mirror of
https://github.com/RGBCube/serenity
synced 2025-07-24 14:47:34 +00:00
LibPDF: Harden the document/parser against errors
This commit is contained in:
parent
d654fe0e41
commit
1ef5071d1b
6 changed files with 217 additions and 108 deletions
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@ -105,7 +105,9 @@ void PDFViewerWidget::open_file(const String& path)
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auto file_result = Core::File::open(path, Core::OpenMode::ReadOnly);
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auto file_result = Core::File::open(path, Core::OpenMode::ReadOnly);
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VERIFY(!file_result.is_error());
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VERIFY(!file_result.is_error());
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m_buffer = file_result.value()->read_all();
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m_buffer = file_result.value()->read_all();
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auto document = adopt_ref(*new PDF::Document(m_buffer));
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auto document = PDF::Document::create(m_buffer);
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// FIXME: Show error dialog if the Document is invalid
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VERIFY(document);
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m_viewer->set_document(document);
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m_viewer->set_document(document);
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m_total_page_label->set_text(String::formatted("of {}", document->get_page_count()));
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m_total_page_label->set_text(String::formatted("of {}", document->get_page_count()));
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m_total_page_label->set_fixed_width(30);
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m_total_page_label->set_fixed_width(30);
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@ -34,20 +34,32 @@ String OutlineItem::to_string(int indent) const
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return builder.to_string();
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return builder.to_string();
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}
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}
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Document::Document(const ReadonlyBytes& bytes)
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RefPtr<Document> Document::create(const ReadonlyBytes& bytes)
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: m_parser(Parser({}, bytes))
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{
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{
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m_parser.set_document(this);
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auto parser = adopt_ref(*new Parser({}, bytes));
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auto document = adopt_ref(*new Document(parser));
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VERIFY(m_parser.perform_validation());
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VERIFY(parser->perform_validation());
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auto [xref_table, trailer] = m_parser.parse_last_xref_table_and_trailer();
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auto xref_table_and_trailer_opt = parser->parse_last_xref_table_and_trailer();
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if (!xref_table_and_trailer_opt.has_value())
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return {};
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m_xref_table = xref_table;
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auto [xref_table, trailer] = xref_table_and_trailer_opt.value();
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m_trailer = trailer;
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m_catalog = m_trailer->get_dict(this, CommonNames::Root);
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document->m_xref_table = xref_table;
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build_page_tree();
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document->m_trailer = trailer;
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build_outline();
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document->m_catalog = document->m_trailer->get_dict(document, CommonNames::Root);
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document->build_page_tree();
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document->build_outline();
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return document;
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}
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Document::Document(const NonnullRefPtr<Parser>& parser)
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: m_parser(parser)
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{
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m_parser->set_document(this);
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}
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}
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Value Document::get_or_load_value(u32 index)
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Value Document::get_or_load_value(u32 index)
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@ -58,7 +70,7 @@ Value Document::get_or_load_value(u32 index)
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VERIFY(m_xref_table.has_object(index));
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VERIFY(m_xref_table.has_object(index));
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auto byte_offset = m_xref_table.byte_offset_for_object(index);
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auto byte_offset = m_xref_table.byte_offset_for_object(index);
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auto indirect_value = m_parser.parse_indirect_value_at_offset(byte_offset);
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auto indirect_value = m_parser->parse_indirect_value_at_offset(byte_offset);
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VERIFY(indirect_value->index() == index);
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VERIFY(indirect_value->index() == index);
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value = indirect_value->value();
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value = indirect_value->value();
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m_values.set(index, value);
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m_values.set(index, value);
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@ -145,14 +157,19 @@ Value Document::resolve(const Value& value)
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return obj;
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return obj;
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}
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}
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void Document::build_page_tree()
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bool Document::build_page_tree()
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{
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{
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if (!m_catalog->contains(CommonNames::Pages))
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return false;
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auto page_tree = m_catalog->get_dict(this, CommonNames::Pages);
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auto page_tree = m_catalog->get_dict(this, CommonNames::Pages);
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add_page_tree_node_to_page_tree(page_tree);
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return add_page_tree_node_to_page_tree(page_tree);
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}
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}
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void Document::add_page_tree_node_to_page_tree(NonnullRefPtr<DictObject> page_tree)
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bool Document::add_page_tree_node_to_page_tree(NonnullRefPtr<DictObject> page_tree)
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{
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{
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if (!page_tree->contains(CommonNames::Kids) || !page_tree->contains(CommonNames::Count))
