sdext/source/pdfimport/inc/pdfparse.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
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   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #ifndef INCLUDED_SDEXT_SOURCE_PDFIMPORT_INC_PDFPARSE_HXX
  21 #define INCLUDED_SDEXT_SOURCE_PDFIMPORT_INC_PDFPARSE_HXX
  22
  23 #include <sal/types.h>
  24 #include <rtl/ustring.hxx>
  25 #include <rtl/string.hxx>
  26
  27 #include <string_view>
  28 #include <unordered_map>
  29 #include <utility>
  30 #include <vector>
  31 #include <memory>
  32
  33 namespace pdfparse
  34 {
  35
  36 struct EmitImplData;
  37 struct PDFContainer;
  38 class EmitContext
  39 {
  40 public:
  41     virtual bool write( const void* pBuf, unsigned int nLen ) = 0;
  42     virtual unsigned int getCurPos() = 0;
  43     virtual bool copyOrigBytes( unsigned int nOrigOffset, unsigned int nLen ) = 0;
  44     virtual unsigned int readOrigBytes( unsigned int nOrigOffset, unsigned int nLen, void* pBuf ) = 0;
  45
  46     explicit EmitContext( const PDFContainer* pTop = nullptr );
  47     virtual ~EmitContext();
  48
  49     // set this to deflate contained streams
  50     bool m_bDeflate;
  51     // set this to decrypt the PDF file
  52     bool m_bDecrypt;
  53
  54 private:
  55     friend struct PDFEntry;
  56     std::unique_ptr<EmitImplData> m_pImplData;
  57 };
  58
  59 struct PDFEntry
  60 {
  61     PDFEntry() {}
  62     virtual ~PDFEntry();
  63
  64     virtual bool emit( EmitContext& rWriteContext ) const = 0;
  65     virtual PDFEntry* clone() const = 0;
  66
  67 protected:
  68     static EmitImplData* getEmitData( EmitContext const & rContext );
  69     static void setEmitData( EmitContext& rContext, EmitImplData* pNewEmitData );
  70 };
  71
  72 struct PDFComment final : public PDFEntry
  73 {
  74     OString  m_aComment;
  75
  76     explicit PDFComment( OString aComment )
  77     : PDFEntry(), m_aComment(std::move( aComment )) {}
  78     virtual ~PDFComment() override;
  79     virtual bool emit( EmitContext& rWriteContext ) const override;
  80     virtual PDFEntry* clone() const override;
  81 };
  82
  83 struct PDFValue : public PDFEntry
  84 {
  85     // abstract base class for simple values
  86     PDFValue() : PDFEntry() {}
  87     virtual ~PDFValue() override;
  88 };
  89
  90 struct PDFName final : public PDFValue
  91 {
  92     OString  m_aName;
  93
  94     explicit PDFName( OString aName )
  95     : PDFValue(), m_aName(std::move( aName )) {}
  96     virtual ~PDFName() override;
  97     virtual bool emit( EmitContext& rWriteContext ) const override;
  98     virtual PDFEntry* clone() const override;
  99
 100     OUString getFilteredName() const;
 101 };
 102
 103 struct PDFString final : public PDFValue
 104 {
 105     OString  m_aString;
 106
 107     explicit PDFString( OString aString )
 108     : PDFValue(), m_aString(std::move( aString )) {}
 109     virtual ~PDFString() override;
 110     virtual bool emit( EmitContext& rWriteContext ) const override;
 111     virtual PDFEntry* clone() const override;
 112
 113     OString getFilteredString() const;
 114 };
 115
 116 struct PDFNumber final : public PDFValue
 117 {
 118     double m_fValue;
 119
 120     explicit PDFNumber( double fVal )
 121     : PDFValue(), m_fValue( fVal ) {}
 122     virtual ~PDFNumber() override;
 123     virtual bool emit( EmitContext& rWriteContext ) const override;
 124     virtual PDFEntry* clone() const override;
 125 };
 126
 127 struct PDFBool final : public PDFValue
 128 {
 129     bool m_bValue;
 130
 131     explicit PDFBool( bool bVal )
 132     : PDFValue(), m_bValue( bVal ) {}
 133     virtual ~PDFBool() override;
 134     virtual bool emit( EmitContext& rWriteContext ) const override;
 135     virtual PDFEntry* clone() const override;
 136 };
 137
 138 struct PDFObjectRef final : public PDFValue
 139 {
 140     unsigned int    m_nNumber;
 141     unsigned int    m_nGeneration;
 142
 143     PDFObjectRef( unsigned int nNr, unsigned int nGen )
 144     : PDFValue(), m_nNumber( nNr ), m_nGeneration( nGen ) {}
 145     virtual ~PDFObjectRef() override;
 146     virtual bool emit( EmitContext& rWriteContext ) const override;
 147     virtual PDFEntry* clone() const override;
 148 };
 149
 150 struct PDFNull final : public PDFValue
 151 {
 152     PDFNull() {}
 153     virtual ~PDFNull() override;
 154     virtual bool emit( EmitContext& rWriteContext ) const override;
 155     virtual PDFEntry* clone() const override;
 156 };
 157
 158 struct PDFObject;
 159 struct PDFContainer : public PDFEntry
 160 {
 161     sal_Int32              m_nOffset;
 162     std::vector<std::unique_ptr<PDFEntry>> m_aSubElements;
 163
 164     // this is an abstract base class for identifying
 165     // entries that can contain sub elements besides comments
 166     PDFContainer() : PDFEntry(), m_nOffset( 0 ) {}
 167     virtual ~PDFContainer() override;
 168     bool emitSubElements( EmitContext& rWriteContext ) const;
 169     void cloneSubElements( std::vector<std::unique_ptr<PDFEntry>>& rNewSubElements ) const;
 170
