looqs/gui/pdfworker.cpp

121 righe
3.1 KiB
C++

#include <QApplication>
#include <QScreen>
#include <QDebug>
#include <QScopedPointer>
#include <QMutexLocker>
#include <QtConcurrent/QtConcurrent>
#include <QtConcurrent/QtConcurrentMap>
#include <atomic>
#include "pdfworker.h"
static QMutex cacheMutex;
struct Renderer
{
typedef PdfPreview result_type;
double scaleX;
double scaleY;
QHash<QString, Poppler::Document *> documentcache;
qsizetype maxTotalPreviewImageMemUsage;
std::atomic<qsizetype> currentTotalPreviewImageMemUsage { 0 };
Renderer(double scaleX, double scaleY, qsizetype maxPreviewImageMemUsage)
{
this->scaleX = scaleX;
this->scaleY = scaleY;
this->maxTotalPreviewImageMemUsage = maxPreviewImageMemUsage;
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}
/*we need this one because std::atomic has none, but this is only a functor for
concurrentmap, thus, it's ok for it to be half-broken*/
Renderer(const Renderer &o)
{
this->scaleX = o.scaleX;
this->scaleY = o.scaleY;
}
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~Renderer()
{
qDeleteAll(documentcache);
}
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Poppler::Document *document(QString path)
{
if(documentcache.contains(path))
return documentcache.value(path);
Poppler::Document *result = Poppler::Document::load(path);
if(result == nullptr)
{
//TODO: some kind of user feedback would be nice
return nullptr;
}
result->setRenderHint(Poppler::Document::TextAntialiasing);
QMutexLocker locker(&cacheMutex);
documentcache.insert(path, result);
return result;
}
PdfPreview operator()(const PdfPreview &preview)
{
PdfPreview result = preview;
if(currentTotalPreviewImageMemUsage.load() < maxTotalPreviewImageMemUsage)
{
Poppler::Document *doc = document(preview.documentPath);
if(doc == nullptr)
{
return preview;
}
if(doc->isLocked())
{
return preview;
}
int p = (int)preview.page - 1;
if(p < 0)
{
p = 0;
}
Poppler::Page *pdfPage = doc->page(p);
QImage img = pdfPage->renderToImage(scaleX, scaleY);
result.previewImage = img;
currentTotalPreviewImageMemUsage += img.sizeInBytes();
}
return result;
}
};
QFuture<PdfPreview> PdfWorker::generatePreviews(const QVector<SearchResult> paths, double scalefactor)
{
QVector<PdfPreview> previews;
for(const SearchResult &sr : paths)
{
for(int page : sr.pages)
{
PdfPreview p;
p.documentPath = sr.fileData.absPath;
p.page = page;
previews.append(p);
}
}
double scaleX = QGuiApplication::primaryScreen()->physicalDotsPerInchX() * scalefactor;
double scaleY = QGuiApplication::primaryScreen()->physicalDotsPerInchY() * scalefactor;
QSettings setting;
qsizetype maxPreviewImageMemUsage = setting.value("maxpreviewimagesmemory", 1024 * 1024 * 1024).toLongLong();
return QtConcurrent::mapped(previews, Renderer(scaleX, scaleY, maxPreviewImageMemUsage));
}