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return false;
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auto kids_array = page_tree->get_array(this, CommonNames::Kids);
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auto kids_array = page_tree->get_array(this, CommonNames::Kids);
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auto page_count = page_tree->get(CommonNames::Count).value().as_int();
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auto page_count = page_tree->get(CommonNames::Count).value().as_int();
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@ -163,20 +180,24 @@ void Document::add_page_tree_node_to_page_tree(NonnullRefPtr<DictObject> page_tr
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for (auto& value : *kids_array) {
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for (auto& value : *kids_array) {
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auto reference_index = value.as_ref_index();
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auto reference_index = value.as_ref_index();
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auto byte_offset = m_xref_table.byte_offset_for_object(reference_index);
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auto byte_offset = m_xref_table.byte_offset_for_object(reference_index);
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auto maybe_page_tree_node = m_parser.conditionally_parse_page_tree_node_at_offset(byte_offset);
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bool ok;
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auto maybe_page_tree_node = m_parser->conditionally_parse_page_tree_node_at_offset(byte_offset, ok);
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if (!ok)
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return false;
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if (maybe_page_tree_node) {
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if (maybe_page_tree_node) {
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add_page_tree_node_to_page_tree(maybe_page_tree_node.release_nonnull());
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if (!add_page_tree_node_to_page_tree(maybe_page_tree_node.release_nonnull()))
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return false;
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} else {
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} else {
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m_page_object_indices.append(reference_index);
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m_page_object_indices.append(reference_index);
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}
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}
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}
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}
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} else {
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return;
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// We know all of the kids are leaf nodes
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for (auto& value : *kids_array)
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m_page_object_indices.append(value.as_ref_index());
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}
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}
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// We know all of the kids are leaf nodes
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return true;
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for (auto& value : *kids_array)
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m_page_object_indices.append(value.as_ref_index());
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}
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}
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void Document::build_outline()
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void Document::build_outline()
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@ -187,8 +208,8 @@ void Document::build_outline()
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auto outline_dict = m_catalog->get_dict(this, CommonNames::Outlines);
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auto outline_dict = m_catalog->get_dict(this, CommonNames::Outlines);
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if (!outline_dict->contains(CommonNames::First))
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if (!outline_dict->contains(CommonNames::First))
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return;
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return;
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if (!outline_dict->contains(CommonNames::Last))
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VERIFY(outline_dict->contains(CommonNames::Last));
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return;
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auto first_ref = outline_dict->get_value(CommonNames::First);
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auto first_ref = outline_dict->get_value(CommonNames::First);
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auto last_ref = outline_dict->get_value(CommonNames::Last);
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auto last_ref = outline_dict->get_value(CommonNames::Last);
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@ -73,7 +73,7 @@ struct OutlineDict final : public RefCounted<OutlineDict> {
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class Document final : public RefCounted<Document> {
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class Document final : public RefCounted<Document> {
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public:
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public:
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explicit Document(const ReadonlyBytes& bytes);
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static RefPtr<Document> create(const ReadonlyBytes& bytes);
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ALWAYS_INLINE const XRefTable& xref_table() const { return m_xref_table; }
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ALWAYS_INLINE const XRefTable& xref_table() const { return m_xref_table; }
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ALWAYS_INLINE const DictObject& trailer() const { return *m_trailer; }
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ALWAYS_INLINE const DictObject& trailer() const { return *m_trailer; }
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@ -123,20 +123,22 @@ public:
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}
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}
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private:
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private:
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explicit Document(const NonnullRefPtr<Parser>& parser);
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// FIXME: Currently, to improve performance, we don't load any pages at Document
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// FIXME: Currently, to improve performance, we don't load any pages at Document
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// construction, rather we just load the page structure and populate
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// construction, rather we just load the page structure and populate
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// m_page_object_indices. However, we can be even lazier and defer page tree node
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// m_page_object_indices. However, we can be even lazier and defer page tree node
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// parsing, as good PDF writers will layout the page tree in a balanced tree to
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// parsing, as good PDF writers will layout the page tree in a balanced tree to
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// improve lookup time. This would reduce the initial overhead by not loading
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// improve lookup time. This would reduce the initial overhead by not loading
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// every page tree node of, say, a 1000+ page PDF file.
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// every page tree node of, say, a 1000+ page PDF file.
