pdf: move parsing into it's own class, rewrite the parser

This moves the parser into it's own class as it is not only
limited to dictionaries.

The parser has been rewritten to handle the array elements
correctly and properly. Previous array elements were filled during
the tokenization step, which is wrong, and the arrays weren't
parsed recursively, making the parsing incomplete in some cases.
This rewrite handles arrays similar to dictionaries and thus
allows them to be parsed properly.

All the sub-classes of PDFElement have been moved into the
header file.

Another change is also to not have a separate input dictionary
for the root object and instead always look into the dictionary
element that should be available instead.

+ many other smaller changes

Change-Id: I7fcf94760967bbd1474a0b432ba3a4e3c9b7cabe
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/105517
Tested-by: Tomaž Vajngerl <quikee@gmail.com>
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

1 files changed, 136 insertions, 5 deletions

diff --git a/include/vcl/filter/pdfdocument.hxx b/include/vcl/filter/pdfdocument.hxx
index b938234b9370..7f7cc8dfb641 100644
--- a/include/vcl/filter/pdfdocument.hxx
+++ b/include/vcl/filter/pdfdocument.hxx
@@ -71,7 +71,6 @@ class VCL_DLLPUBLIC PDFObjectElement final : public PDFElement
     PDFDocument& m_rDoc;
     double m_fObjectValue;
     double m_fGenerationValue;
-    std::map<OString, PDFElement*> m_aDictionary;
     /// If set, the object contains this number element (outside any dictionary/array).
     PDFNumberElement* m_pNumberElement;
     /// Position after the '<<' token.
@@ -97,6 +96,8 @@ class VCL_DLLPUBLIC PDFObjectElement final : public PDFElement
     /// nested dictionaries.
     std::vector<PDFReferenceElement*> m_aDictionaryReferences;
 
+    bool m_bParsed;
+
     void parseIfNecessary();
 
 public:
@@ -125,7 +126,7 @@ public:
     sal_uInt64 GetArrayOffset() const;
     void SetArrayLength(sal_uInt64 nArrayLength);
     sal_uInt64 GetArrayLength() const;
-    PDFArrayElement* GetArray() const;
+    PDFArrayElement* GetArray();
     /// Parse objects stored in this object stream.
     void ParseStoredObjects();
     std::vector<std::unique_ptr<PDFElement>>& GetStoredElements();
@@ -148,6 +149,7 @@ public:
     bool Read(SvStream& rStream) override;
     void PushBack(PDFElement* pElement);
     const std::vector<PDFElement*>& GetElements() const;
+    PDFElement* GetElement(size_t nIndex) const { return m_aElements[nIndex]; }
 
     void writeString(OStringBuffer& rBuffer) override
     {
@@ -226,9 +228,10 @@ class VCL_DLLPUBLIC PDFNameElement final : public PDFElement
 public:
     PDFNameElement();
     bool Read(SvStream& rStream) override;
+    void SetValue(const OString& rValue) { m_aValue = rValue; }
     const OString& GetValue() const;
     sal_uInt64 GetLocation() const;
-    static sal_uInt64 GetLength() { return 0; }
+    sal_uInt64 GetLength() { return m_aValue.getLength(); }
 
     void writeString(OStringBuffer& rBuffer) override
     {
@@ -253,8 +256,6 @@ public:
     PDFDictionaryElement();
     bool Read(SvStream& rStream) override;
 
-    static size_t Parse(const std::vector<std::unique_ptr<PDFElement>>& rElements,
-                        PDFElement* pThis, std::map<OString, PDFElement*>& rDictionary);
     static PDFElement* Lookup(const std::map<OString, PDFElement*>& rDictionary,
                               const OString& rKey);
     void SetKeyOffset(const OString& rKey, sal_uInt64 nOffset);
@@ -266,6 +267,11 @@ public:
     PDFObjectElement* LookupObject(const OString& rDictionaryKey);
     /// Looks up an element which is contained in this dictionary.
     PDFElement* LookupElement(const OString& rDictionaryKey);
+    sal_uInt64 GetLocation() const { return m_nLocation; }
+    void insert(OString const& rKey, PDFElement* pPDFElement)
+    {
+        m_aItems.emplace(rKey, pPDFElement);
+    }
 
     void writeString(OStringBuffer& rBuffer) override
     {
@@ -382,12 +388,100 @@ public:
     PDFNumberElement();
     bool Read(SvStream& rStream) override;
     double GetValue() const;
+    void SetValue(double fValue) { m_fValue = fValue; }
+
     sal_uInt64 GetLocation() const;
     sal_uInt64 GetLength() const;
 
     void writeString(OStringBuffer& rBuffer) override { rBuffer.append(m_fValue); }
 };
 
