transmission/qt/RpcQueue.cc

79 lines
2.1 KiB
C++

// This file Copyright © 2016-2022 Mnemosyne LLC.
// It may be used under GPLv2 (SPDX: GPL-2.0), GPLv3 (SPDX: GPL-3.0),
// or any future license endorsed by Mnemosyne LLC.
// License text can be found in the licenses/ folder.
#include <cassert>
#include "RpcQueue.h"
// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
RpcQueue::Tag RpcQueue::next_tag = {};
RpcQueue::RpcQueue(QObject* parent)
: QObject(parent)
, tag_(next_tag++)
{
connect(&future_watcher_, &QFutureWatcher<RpcResponse>::finished, this, &RpcQueue::stepFinished);
}
void RpcQueue::stepFinished()
{
RpcResponse result;
if (future_watcher_.future().isResultReadyAt(0))
{
result = future_watcher_.result();
RpcResponseFuture future = future_watcher_.future();
// we can't handle network errors, abort queue and pass the error upwards
if (result.networkError != QNetworkReply::NoError)
{
assert(!result.success);
promise_.reportFinished(&result);
deleteLater();
return;
}
// call user-handler for ordinary errors
if (!result.success && next_error_handler_)
{
next_error_handler_(future);
}
// run next request, if we have one to run and there was no error (or if we tolerate errors)
if ((result.success || tolerate_errors_) && !queue_.isEmpty())
{
runNext(future);
return;
}
}
else
{
assert(!next_error_handler_);
assert(queue_.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;
}
promise_.reportFinished(&result);
deleteLater();
}
void RpcQueue::runNext(RpcResponseFuture const& response)
{
assert(!queue_.isEmpty());
auto next = queue_.dequeue();
next_error_handler_ = next.second;
future_watcher_.setFuture((next.first)(response));
}
void RpcQueue::run()
{
runNext(RpcResponseFuture());
}