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void build_page_tree();
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bool build_page_tree();
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void add_page_tree_node_to_page_tree(NonnullRefPtr<DictObject> page_tree);
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bool add_page_tree_node_to_page_tree(NonnullRefPtr<DictObject> page_tree);
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void build_outline();
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void build_outline();
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NonnullRefPtr<OutlineItem> build_outline_item(NonnullRefPtr<DictObject> outline_item_dict);
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NonnullRefPtr<OutlineItem> build_outline_item(NonnullRefPtr<DictObject> outline_item_dict);
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NonnullRefPtrVector<OutlineItem> build_outline_item_chain(const Value& first_ref, const Value& last_ref);
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NonnullRefPtrVector<OutlineItem> build_outline_item_chain(const Value& first_ref, const Value& last_ref);
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Parser m_parser;
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NonnullRefPtr<Parser> m_parser;
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XRefTable m_xref_table;
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XRefTable m_xref_table;
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RefPtr<DictObject> m_trailer;
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RefPtr<DictObject> m_trailer;
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RefPtr<DictObject> m_catalog;
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RefPtr<DictObject> m_catalog;
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@ -24,8 +24,8 @@ static NonnullRefPtr<T> make_object(Args... args) requires(IsBaseOf<Object, T>)
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Vector<Command> Parser::parse_graphics_commands(const ReadonlyBytes& bytes)
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Vector<Command> Parser::parse_graphics_commands(const ReadonlyBytes& bytes)
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{
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{
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Parser parser(bytes);
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auto parser = adopt_ref(*new Parser(bytes));
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return parser.parse_graphics_commands();
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return parser->parse_graphics_commands();
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}
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}
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Parser::Parser(Badge<Document>, const ReadonlyBytes& bytes)
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Parser::Parser(Badge<Document>, const ReadonlyBytes& bytes)
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@ -43,26 +43,34 @@ bool Parser::perform_validation()
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return !sloppy_is_linearized() && parse_header();
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return !sloppy_is_linearized() && parse_header();
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}
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}
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Parser::XRefTableAndTrailer Parser::parse_last_xref_table_and_trailer()
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Optional<Parser::XRefTableAndTrailer> Parser::parse_last_xref_table_and_trailer()
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{
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{
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m_reader.move_to(m_reader.bytes().size() - 1);
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m_reader.move_to(m_reader.bytes().size() - 1);
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VERIFY(navigate_to_before_eof_marker());
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if (!navigate_to_before_eof_marker())
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navigate_to_after_startxref();
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return {};
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VERIFY(!m_reader.done());
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if (!navigate_to_after_startxref())
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return {};
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if (m_reader.done())
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return {};
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m_reader.set_reading_forwards();
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m_reader.set_reading_forwards();
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auto xref_offset_value = parse_number();
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auto xref_offset_value = parse_number();
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VERIFY(xref_offset_value.is_int());
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if (!xref_offset_value.is_int())
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return {};
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auto xref_offset = xref_offset_value.as_int();
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auto xref_offset = xref_offset_value.as_int();
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m_reader.move_to(xref_offset);
