later
else
{
lock (_imageEventLock)
{
// last received image index
_lastReceivedImageIdx = image.Idx;
// if waiting for a new image, signal the reception
if (_imageEventPending)
{
_imageEventPending = false;
Monitor.Pulse(_imageEventLock);
}
}
}
}
catch (Exception exc)
{
Trace.TraceError("Failed to process update, remote session {0} ({1})", RemoteSession.Id, exc);
}
}
// new image
public void ProcessUpdate(string data)
{
try
{
var imgParts = data.Split(new[] { "," }, StringSplitOptions.RemoveEmptyEntries);
if (imgParts.Length != 9)
{
throw new Exception("image can't be deserialized");
}
var image = new RemoteSessionImage
{
Idx = int.Parse(imgParts[0]),
PosX = int.Parse(imgParts[1]),
PosY = int.Parse(imgParts[2]),
Width = int.Parse(imgParts[3]),
Height = int.Parse(imgParts[4]),
Format = (ImageFormat)Enum.Parse(typeof(ImageFormat), imgParts[5]),
Quality = int.Parse(imgParts[6]),
Base64Data = imgParts[7].Replace("\n", ""),
Fullscreen = imgParts[8] == "1"
};
Trace.TraceInformation("Received image {0} ({1}), remote session {2}", image.Idx, (image.Fullscreen ? "screen" : "region"), RemoteSession.Id);
// while a fullscreen update is pending, discard all updates; the fullscreen will replace all of them
if (_fullscreenPending)
{
if (!image.Fullscreen)
{
Trace.TraceInformation("Discarding image {0} (region) as a fullscreen update is pending, remote session {1}", image.Idx, RemoteSession.Id);
return;
}
else
{
Trace.TraceInformation("Fullscreen update received, resuming image(s) processing, remote session {0}", RemoteSession.Id);
_fullscreenPending = false;
}
}
// if using a websocket, send the image
if (WebSocket != null)
{
if (WebSocket.IsAvailable)
{
Trace.TraceInformation("Sending image {0} ({1}) on websocket, remote session {2}", image.Idx, (image.Fullscreen ? "screen" : "region"), RemoteSession.Id);
WebSocket.Send(
image.Idx + "," +
image.PosX + "," +
image.PosY + "," +
image.Width + "," +
image.Height + "," +
image.Format.ToString().ToLower() + "," +
image.Quality + "," +
image.Base64Data + "," +
image.Fullscreen.ToString().ToLower());
}
else
{
Trace.TraceInformation("Websocket is unavailable (connection closed by client?), remote session {0}, status: {1}", RemoteSession.Id, RemoteSession.State);
}
}
// otherwise cache it (will be retrieved later)
else
{
lock (ImageEventLock)
{
_imageCache.Insert(
"remoteSessionImage_" + RemoteSession.Id + "_" + image.Idx,
image,
null,
DateTime.Now.AddMilliseconds(_imageCacheDuration),
Cache.NoSlidingExpiration);
// last received image index
_lastReceivedImageIdx = image.Idx;
// if waiting for a new image, signal the reception
if (ImageEventPending)
{
ImageEventPending = false;
Monitor.Pulse(ImageEventLock);
}
}
}
}
catch (Exception exc)
{
Trace.TraceError("Failed to process update {0}, remote session {1} ({2})", data, RemoteSession.Id, exc);
}
}
// new image
private void ProcessUpdate(byte[] data)
{
try
{
if (data.Length <= 36)
{
throw new Exception("invalid image data");
}
// image info (8 items, 32 bits each => 8 * 4 = 32 bytes)
var imgInfo = new byte[32];
Array.Copy(data, 4, imgInfo, 0, 32);
// CAUTION! if the remote session is reconnected (i.e.: browser resize), a new instance of wfreerdp is spawned
// the image index can no longer be handled by wfreerdp, this must be done by the remote session manager
// the image index provided by wfreerdp is relative to its own instance, if needed
var image = new RemoteSessionImage
{
