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Optimization (basic structures)

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Jakub Melka
2020-05-31 18:31:59 +02:00
parent 23a1275b9f
commit 680252b634
16 changed files with 960 additions and 183 deletions
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189
PdfForQtLib/sources/pdfdocumentbuilder.cpp
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@ -19,7 +19,7 @@
#include "pdfencoding.h"
#include "pdfconstants.h"
#include "pdfdocumentreader.h"
#include "pdfvisitor.h"
#include "pdfobjectutils.h"
#include <QBuffer>
#include <QPainter>
@ -28,155 +28,6 @@
namespace pdf
{
class PDFCollectReferencesVisitor : public PDFAbstractVisitor
{
public:
explicit PDFCollectReferencesVisitor(std::set<PDFObjectReference>& references) :
m_references(references)
{
}
virtual void visitArray(const PDFArray* array) override;
virtual void visitDictionary(const PDFDictionary* dictionary) override;
virtual void visitStream(const PDFStream* stream) override;
virtual void visitReference(const PDFObjectReference reference) override;
private:
std::set<PDFObjectReference>& m_references;
};
void PDFCollectReferencesVisitor::visitArray(const PDFArray* array)
{
acceptArray(array);
}
void PDFCollectReferencesVisitor::visitDictionary(const PDFDictionary* dictionary)
{
for (size_t i = 0, count = dictionary->getCount(); i < count; ++i)
{
dictionary->getValue(i).accept(this);
}
}
void PDFCollectReferencesVisitor::visitStream(const PDFStream* stream)
{
visitDictionary(stream->getDictionary());
}
void PDFCollectReferencesVisitor::visitReference(const PDFObjectReference reference)
{
m_references.insert(reference);
}
class PDFReplaceReferencesVisitor : public PDFAbstractVisitor
{
public:
explicit PDFReplaceReferencesVisitor(const std::map<PDFObjectReference, PDFObjectReference>& replacements) :
m_replacements(replacements)
{
m_objectStack.reserve(32);
}
virtual void visitNull() override;
virtual void visitBool(bool value) override;
virtual void visitInt(PDFInteger value) override;
virtual void visitReal(PDFReal value) override;
virtual void visitString(PDFStringRef string) override;
virtual void visitName(PDFStringRef name) override;
virtual void visitArray(const PDFArray* array) override;
virtual void visitDictionary(const PDFDictionary* dictionary) override;
virtual void visitStream(const PDFStream* stream) override;
virtual void visitReference(const PDFObjectReference reference) override;
PDFObject getObject();
private:
const std::map<PDFObjectReference, PDFObjectReference>& m_replacements;
std::vector<PDFObject> m_objectStack;
};
void PDFReplaceReferencesVisitor::visitNull()
{
m_objectStack.push_back(PDFObject::createNull());
}
void PDFReplaceReferencesVisitor::visitBool(bool value)
{
m_objectStack.push_back(PDFObject::createBool(value));
}
void PDFReplaceReferencesVisitor::visitInt(PDFInteger value)
{
m_objectStack.push_back(PDFObject::createInteger(value));
}
void PDFReplaceReferencesVisitor::visitReal(PDFReal value)
{
m_objectStack.push_back(PDFObject::createReal(value));
}
void PDFReplaceReferencesVisitor::visitString(PDFStringRef string)
{
m_objectStack.push_back(PDFObject::createString(string));
}
void PDFReplaceReferencesVisitor::visitName(PDFStringRef name)
{
m_objectStack.push_back(PDFObject::createName(name));
}
void PDFReplaceReferencesVisitor::visitArray(const PDFArray* array)
{
acceptArray(array);
// We have all objects on the stack
Q_ASSERT(array->getCount() <= m_objectStack.size());
auto it = std::next(m_objectStack.cbegin(), m_objectStack.size() - array->getCount());
std::vector<PDFObject> objects(it, m_objectStack.cend());
PDFObject object = PDFObject::createArray(std::make_shared<PDFArray>(qMove(objects)));
m_objectStack.erase(it, m_objectStack.cend());
m_objectStack.push_back(object);
}
void PDFReplaceReferencesVisitor::visitDictionary(const PDFDictionary* dictionary)
