NioLineCount: WIP. Non-blocking IO

Not working yet
This commit is contained in:
Karsten Jeppesen
2021-04-13 19:43:34 +02:00
parent d06b416c53
commit 860282ccb4
4 changed files with 11873 additions and 0 deletions

View File

@@ -0,0 +1,74 @@
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.channels.AsynchronousFileChannel;
import java.nio.channels.CompletionHandler;
import java.nio.charset.Charset;
import java.nio.file.OpenOption;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
/**
*
*/
/**
* @author KAJE
*
*/
public class NioLineCount {
static int theCount = 0;
private static int lineCount(String thePath, boolean doDance){
if ( ! doDance ) return -1;
ByteBuffer buffer = ByteBuffer.allocate(1024);
long myPosition = 0;
Path myPath = Paths.get( thePath );
try {
AsynchronousFileChannel fileChannel = AsynchronousFileChannel.open(myPath, StandardOpenOption.READ);
fileChannel.read(buffer, myPosition, buffer, new CompletionHandler<Integer,ByteBuffer>() {
@Override
public void completed(Integer result, ByteBuffer attachment) {
System.out.println("Result = " + result + " Limit = " + attachment.limit());
attachment.flip();
//System.out.println(Charset.defaultCharset().decode(buffer));
byte[] data = new byte[attachment.limit()];
attachment.get( data );
System.out.println(new String(data));
System.out.println(">> " + data.toString());
for (int i = 0; i < data.length; i++ ) {
if ( data[i] == '\n' )
theCount++;
//System.out.println("data: " + data[i]);
}
attachment.clear();
}
@Override
public void failed(Throwable exc, ByteBuffer attachment) {
}
});
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return theCount;
}
/**
* @param args
*/
public static void main(String[] args){
long startTime = System.nanoTime();
lineCount("", false);
long dryRun = System.nanoTime() - startTime;
startTime = System.nanoTime();
int lines = lineCount("input.txt", true);
long stopTime = System.nanoTime();
System.out.println("Lines: " + String.valueOf(lines));
System.out.println("Time it took: " + (stopTime - startTime - dryRun) + " " + dryRun);
}
}