Merge pull request #717 from lukaspj/fix/improve-taml-xml-formatting-no-tampering

Improve tinyXml2 output formatting

Engine/source/persistence/taml/fsTinyXml.cpp

@@ -26,6 +26,41 @@
 
 #include "console/console.h"
 
+VfsXMLPrinter::VfsXMLPrinter(FileStream& stream, bool compact, int depth)
+   : XMLPrinter(NULL, compact, depth),
+     m_Stream(stream)
+{
+}
+
+VfsXMLPrinter::~VfsXMLPrinter()
+{
+   m_Stream.flush();
+   m_Stream.close();
+}
+
+
+// Add VFS friendly implementations of output functions
+
+void VfsXMLPrinter::Print(const char* format, ...)
+{
+   va_list     va;
+   va_start(va, format);
+
+   m_Stream.writeFormattedBuffer(format, va);
+
+   va_end(va);
+}
+
+void VfsXMLPrinter::Write(const char* data, size_t size)
+{
+   m_Stream.write(size, data);
+}
+
+void VfsXMLPrinter::Putc(char ch)
+{
+   m_Stream.write(static_cast<U8>(ch));
+}
+
 bool VfsXMLDocument::LoadFile(const char* pFilename)
 {
    // Expand the file-path.
@@ -61,96 +96,6 @@ bool VfsXMLDocument::LoadFile(const char* pFilename)
    return true;
 }
 
