transmission/qt/RpcQueue.cc

95 lines
2.2 KiB
C++

/*
* This file Copyright (C) 2016 Mnemosyne LLC
*
* It may be used under the GNU GPL versions 2 or 3
* or any future license endorsed by Mnemosyne LLC.
*
*/
#include <cassert>
#include "RpcQueue.h"
RpcQueue::RpcQueue(QObject* parent) :
QObject(parent),
myTolerateErrors(false)
{
connect(&myFutureWatcher, SIGNAL(finished()), SLOT(stepFinished()));
}
void RpcQueue::stepFinished()
{
RpcResponse result;
if (myFutureWatcher.future().isResultReadyAt(0))
{
result = myFutureWatcher.result();
RpcResponseFuture future = myFutureWatcher.future();
// we can't handle network errors, abort queue and pass the error upwards
if (result.networkError != QNetworkReply::NoError)
{
assert(!result.success);
myPromise.reportFinished(&result);
deleteLater();
return;
}
// call user-handler for ordinary errors
if (!result.success && myNextErrorHandler)
{
myNextErrorHandler(future);
}
// run next request, if we have one to run and there was no error (or if we tolerate errors)
if ((result.success || myTolerateErrors) && !myQueue.isEmpty())
{
runNext(future);
return;
}
}
else
{
assert(!myNextErrorHandler);
assert(myQueue.isEmpty());
// one way or another, the last step returned nothing.
// assume it is OK and ensure that we're not going to give an empty response object to any of the next steps.
result.success = true;
}
myPromise.reportFinished(&result);
deleteLater();
}
void RpcQueue::runNext(RpcResponseFuture const& response)
{
assert(!myQueue.isEmpty());
RpcResponseFuture const oldFuture = myFutureWatcher.future();
while (true)
{
auto next = myQueue.dequeue();
myNextErrorHandler = next.second;
myFutureWatcher.setFuture((next.first)(response));
if (oldFuture != myFutureWatcher.future())
{
break;
}
if (myQueue.isEmpty())
{
deleteLater();
break;
}
}
}
void RpcQueue::run()
{
runNext(RpcResponseFuture());
}