faster lookup of doxygen tags and finding version without git tags

doc/jekyll/_plugins/tabs.rb

@@ -24,7 +24,7 @@ class TabsConverter < Converter
 			.gsub('<p>__infoEnd</p>', "</div>")
 			.gsub('__breakFix1</a></p>', "")
 			.gsub('<p>__breakFix2', "</a>")
-			.gsub('__version', %x( git describe --tags --always --abbrev=0 ) )
+			.gsub('__version', %x( cat ../VERSION ) )
 			.gsub(/__doxyref\(([^\)]+)\)/){ |m| %x( ./findDoxytag #{$1} ) }
 	end
 end

src/docHelper/findDoxytag.cpp

@@ -13,6 +13,33 @@ int main(int argc, char *argv[]) {
 	std::string memberName(argv[1]);
 	std::ifstream inFile("xerus.tags");
 	std::string line;
+	std::size_t jumpSize = 100;
+	// seek rough position
+	auto lastPos = inFile.tellg();
+	while (!inFile.eof()) {
+		lastPos = inFile.tellg();
+		for (size_t i=0; i<jumpSize; ++i) {
+			std::getline(inFile, line);
+		}
+		std::vector<std::string> parts;
+		boost::split(parts, line, boost::is_any_of("\t"));
+		if (parts[0] == memberName) {
+			std::cout << parts[1] << std::endl;
+			return 0;
+		}
+		if (parts[0] > memberName) {
+			inFile.seekg(lastPos);
+			jumpSize /= 10;
+			if (jumpSize == 1) {
+				break;
+			}
+		}
+	}
+	if (inFile.eof()) {
+		inFile.clear();
+		inFile.seekg(lastPos);
+	}
+	
 	while (std::getline(inFile, line)) {
 		std::vector<std::string> parts;
 		boost::split(parts, line, boost::is_any_of("\t"));