{
Q_ASSERT(dictionary);
std::vector<PDFDictionary::DictionaryEntry> entries;
entries.reserve(dictionary->getCount());
for (size_t i = 0, count = dictionary->getCount(); i < count; ++i)
{
dictionary->getValue(i).accept(this);
entries.emplace_back(dictionary->getKey(i), m_objectStack.back());
m_objectStack.pop_back();
}
m_objectStack.push_back(PDFObject::createDictionary(std::make_shared<PDFDictionary>(qMove(entries))));
}
void PDFReplaceReferencesVisitor::visitStream(const PDFStream* stream)
{
// Replace references in the dictionary
visitDictionary(stream->getDictionary());
PDFObject dictionaryObject = m_objectStack.back();
m_objectStack.pop_back();
m_objectStack.push_back(PDFObject::createStream(std::make_shared<PDFStream>(PDFDictionary(*dictionaryObject.getDictionary()), QByteArray(*stream->getContent()))));
}
void PDFReplaceReferencesVisitor::visitReference(const PDFObjectReference reference)
{
m_objectStack.push_back(PDFObject::createReference(m_replacements.at(reference)));
}
PDFObject PDFReplaceReferencesVisitor::getObject()
{
Q_ASSERT(m_objectStack.size() == 1);
return qMove(m_objectStack.back());
}
void PDFObjectFactory::beginArray()
{
m_items.emplace_back(ItemType::Array, PDFArray());
@ -1015,32 +866,7 @@ std::vector<PDFObject> PDFDocumentBuilder::copyFrom(const std::vector<PDFObject>
{
// 1) Collect all references, which we must copy. If object is referenced, then
// we must also collect references of referenced object.
std::set<PDFObjectReference> references;
{
PDFCollectReferencesVisitor collectReferencesVisitor(references);
for (const PDFObject& object : objects)
{
object.accept(&collectReferencesVisitor);
}
}
// Iterative algorihm, which adds additional references from referenced objects.
// If new reference is added, then we must also check, that all referenced objects
// from this object are added.
std::set<PDFObjectReference> workSet = references;
while (!workSet.empty())
{
std::set<PDFObjectReference> addedReferences;
PDFCollectReferencesVisitor collectReferencesVisitor(addedReferences);
for (const PDFObjectReference& objectReference : workSet)
{
storage.getObject(objectReference).accept(&collectReferencesVisitor);
}
workSet.clear();
std::set_difference(addedReferences.cbegin(), addedReferences.cend(), references.cbegin(), references.cend(), std::inserter(workSet, workSet.cend()));
references.merge(addedReferences);
}
std::set<PDFObjectReference> references = PDFObjectUtils::getReferences(objects, storage);
// 2) Make room for new objects, together with mapping
std::map<PDFObjectReference, PDFObjectReference> referenceMapping;
@ -1053,9 +879,7 @@ std::vector<PDFObject> PDFDocumentBuilder::copyFrom(const std::vector<PDFObject>
for (const PDFObjectReference& sourceReference : references)
{
const PDFObjectReference targetReference = referenceMapping.at(sourceReference);
PDFReplaceReferencesVisitor replaceReferencesVisitor(referenceMapping);
storage.getObject(sourceReference).accept(&replaceReferencesVisitor);
m_storage.setObject(targetReference, replaceReferencesVisitor.getObject());
m_storage.setObject(targetReference, PDFObjectUtils::replaceReferences(storage.getObject(sourceReference), referenceMapping));
}
std::vector<PDFObject> result;
@ -1069,16 +893,15 @@ std::vector<PDFObject> PDFDocumentBuilder::copyFrom(const std::vector<PDFObject>
}
else
{
PDFReplaceReferencesVisitor replaceReferencesVisitor(referenceMapping);
object.accept(&replaceReferencesVisitor);
PDFObject replacedObject = PDFObjectUtils::replaceReferences(object, referenceMapping);
if (createReferences)
{
result.push_back(PDFObject::createReference(addObject(replaceReferencesVisitor.getObject())));
result.push_back(PDFObject::createReference(addObject(qMove(replacedObject))));
}
else
{
result.push_back(replaceReferencesVisitor.getObject());
result.emplace_back(qMove(replacedObject));
}
}
}