//Idx = BitConverter.ToInt32(imgInfo, 0),
Idx = _imageIdx == int.MaxValue ? 1 : ++_imageIdx,
PosX = BitConverter.ToInt32(imgInfo, 4),
PosY = BitConverter.ToInt32(imgInfo, 8),
Width = BitConverter.ToInt32(imgInfo, 12),
Height = BitConverter.ToInt32(imgInfo, 16),
Format = (ImageFormat)BitConverter.ToInt32(imgInfo, 20),
Quality = BitConverter.ToInt32(imgInfo, 24),
Fullscreen = BitConverter.ToInt32(imgInfo, 28) == 1,
Data = new byte[data.Length - 36]
};
Array.Copy(data, 36, image.Data, 0, data.Length - 36);
// cache the image, even if using websocket (used to retrieve the mouse cursor on IE)
_cache.Insert(
"remoteSessionImage_" + RemoteSession.Id + "_" + image.Idx,
image,
null,
DateTime.Now.AddMilliseconds(_imageCacheDuration),
Cache.NoSlidingExpiration);
Trace.TraceInformation("Received image {0} ({1}), remote session {2}", image.Idx, (image.Fullscreen ? "screen" : "region"), RemoteSession.Id);
// a fullscreen update was requested
if (FullscreenEventPending && image.Fullscreen)
{
Trace.TraceInformation("Fullscreen update received, remote session {0}", RemoteSession.Id);
FullscreenEventPending = false;
// screenshot request
if (ScreenshotEventLock != null)
{
lock (ScreenshotEventLock)
{
// screenshot image index
ScreenshotImageIdx = image.Idx;
// if waiting for a screenshot, signal the reception
if (ScreenshotEventPending)
{
ScreenshotEventPending = false;
Monitor.Pulse(ScreenshotEventLock);
}
}
}
}
// send update to client(s)
foreach (var client in Clients.Values)
{
// send the update if the client latency is normal or if it's a fullscreen update
if (client.Latency <= _imageCacheDuration || image.Fullscreen)
{
// websocket(s)
if (client.WebSockets != null && client.WebSockets.Count > 0)
{
// round robin on the client websockets down pool
if (client.WebSocketsRoundRobinIdx >= client.WebSockets.Count)
{
client.WebSocketsRoundRobinIdx = 0;
}
Trace.TraceInformation("Sending image {0} ({1}) on websocket, client {2}, remote session {3}", image.Idx, (image.Fullscreen ? "screen" : "region"), client.Id, RemoteSession.Id);
client.WebSockets[client.WebSocketsRoundRobinIdx++].SendImage(image);
}
// event source
else if (client.EventSource != null)
{
Trace.TraceInformation("Sending image {0} ({1}) on event source, client {2}, remote session {3}", image.Idx, (image.Fullscreen ? "screen" : "region"), client.Id, RemoteSession.Id);
client.EventSource.SendImage(image);
}
// long polling
else if (client.LongPolling != null)
{
Trace.TraceInformation("Sending image {0} ({1}) on long polling, client {2}, remote session {3}", image.Idx, (image.Fullscreen ? "screen" : "region"), client.Id, RemoteSession.Id);
client.LongPolling.SendImage(image);
}
// xhr: updates are polled against the cache by the client
}
}
// image event
lock (_imageEventLock)
{
// last received image index
_lastReceivedImageIdx = image.Idx;
// if waiting for a new image, signal the reception
if (_imageEventPending)
{
_imageEventPending = false;
Monitor.Pulse(_imageEventLock);
}
}
}
catch (Exception exc)
{
Trace.TraceError("Failed to process update, remote session {0} ({1})", RemoteSession.Id, exc);
}
}
public void SendImage(RemoteSessionImage image)
{
Send(GetImageText(image));
}
public void SendImage(RemoteSessionImage image)
{
Send("<script>parent.lpProcessImage(" + GetImageText(image) + ");</script>");
}
public void SendImage(RemoteSessionImage image)
{
Send(string.Format("<script>parent.lpProcessImage({0});</script>", GetImageText(image)));
}