 171     PDFObject* findObject( unsigned int nNumber, unsigned int nGeneration ) const;
 172     PDFObject* findObject( PDFObjectRef const * pRef ) const
 173     { return findObject( pRef->m_nNumber, pRef->m_nGeneration ); }
 174 };
 175
 176 struct PDFArray final : public PDFContainer
 177 {
 178     PDFArray() {}
 179     virtual ~PDFArray() override;
 180     virtual bool emit( EmitContext& rWriteContext ) const override;
 181     virtual PDFEntry* clone() const override;
 182 };
 183
 184 struct PDFDict final : public PDFContainer
 185 {
 186     typedef std::unordered_map<OString,PDFEntry*> Map;
 187     Map m_aMap;
 188
 189     PDFDict() {}
 190     virtual ~PDFDict() override;
 191     virtual bool emit( EmitContext& rWriteContext ) const override;
 192     virtual PDFEntry* clone() const override;
 193
 194     // inserting a value of NULL will remove rName and the previous value
 195     // from the dictionary
 196     void insertValue( const OString& rName, std::unique_ptr<PDFEntry> pValue );
 197     // removes a name/value pair from the dict
 198     void eraseValue( std::string_view rName );
 199     // builds new map as of sub elements
 200     // returns NULL if successful, else the first offending element
 201     PDFEntry* buildMap();
 202 };
 203
 204 struct PDFStream final : public PDFEntry
 205 {
 206     unsigned int    m_nBeginOffset;
 207     unsigned int    m_nEndOffset; // offset of the byte after the stream
 208     PDFDict*        m_pDict;
 209
 210     PDFStream( unsigned int nBegin, unsigned int nEnd, PDFDict* pStreamDict )
 211     : PDFEntry(), m_nBeginOffset( nBegin ), m_nEndOffset( nEnd ), m_pDict( pStreamDict ) {}
 212     virtual ~PDFStream() override;
 213     virtual bool emit( EmitContext& rWriteContext ) const override;
 214     virtual PDFEntry* clone() const override;
 215
 216     unsigned int getDictLength( const PDFContainer* pObjectContainer ) const; // get contents of the "Length" entry of the dict
 217 };
 218
 219 struct PDFTrailer final : public PDFContainer
 220 {
 221     PDFDict*        m_pDict;
 222
 223     PDFTrailer() : PDFContainer(), m_pDict( nullptr ) {}
 224     virtual ~PDFTrailer() override;
 225     virtual bool emit( EmitContext& rWriteContext ) const override;
 226     virtual PDFEntry* clone() const override;
 227 };
 228
 229 struct PDFFileImplData;
 230 struct PDFFile final : public PDFContainer
 231 {
 232 private:
 233     mutable std::unique_ptr<PDFFileImplData> m_pData;
 234     PDFFileImplData*            impl_getData() const;
 235 public:
 236     unsigned int        m_nMajor;           // PDF major
 237     unsigned int        m_nMinor;           // PDF minor
 238
 239     PDFFile();
 240     virtual ~PDFFile() override;
 241
 242     virtual bool emit( EmitContext& rWriteContext ) const override;
 243     virtual PDFEntry* clone() const override;
 244
 245     bool isEncrypted() const;
 246
 247     bool usesSupportedEncryptionFormat() const;
 248
 249     // this method checks whether rPwd is compatible with
 250     // either user or owner password and sets up decrypt data in that case
 251     // returns true if decryption can be done
 252     bool setupDecryptionData( const OString& rPwd ) const;
 253
 254     bool decrypt( const sal_uInt8* pInBuffer, sal_uInt32 nLen,
 255                   sal_uInt8* pOutBuffer,
 256                   unsigned int nObject, unsigned int nGeneration ) const;
 257 };
 258
 259 struct PDFObject final : public PDFContainer
 260 {
 261     PDFEntry*       m_pObject;
 262     PDFStream*      m_pStream;
 263     unsigned int    m_nNumber;
 264     unsigned int    m_nGeneration;
 265
 266     PDFObject( unsigned int nNr, unsigned int nGen )
 267     : m_pObject( nullptr ), m_pStream( nullptr ), m_nNumber( nNr ), m_nGeneration( nGen ) {}
 268     virtual ~PDFObject() override;
 269     virtual bool emit( EmitContext& rWriteContext ) const override;
 270     virtual PDFEntry* clone() const override;
 271
 272     // writes only the contained stream, deflated if necessary
 273     void writeStream( EmitContext& rContext, const PDFFile* pPDFFile ) const;
 274
 275 private:
 276     // returns true if stream is deflated
 277     // fills *ppStream and *pBytes with start of stream and count of bytes
 278     // memory returned in *ppStream must be freed with std::free afterwards
 279     // fills in NULL and 0 in case of error
 280     bool getDeflatedStream( std::unique_ptr<char[]>& rpStream, unsigned int* pBytes, const PDFContainer* pObjectContainer, EmitContext& rContext ) const;
 281 };
 282
 283 struct PDFPart final : public PDFContainer
 284 {
 285     PDFPart() : PDFContainer() {}
 286     virtual ~PDFPart() override;
 287     virtual bool emit( EmitContext& rWriteContext ) const override;
 288     virtual PDFEntry* clone() const override;
 289 };
 290
 291 struct PDFReader
 292 {
 293     PDFReader() = delete;
 294
 295     static std::unique_ptr<PDFEntry> read(std::u16string_view aFileName);
 296 };
 297
 298 } // namespace
 299
 300 #endif
 301
 302 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */