internal void getObject(IAmazonS3 amazonS3, S3ObjectRequest request)
{
Exception exception = null;
long length = request.End - request.Start + 1;
GetObjectRequest getObjectRequest = new GetObjectRequest()
{
BucketName = request.BucketName,
Key = request.Key,
ByteRange = new ByteRange(request.Start, request.End)
};
for (int i = 0; i <= _retryRequests; i++)
{
try
{
GetObjectResponse response = amazonS3.GetObject(getObjectRequest);
using (BufferedStream input = new BufferedStream(response.ResponseStream))
{
byte[] buffer = new byte[length];
int current = 0;
int bytesRead = 0;
int count = buffer.Length;
while ((bytesRead = input.Read(buffer, current, count)) > 0)
{
current += bytesRead;
count -= bytesRead;
}
_s3Reader.addCache(request.Start, buffer);
}
response.Dispose();
exception = null;
return;
}
catch (Exception ex)
{
exception = ex;
//! exponential backoff
//! wait seconds 1, 2, 4, 8, 16, 32, 64 ....
int millisecondsTimeout = (2 ^ i) * 1000;
Thread.Sleep(millisecondsTimeout);
}
}
if (exception != null)
{
throw exception;
}
}
internal void Execute()
{
while (_waitEvent)
{
S3ObjectRequest request = null;
while ((request = getNextPartRequest()) != null)
{
downloadPart(request);
if (_lastException != null)
{
lock (_s3Reader.WAIT_FOR_COMPLETION_LOCK)
{
Monitor.Pulse(_s3Reader.WAIT_FOR_COMPLETION_LOCK);
}
return;
}
}
}
}
int addRequestToDownload(int count)
{
lock (QUEUE_ACECSS_LOCK)
{
int n = 0;
while (n < count)
{
if (_objectRequests.Count == 0)
{
break;
}
S3ObjectRequest request = _objectRequests.Dequeue();
_objectRequestToDownload.Enqueue(request);
addCache(request.Start, null);
n++;
}
return(n);
}
}
internal void downloadPart(S3ObjectRequest request)
{
Exception exception = null;
try
{
getObject(_s3Client, request);
exception = null;
return;
}
catch (ThreadAbortException)
{
throw;
}
catch (Exception ex)
{
exception = ex;
}
if (exception != null)
{
_lastException = exception;
}
}
