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// Copyright (C) 2025 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include "fetchworker.h"
#include <QThread>
static constexpr int s_fetchBlockSize{50};
static constexpr int s_maximumListSize{s_fetchBlockSize * 10};
static constexpr int s_sleepIterations{20};
static constexpr std::chrono::milliseconds s_sleepInterval{100};
FetchWorker::FetchWorker(QObject *parent)
: QObject{parent}
{}
void FetchWorker::fetchDataBlock()
{
if (m_existingItemsCount < s_maximumListSize) {
QList<DataBlock> itemsToSend = slowDataConstruction(m_existingItemsCount);
m_existingItemsCount += itemsToSend.size();
emit dataFetched(itemsToSend);
}
if (m_existingItemsCount >= s_maximumListSize)
emit noMoreToFetch();
}
QList<FetchWorker::DataBlock> FetchWorker::slowDataConstruction(int fromIndex)
{
// Block for two seconds to mimic slow data source, while allowing interruption in case of application close
for (int iterations = s_sleepIterations;
iterations > 0 && !QThread::currentThread()->isInterruptionRequested();
--iterations) {
QThread::sleep(s_sleepInterval);
}
QList<DataBlock> returnValues;
returnValues.reserve(s_fetchBlockSize);
int number = fromIndex;
for (int blocks = 0; blocks < s_fetchBlockSize; ++blocks) {
++number;
returnValues.append({QStringLiteral("Contact %1 name").arg(number),
QStringLiteral("Contact %1 telephone").arg(number),
number});
}
return returnValues;
}
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