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m_reader.move_to(xref_offset);
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auto xref_table = parse_xref_table();
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auto xref_table = parse_xref_table();
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if (!xref_table.has_value())
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return {};
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auto trailer = parse_file_trailer();
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auto trailer = parse_file_trailer();
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if (!trailer)
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return {};
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return { xref_table, trailer };
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return XRefTableAndTrailer { xref_table.value(), trailer.release_nonnull() };
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}
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}
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NonnullRefPtr<IndirectValue> Parser::parse_indirect_value_at_offset(size_t offset)
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RefPtr<IndirectValue> Parser::parse_indirect_value_at_offset(size_t offset)
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{
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{
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m_reader.set_reading_forwards();
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m_reader.set_reading_forwards();
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m_reader.move_to(offset);
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m_reader.move_to(offset);
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@ -103,11 +111,13 @@ bool Parser::parse_header()
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return true;
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return true;
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}
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}
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XRefTable Parser::parse_xref_table()
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Optional<XRefTable> Parser::parse_xref_table()
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{
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{
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VERIFY(m_reader.matches("xref"));
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if (!m_reader.matches("xref"))
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return {};
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m_reader.move_by(4);
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m_reader.move_by(4);
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consume_eol();
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if (!consume_eol())
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return {};
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XRefTable table;
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XRefTable table;
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@ -125,23 +135,28 @@ XRefTable Parser::parse_xref_table()
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for (int i = 0; i < object_count; i++) {
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for (int i = 0; i < object_count; i++) {
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auto offset_string = String(m_reader.bytes().slice(m_reader.offset(), 10));
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auto offset_string = String(m_reader.bytes().slice(m_reader.offset(), 10));
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m_reader.move_by(10);
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m_reader.move_by(10);
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consume(' ');
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if (!consume(' '))
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return {};
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auto generation_string = String(m_reader.bytes().slice(m_reader.offset(), 5));
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auto generation_string = String(m_reader.bytes().slice(m_reader.offset(), 5));
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m_reader.move_by(5);
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m_reader.move_by(5);
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consume(' ');
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if (!consume(' '))
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return {};
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auto letter = m_reader.read();
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auto letter = m_reader.read();
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VERIFY(letter == 'n' || letter == 'f');
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if (letter != 'n' && letter != 'f')
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return {};
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// The line ending sequence can be one of the following:
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// The line ending sequence can be one of the following:
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// SP CR, SP LF, or CR LF
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// SP CR, SP LF, or CR LF
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if (m_reader.matches(' ')) {
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if (m_reader.matches(' ')) {
