diff -r b8274181b061 -r 816094aa1fff src/XmlHandler.h
--- a/src/XmlHandler.h	Sat Jan 05 18:38:14 2019 +0100
+++ b/src/XmlHandler.h	Sun Jan 06 22:15:38 2019 +0100
@@ -29,20 +29,18 @@
 #include <relpipe/reader/TypeId.h>
 #include <relpipe/reader/handlers/RelationalReaderStringHandler.h>
 #include <relpipe/reader/handlers/AttributeMetadata.h>
+#include <relpipe/xmlwriter/XMLWriter.h>
 
 namespace relpipe {
 namespace out {
 namespace xml {
 
 using namespace relpipe::reader;
+using namespace relpipe::xmlwriter;
 
 class XmlHandler : public handlers::RelationalReaderStringHadler {
 private:
-	std::wstring_convert<std::codecvt_utf8<wchar_t>> convertor; // XML output will be always in UTF-8
-	const char* INDENT = "\t";
-
-	std::ostream &output;
-
+	shared_ptr<XMLWriter> xmlWriter;
 	std::vector<TypeId> columnTypes;
 	std::vector<string_t> columnTypeCodes;
 	std::vector<string_t> columnNames;
@@ -50,53 +48,25 @@
 	integer_t columnCount = 0;
 	integer_t relationCount = 0;
 
-	const std::string escapeXmlText(const string_t &value) {
-		// TODO: really bad performance → rewrite
-		// 72 % of whole relpipe-out-xml according to valgrind/callgrind
-		std::wstringstream result;
-
-		for (auto & ch : value) {
-			switch (ch) {
-				case L'&': result << L"&amp;";
-					break;
-				case L'<': result << L"&lt;";
-					break;
-				case L'>': result << L"&gt;";
-					break;
-				case L'\'': result << L"&apos;"; // TODO: escape ' and " only in attributes
-					break;
-				case L'"': result << L"&quot;"; // TODO: escape ' and " only in attributes
-					break;
-				default: result << ch;
-			}
-		}
-
-		return convertor.to_bytes(result.str());
-	}
-
 public:
 
-	XmlHandler(std::ostream& output) : output(output) {
+	XmlHandler(std::ostream& output) : xmlWriter(new XMLWriter(output)) {
 	}
 
 	void startRelation(string_t name, std::vector<handlers::AttributeMetadata> attributes) override {
-		// TODO: refactor and move common XML functions to relpipe-lib-xml
-
 		valueCount = 0;
 		columnCount = 0;
 
 		if (relationCount == 0) {
-			output << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" << std::endl;
-			output << "<pipe xmlns=\"tag:globalcode.info,2018:relpipe\">" << std::endl;
-			// TODO: xmlns
+			xmlWriter->writeStartElement(L"pipe",{L"xmlns", L"tag:globalcode.info,2018:relpipe"});
 		} else {
-			output << INDENT << INDENT << "</record>" << std::endl;
-			output << INDENT << "</relation>" << std::endl;
+			xmlWriter->writeEndElement();
+			xmlWriter->writeEndElement();
 		}
 		relationCount++;
-		output << INDENT << "<relation>" << std::endl;
+		xmlWriter->writeStartElement(L"relation");
 
-		output << INDENT << INDENT << "<name>" << escapeXmlText(name) << "</name>" << std::endl;
+		xmlWriter->writeTextElement(L"name",{}, name);
 
 
 		columnCount = attributes.size();
@@ -108,30 +78,27 @@
 			columnTypes[i] = attributes[i].getTypeId();
 			columnTypeCodes[i] = attributes[i].getTypeName();
 		}
-		
+
 		// TODO: print attribute metadata
 	}
 
 	void attribute(const string_t& value) override {
 		integer_t i = valueCount % columnCount;
 
-		if (i == 0 && valueCount) output << INDENT << INDENT << "</record>" << std::endl;
-		if (i == 0) output << INDENT << INDENT << "<record>" << std::endl;
+		if (i == 0 && valueCount) xmlWriter->writeEndElement();
+		if (i == 0) xmlWriter->writeStartElement(L"record");
 
 		valueCount++;
 
 		// TODO: print attribute metadata (optional)
-		output << INDENT << INDENT << INDENT << "<attribute>";
-		output << escapeXmlText(value);
-		output << "</attribute>" << std::endl;
+		xmlWriter->writeTextElement(L"attribute",{}, value);
 
 	}
 
 	void endOfPipe() {
-		if (valueCount) output << INDENT << INDENT << "</record>" << std::endl;
-		if (relationCount) output << INDENT << "</relation>" << std::endl;
-		output << "</pipe>" << std::endl;
-
+		if (valueCount) xmlWriter->writeEndElement();
+		if (relationCount) xmlWriter->writeEndElement();
+		xmlWriter->writeEndElement();
 	}
 
 };