-bool VfsXMLDocument::SaveFile(const char* pFilename)
-{
-   // Expand the file-name into the file-path buffer.
-   char filenameBuffer[1024];
-   Con::expandScriptFilename(filenameBuffer, sizeof(filenameBuffer), pFilename);
-
-   FileStream stream;
-
-   // File opened?
-   if (!stream.open(filenameBuffer, Torque::FS::File::Write))
-   {
-      // No, so warn.
-      Con::warnf("Taml::writeFile() - Could not open filename '%s' for write.", filenameBuffer);
-      return false;
-   }
-
-   bool ret = SaveFile(stream);
-
-   stream.close();
-   return ret;
-}
-
-void VfsXMLDocument::ClearError()
-{
-   _errorID = tinyxml2::XML_SUCCESS;
-   _errorLineNum = 0;
-   _errorStr.Reset();
-
-   tinyxml2::XMLDocument::ClearError();
-}
-
-void VfsXMLDocument::SetError(tinyxml2::XMLError error, int lineNum, const char* format, ...)
-{
-   TIXMLASSERT(error >= 0 && error < tinyxml2::XML_ERROR_COUNT);
-   _errorID = error;
-   _errorLineNum = lineNum;
-   _errorStr.Reset();
-
-   const size_t BUFFER_SIZE = 1000;
-   char* buffer = new char[BUFFER_SIZE];
-
-   TIXMLASSERT(sizeof(error) <= sizeof(int));
-   dSprintf(buffer, BUFFER_SIZE, "Error=%s ErrorID=%d (0x%x) Line number=%d", ErrorIDToName(error), int(error), int(error), lineNum);
-
-   if (format) {
-      size_t len = strlen(buffer);
-      dSprintf(buffer + len, BUFFER_SIZE - len, ": ");
-      len = strlen(buffer);
-
-      va_list va;
-      va_start(va, format);
-      dSprintf(buffer + len, BUFFER_SIZE - len, format, va);
-      va_end(va);
-   }
-   _errorStr.SetStr(buffer);
-   delete[] buffer;
-}
-
-VfsXMLPrinter::VfsXMLPrinter(FileStream& stream, bool compact, int depth)
-   : XMLPrinter(NULL, compact, depth),
-     m_Stream(stream)
-{
-}
-
-VfsXMLPrinter::~VfsXMLPrinter()
-{
-   m_Stream.flush();
-   m_Stream.close();
-}
-
-void VfsXMLPrinter::Print(const char* format, ...)
-{
-   va_list     va;
-   va_start(va, format);
-
-   m_Stream.writeFormattedBuffer(format, va);
-
-   va_end(va);
-}
-
-void VfsXMLPrinter::Write(const char* data, size_t size)
-{
-   m_Stream.write(size, data);
-}
-
-void VfsXMLPrinter::Putc(char ch)
-{
-   m_Stream.write(static_cast<U8>(ch));
-}
-
 bool VfsXMLDocument::LoadFile(FileStream& stream)
 {
    // Delete the existing data:
@@ -254,6 +199,173 @@ bool VfsXMLDocument::SaveFile(FileStream& stream)
    // for *this* call.
    ClearError();
    VfsXMLPrinter printer(stream, false, 0);
-   Print(&printer);
+   PrettyXMLPrinter prettyPrinter(printer);
+   Print(&prettyPrinter);
    return !Error();
 }
+
+bool VfsXMLDocument::SaveFile(const char* pFilename)
+{
+   // Expand the file-name into the file-path buffer.
+   char filenameBuffer[1024];
+   Con::expandScriptFilename(filenameBuffer, sizeof(filenameBuffer), pFilename);
+
+   FileStream stream;
+
+   // File opened?
+   if (!stream.open(filenameBuffer, Torque::FS::File::Write))
+   {
+      // No, so warn.
+      Con::warnf("Taml::writeFile() - Could not open filename '%s' for write.", filenameBuffer);
+      return false;
+   }
+
+   bool ret = SaveFile(stream);
+
+   stream.close();
+   return ret;
+}
+
+void VfsXMLDocument::ClearError()
+{
+   _errorID = tinyxml2::XML_SUCCESS;
+   _errorLineNum = 0;
+   _errorStr.Reset();
+
+   tinyxml2::XMLDocument::ClearError();
+}
+
+void VfsXMLDocument::SetError(tinyxml2::XMLError error, int lineNum, const char* format, ...)
+{
+   TIXMLASSERT(error >= 0 && error < tinyxml2::XML_ERROR_COUNT);
+   _errorID = error;
+   _errorLineNum = lineNum;
+   _errorStr.Reset();
+
+   const size_t BUFFER_SIZE = 1000;
+   char* buffer = new char[BUFFER_SIZE];
+
+   TIXMLASSERT(sizeof(error) <= sizeof(int));
+   dSprintf(buffer, BUFFER_SIZE, "Error=%s ErrorID=%d (0x%x) Line number=%d", ErrorIDToName(error), int(error), int(error), lineNum);
+
+   if (format) {
+      size_t len = strlen(buffer);
+      dSprintf(buffer + len, BUFFER_SIZE - len, ": ");
+      len = strlen(buffer);
+
+      va_list va;
+      va_start(va, format);
+      dSprintf(buffer + len, BUFFER_SIZE - len, format, va);