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consume();
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consume();
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auto ch = consume();
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auto ch = consume();
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VERIFY(ch == '\r' || ch == '\n');
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if (ch != '\r' && ch != '\n')
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return {};
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} else {
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} else {
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VERIFY(m_reader.matches("\r\n"));
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if (!m_reader.matches("\r\n"))
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return {};
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m_reader.move_by(2);
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m_reader.move_by(2);
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}
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}
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@ -157,23 +172,27 @@ XRefTable Parser::parse_xref_table()
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return table;
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return table;
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}
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}
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NonnullRefPtr<DictObject> Parser::parse_file_trailer()
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RefPtr<DictObject> Parser::parse_file_trailer()
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{
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{
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VERIFY(m_reader.matches("trailer"));
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if (!m_reader.matches("trailer"))
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return {};
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m_reader.move_by(7);
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m_reader.move_by(7);
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consume_whitespace();
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consume_whitespace();
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auto dict = parse_dict();
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auto dict = parse_dict();
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if (!dict)
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return {};
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VERIFY(m_reader.matches("startxref"));
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if (!m_reader.matches("startxref"))
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return {};
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m_reader.move_by(9);
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m_reader.move_by(9);
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consume_whitespace();
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consume_whitespace();
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m_reader.move_until([&](auto) { return matches_eol(); });
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m_reader.move_until([&](auto) { return matches_eol(); });
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consume_eol();
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VERIFY(consume_eol());
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VERIFY(m_reader.matches("%%EOF"));
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if (!m_reader.matches("%%EOF"))
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return {};
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m_reader.move_by(5);
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m_reader.move_by(5);
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consume_whitespace();
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consume_whitespace();
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VERIFY(m_reader.done());
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return dict;
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return dict;
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}
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}
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@ -291,8 +310,10 @@ Value Parser::parse_value()
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if (m_reader.matches("<<")) {
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if (m_reader.matches("<<")) {
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auto dict = parse_dict();
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auto dict = parse_dict();
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if (!dict)
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return {};
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if (m_reader.matches("stream\n"))
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if (m_reader.matches("stream\n"))
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return parse_stream(dict);
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return parse_stream(dict.release_nonnull());
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return dict;
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return dict;
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}
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}
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@ -335,23 +356,28 @@ Value Parser::parse_possible_indirect_value_or_ref()
