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DelayedInputStream.java

package riverrat.testing;

import java.net.*;
import java.io.*;
import java.util.*;

public class DelayedInputStream extends FilterInputStream {
        static final boolean DEBUG = false;

        static final int DELAY_FACTOR = 100; //originally 2000
        static final int BLOCK_SIZE = 10; //originally 48

        private Random fRandom = new Random(System.currentTimeMillis());

        public DelayedInputStream(InputStream in) {
                super(in);
        } // <init>(InputStream)
                
        public int read(byte[] buffer, int offset, int length) throws IOException {
                // keep read small enough for display
                if (length > BLOCK_SIZE) {
                        length = BLOCK_SIZE;
                }
                int count = 0;
                // read bytes and pause
                long before = System.currentTimeMillis();
                count = in.read(buffer, offset, length);
                try {
                        Thread.currentThread().sleep(Math.abs(fRandom.nextInt()) % DELAY_FACTOR);
                } catch (InterruptedException e) {
                        e.printStackTrace(System.err);
                }
                long after = System.currentTimeMillis();
                // print output
                if(DEBUG) {
                        System.out.print("read "+count+" bytes in "+(after-before)+" ms: ");
                        printBuffer(buffer, offset, count);
                        System.out.println();
                }
                // return number of characters read
                return count;
        } // read(byte[],int,int):int

        private void printBuffer(byte[] buffer, int offset, int length) {
                // is there anything to do?
                if (length <= 0) {
                        System.out.print("no data read");
                        return;
                }
                // print buffer
                System.out.print('[');
                for (int i = 0; i < length; i++) {
                        switch ((char)buffer[offset + i]) {
                                case '\r': {
                                        System.out.print("\\r");
                                        break;
                                } case '\n': {
                                        System.out.print("\\n");
                                        break;
                                } default: {
                                        System.out.print((char)buffer[offset + i]);
                                }
                        } //switch
                } //for
                System.out.print(']');
        } // printBuffer(byte[],int,int)
} // class DelayedInputStream

 

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