+      va_end(va);
+   }
+   _errorStr.SetStr(buffer);
+   delete[] buffer;
+}
+
+
+// Overwrite Visitation of elements to add newlines before attributes
+PrettyXMLPrinter::PrettyXMLPrinter(VfsXMLPrinter& innerPrinter, int depth)
+   : mInnerPrinter(innerPrinter),
+   mDepth(depth)
+{
+   for (int i = 0; i < ENTITY_RANGE; ++i) {
+      mEntityFlag[i] = false;
+      mRestrictedEntityFlag[i] = false;
+   }
+   for (int i = 0; i < NUM_ENTITIES; ++i) {
+      const char entityValue = entities[i].value;
+      const unsigned char flagIndex = static_cast<unsigned char>(entityValue);
+      TIXMLASSERT(flagIndex < ENTITY_RANGE);
+      mEntityFlag[flagIndex] = true;
+   }
+   mRestrictedEntityFlag[static_cast<unsigned char>('&')] = true;
+   mRestrictedEntityFlag[static_cast<unsigned char>('<')] = true;
+   mRestrictedEntityFlag[static_cast<unsigned char>('>')] = true;	// not required, but consistency is nice
+}
+
+void PrettyXMLPrinter::PrintString(const char* p, bool restricted)
+{
+   // Look for runs of bytes between entities to print.
+   const char* q = p;
+
+   if (mProcessEntities) {
+      const bool* flag = restricted ? mRestrictedEntityFlag : mEntityFlag;
+      while (*q) {
+         TIXMLASSERT(p <= q);
+         // Remember, char is sometimes signed. (How many times has that bitten me?)
+         if (*q > 0 && *q < ENTITY_RANGE) {
+            // Check for entities. If one is found, flush
+            // the stream up until the entity, write the
+            // entity, and keep looking.
+            if (flag[static_cast<unsigned char>(*q)]) {
+               while (p < q) {
+                  const size_t delta = q - p;
+                  const int toPrint = (INT_MAX < delta) ? INT_MAX : static_cast<int>(delta);
+                  mInnerPrinter.Write(p, toPrint);
+                  p += toPrint;
+               }
+               bool entityPatternPrinted = false;
+               for (int i = 0; i < NUM_ENTITIES; ++i) {
+                  if (entities[i].value == *q) {
+                     mInnerPrinter.Putc('&');
+                     mInnerPrinter.Write(entities[i].pattern, entities[i].length);
+                     mInnerPrinter.Putc(';');
+                     entityPatternPrinted = true;
+                     break;
+                  }
+               }
+               if (!entityPatternPrinted) {
+                  // TIXMLASSERT( entityPatternPrinted ) causes gcc -Wunused-but-set-variable in release
+                  TIXMLASSERT(false);
+               }
+               ++p;
+            }
+         }
+         ++q;
+         TIXMLASSERT(p <= q);
+      }
+      // Flush the remaining string. This will be the entire
+      // string if an entity wasn't found.
+      if (p < q) {
+         const size_t delta = q - p;
+         const int toPrint = (INT_MAX < delta) ? INT_MAX : static_cast<int>(delta);
+         mInnerPrinter.Write(p, toPrint);
+      }
+   }
+   else {
+      mInnerPrinter.Write(p);
+   }
+}
+
+bool PrettyXMLPrinter::VisitEnter(const tinyxml2::XMLElement& element, const tinyxml2::XMLAttribute* attribute)
+{
+   const tinyxml2::XMLElement* parentElem = 0;
+   if (element.Parent()) {
+      parentElem = element.Parent()->ToElement();
+   }
+   const bool compactMode = parentElem ? mInnerPrinter.CompactMode(*parentElem) : mInnerPrinter.CompactMode(element);
+   mInnerPrinter.OpenElement(element.Name(), compactMode);
+   mDepth++;
+   while (attribute) {
+      PushAttribute(attribute->Name(), attribute->Value(), compactMode);
+      attribute = attribute->Next();
+   }
+   return true;
+}
+
+void PrettyXMLPrinter::PushAttribute(const char* name, const char* value, bool compactMode)
+{
+   if (compactMode)
+   {
+      mInnerPrinter.Putc(' ');
+   }
+   else
+   {
+      mInnerPrinter.Putc('\n');
+      mInnerPrinter.PrintSpace(mDepth);
+   }
+   mInnerPrinter.Write(name);
+   mInnerPrinter.Write("=\"");
+   PrintString(value, false);
+   mInnerPrinter.Putc('\"');
+}

