pdf preview generation: Use QtConcurrent::mapped + QFutureWatcher instead of own single-thread solution

This commit is contained in:
Albert S. 2019-04-29 20:50:52 +02:00
orang tua 0d3cfefb36
melakukan 4c8d201f81
6 mengubah file dengan 77 tambahan dan 85 penghapusan

Melihat File

@ -50,7 +50,6 @@ HEADERS += \
commanddelete.h \
commandupdate.h \
filesaver.h \
filedata.h \
databasefactory.h \
sqlitedbservice.h \
logger.h \

Melihat File

@ -4,7 +4,7 @@
#
#-------------------------------------------------
QT += core gui
QT += core concurrent gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
CONFIG += c++14

Melihat File

@ -26,9 +26,6 @@ MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWi
qDebug() << "failed to open database";
throw std::runtime_error("Failed to open database");
}
pdfWorker = new PdfWorker();
pdfWorker->moveToThread(&pdfWorkerThread);
connectSignals();
searchThread.start();
ui->treeResultsList->setContextMenuPolicy(Qt::ContextMenuPolicy::CustomContextMenu);
@ -51,15 +48,19 @@ void MainWindow::connectSignals()
auto results = searchWatcher.future().result();
handleSearchResults(results);
});
connect(&pdfWorkerWatcher, &QFutureWatcher<PdfPreview>::resultReadyAt, this,
[&](int index) { pdfPreviewReceived(pdfWorkerWatcher.resultAt(index)); });
connect(&pdfWorkerWatcher, &QFutureWatcher<PdfPreview>::progressValueChanged, ui->pdfProcessBar,
&QProgressBar::setValue);
// connect(searchWorker, &SearchWorker::searchCancelled, this, &MainWindow::handleCancelledSearch);
// connect(searchWorker, &SearchWorker::searchError, this, &MainWindow::handleSearchError);
connect(ui->treeResultsList, &QTreeWidget::itemActivated, this, &MainWindow::treeSearchItemActivated);
connect(ui->treeResultsList, &QTreeWidget::customContextMenuRequested, this,
&MainWindow::showSearchResultsContextMenu);
connect(ui->tabWidget, &QTabWidget::currentChanged, this, &MainWindow::tabChanged);
connect(this, &MainWindow::startPdfPreviewGeneration, pdfWorker, &PdfWorker::generatePreviews);
connect(pdfWorker, &PdfWorker::previewReady, this, &MainWindow::pdfPreviewReceived);
connect(pdfWorker, &PdfWorker::previewsFinished, [&] { this->pdfDirty = false; });
connect(ui->comboScale, qOverload<const QString &>(&QComboBox::currentIndexChanged), this,
&MainWindow::comboScaleChanged);
}
@ -117,8 +118,6 @@ void MainWindow::pdfPreviewReceived(PdfPreview preview)
ClickLabel *label = new ClickLabel();
label->setPixmap(QPixmap::fromImage(preview.previewImage));
ui->scrollAreaWidgetContents->layout()->addWidget(label);
ui->pdfProcessBar->setValue(++processedPdfPreviews);
connect(label, &ClickLabel::clicked,
[=]()
{
@ -199,11 +198,12 @@ void MainWindow::handleSearchResults(const QVector<SearchResult> &results)
void MainWindow::makePdfPreview()
{
if(!pdfWorkerThread.isRunning())
pdfWorkerThread.start();
pdfWorker->cancelAndWait();
QCoreApplication::processEvents(); // Process not processed images
this->pdfWorkerWatcher.cancel();
this->pdfWorkerWatcher.waitForFinished();
QCoreApplication::processEvents(); // Maybe not necessary anymore, depends on whether it's possible that a slot is
// still to be fired.
qDeleteAll(ui->scrollAreaWidgetContents->children());
ui->scrollAreaWidgetContents->setLayout(new QHBoxLayout());
@ -211,8 +211,10 @@ void MainWindow::makePdfPreview()
processedPdfPreviews = 0;
QString scaleText = ui->comboScale->currentText();
scaleText.chop(1);
emit startPdfPreviewGeneration(this->pdfSearchResults, scaleText.toInt() / 100.);
PdfWorker worker;
this->pdfWorkerWatcher.setFuture(worker.generatePreviews(this->pdfSearchResults, scaleText.toInt() / 100.));
ui->pdfProcessBar->setMaximum(this->pdfWorkerWatcher.progressMaximum());
ui->pdfProcessBar->setMinimum(this->pdfWorkerWatcher.progressMinimum());
}
void MainWindow::handleCancelledSearch()

Melihat File

@ -32,7 +32,7 @@ class MainWindow : public QMainWindow
QSqlDatabase db;
QFuture<QVector<SearchResult>> searchFuture;
QFutureWatcher<QVector<SearchResult>> searchWatcher;
PdfWorker *pdfWorker;
QFutureWatcher<PdfPreview> pdfWorkerWatcher;
void add(QString path, unsigned int page);
QThread searchThread;
QThread pdfWorkerThread;

