import java.nio.charset.CharsetEncoder;
import java.nio.charset.Charset;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;

public class ASCIIEncodingBenchmark {
	long numberOfConversions = 0;
	CharsetEncoder encoder = Charset.forName("US-ASCII").newEncoder();
	ByteBuffer bytebuffer;
	CharBuffer charbuffer;
	char[] chars;
	
	public static void main(String[] args){
		ASCIIEncodingBenchmark a = new ASCIIEncodingBenchmark();
		a.runTest(Integer.parseInt(args[0]));
	}
	
	public void runTest(int numberOfChars) {
		System.out.println("Char-Byte Test Start");
		
		//Set variables
		char[] alphabet = {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'};
		bytebuffer = ByteBuffer.allocate(numberOfChars);
		charbuffer = CharBuffer.allocate(numberOfChars);
		for (int i = 0 ; numberOfChars > i ; i++) charbuffer.append(alphabet[i % 26]);
		
		//Start time
		long start = System.currentTimeMillis();
		
		//Convert chars to bytes for 30 seconds.
		System.out.println("Warming up for 30 seconds.");
		long endOfWarmup = start + (30 * 1000);
		while(endOfWarmup > System.currentTimeMillis()) convertCharToByte();
		System.out.println("Warm up is Complete. Beginning test.");
		
		//Continue for another 10 seconds, while tracking the number of conversions made.
		long endOfTest = System.currentTimeMillis() + (10 * 1000);
		while(endOfTest > System.currentTimeMillis()) {
			convertCharToByte();
			numberOfConversions++;
		}
		
		//Print number of conversions made.
		System.out.println("After a 30 second warmup, 10 seconds saw " + numberOfConversions + " chars turned into bytes");
		
		//End
		System.out.println("Char-Byte Test End");
	}
	
	private void convertCharToByte(){
		encoder.reset();
		bytebuffer.clear();
		charbuffer.position(0);
		encoder.encode(charbuffer,bytebuffer,true);
	}
}