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// Copyright 2016 PDFium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
#ifndef CORE_FPDFAPI_PARSER_CPDF_PARSER_H_
#define CORE_FPDFAPI_PARSER_CPDF_PARSER_H_
#include <limits>
#include <map>
#include <memory>
#include <set>
#include <vector>
#include "core/fpdfapi/parser/cpdf_syntax_parser.h"
#include "core/fxcrt/fx_string.h"
#include "core/fxcrt/fx_system.h"
#include "core/fxcrt/retain_ptr.h"
#include "core/fxcrt/unowned_ptr.h"
class CPDF_Array;
class CPDF_CryptoHandler;
class CPDF_Dictionary;
class CPDF_Document;
class CPDF_IndirectObjectHolder;
class CPDF_LinearizedHeader;
class CPDF_Object;
class CPDF_ReadValidator;
class CPDF_SecurityHandler;
class CPDF_StreamAcc;
class CPDF_SyntaxParser;
class IFX_SeekableReadStream;
class CPDF_Parser {
public:
enum Error {
SUCCESS = 0,
FILE_ERROR,
FORMAT_ERROR,
PASSWORD_ERROR,
HANDLER_ERROR
};
// A limit on the maximum object number in the xref table. Theoretical limits
// are higher, but this may be large enough in practice.
static const uint32_t kMaxObjectNumber = 1048576;
static const size_t kInvalidPos = std::numeric_limits<size_t>::max();
CPDF_Parser();
~CPDF_Parser();
Error StartParse(const RetainPtr<IFX_SeekableReadStream>& pFile,
CPDF_Document* pDocument);
Error StartLinearizedParse(const RetainPtr<CPDF_ReadValidator>& validator,
CPDF_Document* pDocument);
void SetPassword(const char* password) { m_Password = password; }
ByteString GetPassword() { return m_Password; }
CPDF_Dictionary* GetTrailer() const;
// Returns a new trailer which combines the last read trailer with the /Root
// and /Info from previous ones.
std::unique_ptr<CPDF_Dictionary> GetCombinedTrailer() const;
FX_FILESIZE GetLastXRefOffset() const { return m_LastXRefOffset; }
uint32_t GetPermissions() const;
uint32_t GetRootObjNum();
uint32_t GetInfoObjNum();
const CPDF_Array* GetIDArray() const;
CPDF_Dictionary* GetEncryptDict() const { return m_pEncryptDict.Get(); }
std::unique_ptr<CPDF_Object> ParseIndirectObject(
CPDF_IndirectObjectHolder* pObjList,
uint32_t objnum);
uint32_t GetLastObjNum() const;
bool IsValidObjectNumber(uint32_t objnum) const;
FX_FILESIZE GetObjectPositionOrZero(uint32_t objnum) const;
uint16_t GetObjectGenNum(uint32_t objnum) const;
bool IsObjectFreeOrNull(uint32_t objnum) const;
CPDF_SecurityHandler* GetSecurityHandler() const {
return m_pSecurityHandler.get();
}
RetainPtr<IFX_SeekableReadStream> GetFileAccess() const;
bool IsObjectFree(uint32_t objnum) const;
FX_FILESIZE GetObjectOffset(uint32_t objnum) const;
int GetFileVersion() const { return m_FileVersion; }
bool IsXRefStream() const { return m_bXRefStream; }
std::unique_ptr<CPDF_Object> ParseIndirectObjectAt(
CPDF_IndirectObjectHolder* pObjList,
FX_FILESIZE pos,
uint32_t objnum);
std::unique_ptr<CPDF_Object> ParseIndirectObjectAtByStrict(
CPDF_IndirectObjectHolder* pObjList,
FX_FILESIZE pos,
uint32_t objnum,
FX_FILESIZE* pResultPos);
uint32_t GetFirstPageNo() const;
protected:
enum class ObjectType : uint8_t {
kFree = 0x00,
kNotCompressed = 0x01,
kCompressed = 0x02,
kNull = 0xFF,
};
struct ObjectInfo {
ObjectInfo() : pos(0), type(ObjectType::kFree), gennum(0) {}
// if type is ObjectType::kCompressed the archive_obj_num should be used.
// if type is ObjectType::kNotCompressed the pos should be used.
