public void DownloadStringAsync(Uri address, DownloadStringAsync_Completed callback)
{
CacheCalls++;
// lookup address in cache
Stream cachedResult = CacheLookup(address);
if (cachedResult != null)
{
CacheHits++;
CacheDownloadStringCompletedEventArgs eventArgs = new CacheDownloadStringCompletedEventArgs(new StreamReader(cachedResult), address);
// Invoke on a different thread. Otherwise we make the callback from the same thread as the
// original call and wierd things could happen.
Thread thread = new Thread(() => callback(this, eventArgs));
thread.Start();
}
else
{
CacheMisses++;
// not found, request data
HttpWebRequest requestGetter = (HttpWebRequest)HttpWebRequest.Create(address);
requestGetter.BeginGetResponse(
new AsyncCallback(new CacheCallback(this, callback, address).Callback),
requestGetter);
}
}
public void DownloadStringAsync(Uri address, DownloadStringAsync_Completed callback)
{
CacheCalls++;
// lookup address in cache
Stream cachedResult = CacheLookup(address);
if (cachedResult != null)
{
CacheHits++;
CacheDownloadStringCompletedEventArgs eventArgs = new CacheDownloadStringCompletedEventArgs(new StreamReader(cachedResult), address);
// Invoke on a different thread. Otherwise we make the callback from the same thread as the
// original call and wierd things could happen.
Thread thread = new Thread(() => callback(this, eventArgs));
thread.Start();
}
else
{
CacheMisses++;
// not found, request data
HttpWebRequest requestGetter = (HttpWebRequest)HttpWebRequest.Create(address);
requestGetter.BeginGetResponse(
new AsyncCallback(new CacheCallback(this, callback, address).Callback),
requestGetter);
}
}
public void Callback(IAsyncResult asyncResult)
{
CacheDownloadStringCompletedEventArgs newArgs;
try
{
HttpWebRequest request = (HttpWebRequest)asyncResult.AsyncState;
HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(asyncResult);
string statusDescr = response.StatusDescription;
long totalBytes = response.ContentLength;
if (response.StatusCode != HttpStatusCode.OK)
{
throw new WebserviceResponseException(response.StatusCode, request.RequestUri.ToString(), response.ToString(), null);
}
Stream s = response.GetResponseStream();
// no errors -- add data to the cache
TextReader result = owner.CacheAddResult(requestedAddress, s);
newArgs = new CacheDownloadStringCompletedEventArgs(result, requestedAddress);
}
catch (Exception e)
{
// TODO: Web exceptions will be caught here, and we just pass up
// that exception instead of recasting it to a WebserviceResponseException().
// This will result in the loss of the RequestUrl.
Debug.Assert(false);
newArgs = new CacheDownloadStringCompletedEventArgs(e, requestedAddress);
}
callback(this, newArgs);
}
public void Callback(IAsyncResult asyncResult)
{
CacheDownloadStringCompletedEventArgs newArgs;
try
{
HttpWebRequest request = (HttpWebRequest)asyncResult.AsyncState;
HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(asyncResult);
string statusDescr = response.StatusDescription;
long totalBytes = response.ContentLength;
if (response.StatusCode != HttpStatusCode.OK)
{
throw new WebserviceResponseException(response.StatusCode, request.RequestUri.ToString(), response.ToString(), null);
}
Stream s = response.GetResponseStream();
// no errors -- add data to the cache
TextReader result = owner.CacheAddResult(requestedAddress, s);
newArgs = new CacheDownloadStringCompletedEventArgs(result, requestedAddress);
}
catch (Exception e)
{
// TODO: Web exceptions will be caught here, and we just pass up
// that exception instead of recasting it to a WebserviceResponseException().
// This will result in the loss of the RequestUrl.
Debug.Assert(false);
newArgs = new CacheDownloadStringCompletedEventArgs(e, requestedAddress);
}
callback(this, newArgs);
}