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return first_number;
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return first_number;
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}
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}
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NonnullRefPtr<IndirectValue> Parser::parse_indirect_value(int index, int generation)
|
RefPtr<IndirectValue> Parser::parse_indirect_value(int index, int generation)
|
||||||
{
|
{
|
||||||
VERIFY(m_reader.matches("obj"));
|
if (!m_reader.matches("obj"))
|
||||||
|
return {};
|
||||||
m_reader.move_by(3);
|
m_reader.move_by(3);
|
||||||
if (matches_eol())
|
if (matches_eol())
|
||||||
consume_eol();
|
consume_eol();
|
||||||
auto value = parse_value();
|
auto value = parse_value();
|
||||||
VERIFY(m_reader.matches("endobj"));
|
if (!m_reader.matches("endobj"))
|
||||||
|
return {};
|
||||||
|
|
||||||
return make_object<IndirectValue>(index, generation, value);
|
return make_object<IndirectValue>(index, generation, value);
|
||||||
}
|
}
|
||||||
|
|
||||||
NonnullRefPtr<IndirectValue> Parser::parse_indirect_value()
|
RefPtr<IndirectValue> Parser::parse_indirect_value()
|
||||||
{
|
{
|
||||||
auto first_number = parse_number();
|
auto first_number = parse_number();
|
||||||
|
if (!first_number.is_int())
|
||||||
|
return {};
|
||||||
auto second_number = parse_number();
|
auto second_number = parse_number();
|
||||||
VERIFY(first_number.is_int() && second_number.is_int());
|
if (!second_number.is_int())
|
||||||
|
return {};
|
||||||
return parse_indirect_value(first_number.as_int(), second_number.as_int());
|
return parse_indirect_value(first_number.as_int(), second_number.as_int());
|
||||||
}
|
}
|
||||||
|
|
||||||
|
@ -387,9 +413,10 @@ Value Parser::parse_number()
|
||||||
return Value(static_cast<int>(f));
|
return Value(static_cast<int>(f));
|
||||||
}
|
}
|
||||||
|
|
||||||
NonnullRefPtr<NameObject> Parser::parse_name()
|
RefPtr<NameObject> Parser::parse_name()
|
||||||
{
|
{
|
||||||
consume('/');
|
if (!consume('/'))
|
||||||
|
return {};
|
||||||
StringBuilder builder;
|
StringBuilder builder;
|
||||||
|
|
||||||
while (true) {
|
while (true) {
|
||||||
|
@ -400,7 +427,8 @@ NonnullRefPtr<NameObject> Parser::parse_name()
|
||||||
int hex_value = 0;
|
int hex_value = 0;
|
||||||
for (int i = 0; i < 2; i++) {
|
for (int i = 0; i < 2; i++) {
|
||||||
auto ch = consume();
|
auto ch = consume();
|
||||||
VERIFY(isxdigit(ch));
|
if (!isxdigit(ch))
|
||||||
|
return {};
|
||||||
hex_value *= 16;
|
hex_value *= 16;
|
||||||
if (ch <= '9') {
|
if (ch <= '9') {
|
||||||
hex_value += ch - '0';
|
hex_value += ch - '0';
|
||||||
|
@ -420,7 +448,7 @@ NonnullRefPtr<NameObject> Parser::parse_name()
|
||||||
return make_object<NameObject>(builder.to_string());
|
return make_object<NameObject>(builder.to_string());
|
||||||
}
|
}
|
||||||
|
|
||||||
NonnullRefPtr<StringObject> Parser::parse_string()
|
RefPtr<StringObject> Parser::parse_string()
|
||||||
{
|
{
|
||||||
ScopeGuard guard([&] { consume_whitespace(); });
|
ScopeGuard guard([&] { consume_whitespace(); });
|
||||||
|
|
||||||
|
@ -435,6 +463,9 @@ NonnullRefPtr<StringObject> Parser::parse_string()
|
||||||
is_binary_string = true;
|
is_binary_string = true;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
if (string.is_null())
|
||||||
|
return {};
|
||||||
|
|
||||||
if (string.bytes().starts_with(Array<u8, 2> { 0xfe, 0xff })) {
|
if (string.bytes().starts_with(Array<u8, 2> { 0xfe, 0xff })) {
|
||||||
// The string is encoded in UTF16-BE
|
// The string is encoded in UTF16-BE
|
||||||
string = TextCodec::decoder_for("utf-16be")->to_utf8(string.substring(2));
|
string = TextCodec::decoder_for("utf-16be")->to_utf8(string.substring(2));
|
||||||
|
@ -449,7 +480,8 @@ NonnullRefPtr<StringObject> Parser::parse_string()
|
||||||
|
|
||||||
String Parser::parse_literal_string()
|
String Parser::parse_literal_string()
|
||||||
{
|
{
|
||||||
consume('(');
|
if (!consume('('))
|
||||||
|
return {};
|
||||||
StringBuilder builder;
|
StringBuilder builder;
|
||||||
auto opened_parens = 0;
|
auto opened_parens = 0;
|
||||||
|
|
||||||
|
@ -470,7 +502,9 @@ String Parser::parse_literal_string()
|
||||||
continue;
|
continue;
|
||||||
}
|
}
|
||||||
|
|
||||||
VERIFY(!m_reader.done());
|
if (m_reader.done())
|
||||||
|
return {};
|
||||||
|
|
||||||
auto ch = consume();
|
auto ch = consume();
|
||||||
switch (ch) {
|
switch (ch) {
|
||||||
case 'n':
|
case 'n':
|
||||||
|
@ -520,13 +554,16 @@ String Parser::parse_literal_string()
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
VERIFY(opened_parens == 0);
|
if (opened_parens != 0)
|
||||||
|
return {};
|
||||||
|
|
||||||
return builder.to_string();
|
return builder.to_string();
|
||||||
}
|
}
|
||||||
|
|
||||||
String Parser::parse_hex_string()
|
String Parser::parse_hex_string()
|
||||||
{
|
{
|
||||||
consume('<');
|
if (!consume('<'))
|
||||||
|
return {};
|
||||||
StringBuilder builder;
|
StringBuilder builder;
|
||||||
|
|
||||||
while (true) {
|
while (true) {
|
||||||
|
@ -546,7 +583,9 @@ String Parser::parse_hex_string()
|
||||||
builder.append(static_cast<char>(hex_value));
|
builder.append(static_cast<char>(hex_value));
|
||||||
return builder.to_string();
|
return builder.to_string();
|
||||||
}
|
}
|
||||||
VERIFY(isxdigit(ch));
|
|
||||||
|
if (!isxdigit(ch))
|
||||||
|
return {};
|
||||||
|
|
||||||
hex_value *= 16;
|
hex_value *= 16;
|
||||||
if (ch <= '9') {
|
if (ch <= '9') {
|
||||||
|
@ -561,25 +600,31 @@ String Parser::parse_hex_string()
