private void SegmentThreadProc(object objSegment)
{
Segment segment = (Segment)objSegment;
segment.LastError = null;
try
{
if (segment.EndPosition > 0 && segment.StartPosition >= segment.EndPosition)
{
segment.State = SegmentState.Finished;
// raise the event
OnSegmentStoped(segment);
return;
}
int buffSize = 8192;
byte[] buffer = new byte[buffSize];
segment.State = SegmentState.Connecting;
// raise the event
OnSegmentStarting(segment);
if (segment.InputStream == null)
{
// get the next URL (It can the the main url or some mirror)
ResourceLocation location = this.MirrorSelector.GetNextResourceLocation();
// get the protocol provider for that mirror
IProtocolProvider provider = location.BindProtocolProviderInstance(this);
while (location != this.ResourceLocation)
{
Stream tempStream;
// get the remote file info on mirror
RemoteFileInfo tempRemoteInfo = provider.GetFileInfo(location, out tempStream);
if (tempStream != null)
{
tempStream.Dispose();
}
// check if the file on mirror is the same
if (tempRemoteInfo.FileSize == remoteFileInfo.FileSize &&
tempRemoteInfo.AcceptRanges == remoteFileInfo.AcceptRanges)
{
// if yes, stop looking for the mirror
break;
}
lock (mirrors)
{
// the file on the mirror is not the same, so remove from the mirror list
mirrors.Remove(location);
}
// the file on the mirror is different
// so get other mirror to use in the segment
location = this.MirrorSelector.GetNextResourceLocation();
provider = location.BindProtocolProviderInstance(this);
}
// get the input stream from start position
segment.InputStream = provider.CreateStream(location, segment.StartPosition, segment.EndPosition);
// change the segment URL to the mirror URL
segment.CurrentURL = location.URL;
}
else
{
// change the segment URL to the main URL
segment.CurrentURL = this.resourceLocation.URL;
}
using (segment.InputStream)
{
// raise the event
OnSegmentStarted(segment);
// change the segment state
segment.State = SegmentState.Downloading;
segment.CurrentTry = 0;
long readSize;
do
{
// reads the buffer from input stream
readSize = segment.InputStream.Read(buffer, 0, buffSize);
// check if the segment has reached the end
if (segment.EndPosition > 0 &&
segment.StartPosition + readSize > segment.EndPosition)
{
// adjust the 'readSize' to write only necessary bytes
readSize = (segment.EndPosition - segment.StartPosition);
if (readSize <= 0)
{
segment.StartPosition = segment.EndPosition;
break;
}
}
// locks the stream to avoid that other threads changes
// the position of stream while this thread is writing into the stream
lock (segment.OutputStream)
{
segment.OutputStream.Position = segment.StartPosition;
segment.OutputStream.Write(buffer, 0, (int)readSize);
}
// increse the start position of the segment and also calculates the rate
segment.IncreaseStartPosition(readSize);
// check if the stream has reached its end
if (segment.EndPosition > 0 && segment.StartPosition >= segment.EndPosition)
{
segment.StartPosition = segment.EndPosition;
break;
}
// check if the user have requested to pause the download
if (state == DownloaderState.Pausing)
{
segment.State = SegmentState.Paused;
break;
}
//Thread.Sleep(1500);
}while (readSize > 0);
if (segment.State == SegmentState.Downloading)
{
segment.State = SegmentState.Finished;
// try to create other segment,
// spliting the missing bytes from one existing segment
AddNewSegmentIfNeeded();
}
}
// raise the event
OnSegmentStoped(segment);
}
catch (Exception ex)
{
// store the error information
segment.State = SegmentState.Error;
segment.LastError = ex;
Debug.WriteLine(ex.ToString());
// raise the event
OnSegmentFailed(segment);
}
finally
{
// clean up the segment
segment.InputStream = null;
}
}
