private static Stack <UpdateXML> FindNeededUpdates(UpdateXML firstUpdateToStack)
{
//Console.WriteLine("Finding what updates to download");
Stack <UpdateXML> updateStack = new Stack <UpdateXML>();
updateStack.Push(firstUpdateToStack);
UpdateXML currentUpdate = firstUpdateToStack;
while (true)
{
// Look at the previous version provided by the current UpdateXML.
// If the previous version is not greater than this client's version, or parsing
// failed, stop stacking and get ready for updating.
if (!UpdateExistsAndIsNewerThanClient(out UpdateXML lastUpdate,
UpdateInfo.GetPreviousVersionXMLPath(currentUpdate.PreviousVersion)))
{
break;
}
// Otherwise, add it to the stack
updateStack.Push(lastUpdate);
// Prepare for next loop
currentUpdate = lastUpdate;
}
return(updateStack);
}
private static bool UpdateExistsAndIsNewerThanClient(out UpdateXML updateXML, string xmlPath)
{
// updateXML is expected to be changed.
updateXML = null;
//Console.WriteLine("Checking if updateXML location exists.");
// If the xml doesn't exist on the server, return false.
Uri xmlLocation = new Uri(xmlPath);
if (!UpdateXML.Exists(xmlLocation))
{
return(false);
}
//Console.WriteLine("It exists!");
// If it does exist, assign updateXML to it and compare to the client version.
updateXML = UpdateXML.Parse(xmlLocation);
return(updateXML != null && updateXML.PreviousVersion >= Pulsarc.CurrentVersion);
}
private void HandleUpdateXML(UpdateXML update, bool retry = false)
{
string tempFilePath = Path.GetTempFileName();
try
{
using (webClient)
{
webClient.DownloadFile(update.DownloadUri, tempFilePath);
}
}
catch
{
// If we already tried once, stop trying.
if (retry)
{
return;
}
// Try one more time.
DeleteFileAndTryAgain();
}
// Checksum with md5, try again if there's an issue
if (!File.Exists(tempFilePath) ||
Hasher.HashFile(tempFilePath, HashType.MD5) != update.MD5)
{
// If we already tried once, stop trying.
if (retry)
{
return;
}
// Try one more time
DeleteFileAndTryAgain();
}
// Otherwise add it to the queue of patches
patchFileLocations.Enqueue(tempFilePath);
bool anotherOne = updates.TryPop(out UpdateXML nextUpdate);
// If the Pop was successful, handle it, otherwise we are done and have suceeded!
if (anotherOne)
{
HandleUpdateXML(nextUpdate);
}
void DeleteFileAndTryAgain()
{
// Give everything a break
Thread.Sleep(333);
// Try to delete the temp file twice
try { File.Delete(tempFilePath); }
catch
{
try { File.Delete(tempFilePath); }
catch { }
}
HandleUpdateXML(update, true);
}
}