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
NonnullRefPtr<ArrayObject> Parser::parse_array()
|
RefPtr<ArrayObject> Parser::parse_array()
|
||||||
{
|
{
|
||||||
consume('[');
|
if (!consume('['))
|
||||||
|
return {};
|
||||||
consume_whitespace();
|
consume_whitespace();
|
||||||
Vector<Value> values;
|
Vector<Value> values;
|
||||||
|
|
||||||
while (!m_reader.matches(']'))
|
while (!m_reader.matches(']')) {
|
||||||
values.append(parse_value());
|
auto value = parse_value();
|
||||||
|
if (!value)
|
||||||
|
return {};
|
||||||
|
values.append(value);
|
||||||
|
}
|
||||||
|
|
||||||
consume(']');
|
if (!consume(']'))
|
||||||
|
return {};
|
||||||
consume_whitespace();
|
consume_whitespace();
|
||||||
|
|
||||||
return make_object<ArrayObject>(values);
|
return make_object<ArrayObject>(values);
|
||||||
}
|
}
|
||||||
|
|
||||||
NonnullRefPtr<DictObject> Parser::parse_dict()
|
RefPtr<DictObject> Parser::parse_dict()
|
||||||
{
|
{
|
||||||
consume('<');
|
if (!consume('<') || !consume('<'))
|
||||||
consume('<');
|
return {};
|
||||||
consume_whitespace();
|
consume_whitespace();
|
||||||
HashMap<FlyString, Value> map;
|
HashMap<FlyString, Value> map;
|
||||||
|
|
||||||
|
@ -587,28 +632,38 @@ NonnullRefPtr<DictObject> Parser::parse_dict()
|
||||||
if (m_reader.matches(">>"))
|
if (m_reader.matches(">>"))
|
||||||
break;
|
break;
|
||||||
auto name = parse_name();
|
auto name = parse_name();
|
||||||
|
if (!name)
|
||||||
|
return {};
|
||||||
auto value = parse_value();
|
auto value = parse_value();
|
||||||
|
if (!value)
|
||||||
|
return {};
|
||||||
map.set(name->name(), value);
|
map.set(name->name(), value);
|
||||||
}
|
}
|
||||||
|
|
||||||
consume('>');
|
if (!consume('>') || !consume('>'))
|
||||||
consume('>');
|
return {};
|
||||||
consume_whitespace();
|
consume_whitespace();
|
||||||
|
|
||||||
return make_object<DictObject>(map);
|
return make_object<DictObject>(map);
|
||||||
}
|
}
|
||||||
|
|
||||||
RefPtr<DictObject> Parser::conditionally_parse_page_tree_node_at_offset(size_t offset)
|
RefPtr<DictObject> Parser::conditionally_parse_page_tree_node_at_offset(size_t offset, bool& ok)
|
||||||
{
|
{
|
||||||
|
ok = true;
|
||||||
|
|
||||||
m_reader.move_to(offset);
|
m_reader.move_to(offset);
|
||||||
parse_number();
|
parse_number();
|
||||||
parse_number();
|
parse_number();
|
||||||
VERIFY(m_reader.matches("obj"));
|
if (!m_reader.matches("obj")) {
|
||||||
|
ok = false;
|
||||||
|
return {};
|
||||||
|
}
|
||||||
|
|
||||||
m_reader.move_by(3);
|
m_reader.move_by(3);
|
||||||
consume_whitespace();
|
consume_whitespace();
|
||||||
|
|
||||||
consume('<');
|
if (!consume('<') || !consume('<'))
|
||||||
consume('<');
|
return {};
|
||||||
consume_whitespace();
|
consume_whitespace();
|
||||||
HashMap<FlyString, Value> map;
|
HashMap<FlyString, Value> map;
|
||||||
|
|
||||||
|
@ -616,12 +671,21 @@ RefPtr<DictObject> Parser::conditionally_parse_page_tree_node_at_offset(size_t o
|
||||||
if (m_reader.matches(">>"))
|
if (m_reader.matches(">>"))
|
||||||
break;
|
break;
|
||||||
auto name = parse_name();
|
auto name = parse_name();
|
||||||
|
if (!name) {
|
||||||
|
ok = false;
|
||||||
|
return {};
|
||||||
|
}
|
||||||
|
|
||||||
auto name_string = name->name();
|
auto name_string = name->name();
|
||||||
if (!name_string.is_one_of(CommonNames::Type, CommonNames::Parent, CommonNames::Kids, CommonNames::Count)) {
|
if (!name_string.is_one_of(CommonNames::Type, CommonNames::Parent, CommonNames::Kids, CommonNames::Count)) {
|
||||||
// This is a page, not a page tree node
|
// This is a page, not a page tree node
|
||||||
return {};
|
return {};
|
||||||
}
|
}
|
||||||
auto value = parse_value();
|
auto value = parse_value();
|
||||||
|
if (!value) {
|
||||||
|
ok = false;
|
||||||
|
return {};
|
||||||
|
}
|
||||||
if (name_string == CommonNames::Type) {
|
if (name_string == CommonNames::Type) {
|
||||||
if (!value.is_object())
|
if (!value.is_object())
|
||||||
return {};
|
return {};
|
||||||
|
@ -635,18 +699,20 @@ RefPtr<DictObject> Parser::conditionally_parse_page_tree_node_at_offset(size_t o
|
||||||
map.set(name->name(), value);
|
map.set(name->name(), value);
|
||||||
}
|
}
|
||||||
|
|
||||||
consume('>');
|
if (!consume('>') || !consume('>'))
|
||||||
consume('>');
|
return {};
|
||||||
consume_whitespace();
|
consume_whitespace();
|
||||||
|
|
||||||
return make_object<DictObject>(map);
|
return make_object<DictObject>(map);
|
||||||
}
|
}
|
||||||
|
|
||||||
NonnullRefPtr<StreamObject> Parser::parse_stream(NonnullRefPtr<DictObject> dict)
|
RefPtr<StreamObject> Parser::parse_stream(NonnullRefPtr<DictObject> dict)
|
||||||
{
|
{
|
||||||
VERIFY(m_reader.matches("stream"));
|
if (!m_reader.matches("stream"))
|
||||||
|
return {};
|
||||||
m_reader.move_by(6);
|
m_reader.move_by(6);
|
||||||
consume_eol();
|
if (!consume_eol())
|
||||||
|
return {};
|
||||||
|
|
||||||
ReadonlyBytes bytes;
|
ReadonlyBytes bytes;
|
||||||
|
|
||||||
|
@ -681,8 +747,8 @@ NonnullRefPtr<StreamObject> Parser::parse_stream(NonnullRefPtr<DictObject> dict)
|
||||||
if (dict->contains(CommonNames::Filter)) {
|
if (dict->contains(CommonNames::Filter)) {
|
||||||
auto filter_type = dict->get_name(m_document, CommonNames::Filter)->name();
|
auto filter_type = dict->get_name(m_document, CommonNames::Filter)->name();
|
||||||
auto maybe_bytes = Filter::decode(bytes, filter_type);
|
auto maybe_bytes = Filter::decode(bytes, filter_type);
|
||||||
// FIXME: Handle error condition
|
if (!maybe_bytes.has_value())
|
||||||
VERIFY(maybe_bytes.has_value());
|
return {};
|
||||||