// In other cases its are unused.
union {
FX_FILESIZE pos;
FX_FILESIZE archive_obj_num;
};
ObjectType type;
uint16_t gennum;
};
std::unique_ptr<CPDF_SyntaxParser> m_pSyntax;
std::map<uint32_t, ObjectInfo> m_ObjectInfo;
bool LoadCrossRefV4(FX_FILESIZE pos, bool bSkip);
bool RebuildCrossRef();
private:
friend class CPDF_DataAvail;
class TrailerData;
enum class ParserState {
kDefault,
kComment,
kWhitespace,
kString,
kHexString,
kEscapedString,
kXref,
kObjNum,
kPostObjNum,
kGenNum,
kPostGenNum,
kTrailer,
kBeginObj,
kEndObj
};
struct CrossRefObjData {
uint32_t obj_num = 0;
ObjectInfo info;
};
Error StartParseInternal(CPDF_Document* pDocument);
FX_FILESIZE ParseStartXRef();
bool LoadAllCrossRefV4(FX_FILESIZE pos);
bool LoadAllCrossRefV5(FX_FILESIZE pos);
bool LoadCrossRefV5(FX_FILESIZE* pos, bool bMainXRef);
std::unique_ptr<CPDF_Dictionary> LoadTrailerV4();
Error SetEncryptHandler();
void ReleaseEncryptHandler();
bool LoadLinearizedAllCrossRefV4(FX_FILESIZE pos);
bool LoadLinearizedAllCrossRefV5(FX_FILESIZE pos);
Error LoadLinearizedMainXRefTable();
RetainPtr<CPDF_StreamAcc> GetObjectStream(uint32_t number);
std::unique_ptr<CPDF_LinearizedHeader> ParseLinearizedHeader();
void SetEncryptDictionary(CPDF_Dictionary* pDict);
void ShrinkObjectMap(uint32_t size);
// A simple check whether the cross reference table matches with
// the objects.
bool VerifyCrossRefV4();
// If out_objects is null, the parser position will be moved to end subsection
// without additional validation.
bool ParseAndAppendCrossRefSubsectionData(
uint32_t start_objnum,
uint32_t count,
std::vector<CrossRefObjData>* out_objects);
bool ParseCrossRefV4(std::vector<CrossRefObjData>* out_objects);
void MergeCrossRefObjectsData(const std::vector<CrossRefObjData>& objects);
std::unique_ptr<CPDF_Object> ParseIndirectObjectAtInternal(
CPDF_IndirectObjectHolder* pObjList,
FX_FILESIZE pos,
uint32_t objnum,
CPDF_SyntaxParser::ParseType parse_type,
FX_FILESIZE* pResultPos);
bool InitSyntaxParser(const RetainPtr<CPDF_ReadValidator>& validator);
bool ParseFileVersion();
ObjectType GetObjectType(uint32_t objnum) const;
ObjectType GetObjectTypeFromCrossRefStreamType(
int cross_ref_stream_type) const;
UnownedPtr<CPDF_Document> m_pDocument;
bool m_bHasParsed;
bool m_bXRefStream;
int m_FileVersion;
// m_TrailerData must be destroyed after m_pSecurityHandler due to the
// ownership of the ID array data.
std::unique_ptr<TrailerData> m_TrailerData;
UnownedPtr<CPDF_Dictionary> m_pEncryptDict;
FX_FILESIZE m_LastXRefOffset;
std::unique_ptr<CPDF_SecurityHandler> m_pSecurityHandler;
ByteString m_Password;
std::unique_ptr<CPDF_LinearizedHeader> m_pLinearized;
// A map of object numbers to indirect streams.
std::map<uint32_t, RetainPtr<CPDF_StreamAcc>> m_ObjectStreamMap;
// Mapping of object numbers to offsets. The offsets are relative to the first
// object in the stream.
using StreamObjectCache = std::map<uint32_t, uint32_t>;
// Mapping of streams to their object caches. This is valid as long as the
// streams in |m_ObjectStreamMap| are valid.
std::map<RetainPtr<CPDF_StreamAcc>, StreamObjectCache> m_ObjCache;
// All indirect object numbers that are being parsed.
std::set<uint32_t> m_ParsingObjNums;
uint32_t m_MetadataObjnum = 0;
};
#endif // CORE_FPDFAPI_PARSER_CPDF_PARSER_H_
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