Melihat File

@ -3,77 +3,80 @@
#include <QScreen>
#include <QDebug>
#include <QScopedPointer>
#include <QMutexLocker>
#include <QtConcurrent/QtConcurrent>
#include <QtConcurrent/QtConcurrentMap>
#include "pdfworker.h"
PdfWorker::PdfWorker()
static QMutex cacheMutex;
struct Renderer
{
}
Poppler::Document *PdfWorker::document(QString path)
{
if(this->documentcache.contains(path))
return this->documentcache.value(path);
Poppler::Document *result = Poppler::Document::load(path);
if(result == nullptr)
typedef PdfPreview result_type;
double scaleX;
double scaleY;
QHash<QString, Poppler::Document *> documentcache;
Renderer(double scaleX, double scaleY)
{
return nullptr;
this->scaleX = scaleX;
this->scaleY = scaleY;
}
result->setRenderHint(Poppler::Document::TextAntialiasing);
this->documentcache.insert(path, result);
return result;
}
void PdfWorker::generatePreviews(QVector<SearchResult> paths, double scalefactor)
{
this->cancelCurrent = false;
this->generating = true;
for(SearchResult &sr : paths)
Poppler::Document *document(QString path)
{
if(this->cancelCurrent.load())
if(documentcache.contains(path))
return documentcache.value(path);
Poppler::Document *result = Poppler::Document::load(path);
if(result == nullptr)
{
break;
return nullptr;
}
Poppler::Document *doc = document(sr.fileData.absPath);
result->setRenderHint(Poppler::Document::TextAntialiasing);
QMutexLocker locker(&cacheMutex);
documentcache.insert(path, result);
return result;
}
PdfPreview operator()(const PdfPreview &preview)
{
Poppler::Document *doc = document(preview.documentPath);
if(doc == nullptr)
{
continue;
return preview;
}
if(doc->isLocked())
{
continue;
return preview;
}
for(unsigned int page : sr.pages)
int p = (int)preview.page - 1;
if(p < 0)
{
int p = (int)page - 1;
if(p < 0)
p = 0;
Poppler::Page *pdfPage = doc->page(p);
QImage image =
pdfPage->renderToImage(QGuiApplication::primaryScreen()->physicalDotsPerInchX() * scalefactor,
QGuiApplication::primaryScreen()->physicalDotsPerInchY() * scalefactor);
p = 0;
}
Poppler::Page *pdfPage = doc->page(p);
PdfPreview result = preview;
result.previewImage = pdfPage->renderToImage(scaleX, scaleY);
return result;
}
};
PdfPreview preview;
preview.previewImage = image;
preview.documentPath = sr.fileData.absPath;
preview.page = page;
emit previewReady(preview);
QFuture<PdfPreview> PdfWorker::generatePreviews(QVector<SearchResult> paths, double scalefactor)
{
QVector<PdfPreview> previews;
for(SearchResult &sr : paths)
{
for(int page : sr.pages)
{
PdfPreview p;
p.documentPath = sr.fileData.absPath;
p.page = page;
previews.append(p);
}
}
isFreeMutex.lock();
isFree.wakeOne();
isFreeMutex.unlock();
generating = false;
emit previewsFinished();
}
void PdfWorker::cancelAndWait()
{
if(this->generating.load())
{
this->cancelCurrent = true;
double scaleX = QGuiApplication::primaryScreen()->physicalDotsPerInchX() * scalefactor;
double scaleY = QGuiApplication::primaryScreen()->physicalDotsPerInchY() * scalefactor;
isFreeMutex.lock();
isFree.wait(&isFreeMutex);
isFreeMutex.unlock();
}
return QtConcurrent::mapped(previews, Renderer(scaleX, scaleY));
}

Melihat File

@ -6,29 +6,17 @@
#include <QThread>
#include <QMutex>
#include <QWaitCondition>
#include <QMutex>
#include <QFuture>
#include <poppler-qt5.h>
#include "pdfpreview.h"
#include "searchresult.h"
class PdfWorker : public QObject
{
Q_OBJECT
private:
QHash<QString, Poppler::Document *> documentcache;
Poppler::Document *document(QString path);
std::atomic<bool> cancelCurrent{false};
std::atomic<bool> generating{false};
QMutex isFreeMutex;
QWaitCondition isFree;
public:
PdfWorker();
void cancelAndWait();
public slots:
void generatePreviews(QVector<SearchResult> paths, double scalefactor);
signals:
void previewReady(PdfPreview p);
void previewsFinished();
QFuture<PdfPreview> generatePreviews(QVector<SearchResult> paths, double scalefactor);
};
#endif // PDFWORKER_H