return make_object<EncodedStreamObject>(dict, move(maybe_bytes.value()));
|
return make_object<EncodedStreamObject>(dict, move(maybe_bytes.value()));
|
||||||
}
|
}
|
||||||
|
|
||||||
|
@ -752,14 +818,15 @@ bool Parser::matches_regular_character() const
|
||||||
return !matches_delimiter() && !matches_whitespace();
|
return !matches_delimiter() && !matches_whitespace();
|
||||||
}
|
}
|
||||||
|
|
||||||
void Parser::consume_eol()
|
bool Parser::consume_eol()
|
||||||
{
|
{
|
||||||
if (m_reader.matches("\r\n")) {
|
if (m_reader.matches("\r\n")) {
|
||||||
consume(2);
|
consume(2);
|
||||||
} else {
|
return true;
|
||||||
auto consumed = consume();
|
|
||||||
VERIFY(consumed == 0xd || consumed == 0xa);
|
|
||||||
}
|
}
|
||||||
|
|
||||||
|
auto consumed = consume();
|
||||||
|
return consumed == 0xd || consumed == 0xa;
|
||||||
}
|
}
|
||||||
|
|
||||||
bool Parser::consume_whitespace()
|
bool Parser::consume_whitespace()
|
||||||
|
@ -777,9 +844,15 @@ char Parser::consume()
|
||||||
return m_reader.read();
|
return m_reader.read();
|
||||||
}
|
}
|
||||||
|
|
||||||
void Parser::consume(char ch)
|
void Parser::consume(int amount)
|
||||||
{
|
{
|
||||||
VERIFY(consume() == ch);
|
for (size_t i = 0; i < static_cast<size_t>(amount); i++)
|
||||||
|
consume();
|
||||||
|
}
|
||||||
|
|
||||||
|
bool Parser::consume(char ch)
|
||||||
|
{
|
||||||
|
return consume() == ch;
|
||||||
}
|
}
|
||||||
|
|
||||||
}
|
}
|
||||||
|
|
|
@ -16,7 +16,7 @@ namespace PDF {
|
||||||
|
|
||||||
class Document;
|
class Document;
|
||||||
|
|
||||||
class Parser {
|
class Parser final : public RefCounted<Parser> {
|
||||||
public:
|
public:
|
||||||
static Vector<Command> parse_graphics_commands(const ReadonlyBytes&);
|
static Vector<Command> parse_graphics_commands(const ReadonlyBytes&);
|
||||||
|
|
||||||
|
@ -30,18 +30,18 @@ public:
|
||||||
XRefTable xref_table;
|
XRefTable xref_table;
|
||||||
NonnullRefPtr<DictObject> trailer;
|
NonnullRefPtr<DictObject> trailer;
|
||||||
};
|
};
|
||||||
XRefTableAndTrailer parse_last_xref_table_and_trailer();
|
Optional<XRefTableAndTrailer> parse_last_xref_table_and_trailer();
|
||||||
|
|
||||||
NonnullRefPtr<IndirectValue> parse_indirect_value_at_offset(size_t offset);
|
RefPtr<IndirectValue> parse_indirect_value_at_offset(size_t offset);
|
||||||
|
|
||||||
RefPtr<DictObject> conditionally_parse_page_tree_node_at_offset(size_t offset);
|
RefPtr<DictObject> conditionally_parse_page_tree_node_at_offset(size_t offset, bool& ok);
|
||||||
|
|
||||||
private:
|
private:
|
||||||
explicit Parser(const ReadonlyBytes&);
|
explicit Parser(const ReadonlyBytes&);
|
||||||
|
|
||||||
bool parse_header();
|
bool parse_header();
|
||||||
XRefTable parse_xref_table();
|
Optional<XRefTable> parse_xref_table();
|
||||||
NonnullRefPtr<DictObject> parse_file_trailer();
|
RefPtr<DictObject> parse_file_trailer();
|
||||||
|
|
||||||
bool navigate_to_before_eof_marker();
|
bool navigate_to_before_eof_marker();
|
||||||
bool navigate_to_after_startxref();
|
bool navigate_to_after_startxref();
|
||||||
|
@ -58,16 +58,16 @@ private:
|
||||||
|
|
||||||
Value parse_value();
|
Value parse_value();
|
||||||
Value parse_possible_indirect_value_or_ref();
|
Value parse_possible_indirect_value_or_ref();
|
||||||
NonnullRefPtr<IndirectValue> parse_indirect_value(int index, int generation);
|
RefPtr<IndirectValue> parse_indirect_value(int index, int generation);
|
||||||
NonnullRefPtr<IndirectValue> parse_indirect_value();
|
RefPtr<IndirectValue> parse_indirect_value();
|
||||||
Value parse_number();
|
Value parse_number();
|
||||||
NonnullRefPtr<NameObject> parse_name();
|
RefPtr<NameObject> parse_name();
|
||||||
NonnullRefPtr<StringObject> parse_string();
|
RefPtr<StringObject> parse_string();
|
||||||
String parse_literal_string();
|
String parse_literal_string();
|
||||||
String parse_hex_string();
|
String parse_hex_string();
|
||||||
NonnullRefPtr<ArrayObject> parse_array();
|
RefPtr<ArrayObject> parse_array();
|
||||||
NonnullRefPtr<DictObject> parse_dict();
|
RefPtr<DictObject> parse_dict();
|
||||||
NonnullRefPtr<StreamObject> parse_stream(NonnullRefPtr<DictObject> dict);
|
RefPtr<StreamObject> parse_stream(NonnullRefPtr<DictObject> dict);
|
||||||
|
|
||||||
Vector<Command> parse_graphics_commands();
|
Vector<Command> parse_graphics_commands();
|
||||||
|
|
||||||
|
@ -77,10 +77,11 @@ private:
|
||||||
bool matches_delimiter() const;
|
bool matches_delimiter() const;
|
||||||
bool matches_regular_character() const;
|
bool matches_regular_character() const;
|
||||||
|
|
||||||
void consume_eol();
|
bool consume_eol();
|
||||||
bool consume_whitespace();
|
bool consume_whitespace();
|
||||||
char consume();
|
char consume();
|
||||||
void consume(char);
|
void consume(int amount);
|
||||||
|
bool consume(char);
|
||||||
|
|
||||||
Reader m_reader;
|
Reader m_reader;
|
||||||
RefPtr<Document> m_document;
|
RefPtr<Document> m_document;
|
||||||
|
|
|
@ -61,6 +61,16 @@ public:
|
||||||
m_as_ref = (generation_index << 14) | index;
|
m_as_ref = (generation_index << 14) | index;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
template<IsObject T>
|
||||||
|
Value(RefPtr<T> obj)
|
||||||
|
: m_type(obj ? Type::Object : Type::Empty)
|
||||||
|
{
|
||||||
|
if (obj) {
|
||||||
|
obj->ref();
|
||||||
|
m_as_object = obj;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
template<IsObject T>
|
template<IsObject T>
|
||||||
Value(NonnullRefPtr<T> obj)
|
Value(NonnullRefPtr<T> obj)
|
||||||
: m_type(Type::Object)
|
: m_type(Type::Object)
|
||||||
|
|
Loading…
Add table
Add a link
Reference in a new issue