Add support for full document write operation

README.md

@@ -2,7 +2,7 @@ Introduction
 ------------
 
 A very simple PDF parser that will load PDF objects without interpretation (zlib, streams, string encoding...).
-It currently only allows to update PDF file with new objects.
+It's also possible to write a new PDF or update one.
 
 
 Compilation

include/uPDFParser.h

@@ -35,14 +35,16 @@
 
 namespace uPDFParser
 {
+    class XRefValue;
+    
     /**
      * @brief PDF Parser
      */
     class Parser
     {
     public:
-	Parser():
+	Parser(int version_major=1, int version_minor=6):
-	    fd(0)
+	    version_major(version_major), version_minor(version_minor), fd(0)
 	{}
 
 	~Parser()
@@ -77,9 +79,26 @@ namespace uPDFParser
 	 * @brief Add an object
 	 */
 	void addObject(Object* object) { _objects.push_back(object); }
+
+	/**
+	 * @brief Return trailer object
+	 */
+	Object& getTrailer() {return trailer; }
+
+	/**
+	 * @brief Return xref table. This table is read and updated only once after parse
+	 * Further add/delete will make it incoherent
+	 */
+	const std::vector<XRefValue>& xrefTable() {return _xrefTable;}
+
+	/**
+	 * @brief Return a specific object
+	 */
+	Object* getObject(int objectId, int generationNumber=0);
 	
     private:
 	void parseObject(std::string& token);
+	void parseHeader();
 	void parseStartXref();
 	bool parseXref();
 	bool parseTrailer();
@@ -98,12 +117,38 @@ namespace uPDFParser
 	Name* parseName(std::string& token);
 
 	void writeUpdate(const std::string& filename);
-	
+
+	int version_major, version_minor;
 	std::vector<Object*> _objects;
 	Object trailer;
 	off_t xrefOffset;
 	int fd;
 	off_t curOffset;
+	std::vector<XRefValue> _xrefTable;
+    };
+
+    class XRefValue
+    {
+    public:
+	XRefValue(int objectId, int offset, int generationNumber, bool used, Object* object=0):
+	    _objectId(objectId), _offset(offset), _generationNumber(generationNumber), _used(used),
+	    _object(object)
+	{}
+
+	int objectId() {return _objectId;}
+	int offset() {return _offset;}
+	int generationNumber() {return _generationNumber;}
+	bool used() {return _used;}
+	
+	void setObject(Object* object) { _object = object; }
+	Object* object() { return _object; }
+	
+    private:
+	int _objectId;
+	int _offset;
+	int _generationNumber;
+	bool _used;
+	Object* _object;
     };
 }
 

include/uPDFTypes.h

@@ -259,6 +259,29 @@ namespace uPDFParser
 	std::map<std::string, DataType*>& value() {return _value;}
 	virtual std::string str();
 
+	bool empty() { return _value.empty(); }
+
+	bool hasKey(const std::string& key) { return _value.count(key)?true:false;}
+
+	void deleteKey(const std::string& key) {
+	    if (!hasKey(key)) return;
+	    delete _value[key];
+	    _value.erase(key);
+	}
+
+	void replace(const std::string& key, DataType* data, bool freeData=true)
+	{
+	    if (hasKey(key))
+	    {
+		if (freeData)
+		    deleteKey(key);
+		else
+		    _value.erase(key);
+
+		addData(key, data);
+	    }
+	}
+
     private:
 	std::map<std::string, DataType*> _value;
     };

src/uPDFParser.cpp

@@ -799,10 +799,8 @@ namespace uPDFParser
 	std::string xrefStr = xref.str();
 	::write(newFd, xrefStr.c_str(), xrefStr.size());
 
-	if (trailer.hasKey("Prev"))
+	trailer.deleteKey("Prev");
-	    delete trailer["Prev"];
+	trailer.dictionary().addData("Prev", new Integer((int)xrefOffset));
-	
-	trailer["Prev"] = new Integer((int)xrefOffset);
 
 	std::string trailerStr = trailer.dictionary().str();
 	::write(newFd, "trailer\n", 8);
@@ -821,8 +819,65 @@ namespace uPDFParser
     {
 	if (update)
 	    return writeUpdate(filename);
-	else
-	    EXCEPTION(NOT_IMPLEMENTED, "Full write not implemented");
-    }
 
+	int newFd = open(filename.c_str(), O_WRONLY|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR);
+
+	if (newFd <= 0)
+	    EXCEPTION(UNABLE_TO_OPEN_FILE, "Unable to open " << filename << " (%m)");
+
+	char header[18];
+	int ret = snprintf(header, sizeof(header), "%%PDF-%d.%d\r%%%c%c%c%c\r\n",
+			   version_major, version_minor,
+			   0xe2, 0xe3, 0xcf, 0xd3);
+	
+	::write(newFd, header, ret);
+
+	int nbObjects = 1;
+	std::stringstream xref;
+
+	xref << std::setfill('0');
+	xref << "xref\n";
+	xref << "0 1 f\r\n";
+	xref << "0000000000 65535 f\r\n";
+	
+	std::vector<Object*>::iterator it;
+	for(it=_objects.begin(); it!=_objects.end(); it++)
+	{
+	    std::string objStr = (*it)->str();
+	    curOffset = lseek(newFd, 0, SEEK_CUR);
+	    ::write(newFd, objStr.c_str(), objStr.size());
+	    xref << std::setw(0) << (*it)->objectId() << " 1\n";
+	    xref << std::setw(10) << curOffset << " " << std::setw(5) << (*it)->generationNumber();
+	    if ((*it)->used())
+		xref << " n";
+	    else
+		xref << " f" ; 
+	    xref << "\r\n" ; // Here \r seems important
+	    nbObjects++;
+	}
+
+
+	off_t newXrefOffset = lseek(newFd, 0, SEEK_CUR);
+
+	std::string xrefStr = xref.str();
+	::write(newFd, xrefStr.c_str(), xrefStr.size());
+
+	trailer.deleteKey("Prev");
+	trailer.deleteKey("Size");
+	trailer.dictionary().addData("Size", new Integer((int)nbObjects));
+
+	trailer.deleteKey("XRefStm");
+	
+	std::string trailerStr = trailer.dictionary().str();
+	::write(newFd, "trailer\n", 8);
+	::write(newFd, trailerStr.c_str(), trailerStr.size());
+
+	std::stringstream startxref;
+	startxref << "startxref\n" << newXrefOffset << "\n%%EOF";
+	
+	std::string startxrefStr = startxref.str();
+	::write(newFd, startxrefStr.c_str(), startxrefStr.size());
+	
+	close(newFd);
+    }
 }

tests/test.cpp

@@ -16,6 +16,8 @@ int main(int argc, char** argv)
     try
     {
         parser.parse(argv[1]);
+	std::cout << "Write a.pdf" << std::endl;
+        parser.write("a.pdf");
     }
     catch(uPDFParser::Exception e)
     {