cpdf_hint_tables.h

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// Copyright 2016 The PDFium Authors
// 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_HINT_TABLES_H_
#define CORE_FPDFAPI_PARSER_CPDF_HINT_TABLES_H_
 
#include <memory>
#include <vector>
 
#include "core/fpdfapi/parser/cpdf_data_avail.h"
#include "core/fxcrt/unowned_ptr.h"
 
class CFX_BitStream;
class CPDF_LinearizedHeader;
class CPDF_ReadValidator;
class CPDF_Stream;
class CPDF_SyntaxParser;
 
class CPDF_HintTables {
 public:
  struct SharedObjGroupInfo {
    FX_FILESIZE m_szOffset = 0;
    uint32_t m_dwLength = 0;
    uint32_t m_dwObjectsCount = 0;
    uint32_t m_dwStartObjNum = 0;
  };
 
  class PageInfo {
   public:
    PageInfo();
    ~PageInfo();
 
    void set_objects_count(uint32_t objects_count) {
      m_dwObjectsCount = objects_count;
    }
    uint32_t objects_count() const { return m_dwObjectsCount; }
 
    void set_page_offset(FX_FILESIZE offset) { m_szOffset = offset; }
    FX_FILESIZE page_offset() const { return m_szOffset; }
 
    void set_page_length(uint32_t length) { m_dwLength = length; }
    uint32_t page_length() const { return m_dwLength; }
 
    void set_start_obj_num(uint32_t start_obj_num) {
      m_dwStartObjNum = start_obj_num;
    }
    uint32_t start_obj_num() const { return m_dwStartObjNum; }
 
    void AddIdentifier(uint32_t Identifier) {
      m_dwIdentifierArray.push_back(Identifier);
    }
 
    const std::vector<uint32_t>& Identifiers() const {
      return m_dwIdentifierArray;
    }
 
   private:
    uint32_t m_dwObjectsCount = 0;
    FX_FILESIZE m_szOffset = 0;
    uint32_t m_dwLength = 0;
    uint32_t m_dwStartObjNum = 0;
    std::vector<uint32_t> m_dwIdentifierArray;
 
    PageInfo(const PageInfo& other) = delete;
    PageInfo& operator=(const PageInfo&) = delete;
  };
 
  static std::unique_ptr<CPDF_HintTables> Parse(
      CPDF_SyntaxParser* parser,
      const CPDF_LinearizedHeader* pLinearized);
 
  CPDF_HintTables(CPDF_ReadValidator* pValidator,
                  const CPDF_LinearizedHeader* pLinearized);
  virtual ~CPDF_HintTables();
 
  bool GetPagePos(uint32_t index,
                  FX_FILESIZE* szPageStartPos,
                  FX_FILESIZE* szPageLength,
                  uint32_t* dwObjNum) const;
 
  CPDF_DataAvail::DocAvailStatus CheckPage(uint32_t index);
 
  bool LoadHintStream(CPDF_Stream* pHintStream);
 
  const std::vector<PageInfo>& PageInfos() const { return m_PageInfos; }
  const std::vector<SharedObjGroupInfo>& SharedGroupInfos() const {
    return m_SharedObjGroupInfos;
  }
 
  FX_FILESIZE GetFirstPageObjOffset() const { return m_szFirstPageObjOffset; }
 
 protected:
  bool ReadPageHintTable(CFX_BitStream* hStream);
  bool ReadSharedObjHintTable(CFX_BitStream* hStream, uint32_t offset);
 
 private:
  FX_FILESIZE HintsOffsetToFileOffset(uint32_t hints_offset) const;
 
  uint32_t m_nFirstPageSharedObjs = 0;
  FX_FILESIZE m_szFirstPageObjOffset = 0;
  std::vector<PageInfo> m_PageInfos;
  std::vector<SharedObjGroupInfo> m_SharedObjGroupInfos;
  UnownedPtr<CPDF_ReadValidator> m_pValidator;
  UnownedPtr<const CPDF_LinearizedHeader> const m_pLinearized;
};
 
#endif  // CORE_FPDFAPI_PARSER_CPDF_HINT_TABLES_H_