+/// A one-liner comment.
+class VCL_DLLPUBLIC PDFCommentElement : public PDFElement
+{
+    PDFDocument& m_rDoc;
+    OString m_aComment;
+
+public:
+    explicit PDFCommentElement(PDFDocument& rDoc);
+    bool Read(SvStream& rStream) override;
+    void writeString(OStringBuffer& /*rBuffer*/) override {}
+};
+
+/// End of a dictionary: '>>'.
+class VCL_DLLPUBLIC PDFEndDictionaryElement : public PDFElement
+{
+    /// Offset before the '>>' token.
+    sal_uInt64 m_nLocation = 0;
+
+public:
+    PDFEndDictionaryElement();
+    bool Read(SvStream& rStream) override;
+    sal_uInt64 GetLocation() const;
+
+    void writeString(OStringBuffer& /*rBuffer*/) override {}
+};
+
+/// End of a stream: 'endstream' keyword.
+class VCL_DLLPUBLIC PDFEndStreamElement : public PDFElement
+{
+public:
+    bool Read(SvStream& rStream) override;
+
+    void writeString(OStringBuffer& /*rBuffer*/) override {}
+};
+
+/// End of an object: 'endobj' keyword.
+class VCL_DLLPUBLIC PDFEndObjectElement : public PDFElement
+{
+public:
+    bool Read(SvStream& rStream) override;
+
+    void writeString(OStringBuffer& /*rBuffer*/) override {}
+};
+
+/// End of an array: ']'.
+class VCL_DLLPUBLIC PDFEndArrayElement : public PDFElement
+{
+    /// Location before the ']' token.
+    sal_uInt64 m_nOffset = 0;
+
+public:
+    PDFEndArrayElement();
+    bool Read(SvStream& rStream) override;
+    sal_uInt64 GetOffset() const;
+
+    void writeString(OStringBuffer& /*rBuffer*/) override {}
+};
+
+/// Boolean object: a 'true' or a 'false'.
+class VCL_DLLPUBLIC PDFBooleanElement : public PDFElement
+{
+    bool m_aValue;
+
+public:
+    explicit PDFBooleanElement(bool bValue)
+        : m_aValue(bValue)
+    {
+    }
+
+    bool Read(SvStream& rStream) override;
+
+    void writeString(OStringBuffer& rBuffer) override
+    {
+        rBuffer.append(m_aValue ? "true" : "false");
+    }
+};
+
+/// Null object: the 'null' singleton.
+class VCL_DLLPUBLIC PDFNullElement : public PDFElement
+{
+public:
+    bool Read(SvStream& rStream) override;
+
+    void writeString(OStringBuffer& rBuffer) override { rBuffer.append("null"); }
+};
+
 /**
  * In-memory representation of an on-disk PDF document.
  *
@@ -502,6 +596,43 @@ public:
     bool writeBuffer(const void* pBuffer, sal_uInt64 nBytes) override;
 };
 
+/// The trailer singleton is at the end of the doc.
+class VCL_DLLPUBLIC PDFTrailerElement : public PDFElement
+{
+    PDFDocument& m_rDoc;
+    PDFDictionaryElement* m_pDictionaryElement;
+    /// Location of the end of the trailer token.
+    sal_uInt64 m_nOffset = 0;
+
+public:
+    explicit PDFTrailerElement(PDFDocument& rDoc);
+    bool Read(SvStream& rStream) override;
+    PDFElement* Lookup(const OString& rDictionaryKey);
+    sal_uInt64 GetLocation() const;
+
+    void SetDictionary(PDFDictionaryElement* pDictionaryElement)
+    {
+        m_pDictionaryElement = pDictionaryElement;
+    }
+
+    PDFDictionaryElement* GetDictionary() { return m_pDictionaryElement; }
+
+    void writeString(OStringBuffer& /*rBuffer*/) override { assert(false && "not implemented"); }
+};
+
+class VCL_DLLPUBLIC PDFObjectParser final
+{
+    const std::vector<std::unique_ptr<PDFElement>>& mrElements;
+
+public:
+    PDFObjectParser(std::vector<std::unique_ptr<PDFElement>> const& rElements)
+        : mrElements(rElements)
+    {
+    }
+
+    size_t parse(PDFElement* pParsingElement, size_t nStartIndex = 0, int nCurrentDepth = 0);
+};
+
 } // namespace vcl::filter
 
 #endif // INCLUDED_VCL_FILTER_PDFDOCUMENT_HXX