1 // Copyright 2018 PDFium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef CORE_FPDFAPI_PARSER_CPDF_CROSS_REF_TABLE_H_ 6 #define CORE_FPDFAPI_PARSER_CPDF_CROSS_REF_TABLE_H_ 7 8 #include <map> 9 #include <memory> 10 11 #include "core/fxcrt/fx_system.h" 12 #include "core/fxcrt/retain_ptr.h" 13 14 class CPDF_Dictionary; 15 16 class CPDF_CrossRefTable { 17 public: 18 enum class ObjectType : uint8_t { 19 kFree = 0x00, 20 kNormal = 0x01, 21 kNotCompressed = kNormal, 22 kCompressed = 0x02, 23 kObjStream = 0xFF, 24 kNull = kObjStream, 25 }; 26 27 struct ObjectInfo { ObjectInfoObjectInfo28 ObjectInfo() : pos(0), type(ObjectType::kFree), gennum(0) {} 29 // if type is ObjectType::kCompressed the archive_obj_num should be used. 30 // if type is ObjectType::kNotCompressed the pos should be used. 31 // In other cases its are unused. 32 union { 33 FX_FILESIZE pos; 34 uint32_t archive_obj_num; 35 }; 36 ObjectType type; 37 uint16_t gennum; 38 }; 39 40 // Merge cross reference tables. Apply top on current. 41 static std::unique_ptr<CPDF_CrossRefTable> MergeUp( 42 std::unique_ptr<CPDF_CrossRefTable> current, 43 std::unique_ptr<CPDF_CrossRefTable> top); 44 45 CPDF_CrossRefTable(); 46 explicit CPDF_CrossRefTable(RetainPtr<CPDF_Dictionary> trailer); 47 ~CPDF_CrossRefTable(); 48 49 void AddCompressed(uint32_t obj_num, uint32_t archive_obj_num); 50 void AddNormal(uint32_t obj_num, uint16_t gen_num, FX_FILESIZE pos); 51 void SetFree(uint32_t obj_num); 52 53 void SetTrailer(RetainPtr<CPDF_Dictionary> trailer); trailer()54 const CPDF_Dictionary* trailer() const { return trailer_.Get(); } GetMutableTrailerForTesting()55 CPDF_Dictionary* GetMutableTrailerForTesting() { return trailer_.Get(); } 56 57 const ObjectInfo* GetObjectInfo(uint32_t obj_num) const; 58 objects_info()59 const std::map<uint32_t, ObjectInfo>& objects_info() const { 60 return objects_info_; 61 } 62 63 void Update(std::unique_ptr<CPDF_CrossRefTable> new_cross_ref); 64 65 void ShrinkObjectMap(uint32_t objnum); 66 67 private: 68 void UpdateInfo(std::map<uint32_t, ObjectInfo>&& new_objects_info); 69 void UpdateTrailer(RetainPtr<CPDF_Dictionary> new_trailer); 70 71 RetainPtr<CPDF_Dictionary> trailer_; 72 std::map<uint32_t, ObjectInfo> objects_info_; 73 }; 74 75 #endif // CORE_FPDFAPI_PARSER_CPDF_CROSS_REF_TABLE_H_ 76