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/*
* Copyright (c) 2021-2022, Matthew Olsson <mattco@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <LibPDF/Parser.h>
namespace PDF {
class DocumentParser final : public RefCounted<DocumentParser>
, public Parser {
public:
DocumentParser(Document*, ReadonlyBytes);
enum class LinearizationResult {
NotLinearized,
Linearized,
};
[[nodiscard]] ALWAYS_INLINE RefPtr<DictObject> const& trailer() const { return m_trailer; }
// Parses the header and initializes the xref table and trailer
PDFErrorOr<void> initialize();
PDFErrorOr<Value> parse_object_with_index(u32 index);
// Specialized version of parse_dict which aborts early if the dict being parsed
// is not a page object
PDFErrorOr<RefPtr<DictObject>> conditionally_parse_page_tree_node(u32 object_index);
private:
struct LinearizationDictionary {
u32 length_of_file { 0 };
u32 primary_hint_stream_offset { 0 };
u32 primary_hint_stream_length { 0 };
u32 overflow_hint_stream_offset { 0 };
u32 overflow_hint_stream_length { 0 };
u32 first_page_object_number { 0 };
u32 offset_of_first_page_end { 0 };
u16 number_of_pages { 0 };
u32 offset_of_main_xref_table { 0 };
u32 first_page { 0 }; // The page to initially open (I think, the spec isn't all that clear here)
};
struct PageOffsetHintTable {
u32 least_number_of_objects_in_a_page { 0 };
u32 location_of_first_page_object { 0 };
u16 bits_required_for_object_number { 0 };
u32 least_length_of_a_page { 0 };
u16 bits_required_for_page_length { 0 };
u32 least_offset_of_any_content_stream { 0 };
u16 bits_required_for_content_stream_offsets { 0 };
u32 least_content_stream_length { 0 };
u16 bits_required_for_content_stream_length { 0 };
u16 bits_required_for_number_of_shared_obj_refs { 0 };
u16 bits_required_for_greatest_shared_obj_identifier { 0 };
u16 bits_required_for_fraction_numerator { 0 };
u16 shared_object_reference_fraction_denominator { 0 };
};
struct PageOffsetHintTableEntry {
u32 objects_in_page_number { 0 };
u32 page_length_number { 0 };
u32 number_of_shared_objects { 0 };
Vector<u32> shared_object_identifiers {};
Vector<u32> shared_object_location_numerators {};
u32 page_content_stream_offset_number { 0 };
u32 page_content_stream_length_number { 0 };
};
friend struct AK::Formatter<LinearizationDictionary>;
friend struct AK::Formatter<PageOffsetHintTable>;
friend struct AK::Formatter<PageOffsetHintTableEntry>;
PDFErrorOr<void> parse_header();
PDFErrorOr<LinearizationResult> initialize_linearization_dict();
PDFErrorOr<void> initialize_linearized_xref_table();
PDFErrorOr<void> initialize_non_linearized_xref_table();
PDFErrorOr<void> validate_xref_table_and_fix_if_necessary();
PDFErrorOr<void> initialize_hint_tables();
PDFErrorOr<PageOffsetHintTable> parse_page_offset_hint_table(ReadonlyBytes hint_stream_bytes);
Vector<PageOffsetHintTableEntry> parse_all_page_offset_hint_table_entries(PageOffsetHintTable const&, ReadonlyBytes hint_stream_bytes);
PDFErrorOr<NonnullRefPtr<XRefTable>> parse_xref_stream();
PDFErrorOr<NonnullRefPtr<XRefTable>> parse_xref_table();
PDFErrorOr<NonnullRefPtr<DictObject>> parse_file_trailer();
PDFErrorOr<Value> parse_compressed_object_with_index(u32 index);
bool navigate_to_before_eof_marker();
bool navigate_to_after_startxref();
RefPtr<XRefTable> m_xref_table;
RefPtr<DictObject> m_trailer;
Optional<LinearizationDictionary> m_linearization_dictionary;
};
}
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