Engine/source/persistence/taml/fsTinyXml.h

@@ -40,9 +40,18 @@ public:
    VfsXMLPrinter(FileStream& stream, bool compact = false, int depth = 0);
    ~VfsXMLPrinter() override;
 
+   // Re-implement protected functionality in TinyXML2 library, and make it public
+   // (This is a bit dirty, but it's necessary for the PrettyXMLPrinter)
+   bool CompactMode(const tinyxml2::XMLElement& element) override { return tinyxml2::XMLPrinter::CompactMode(element); }
+   void PrintSpace(int depth) override { tinyxml2::XMLPrinter::PrintSpace(depth); }
+   inline void Write(const char* data) { Write(data, strlen(data)); }
+
+   // Add VFS friendly implementations of output functions
    void Print(const char* format, ...) override;
    void Write(const char* data, size_t size) override;
    void Putc(char ch) override;
+
+   // Accept a virtual FileStream instead of a FILE pointer
    FileStream& m_Stream;
 };
 
@@ -127,4 +136,103 @@ public:
    }
 };
 
+class PrettyXMLPrinter : public tinyxml2::XMLPrinter
+{
+   // Re-implement private functionality in TinyXML2
+   static const char LINE_FEED = static_cast<char>(0x0a); // all line endings are normalized to LF
+   static const char LF = LINE_FEED;
+   static const char CARRIAGE_RETURN = static_cast<char>(0x0d); // CR gets filtered out
+   static const char CR = CARRIAGE_RETURN;
+   static const char SINGLE_QUOTE = '\'';
+   static const char DOUBLE_QUOTE = '\"';
+
+   struct Entity
+   {
+      const char* pattern;
+      int length;
+      char value;
+   };
+
+   static const int NUM_ENTITIES = 5;
+   static constexpr  Entity entities[NUM_ENTITIES] = {
+      {"quot", 4, DOUBLE_QUOTE},
+      {"amp", 3, '&'},
+      {"apos", 4, SINGLE_QUOTE},
+      {"lt", 2, '<'},
+      {"gt", 2, '>'}
+   };
+public:
+   PrettyXMLPrinter(VfsXMLPrinter& innerPrinter, int depth = 0);
+
+   /// Visit a document.
+   virtual bool VisitEnter(const tinyxml2::XMLDocument& doc)
+   {
+      mProcessEntities = doc.ProcessEntities();
+      return mInnerPrinter.VisitEnter(doc);
+   }
+
+   /// Visit a document.
+   virtual bool VisitExit(const tinyxml2::XMLDocument& doc)
+   {
+      return mInnerPrinter.VisitExit(doc);
+   }
+
+   /// Visit an element.
+   virtual bool VisitEnter(const tinyxml2::XMLElement& element, const tinyxml2::XMLAttribute* firstAttribute);
+   /// Visit an element.
+   virtual bool VisitExit(const tinyxml2::XMLElement& element)
+   {
+      mDepth--;
+      return mInnerPrinter.VisitExit(element);
+   }
+
+   /// Visit a declaration.
+   virtual bool Visit(const tinyxml2::XMLDeclaration& declaration)
+   {
+      return mInnerPrinter.Visit(declaration);
+   }
+
+   /// Visit a text node.
+   virtual bool Visit(const tinyxml2::XMLText& text)
+   {
+      return mInnerPrinter.Visit(text);
+   }
+
+   /// Visit a comment node.
+   virtual bool Visit(const tinyxml2::XMLComment& comment)
+   {
+      return mInnerPrinter.Visit(comment);
+   }
+
+   /// Visit an unknown node.
+   virtual bool Visit(const tinyxml2::XMLUnknown& unknown)
+   {
+      return mInnerPrinter.Visit(unknown);
+   }
+   
+   void PushAttribute(const char* name, const char* value, bool compactMode);
+
+   // Re-implement private functionality in TinyXML2 library, this is just a copy-paste job
+   void PrintString(const char*, bool restrictedEntitySet); // prints out, after detecting entities.
+
+   // The inner printer we are wrapping, we only support VfsXMLPrinter based classes because
+   // stock tinyxml printer is very closed
+   VfsXMLPrinter& mInnerPrinter;
+
+   // Track private fields that are necessary for private functionality in TinyXML2
+   int mDepth;
+   bool mProcessEntities;
+   bool mCompactMode;
+
+   enum
+   {
+      ENTITY_RANGE = 64,
+      BUF_SIZE = 200
+   };
+
+   bool mEntityFlag[ENTITY_RANGE];
+   bool mRestrictedEntityFlag[ENTITY_RANGE];
+};
+
+
 #endif //_FSTINYXML_H_